Colon Polyps and the Prevention of Colorectal Cancer

Omer Engin Editor

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Colon Polyps and the Prevention of Colorectal Cancer

Omer Engin Editor

Colon Polyps and the Prevention of Colorectal Cancer

Editor Omer Engin Department of Surgery Izmir Buca Hospital Buca, Izmir Turkey

ISBN 978-3-319-17992-6 ISBN 978-3-319-17993-3 DOI 10.1007/978-3-319-17993-3

(eBook)

Library of Congress Control Number: 2015944511 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com)

Preface

Today, lethal diseases have been determined by the help of advances in medical knowledge. The risk factors which cause these diseases have been also determined along with the advance in preventive medicine. I want to impress that more researches are needed on this field. The lung cancer is one of the most frequently lethal cancers in men. Smoking is the leading one among the factors causing lung cancer. Cessation or decrease of smoking results in decrease in lung cancer incidence. The most frequent cancer-dependent cause is breast cancer in female. Breast ultrasonography and mammography screenings have provided early diagnosis of this disease, and early diagnosis increases success of treatment. The second most common cancer-dependent cause of death in both male and female is colon cancer. Some polyps may transform into colon cancer by time. These polyps can be detected and polypectomy can be performed by colonoscopy. Owing to this, development of colon cancer can be prevented. Also, early diagnosis of colon cancer can be done by means of colonoscopy. Polyps, risk factors of colon cancer and knowledge about colonoscopy have been explained in the book. Colonoscopy is not only used in the diagnosis of colon cancer but also in other cancer types. The details of colonoscopy and the preparation period have been explained widely in our book. We prepared this book based on my 12 years of experience on endoscopy and 21 years of experience on surgery at government hospitals and training and research hospitals (Taksim Training and Research Hospital, Bozyaka Training and Research Hospital, Tepecik Training and Research Hospital), combining the experience of my colleagues who are experts on their fields. The content of the book has been prepared to address both the academic staff and our patients. I thank all my colleagues who worked on the preparation of this book. Have a nice reading. Izmir 2015

Omer Engin

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Contents

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Colorectal Embryology and Anatomy. . . . . . . . . . . . . . . . . . . . . . . . . . Ersin Gurkan Dumlu, Mehmet Tokac, and Derya Karakoc

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Preoperative, Intraoperative and Postoperative Management of Colonoscopic Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oguzhan Sunamak, Serdal Mutan, and Ali Sahin

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Colonoscopy and Cardiovascular System . . . . . . . . . . . . . . . . . . . . . . . Ozkan Duman

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Pre-operative Pulmonary System Evaluation . . . . . . . . . . . . . . . . . . . Mesut Subak and Fatma Topbas Subak

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Colonoscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Omer Engin, Mebrure Evnur Uyar, Oguzhan Sunamak, and Fuat Ipekci

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Colonoscopy and Infectious Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Serpil Ertem and Mebrure Evnur Uyar

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Lower Gastrointestinal Tract Endoscopy in Pregnant Women . . . . . 131 Ulas Urganci

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Follow-Up of a Pregnant Patient During Colonoscopy . . . . . . . . . . . . 137 Ibrahim Uyar

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Colorectal Polyps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Nalan Gülşen Ünal and Ali Ozturk

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Surgical Management of Colon Polyps . . . . . . . . . . . . . . . . . . . . . . . . . 153 Okan Demiray and Dogan Gonullu

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Colon Polyps and Pathologic Features . . . . . . . . . . . . . . . . . . . . . . . . . 163 Fatmagul Kusku Cabuk, Gulen Bulbul Dogusoy, Nuray Bassullu, and Elvin Kusku

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Colon Polyps and Radiologic Approach . . . . . . . . . . . . . . . . . . . . . . . . 221 Ali Tosun

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Colon Cancer Risk and Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 Omer Engin, Mebrure Evnur Uyar, Oguzhan Sunamak, and Fuat Ipekci vii

Contributors

Editor Omer Engin, MD Surgery Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Authors Nuray Bassullu, MD Pathology Department, Acibadem Hospital, Istanbul, Turkey Okan Demiray, MD Surgery Department, Gaziosmanpasa Taksim Teaching and Training Hospital, Istanbul, Turkey Gulen Bulbul Dogusoy, MD Pathology Department, Medicine Faculty, Gayrettepe Florence Nightingale Training and Research Hospital, Istanbul Bilim University, Istanbul, Turkey Ozkan Duman, MD Cardiology Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Ersin Gurkan Dumlu, MD Surgery Department, Ataturk Teaching and Research Hospital, Ankara, Turkey Serpil Ertem, MD Infection Diseases Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Dogan Gonullu, MD Surgery Department, Gaziosmanpasa Taksim Teaching and Training Hospital, Istanbul, Turkey Fuat Ipekci, MD Surgery Department, Tepecik Training and Research Hospital, Izmir, Turkey Derya Karakoc, MD Surgery Department, Medicine Faculty, Hacettepe University, Ankara, Turkey Fatmagul Kusku Cabuk, MD Pathology Department, Medicine Faculty, Gayrettepe Florence Nightingale Training and Research Hospital, Istanbul Bilim University, Istanbul, Turkey Elvin Kusku, MD Pathology Department, Aksehir State Hospital, Aksehir, Turkey ix

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Contributors

Serdal Mutan, MD Anesthesiology and Reanimation Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Ali Ozturk, MD Gastroenterology Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Ali Sahin, MD Anesthesiology and Reanimation Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Mesut Subak, MD Pulmonology Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Fatma Topbas Subak, MD Emergency Department, Bozyaka Training and Research Hospital, Izmir, Turkey Oguzhan Sunamak, MD Surgery Department, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey Mehmet Tokac, MD Surgery Department, Ataturk Teaching and Research Hospital, Ankara, Turkey Ali Tosun, MD Radiology Department, Sanliurfa Mehmet Akif Inan Training and Research Hospital, Sanliurfa, Turkey Nalan Gülşen Ünal, MD Gastroenterology Department, Medicine Faculty, Ege University, Izmir, Turkey Ulas Urganci, MD Surgery Department, Bozyaka Training and Research Hospital, Izmir, Turkey Mebrure Evnur Uyar, MD Emergency Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey Ibrahim Uyar, MD Gynaecology and Obstetrics Department, Tepecik Teaching and Training Hospital, Izmir, Turkey

1

Colorectal Embryology and Anatomy Ersin Gurkan Dumlu, Mehmet Tokac, and Derya Karakoc

Embryology Colon Embryology The primitive intestinal tube develops from the yolk sac’s endodermal roof. Primitive intestines begin as a simple tube suspended by a common mesentery on a sagittal plane. This tube is split into three regions during the third week of development: the cranial fold foregut; the hindgut, at the smaller caudal fold with the ventral allantoic eminence, and midgut, which is positioned between these two; and the front, which is the opening to the yolk sac [1]. Embryologic development is completed in three phases. The first phase of the rotation starts between the sixth and eighth weeks of intrauterine life. It takes place over the primitive intestinal tube mesentery, around the superior mesenteric artery and protrudes into the umbilical cord. This event is called temporary physiological intestinal herniation. This intraumbilical part rotates 90° counterclockwise, from the sagittal plane to the horizontal plane, at the eighth week of embryological development [2]. The second phase of the rotation occurs at the 10th week. At this phase, the midgut part returns to the peritoneal cavity from the umbilical cord and, at the same time, turns 180° counterclockwise around the pedicle made by the mesenteric root. The pre-arterial segment of the midgut, or the duodenojejunal loop, comes back to the abdominal cavity. Thus, the duodenum stays behind the superior mesenteric artery. The post-arterial segment, or cecocolic part, descends and settles in front of the arteria mesenterica superior. Anomalies are more common in the second phase E.G. Dumlu, MD (*) • M. Tokac, MD Surgery Department, Ataturk Teaching and Research Hospital, Ankara, Turkey e-mail: [email protected] D. Karakoc, MD Surgery Department, Medicine Faculty, Hacettepe University, Ankara, Turkey © Springer International Publishing Switzerland 2015 O. Engin (ed.), Colon Polyps and the Prevention of Colorectal Cancer, DOI 10.1007/978-3-319-17993-3_1

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than in the first phase. Nonrotation, malrotation, adverse rotation, intestinal hernia, and omphalocele are some of these anomalies [3]. The third phase of rotation is the fixation of the midgut. This starts with the return to the peritoneal cavity and ends with birth. While the total rotation of 270° counterclockwise continues, the cecum, which is situated at the epigastrium, moves to the right bottom quadrant. Fixation starts after the gastrointestinal rotation is completed, during the first trimester. The primitive mesentery parts combine in time and the duodenum and ascending and descending colon settle into their final places. Anomalies of this phase are common, including mobile cecum, subhepatic or undescended cecum, hyperdescended cecum, and persistent colonic mesentery. This segment is fed by the arteria mesenterica superior, with venous and lymphatic drainage via the relevant veins. Neuroenteric ganglion cells move from the neural crest to the upper part of the alimentary canal and then follow the vagal neuron fibers downward. Sympathetic innervations of the midgut and hindgut come from T8-L2 with the splanchnic nerves and autonomic abdominopelvic plexuses. The 10th cranial nerve connects the parasympathetic system to the midgut. The part of the distal colon, rectum, and anal canal that is above the linea dentalis is composed of hindgut. Therefore, this segment is fed by the a. hindgut (inferior mesenteric artery) and drained by the relevant lymph and veins. Parasympathetic innervation is provided by the n. splanchnicus from S2-S3-S4 [4].

Anus and Rectum Embryology The linea dentalis indicates the intersection of the endodermal and ectodermal tubes. Here, the end part of hindgut (or cloaca) comes together with the proctedeum. The cloaca is formed of the part of the rectum that rests below the pubococcygeal line. The hindgut develops from the upper part of this point. Before the 5th week of development, the intestinal and urogenital tracts are combined at their bottom parts into the cloaca. Between the 6th and 8th weeks, the urorectal septum of Tourneux moves to the caudal and separates the cloaca into two parts: the urogenital plate in front and the anorectal plate in the posterior. A little shift of the septum more posterior during the migration leads to a smaller anal cavity and, thus, anorectal problems. The cloacal part of the anal canal includes both endodermal and ectodermal elements, and this part forms the transition region after the membrane comes down. At the 10th week, the anal condyluses, which are a pair of eminences around the proctedeal fossa, combine toward the dorsal side and make a horseshoe structure. They form the perineal corpuscle in the front. This corpuscle separates the cloacal sphincter into urogenital and anal parts. This forms the outer anal sphincter. The inner anal sphincter is formed afterward, between the 6th and 12th weeks, by the widening of the circular muscle line of the rectum. In females, the müllerian ducts, which form the uterus and vagina by combining, arrive in the urogenital sinus at the 16th week by moving downward. In males, the region where the urogenital membrane exists is filled by the combination of genital folds and forms the sinus urethra [5].

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Colon Anatomy The colon is the tubular structure that extends from the end of the ileum to the junction between the sigmoid colon and rectum, including the ileocecal valve and appendix, and wraps the small intestines like an arch. Together with the rectum and anus, it forms the whole large intestine. Classical divisions of the colon are the cecum, ascending colon, transverse colon, descending colon, and sigmoid colon. The colon is approximately one fourth the length of the small intestines, with a length of 150 cm (120–200 cm). It is widest at the cecum (7.5 cm) and narrowest at the rectosigmoid junction (2.5 cm) [6]. Three structures are helpful in making the macroscopic differentiation of the colon from the small intestine: the tenia coli, haustra coli, and appendix epiploica. The tenia coli is formed by the concentration of longitudinal muscular layer of large intestines in the form of three bands and continues from the appendix root to the rectosigmoid junction [7]. As these tenias are shorter than the intestine length, they form the haustras that give the colon its saccular appearance [8]. Except for the appendix and the cecum, most parts of the colon are surrounded by the appendix epiploica formed by the adipose tissue, which is mostly covered by peritoneum.

Cecum The cecum is the widest part of the colon, situated on the right iliac fossa and starting at the termination of the terminal ileum. It is approximately 6–8 cm diameter. As the cecum and ascending colon are close to the psoas major muscle posteriorly, the lateral femoral cutanous nerve, the femoral nerve, the genitofemoral nerves, the gonadal arteries and veins, and the ureter, caution must be exercised to preserve these structures while the right colon is liberalized. The cecum is adjacent to the anterior abdominal wall anteriorly [9]. In many people, more than 90 % of the cecum’s surface is covered by peritoneum. A peritoneal fold separated from terminal ileum mesentery may cross over the ileum to attach to the bottom part of the colon and cecum. This is called the superior ileocecal fold, and the anterior cecal artery passes through it. On the anterior part of the terminal ileum and anterior to the appendix mesentery, the inferior ileocecal fold is present, and no anatomic structure passes through it [10]. The ileum opens by a conical papillary eminence, called the ileocecal valve in humans, extending toward the cecum. Kumar and Philips noted that the superior and inferior ileocecal ligaments were responsible for the ileocecal valve’s competence [11]. This valve not only prevents the cecum’s contents from refluxing into the ileum, but also prevents ileal content from passing too quickly to the cecum [12]. Bogers and Van Mark stated that this valve has a sphincter function [13]. However, barium enema studies have shown that ileocecal valve function is often not sufficient, even in people without any disease. The appendix vermiformis is a blind-ended tubular structure situated approximately 3 cm from the ileocecal junction. Its length is 2–20 cm (average of 8–10 cm)

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and its diameter is 5 mm. Because of its high mobility, the appendix may be in many positions. While it is in the posteromedial position in 85 % of humans, it may be in the retrocecal, pelvic, subcecal, preileal, or retroileal position [14]. The point where three tenias conjoin on the cecum may assist in locating the appendix root. The wall of the cecum is thin compared with the walls of other colonic segments. For this reason, tenias are the most appropriate parts for such surgical procedures as anastomoses and cecopexy. Cecum volvulus is rarely seen because of posterior fixations.

Ascending Colon The ascending colon extends at the right side of the cavity in front of the quadratus lumborum and transverses the abdominis muscle. The ascending colon, which is the division between the cecum and the hepatic flexure, is 12–20 cm long on average. It is in relation with the m. iliacus, ileolumbar ligament, m. quadratus lumborum, transversus abdominis, perirenal fat tissue, right kidney, lateral cutaneous nerve, and ilioinguinal and iliohypogastric nerves posteriorly. It resides near the ureter, which extends over the psoas muscle and gonadal veins. Anteriorly, it neighbors the small intestines, omentum, and anterior abdominal wall. The ascending colon is covered with peritoneum, except at its posterior surface, but it is not rare that it is fully covered and has a short mesocolon. Reduced mobility of the colon may be because of abnormal connective tissue bands that crosscut the ascending colon under the peritoneum. If the band is wide enough to cover a large part of the colon, it is called Jackson’s membrane. Treves determined that there was mesocolon in 12 % of the ascending colon and 22 % of the descending colon of the cadavers [15]. The ascending colon forms the hepatic flexure by turning to the left below the inferior part of the liver, lateral to the gallbladder. Sometimes, it extends over the second part of the duodenum by attaching to it via a peritoneal fold called a duodenocolic ligament. The hepatic flexure may move between 2.5 and 7.5 cm vertically during respiration [16].

Transverse Colon The transverse colon starts at the point where the colon sharply turns to left (hepatic flexure), just below the right lobe inferior face of the liver. Its approximate length is 45 cm, and it is the longest segment of the colon. Almost all of the transverse colon is covered with peritoneum, and it is attached to the posterior abdominal wall with a long mesentery, which gives it mobility [17]. The root of the transverse mesocolon begins at the inferior pole of the right kidney and crosses over the second part of duodenum, continues past the pancreas head, body, and tail, and ends at the hilus of the left kidney. This is generally accepted as an anatomic landmark separating the supramesocolic and inframesocolic compartments. This region is like a barrier separating both compartments in infectious situations.

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Different from the ascending and descending colon, the transverse colon has a mesentery that is formed by the subsequent junction with the omental bursa’s posterior face. Because of the splenic flexure’s proximity to the inferior face of the spleen and its relation with the diaphragm through the phrenocolic ligament, caution must be exercised during mobilization. Dissection should be performed from the transverse colon toward the splenic flexure. The transverse mesocolon includes the middle colic artery and vein along with the lymph nodes and nerves. Sometimes, the transverse mesocolon’s superior fold attaches to the stomach’s posterior wall. Gastric ulcers and benign or malignant tumors may tightly attach to the mesocolon, and the middle colic artery may be damaged during the separation of the stomach wall from the mesocolon [18].

Descending Colon The descending colon, approximately 25 cm length, is the colonic segment extending from the splenic flexure to the pelvic unit. It arrives at the iliac crest by descending vertically from the lateral border of the left kidney between the psoas and quadratus and ends at the sigmoid colon, turning medially on the anterior of the psoas muscle and iliac bone. Like the ascending colon, the descending colon is surrounded by peritoneum on the anterior, medial, and lateral surfaces and has a short mesocolon. Existence of the fascia of Toldt, which provides posterior fixation of the colon in many people, enables dissection with little bleeding during an operation. At its posterior face, the descending colon neighbors the lower pole of the left kidney, the origin of the transversus abdominis muscle, the quadratus lumborum, the iliac and psoas major muscles, the subcostal vein and nerves, the iliohypogastric and ilioinguinal nerves, the 4th lumbar artery, the lateral femoral, femoral, and genitofemoral nerves, the gonadal veins, and the external iliac artery. Anteriorly, however, it neighbors the small intestines and anterior abdominal wall anteroinferiorly. Having a deeper settlement compared with the ascending colon, the descending colon is more posterolaterally settled, especially in young females [19].

Sigmoid Colon When the descending colon comes to the iliac crest level, it becomes the sigmoid colon and has a mesentery. Sigmoid colon, with an average length of 35–40 cm, may show variations in terms of length, position, and fixation. The sigmoid colon has two parts; the iliac part is settled and fixed in the left iliac fossa while the pelvic part is mobile. The sigmoid colon starts at the level of iliac crest and ends at the level of the 3rd sacral vertebra [20]. The sigmoid colon, which is fully covered with peritoneum, generally has a V-shaped and sometimes U-shaped mesocolon, extending from the left iliac fossa to the pelvic unit. The apex of the “V” points at the bifurcation point of the common iliac veins extending over the sacroiliac junction. The left ureter passes at this point

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between the peritoneum and the common iliac artery and is an important landmark in the detection of the ureter. The sigmoid mesocolon is longer at the center, whereas it is shorter in the rectum and descending colon junctions, and this causes a relative fixation at the tips of the sigmoid. In the 1800s, because it was observed that the sigmoid colon was generally empty and contracted, this part of the colon was thought to have a role in continence as a fecal reservoir [21]. Later, as the thickening of the circular muscular layer between the rectum and sigmoid was noted, the terms “sphincter ani,” “tertius rectosigmoid sphincter,” and “piloris sigmoido rectalis” came into use [22]. The rectosigmoid junction may be described by surgeons as a zone between the last 5–8 cm of the sigmoid and the upper 5 cm of the rectum [23]. By endoscopists, however, it is seen as a narrow and sharp-angled segment, in spite of knowledge that it is a well-identified segment that is the narrowest part of the large intestine [24]. In a study on cadavers, the rectosigmoid junction was identified as the zone where the tenia libera and the tenia omentalis form a single anterior tenia below 6–7 cm of the promontorium and the haustra and mesocolon disappear [25]. Although it does not fit the definition of an anatomic sphincter formed by thickened circular muscle layers closing the lumen by rectosigmoid contraction, this segment may be accepted as a functional sphincter because of its active dilatation and passive closing mechanisms [26].

Rectum The proximal and distal borders of the rectum are controversial. While the rectosigmoid junction is at the 3rd vertebra level according to anatomists and at the sacral promontorium level according to surgeons, the distal border is the dentate line for anatomists and the anorectal ring for surgeons. The rectum is approximately 12–14 cm in length and has three curves. While the upper and lower parts are curved to the right, the middle part is curved to the left. These curves are intraluminally related to Houston’s valves. The middle valve (Kohlrausch plica) is the most stable, at the level of the anterior perineal reflection. As the rectal valves do not include all muscle layers, performing a rectal biopsy at this location is quite convenient because of the low risk of perforation [8, 27]. The rectum mucosa is soft, pink, and transparent, enabling visualization of all mucosal veins. This characteristic vascular pattern disappears in inflammatory cases and melanosis coli. The rectum is characterized by its wide and stretchable structure, having no tenia, epiploic appendix, haustra, or mesentery. As it is normally extraperitoneal, the rectum is attached to the sacral groove. Actually, what is falsely termed the “mesorectum” by surgeons is the perirectal areolar tissue, which is covered by fascia propria and includes the inferior mesenteric veins’ terminal branches [28, 29]. Mesorectum may be the metastatic zone for rectal cancers and, as no functional nerve passes through, it may be removed in rectal cancer surgery without any sequel. Generally, we may say of the rectum that the upper one-third is covered by peritoneum on its anterior and lateral, the middle one-third is covered by peritoneum at the anterior face, and the inferior one third is extraperitoneal. The rectum continues

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along the sacral concavity and ends 2–3 cm anterolaterally to the tip of the coccyx. At this point, it forms the anal canal between the levators with a sharp angle [6]. The rectum is close to the uterine cervix in females. In males, anteriorly it is neighbor to the bladder, seminal duct, seminal vesicle, and prostate. Posteriorly, it is adjacent to the median sacral veins and sacral nerve plexuses.

Anal Canal There are two definitions of the anal canal. The anatomic anal canal is a segment of 2 cm length near the proctodeal membrane extending from the anal verge to the dentate line; surgically or functionally the anal canal is the 4 cm length from the anal verge to the anorectal ring. This second definition of the anal canal was first described by Milligan and Morgan [30]. The anorectal ring is at the distal level of the ampullar part of the rectum and forms the anorectal angle. This is the zone where high intraluminal pressure begins. The anal canal neighbors the coccyx posteriorly and, anteriorly, the perineal body, and, in females, the posterior vaginal wall and, in males, the urethra. It neighbors the ischium and ischiorectal fossa on both its sides. This fossa includes inferior rectal veins and nerves passing through lipid tissue and the anal canal wall. The muscular component of the continence mechanism is listed in three functional groups as the lateral compression of the pubococcygeus muscle, the circumferential closing of the internal and external anal sphincters, and the angling of the puborectalis muscle. The anal canal has upper mucosal (endoderm) and lower cutaneous (ectoderm) segments. The dentate line is a sawtooth-shaped junction zone separating venous and lymphatic drainage, innervations, and the epithelial surface of these two regions. The innervation is provided by sympathetic and parasympathetic systems above this line, and the blood supply and lymphatic drainage are provided by hypogastric vessels. The part below this line is innerved by the somatic nervous system, and the blood supply and lymphatic drainage are provided by the inferior hemorrhoidal vessels. This difference is quite important in the classification and treatment of hemorrhoids [31]. The dentate line is related to the anal valves formed by proctodeal membrane residues. There are small pockets known as anal sinuses or crypts on the upper part of each valve. These crypts are connected to six glands on average [32]. While more than one gland may open to the same crypt, some crypts have no connection at all. Anal gland canals penetrate into the submucosa downward and upward. Two-thirds of them penetrate into the internal anal sphincter and the rest enter the intersphincteric zone [33]. Blockage of these canals leads to perianal abscess and fistula formation [34]. There are 8–14 longitudinal folds on the dentate line known as columns of Morgagni. At the end of the columns, there are anal papillae. The mucosa of the columns is formed by multi-folded cuboid cells and has a pink color because of the internal hemorrhoidal plexus under it. This area of 0.5–1 cm on the dentate line is known as the anal transition or cloacogenic area. The cutaneous part of the anal canal is covered with modified squamous epithelium, which is a thin and soft structure. The terms pecten and pecten band are used for this segment [35].

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Arterial Supply The superior mesenteric artery (SMA) is a large-diameter artery that originates from a narrow opening on the aorta. This situation makes it the mesenteric vessel that is most prone to embolic events. It is the second largest intraabdominal branch of the aorta and supplies the whole embryologic midgut. Generally, the AMS has many more branches supplying the distal intestine. This creates a higher potential for distal anastomoses. The AMS originates 1 cm below the a. coeliacus, at the L1 vertebra level, travels down and rightward, and ends as the a. ileocolica. Its main branches are the a. pancreaticoduodenale inferior, the a. colica media, the a. colica dextra, and 4–6 jejunal and 9–13 ileal branches. The a. colica media typically originates from the AMS’s proximal part, supplies the transverse colon, and forms anastomoses with the branches of the a. mesenterica inferior. The splenic flexure is a border zone between these two mesenteric veins. Therefore, ischemic colitis is seen more commonly here [36]. The inferior mesenteric artery (IMA) is the smallest of the mesenteric arteries and originates 6–7 cm below the AMS at the L3 level and supplies the distal transverse colon, splenic flexure, descending colon, and rectosigmoid. The IMA is a small diameter artery and its branching angle to the aorta protects it against embolic events. Its main branches are the a. colica sinistra, the sigmoid, and the hemorrhoidal arteries. The branches of the a. colica sinistra reach the splenic flexure in 80–85 % and extend to middle transverse colon in 15–20 % of population. At this point, they anastomose with the branches of the a. colica media, coming from the AMS. Its sigmoid branches anastomose with the a. colica sinistra and a. hemorrhoidalis superior. The a. hemorrhodialis superior supplies the upper two-thirds wall of rectum and the mucosa of the lower one-third. The a. hemorrhoidalis media originates from the anterior face of the a. iliaca or its vesical branch. It crosses over the infraperitoneal pelvis at the lateral ligaments and supplies the middle one-third of the rectum. The a. hemorrhoidalis inferior is a branch of the a. iliaca internas’ anterior face. After traveling for a short distance at the hip, it turns toward the pelvis by passing the ischiarectal fossa. This may lead to significant bleeding during abdominoperitonial rectum resection. This artery supplies the m. levator ani and sphincters as well as the lower rectum and anal canal [37].

A. marginalis (Drummond) The a. marginalis is composed of a line that is made of the intersecting branches of the a. ileocolica, a. colica dextra, a. colica sinistra, a. colica media, and a. sigmoidalis. These arteries form a single and arching vessel. The a. marginalis passes parallel to its mesenteric border, roughly 1–8 cm from the large intestines. It may end at the a. rectalis superior. Griffith identified a point on the splenic flexure where circulation was weak [38]. Michel et al. found 61 % good and 32 % weak anastomoses in a 200-patient study [39]. In 7 % of the cases, no anastomosis was found.

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Venous Drainage The colon’s veins escort the arteries. On the right (cecum, descending, and right transverse colon), veins join and form the v. mesenterica. The hepatic flexure veins and right side veins of the transverse colon pour into v. gastroepiploica and v. pancreaticoduodenale anterior superior. Voiglio was the first to identify v. gastrocolica and reported two avulsion cases that were secondary to abdominal trauma [40]. It is a short (one-body system or one major system; no immediate danger of death; controlled CHF, stable angina, previous heart attack, poorly controlled hypertension, morbid obesity, chronic renal failure; bronchospastic disease with intermittent symptoms Patients with severe Has at least one severe disease that is poorly controlled systemic disease that or at end stage; possible risk of death; unstable angina, is a constant threat to symptomatic COPD, symptomatic CHF, hepatorenal life failure Moribund patients Not expected to survive >24 h without surgery; who are not expected imminent risk of death; multiorgan failure, sepsis to survive without the syndrome with hemodynamic instability, hypothermia, operation poorly controlled coagulopathy A declared brain-dead patient whose organs are being removed for donor purposes

ASA American Society of Anesthesiologists, COPD chronic obstructive pulmonary disease, CHF congestive heart failure

anaesthesia. In minimal sedation, patients can response to verbal stimulus and there is no effect on cardiopulmonary system. In moderate sedation, response to the verbal stimuli is minimal and may necessitate light tactile stimulus. Deep sedation means there is no response to verbal or tactile stimuli, but may be a weak response to painful one. These patients need support for airway clearance and nasal oxygen must be given. General anaesthesia describes the deepest level of sedation and the patient is not responsive to painful stimuli. Another current approach is ‘conscious sedation’ or ‘monitored anaesthesia care’. It is a kind of sedation under which very painful procedures can be performed and there is not a real situation of consciousness. But, cardiopulmonary system is stable and it is a sedation level that needs monitoring and experienced staff. “The American Society of Anesthesiologists (ASA)” scale is frequently used to choose drug, dose and method of application (Table 2.1). A moderate sedation and analgesia are enough to perform most of the painful procedures according to ASA. But, this spectrum may vary from minimal to deep sedation depending on condition of patient, conditions for monitoring and experience of staff. Gas insufflation in colonoscopy may cause both pain and perforation. Deep sedation both relaxes intestinal wall and provides patient comfort [8–10].

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Widely Used Sedatives/Analgesics Benzodiazepines and opioids are the most frequently used sedative/analgesics. As the most frequently used benzodiazepine, midazolam is generally used alone or combined with propofol. It is a good sedative with antegrade and retrograde amnesic, anxiolytic, hypnotic and centrally acting muscle relaxing effects. It acts on GABA-A receptors and increases the affinity of receptor affinity for GABA, thus potentiating GABAergic neurotransmission. Shortly after IM or IV injection, anxiolytic and sedating effects are seen. Its mean affectivity period is 30 min and midazolam is metabolized completely in liver and its metabolites are excreted in urine. It is transported by albumin in plasma. Its effects may be exacerbated even in smaller doses in aged and debilitated patients due to hypoalbunemia. Also, in sedative doses, it inhibits ventilator response to hypoxia and may cause hypoxemia, hypoventilation, airway obstruction, apnoea, arrhythmia, hypotension and vasovagal reactions. The side effects may occur more easily in patients with COPD. Thus, it is more proper to use the drug in titrated doses or change to another drug in this group of patients. Midazolam-opioid combinations are mostly used for their sedating effect, but sedative and hypnotic effects may show synergistic action. The complications in GI practice are not because of the procedure, but due to these drug combination (Table 2.2) [11–13]. One of the sedative agents, getting popular recently, is propofol. Respiratory depressing effect in its sedative doses necessitates experienced personnel in airway maintenance. In combined forms, it is very useful for moderate sedation, but it can result in deep sedation if used as a single agent. Depending on dose, it has a wide spectrum of side effects, varying from sedation and anxiolysis to CNS depression, hypnosis, hypotension and respiratory depression. Myocardial ischemia may occur due to respiratory depression and hypotension. Again, exacerbated responses may be seen in hypoalbunemic aged and debilitated patients. But, these side effects can be lessened by titrating dose and administration by experienced staff. Propofol combination with opioids shows synergistic action. Nevertheless, rapid redistribution and rapid clearance are important advantages. 2–3 mg/kg of propofol is enough for minimal sedation; it depresses cough reflex and permits a colonoscopic procedure of 10–15 min. But, if procedure lengthens or level of sedation gets deeper, aspiration risk, hypotension and cardiovascular depression may occur. Experienced staff is again necessary for patients’ safety. Immobilization and pain non-sensation are very important to perform a colonoscopic procedure; this necessitates moderate or deep sedation most of the times [9, 11–17].

Dexmedetomidine Having more central and less peripheral sympatholytic effects and being sedative, anxiolytic and analgesic via imidazole receptors, it is a good candidate to use in GI practice. Sympatholytic effect results in a balanced hypotension and slight bradycardia by depressing noradrenaline secretion. Acting on alpha 2 receptors, it is a more centrally acting drug. Most of it (>90 %) is transported coupled to albumin in plasma and metabolized by glucuronidation in liver and excreted by kidneys mainly and via

b

For 5 C Agitation, withdrawal symptoms Ketamine (mg) 2 B Narcotic withdrawal Nitrous oxide 2–3 Dose 15–30 Titrate to effect C N/A Respiratory depression, headache depended Propofol (mg) 90 Consciousness Fully awake Arousable on calling Circulation B/P ± 20 % of B/P ± 20–50 % of preanesthetic level preanesthetic level Activity Able to move 4 Able to move 2 extremities voluntarily extremities voluntarily or or on command on command

0 Apnoeic SpO2 < 90 % on O2 support No response B/P ± 50 % of preanesthetic level Able to move 0 extremities voluntarily or on command

biliary tract in a lesser amount. It has a distribution half-life of 4–6 min and elimination half-life of 2 h. Preventing reflex tachycardia and making balanced hypotension, and having analgesic and sedative effects altogether, it decreases infarction risk in elderly patients by decreasing oxygen demand of myocardium. But, it must be administered by IV infusion because of its short distribution half-life. During sedoanelgesia, the aimed sedation level may exceed and progress to deeper sedation, even general anaesthesia and respiratory and cardiac depression may occur. Thus, modified Aldrete sedation scoring is useful to evaluate level of sedation during and after the procedure (Table 2.3). The patient can be discharged if has an Aldrete score of 9 or more. The preferred sedoanelgesic drug depends on experience of anaesthesiologist, medical history and physical condition (ASA score) of patient and type of procedure planned. Anaesthesiologist should choose sedation technique, drugs and their way of application individually according to health status of the patient and procedure. Therefore, pharmacologic properties and application way of each drug are not mentioned here (Table 2.2). It is clear that combining a sedative drug with an opioid one results in moderate to deep sedation. But, it must be remembered that drug combinations may cause severe side effects, respiratory depression and hypoxemia. Oxygenation of the patient during moderate and deep sedation reduces these risks. The drug dosage must be titrated until required sedoanelgesia level is achieved in intravenous application. They must not be given in a single dose, considering age of patient and weight. In other ways of drug application (oral, rectal, transmocousal, intramuscular, etc.), enough time interval for drug absorption should be allowed [9, 11, 13–16]

Monitoring of the Patient During Procedure Level of Consciousness Response of the patient to verbal stimuli during moderate sedation should be evaluated, except for children, the adults that cannot communicate or the procedures that need still position. The patient, who cannot response to verbal or tactile stimuli

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Table 2.4 Ramsay sedation scale1 and modified observer’s assessment of alertness/sedation scale2 Response to verbal stimulation1 Agitated Responds readily to name spoken in normal tone Lethargic response to name spoken in normal tone Responds only after name called loudly and/or repeatedly Responds only after mild prodding or shaking Does not respond after mild prodding or shaking Does not respond to test stimulus Responsiveness2 Responds readily to name spoken in normal tone Lethargic response to name spoken in normal tone Responds only after name is called loudly and / or repeatedly Responds only after mild prodding or shaking Responds only after painful trapezius squeezea No response after painful trapezius squeeze a

Numerical score 6 5 4 3 2 1 0 Numerical score 5 4 3 2 1 0

Purposeful response, not withdrawal

because of procedure, should be asked to reply by hand movements. Some scales are also used to evaluate sedation level during sedoanelgesia, other than Aldrete scoring system (Table 2.4) [18].

Oxygenation Blood saturation of all patients should be monitored with pulse oximetry between certain limits. Respiration movements are either observed visually or by listening. All the patients who are in deep sedation and the ones in moderate sedation but ventilation cannot be observed directly, end expiration carbon monoxide level must be monitored.

Haemodynamics Blood pressure and heart rate should be measured before sedoanalgesia is started and continuously measured during procedure at intervals not longer than 3 min. Electrocardiographic monitoring should be used in moderate and deep sedation and even in light sedation in patients with severe cardiovascular disease and in procedures which may cause arrhythmia. One of the anaesthesia staff other than the performer must be employed to observe the patient. The standards of patient care in non-theatre procedures are not different from in-theatre anaesthetic care standards: • Anaesthetic care should be provided by an experienced staff. • Anaesthetic care plan should be prepared for each patient and aimed sedation/ analgesia level should be determined [10, 19–21]. • Pre-anaesthetic evaluation of patient should be done. • The patient and/or their family should be informed before anaesthesia/sedation is given. • Vital signs and sedation level of each patient should be monitored and recorded during procedure and interval of vital sign monitoring should not be longer than 10 min.

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• Even in minimally sedated patients, vital signs should be measured at least once before, during and after procedure and recorded. Vitals signs and sedation level should be evaluated during and after procedure. Patient monitoring is the most important part of endoscopic sedation and it includes evaluation of physiologic parameters along with visual observation of the patient [2, 5].

Specifications of Staff Performing Monitoring and Necessary Tools and Equipment in Procedure Room A qualified staff in sedation for endoscopy in endoscopy unit must be formed and educated by anaesthesiology, and this staff must be next to the patient through the procedure. Sedation procedure should be under close observation of an anaesthesiologist. The staff should be able to evaluate phase of sedation, monitor physiologic parameters and evaluate them and make intervention when necessary [2–5, 22] Equipment that should be present in endoscopy unit Syringe, tourniquet IV solutions, IV catheters Basic airway support tools Oxygen supply Aspirator and catheter Nasal cannula and mask Ambu bag and mask Oral or nasal airway kit Advanced airway support tools Laryngoscope Endotracheal tubes Laryngeal mask airway (LMA) Cardiac tools Pulse oxymetry Defibrillator Emergency drugs Atropine Diphenhydramine Ephedrine Flumazenil Glucose (50 %) Hydrocortisone Lidocaine Naloxone Sodium bicarbonate Anexate

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Parameters Used in Monitoring The most important parameters are heart rate and blood pressure and should be measured and recorded at onset and at 3–5 min intervals throughout the procedure. Changes in blood pressure and heart rate may give significant clue about sufficiency of the sedation; bradycardia and hypotension in excessive sedation and tachycardia and hypertension in insufficient sedation. Also, it is useful in basic evaluation before the procedure, for example excess use of cathartics may suggest hypovolemia causing hypotension and tachycardia. Clinical benefit of ECG monitoring during the procedure was not shown except for some drugs such as droperidol and for specific patients with history of arrhythmia, CAD and advanced cardiac failure [5]. Pulse oximetry monitoring is a popular measurement in endoscopic sedation but its clinical benefit is debatable: Its sensitivity in detecting hypoventilation earlier is low (it is over 90 % till PO2 decreases below 70 mmHg). Oxygen supplementation to the patient during procedure also decreases its sensitivity. On the other hand, it has no efficiency in determining hypothermia, low cardiac output or tremor. Therefore, pulse oximetry should never replace direct observation of respiratory movements. Transient desaturation was reported in some patients by pulse oximetry monitoring during procedure, but clinical importance of it still cannot be understood [2]. Capnography shows partial pressure of carbon monoxide in expired air. It is another non-invasive measurement, which is more sensitive than pulse oximetry. It was shown to detect hypoventilation earlier compared to pulse oximetry. Capnography monitoring is suggested by ASA to be used in all patients who are given deep sedation and in patients who are sedated moderately but respiratory monitoring will not be performed [5]. BIS (Bispectral Index): The BIS monitor displays a real-time electroencephalography (EEG) trace, acquired from frontotemporal area. Types of waves show difference, depending on the consciousness level of the patient. A computer analyses spectrum and frequency of waves and gives a BIS index between 0 and 100 units. In this index, scores between 70 and 90 shows moderate, 60–69 deep sedation and 40–90 means general anaesthesia [20]. We need further studies to show benefits of endoscopic (moderate) sedation. Although oxygen support is suggested in sedationgiven patients by nearly all anaesthesiology and gastroenterology associations, there is not any clue to decrease cardiovascular complications yet.

Postoperative Care and Discharge Postoperative care and decision for discharge of the patients who undergo outpatient endoscopy and colonoscopy is as important as preoperative evaluation and completion of procedure safely. The outpatient patients have generally stable vital signs and it is expected to be discharged as the same. The responsibility of anaesthesiologist or the physician who decides discharge has not ended with the decision of

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discharge. During the first 24 h following the procedure, keeping communication with the patient by a nurse is important to follow and prevent possible complications [2, 23]. Endoscopy unit should have sufficient physical conditions for a safe recovery period along with a safe procedure period. The recovery period of the patients who undergo intravenous sedation includes the transfer and observation and monitoring of the patient in the recovery room [2]. The transfer of the patient to the recovery room on the same wheeled bed on which the procedure was performed and enough width of the transfer corridors for a safe patient transfer are important. Also, education, experience and carefulness of the team who transfers patients are necessary [24].

Observation and Monitoring in Recovery Room The patients taken into the recovery room may have different sedation and anaesthesia levels. American society of Anesthesiologist (ASA) described four levels of sedation and anaesthesia groups as light, moderate, deep and general anaesthesia [25, 26]. Light sedation level patients have a normal response to verbal stimuli, unaffected airway and spontaneous respiration and stable cardiovascular functions. Moderate sedation level patients can keep spontaneous respiration sufficiently and generally do not need respiratory intervention. In deep sedation level, patients do not respond to verbal stimuli and pain and may need airway and respiratory support sometimes. Determination and recording of sedation level is necessary. Information transfer between rooms should be careful and correct; drug documentation is important and the information given should alert the recovery room nurse. Benzodiazepines and opioids are the most frequently used drugs [27] and the information, that opioid-depended respiratory depression bradycardia, nausea vomiting might be seen, should be known by the nurse and observation should be done accordingly. Combined use of drugs might increase frequency of these complications [8]. The information that another frequently used drug, propofol, might cause deeper anaesthesia level with respiratory and cardiac depression and has any antagonist is also important. Taken from the operation room into recovery room, the patient is monitored immediately. Monitoring device should monitor oxygen saturation, heart rate, non-invasively measured blood pressure, respiratory rate, ECG and determine alteration and alert the team by alarm system [23]. All the patients given intravenous sedation should be monitored by non-invasive blood pressure measurement [28]. Small decreases in oxygen saturation measured by oximeter are an important early sign of hypoventilation. American Society of Anesthesiologists (ASA) necessitates principally pulse oximetry, ECG and non-invasive blood pressure measurement and recommends continuous ECG monitoring in patient with serious cardiovascular disease or arrhythmia if moderate sedation is used [26]. This should be both during procedure and recovery. An experienced and educated nurse on this subject should be employed in the recovery room [2, 26]. Recovery room nurse should have knowledge and experience in monitoring, interpreting the physiologic parameters and should be the one

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who attended basic or advanced cardiac life support courses; should be able provide an safe airway and ventilate the patient by using ambu bag [2]. Consciousness of the patient, response to verbal and tactile stimuli, if conscious, presence of any complaint or not, clearance of airway and any obstruction due to pressure of tongue base, airway continuity and ability of spontaneous respiration without support, skin colour and temperature should be evaluated immediately; level of consciousness, blood pressure, heart rate, oxygen saturation and presence or absence of pain should be recorded as basic data [2]. ASA recommends giving oxygen via nasal cannula or mask in moderate sedation given patients [29]. Heating blankets should be provided for hypothermic patients in the recovery room. Patients might response in variable levels to the sedative drugs administered. Awakening periods may vary. If flumazenil or naloxane is administered, the patients should be monitored over 2 h in recovery room. The action period of these drugs are shorter than that of benzodiazepines and narcotics; therefore patients might change into sedation again [2]. The presence and periodic control of the equipment and drugs for emergency situations that might occur in recovery room is important. Cardiac arrest, arrhythmias, pulmonary edema, hypotension and hypertension, anaphylaxis, simple allergic reactions and bronchospasm are some emergent clinical situations necessitating intervention. • • • • • • • • • •

Emergency cardiopulmonary resuscitation equipment Intubation tubes in proper size and styles Laryngoscope set Ventilation bag and mask Airways and laryngeal masks of proper size Nasal cannula and oxygen masks Oxygen generator Syringes, intracatheters, tourniquets Intravenous solutions Emergency drugs; atropine, adrenaline, lidocaine, sodium bicarbonate, ephedrine • Naloxane, flumazenil • Diphenhydramine, hydrocortisone • Defibrillator Periodic meeting and self-evaluation of health team working in the unit will provide development in quality.

Decision of Patients’ Discharge Some criteria are needed to decide discharge of the patient. These criteria accelerate evaluation period, enable us recording the data and prevent us from making false. Many scales have been formed until now and nearly all combine in common criteria [2].

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Consciousness and Neurologic State of the Patient The patient should be conscious, co-operative, be well-oriented and aware of people, respond to verbal stimuli, spontaneously move upper and lower extremities easily, able to dress, can stand up and walk in balance, can drink liquids and urinate. Respiration of the Patient Airway is open, the patient is able to breathe easily and strongly, cough, has no dyspnoea. Saturation O2 is more than 95 % [2]. Cardiovascular Function The patient has a normal blood pressure level (±20 mmHg), near to the base level [21]. Heart rate is within normal limits and ECG is sinus rhythm without arrhythmia.

Evaluation of Co-existing Diseases Blood sugar level should be measured in diabetic patients. Attendance of a careful adult person familiar to the patient should be provided during discharge form hospital. Necessary prescription and diet suggestion should be described to the patient and the information should be given in written form to the patient and their relatives. Because verbal information might cause some misunderstandings, written information is more helpful to the patient and their relatives as a reference. Twentyfour hours after discharge, a nurse should evaluate the patient by telephone call and recall to the hospital if necessary [2].

References 1. Dripps RD, Lamont A, Eckenhoff JE. The role of anesthesia in surgical mortality. JAMA. 1961;178:261–6. 2. Cohen LB, DeLegge MH, Aisenberg J, Brill JV, Inadomi JM, Kochman ML, Piorkowski Jr JD. AGA Institute review of endoscopic sedation. Gastroenterology. 2007;133(2):675–701. 3. Lichtenstein DR, Jagannath S, Baron TH, et al. Sedation and anesthesia in GI endoscopy. Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy. Gastrointest Endosc. 2008;68:815–26. 4. Regula J, Sokol-Kobielska E. Sedation in endoscopy: when and how. Best Pract Res Clin Gastroenterol. 2008;22:945–57. 5. Gross JB, Bailey PL, Connis RT, et al. American Society of Anesthesiologists task force on sedation and analgesia by Non-anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology. 2002;96:1004–17. 6. Mallampati SR, Gatt SP, Gugino LD, et al. A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J. 1985;32:429–34. 7. Qureshi WA, Adler DG, Davila RE, et al. ASGE guideline: guidelines for endoscopy in pregnant and lactating women. Gastrointest Endosc. 2005;61:357–62. 8. Bailey PL, Pace NL, Ashburn MA, et al. Frequent hypoxemia and apnea after sedation with midazolam and fentanyl. Anesthesiology. 1990;73:826–30. 9. Rex DK, Heuss LT, Walker JA, Qi R. Trained registered nurses/endoscopy teams can administer propofol safely for endoscopy. Gastroenterology. 2005;129:1384–91.

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10. Turkish Society of Anesthegiology and Reanimation (TARD) Anesthesia procedures out of Operation Theatre. http://www.tard.org.tr/assets/kilavuz/1.pdf (in Turkish). 11. Byrne MF, Baillie J. Nurse-assisted propofol sedation: the jury is in. Gastroenterology. 2005;129:1781–2. 12. Heuss LT, Schnieper P, Drewe J, et al. Safety of propofol for conscious sedation during endoscopic procedures in high-risk patients – a prospective, controlled study. Am J Gastroenterol. 2003;98:1751–7. 13. Joint Statement of a Working Group from the American College of Gastroenterology (ACG), the American Gastroenterological Association (AGA), and the American Society for Gastrointestinal Endoscopy (ASGE). Recommendations on the administration of sedation for the performance of endoscopic procedures. http://www.gastro.org/news/articles/2004/03/08/ gastroenterology-societies-reach-consensus-on-recommendations-for-sedation-duringendoscopic-procedures. 14. Clarke AC, Chiragakis L, Hillman LC, Kaye GL. Sedation for endoscopy: the safe use of propofol by general practitioner sedationists. Med J Aust. 2002;176(4):158–61. 15. Tohda G, Higashi S, Wakahara S, et al. Propofol sedation during endoscopic procedures: safe and effective administration by registered nurses supervised by endoscopists. Endoscopy. 2006;38:360–7. 16. Cohen LB, Hightower CD, Wood DA, et al. Moderate level sedation during endoscopy: a prospective study using low-dose propofol, meperidine/fentanyl, and midazolam. Gastrointest Endosc. 2004;59:795–803. 17. Cohen LB, Dubovsky AN, Aisenberg J, Miller KM. Propofol for endoscopic sedation: a protocol for safe and effective administration by the gastroenterologist. Gastrointest Endosc. 2003;8:725–32. 18. Vargo JJ, DeLegge LH, Feld AD, et al. Practice Guidelines: Multisociety Sedation Curriculum for Gastrointestinal Endoscopy. Am J Gastroenterol advance online publication, 22 May 2012; doi: 10.1038/ajg.2012.112. 19. Rudner R, Jalowiecki P, Kawecki P, et al. Conscious analgesia/sedation with remifentanil and propofol versus total intravenous anesthesia with fentanyl, midazolam, and propofol for outpatient colonoscopy. Gastrointest Endosc. 2003;57:657–63. 20. Rosow C, Manberg PJ. Bispectral index monitoring. Anesthesiol Clin North America. 2001;19:947–66. 21. Chung F, Chan V, Ong D. A post anesthetic discharge scoring system for home readiness after ambulatory surgery. J Clin Anesth. 1995;7:500–6. 22. Knape JT, Adriaensen H, van Aken H, et al. Guidelines for sedation and/or analgesia by nonanaesthesiology doctors. Eur J Anaesthesiol. 2007;24:563–7. 23. Bergtröm Y, Carlson T, Jonsson A. Nursing care for day surgery: the concept and organızation of nursing care. Ambul Surg. 2000;8:3–5. 24. Nolan DM. Issues involved in safe practice. In: Whitwam JG, editor. Day-case anesthesia and sedation. Oxford: Blackwell Science; 1994. p. 347–68. 25. Paigel DO, Baron TH, Goldstein JL, et al. Standards Practice Committee, American Society for Gastrointestinal Endoscopy: guide lines for the use of deep sedation and anesthesia for GI endoscopy. Gastrointest Endosc. 2002;56:613–7. 26. Practice quidelines for sedation and analgesia by non- anesthesiologists. Anesthesiology. 2002;96:1004–17. 27. Cohen LB, Wecsler JS, Gaetana JN, Benson AA, Miller KM, Durkalski V, et al. Endoscopic sedation in the United States: results from a nation wide survey. Am J Gastroenterol. 2006;101:967–74. 28. Council on Scientific Affairs American Medical Association. The use of pulse oximetery during conscious sedation. JAMA. 1993;270:1463–8. 29. Sharma UK, Nguyen CC, Crowell MD, et al. A national study of cardiopulmonary unplanned events after GI endoscopy. Gastrointest Endosc. 2007;66:27–34.

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Colonoscopy and Cardiovascular System Ozkan Duman

Recently, complications of non-cardiac interventional procedures gradually have decreased as a result of developments in techniques of interventional procedures and anaesthesia, and gaining experience. On the other hand, both cardiovascular complications and mortality might be seen in cardiac patients or patients with high risk for cardiovascular disease, during or after the procedures. Cardiac complications, seen following non-cardiac interventional procedures, depend not only on specific risk factors but also type and conditions of the procedure [1]. Being used in diagnosis and treatment of gastrointestinal diseases in clinical practice widely, colonoscopic procedures consist of a considerable number among non-cardiac interventional procedures. However, since colonoscopy is a frequently used, non-invasive and of a short-duration procedure, preoperative cardiovascular evaluation of patients is occasionally neglected, and therefore, various problems might be encountered. Similar to other non-cardiac interventional procedures, during colonoscopy, cardiovascular system confronts an additional load due to myocardial contractility, respiratory depression, alterations in arterial pressure and ventricular filling pressure and changes in autonomic nervous system activity. Consequently, during or right after the procedure, respiratory depression, hypoxia, dyspnoea, hypotension or hypertension, bradycardia or tachycardia, vasovagal reaction, various cardiac arrhythmias and chest pain might occur. Fortunately, most of these complications can be settled by small and limited number of interventions. In a colonoscopy study on 21,375 patients, Ko et al. reported that urgent cardiovascular complications were only in 105 cases (49/10,000) [2]. Hence, endoscopic procedures are included in low cardiac risk group, and cardiac death and myocardial infarction incidence is less than 1 % [3] (Table 3.1).

O. Duman, MD Cardiology Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey e-mail: [email protected] © Springer International Publishing Switzerland 2015 O. Engin (ed.), Colon Polyps and the Prevention of Colorectal Cancer, DOI 10.1007/978-3-319-17993-3_3

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Table 3.1 Risk of cardiovascular event regarding the operation type Low risk 5 % Aortic and major vascular surgery Peripheral vascular surgery

Table 3.2 Approximate energy requirements for various activities. MET: Metabolic Equivalent 1 MET

Meeting the daily life requirements by oneself (eating, getting dressed, going to bathroom) Going around indoors Short distance walking on straight road

4 MET

Going up a hill or climbing two flights of stairs Short-distance jogging General housework (wiping the floors, moving items)

>10 MET

Long-distance jogging Demanding sports (swimming, basketball, football)

Determination of functional capacity is a highly important step in evaluation of preoperative cardiac risk. If patient’s recent exercise test is unavailable, functional capacity can be easily estimated by questioning daily life activities in patient’s history [4]. Functional capacity is measured in metabolic equivalents (METs). One MET is equal to basal metabolic rate. Considering that 1 MET stands for the metabolic requirement at rest, 4 METs are needed for climbing two flights of stairs whereas for challenging sports that require some effort such as swimming, more than 10 METs is needed (Table 3.2). Perioperative cardiac risk increases in the patients whose functional capacity is below 4 METs. Evaluation of patient’s preoperative risk factors is highly important in terms of cardiac complications that might occur during and after a colonoscopic procedure. The physician who conducts the procedure must watch out for a cardiac event in patients with coronary artery disease history or patients without coronary artery disease history but a high risk. During or after the procedure, acute coronary syndrome might develop in the patient. The endoscopist should have knowledge of acute coronary syndrome to diagnose and, in case of doubt, consultation with a cardiologist is essential. Acute coronary syndromes are myocardial perfusion disrupting disease groups which generally develops on atherosclerotic coronary artery disease base and characterized by short-term occlusion in coronary arteries. It is an acute urgent case, having risk of progress into myocardial infarction or cardiac death (Figs. 3.1 and 3.2). In suspicion of acute coronary syndrome regarding urgent medical treatment and revascularization strategies, a cardiologist opinion should be obtained.

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ACUTE CORONARY SYNDROME

Persistent STsegment elevation

ECG

Cardiac Markers

ST segment/T wave abnormalities

Troponin rise/fall

Diagnosis

STEMI

NSTEMI

Normal or undetermined ECG

Troponin normal

Unstable Angina

Fig. 3.1 Classification of acute coronary syndrome. STEMI (ST elevated MI), NSTEMI (non ST elevated MI) Normal ECG R

ST segement T

P Q

S

STEMI

NSTEMI/UA

Fig. 3.2 ST elevated MI/non ST elevated MI – unstable angina

Endoscopy-Related Factors Leading to Acute Coronary Syndrome There are various factors that increase cardiac stress during endoscopy procedures [5]: • Autonomic nervous system • Tachycardia, myocardial ischaemia and cardiac arrhythmia might occur in consequence of activation of the sympathetic nervous system. Increase in parasympathetic activity is at the forefront in colonoscopy, and bradycardia, hypotension and syncope attacks might be encountered. • Procedure-related mechanic stress

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• Fluctuations in cardiac rhythm might be seen particularly during the insufflation of the colon. • Anxiety and neuroendocrine stress response • It is demonstrated that the serum catecholamine, cortisol, glucose levels are raised before and after procedure. • Sedation and analgesia • In a study, 94 % of the cardiorespiratory events during the endoscopy were attributed to sedation [6]. Furthermore, there is no systematic study showing that sedation lowers haemodynamic stress in patients at risk. Even if the oxygen saturation is normal, apnoea and hypopnoea periods were shown by endtidal CO2 measurements. Confidence interval of Propofol is particularly narrow and vasodilator effect is present. For these reasons, it might cause complications in elderly, comorbid and hypovolemic patients. It is vital to choose the anaesthetic agents to be used during colonoscopy, according to patient’s evaluation of cardiovascular risks. Cardiopulmonary events were experienced frequently in case of high-dose Meperidine usage while the event incidence was inversely proportional in case of Fentanyl and Midazolam usage [7]. QT extension and Torsade de Pointes are among the complications of Droperidol which is used in conscious sedation for particularly challenging endoscopy procedures. However, in a study, no relation was detected between Droperidol usage in conscious sedation and rise in cardiopulmonary event [7]. It is suggested to avoid analgesic agents (Morphine, Droperidol, barbiturates) that could induce hypertension in patients with heart failure, severe stenosis and tachyarrhythmia.

Essential Investigations for Preoperative Cardiac Evaluation Electrocardiography (ECG) ECG should be requested for patients who have angina or coronary event history in last 2 months, arrhythmia history, diabetes mellitus (DM) for asymptomatic patients older than 45 for males and 55 for females who have two and more risk factors. Nevertheless, ECG should not be ordered routinely for asymptomatic patients who do not fit these criteria.

Echocardiography It can be obtained in patients with decompensated congestive heart failure symptoms and in case of detected murmur and prior CHF (congestive heart failure) history. Otherwise, routine echocardiography request is class 3 [8].

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Stress Test Exercise stress test can be obtained in case of coronary artery disease or revascularization history in presence of angina complaints and it can be obtained in moderate or high-risk patients whose basal ECG is normal. Myocardial perfusion scintigraphy can be ordered for the patients with left bundle branch block, poor effort capacity and respiratory diseases.

Coronary Angiography Electively planned operation should be postponed for patients who show high risk at stress test, whose angina continues despite the medical treatment and who has high risk for coronary artery disease, and coronary angiography should be proposed.

Regulation of Medication Increasing Tendency to Preoperative Bleeding Antiaggregant Medications Aspirin therapy is generally discontinued in perioperative period since it is considered to increase haemorrhagic complications. A large-scale meta-analysis of 41 studies comparing the bleeding risks of continuation to discontinuation of aspirin in perioperative period was conducted in 49,590 patients. As a result of this analysis, it is determined that risk of bleeding complication increased 1.5 times but aspirin did not cause more severe bleeding complications [9]. Systematical analysis of patients at risk and patients who have ischaemic heart disease demonstrated three times more increase in risk of major adverse cardiac event with discontinuation of aspirin therapy (odds ratio (OR) = 3,14, %95 confidence interval (CI) 1,8-5,6). Aspirin therapy should be discontinued only if bleeding risk is more than the cardiac benefit. Before minor surgical or endoscopic procedures, a careful evaluation about discontinuation of antithrombotic medications should be carried out. Principally, when individual risk and benefit assessment is taken into consideration, patients who get antiplatelet therapy do not have to stop their medication before aforementioned interventions. Platelet transfusion or use of other prohemostatic medications is recommended for patients who receive antiplatelet therapy such as Acetylsalicylic acid, Ticlopidine, Clopidogrel; for Prasugrel or Ticagrelor users and patients who have excessive or life-threatening perioperative bleeding. The decision-making on discontinuing antiplatelet therapy or not is hardest for the patient group who had previous cardiac revascularization procedure and received dual antiplatelet therapy. In percutaneous revascularization-applied patients, one of the antiplatelet therapies is stopped and treatment continues with acetylsalicylic acid ideally after 3 months and 12 months

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for bare metal stent-inserted ones and drug-eluting stent-inserted ones, respectively. It is suggested that the elective procedures should be postponed within these periods and performed afterwards under acetylsalicylic acid therapy [10, 11].

Anticoagulant Medications Anticoagulant therapy is associated with increased bleeding in non-cardiac surgery. The benefit of the anticoagulant therapy is more than its risk in some patient groups. Patients who are given vitamin K antagonists (VKAs) oral anticoagulant therapy have higher risk of perioperative and postoperative bleeding. If the international normalized ratio (INR) < 1.5, surgery could be safely performed. On the other hand, discontinuation of VKAs is dangerous for patients who have high risk of thromboembolism, and these patients should receive IV (intravenous) or subcutaneous ultrafractionated heparin (UFH) or bridge therapy with low molecular weight heparin at therapeutic doses [12–14]. There is a high risk of thromboembolism in patients with atrial fibrillation (AF), mechanical prosthetic cardiac valve, in patients who had his or her biological prosthetic cardiac or mitral valve repaired within last 3 months or in patients who have venous thromboembolism ( 1.5 cm2), patients who have significant mitral stenosis (valve area < 1.5 cm2) and asymptomatic patients having systolic pulmonary artery pressure < 50 mmHg. Fixation of MS with preoperative surgery is not necessary in these patients. Heart rate monitoring should be done in order to prevent the tachycardia that leads pulmonary oedema. Close monitoring of excess fluid load is also important. Atrial fibrillation could significantly worsen the situation. Control of anticoagulation becomes more of an issue due to high risk of embolism.

Aortic Regurgitation and Mitral Regurgitation Insignificant aortic regurgitation (AR) and mitral regurgitation (MR) do not independently increase risk of cardiovascular complication during an interventional procedure. Procedure can be performed without additional risk on asymptomatic patients with severe AR and MR who have preserved left ventricle function.

Arrhythmias Supraventricular tachycardia (SVT) and atrial fibrillation could be encountered rather than ventricular arrhythmias in most of the patients who have non-cardiac operation [17]. Sympathetic activity is the main responsible autonomic mechanism for inducing atrial fibrillation [18]. In some cases, vagal manoeuvres could terminate SVT. When SVT is resistant, arrhythmias could be terminated with short-acting β-blockers or a calcium channel blocker which is not a member of the Dihydropyridine group (Diltiazem and Verapamil) or Amiodarone (IV) [18]. The goal of the treatment is controlling the ventricular rate in perioperative AF. β-blockers and calcium channel blockers which are not a member of the dihydropyridine group (Diltiazem and Verapamil) are used in rate control in AF [19, 20].

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Patient with Cardiac Pacemaker Unipolar electrocautery establishes an important risk factor for pacemakerdependent patients. Electrical stimulus emitted by electrocautery could inhibit or reprogram demand pacemaker devices. Nonetheless, these problems can be solved by using bipolar cautery and removing electric current from generator with placement of a grounding sheet on electric circuitry [17–20].

Infective Endocarditis Prophylaxis For infective endocarditis prophylaxis, antibiotics are not recommended before endoscopy procedures but in the case of an established infection or if antibiotic therapy is indicated to prevent wound infection or sepsis associated with a gastrointestinal tract procedure in highest risk patients (patients with prosthetic valve or prosthetic material used for cardiac valve repair, patient with previous infective endocarditis and patient with congenital heart disease), it is reasonable that the antibiotic regimen includes an agent active against enterococci, e.g. ampicilin, amoxicillin or vancomycin [21].

Editorial Comments for Patients Dr Omer Engin Most of our patients have generally known if they have cardiovascular illness or not during application to our clinics. However, some of them hear their illness for the first time during preoperative evaluation. The patients should talk to the endoscopist about their complaints and cardiac illnesses and risks to undergo cardiac evaluation, if necessary. Pre- and post-colonoscopic evaluation and monitoring during colonoscopy of the risky patients is very important. I believe that colonoscopic procedures on such patients should be performed at hospitals where possible cardiac complications could be solved.

References 1. Wirthlin DJ, Cambria RP. Surgery-specific considerations in the cardiac patient undergoing noncardiac surgery. Prog Cardiovasc Dis. 1998;40:453–68. 2. Ko CW, Riffle S, Michaels L, Morris C, Holub J, Shapiro JA, Ciol MA, Kimmey MB, Seeff LC, Lieberman D. Serious complications within 30 days of screening and surveillance colonoscopy are uncommon. Clin Gastroenterol Hepatol. 2010;8(2):166–73. 3. Boersma E, Kertai MD, Schouten O, Bax JJ, Noordzij P, Steyerberg EW, Schinkel AF, van Santen M, Simoons ML, Thomson IR, Klein J, van Urk H, Poldermans D. Perioperative cardiovascular mortality in noncardiac surgery: validation of the Lee cardiac risk index. Am J Med. 2005;118:1134–41. 4. Fletcher GF, Balady GJ, Amsterdam EA, Chaitman B, Eckel R, Fleg J, Froelicher VF, Leon AS, Pina IL, Rodney R, Simons-Morton DA, Williams MA, Bazzarre T. Exercise standards for

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5. 6.

7.

8.

9.

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13.

14.

15.

16.

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testing and training: a statement for healthcare professionals from the American Heart Association. Circulation. 2001;104:1694–740. Ross C, Frishman WH, Peterson SJ, Lebovics E. Cardiovascular considerations in patients undergoing gastrointestinal endoscopy. Cardiol Rev. 2008;16:76–81. Arrowsmith JB, Gerstman BB, Fleischer DE, Benjamin SB. Results from the American Society for Gastrointestinal Endoscopy/U.S. Food and Drug Administration collaborative study on complication rates and drug use during gastrointestinal endoscopy. Gastrointest Endosc. 1991;37:421–7. Sharma VK, Nguyen CC, Crowell MD, Lieberman DA, de Garmo P, Fleischer DE. A national study of cardiopulmonary unplanned events after GI endoscopy. Gastrointest Endosc. 2007;66(1):27–34. Halm EA, Browner WS, Tubau JF, Tateo IM, Mangano DT. Echocardiography for assessing cardiac risk in patients having noncardiac surgery. Study of Peri-operative Ischemia Research Group. Ann Intern Med. 1996;125:433–41. Burger W, Chemnitius JM, Kneissl GD, Rucker G. Low-dose aspirin for secondary cardiovascular prevention—cardiovascular risks after its perioperative withdrawal versus bleeding risks with its continuation—review and meta-analysis. J Intern Med. 2005;257:399–414. Nuttall GA, Brown MJ, Stombaugh JW, Michon PB, Hathaway MF, Lindeen KC, Hanson AC, Schroeder DR, Oliver WC, Holmes DR, Rihal CS. Time and cardiac risk of surgery after baremetal stent percutaneous coronary intervention. Anesthesiology. 2008;109:588–95. Rabbitts JA, Nuttall GA, Brown MJ, Hanson AC, Oliver WC, Holmes DR, Rihal CS. Cardiac risk of noncardiac surgery after percutaneous coronary intervention with drug-eluting stents. Anesthesiology. 2008;109:596–604. Douketis JD, Johnson JA, Turpie AG. Low-molecular-weight heparin as bridging anticoagulation during interruption of warfarin: assessment of a standardized periprocedural anticoagulation regimen. Arch Intern Med. 2004;164:1319–26. Vahanian A, Baumgartner H, Bax J, Butchart E, Dion R, Filippatos G, Flachskampf F, Hall R, Iung B, Kasprzak J, Nataf P, Tornos P, Torracca L, Wenink A. Guidelines on the management of valvular heart disease: the Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology. Eur Heart J. 2007;28:230–68. De Caterina R, Husted S, Wallentin L, Agnelli G, Bachmann F, Baigent C, Jespersen J, Kristensen SD, Montalescot G, Siegbahn A, Verheugt FW, Weitz J. Anticoagulants in heart disease: current status and perspectives. Eur Heart J. 2007;28:880–913. Mancia G, De Backer G, Dominiczak A, Cifkova R, Fagard R, Germano G, Grassi G, Heagerty AM, Kjeldsen SE, Laurent S, Narkiewicz K, Ruilope L, Rynkiewicz A, Schmieder RE, Struijker Boudier HA, Zanchetti A, The Task Force for the Management of Arterial Hypertension of the European Society of Hypertension, The Task Force for the Management of Arterial Hypertension of the European Society of Cardiology. 2007 guidelines for the management of arterial hypertension: the Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Eur Heart J. 2007;28:1462–536. Weksler N, Klein M, Szendro G, Rozentsveig V, Schily M, Brill S, Tarnopolski A, Ovadia L, Gurman GM. The dilemma of immediate preoperative hypertension: to treat and operate, or to postpone surgery? J Clin Anesth. 2003;15:179–83. Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G, Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy C, Smith Jr SC, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA, Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Blanc JJ, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL, Zamorano JL. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/ American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). J Am Coll Cardiol. 2006;48:e247–346.

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18. Amar D, Zhang H, Miodownik S, Kadish AH. Competing autonomic mechanisms precede the onset of postoperative atrial fibrillation. J Am Coll Cardiol. 2003;42:1262–8. 19. Maisel WH, Rawn JD, Stevenson WG. Atrial fibrillation after cardiac surgery. Ann Intern Med. 2001;135:1061–73. 20. Balser JR. Perioperative arrhythmias: incidence, risk assessment, evaluation, and management. Card Electrophysiol Rev. 2002;6:96–9. 21. Habib G, Hoen B, Tornos P, Thuny F, Prendergast B, Vilacosta I, Moreillon P, de Jesus AM, Thilen U, Lekakis J, Lengyel M, Müller L, Naber CK, Nihoyannopoulos P, Moritz A, Zamorano JL, ESC Committee for Practice Guidelines. Guidelines on the prevention, diagnosis, and treatment of infective endocarditis (new version 2009). The task force on the prevention, diagnosis, and treatment of infective endocarditis of the European Society of Cardiology (ESC). Eur Heart J. 2009;30:2369–413.

4

Pre-operative Pulmonary System Evaluation Mesut Subak and Fatma Topbas Subak

Colonoscopy is an interventional procedure that could be performed under sedoanalgesia and usually completed without complications. Laparotomy under general anaesthesia might be necessary for rarely seen complications like intestinal perforation or spleen rupture. Also during colonoscopy, pulmonary functions may worsen as a result of increased intraabdominal pressure due to air insufflation. In our opinion, pre-procedural evaluation by a pulmonary specialist is necessary in patients with pulmonary disease. In this chapter, pre-procedural pulmonary system evaluation for both colonoscopy and laparotomy is mentioned. The purpose of pre-operative evaluation is to determine complication and mortality risk and to plan post-operative follow-up. Pulmonary complications arise due to volume changes that depend on changes in lung wall mechanics and respiratory muscle dysfunction and prolong hospitalization and increase morbidity and mortality following surgery. Obesity, general anaesthesia, supine position, ascites, advanced age, smoking, volume load, pulmonary edema, bronchospasm and excessive secretion in airways increase post-operative pulmonary risk. Types of surgery, anaesthesia and pharmacological agent used also affect post-operative risk. COPD (Chronic Obstructive pulmonary Disease) patients have three to fivefold increase in post-operative pulmonary complications [1]. There is no clinical data in terms of post-operative risk in patients with stable asthma, restrictive lung disease and vascular lung diseases. In case of an asthma attack, operation should be postponed and attack should be treated first. The more distant a surgical procedure is performed to the chest wall, the more decrease in pulmonary complication rate is seen. Vital capacity (VC) and functional residual capacity (FRC) might decrease after surgery [2–5]. Decrease in FRC is the most important parameter for the development of pulmonary complications [6]. M. Subak, MD (*) Pulmonology Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey e-mail: [email protected] F.T. Subak, MD Emergency Department, Bozyaka Training and Research Hospital, Izmir, Turkey © Springer International Publishing Switzerland 2015 O. Engin (ed.), Colon Polyps and the Prevention of Colorectal Cancer, DOI 10.1007/978-3-319-17993-3_4

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FRC and VC may decrease when intraabdominal pressure increases as the bowel is insufflated with air and complications such as pneumonia and respiratory failure may develop due to decreased regional ventilation and atelectasis [6, 7]. During post-operative period, diaphragm dysfunction (trauma during surgery, inhibitory reflexes due to vagal and splanchnic receptor stimulation), gas exchange disorders (ventilation-perfusion mismatch), respiratory depression (due to anaesthesia) and diminished cough and mucociliary clearance activity increase pulmonary infection risk [8].

Pre-operative Evaluation Clinical Evaluation Evaluation of the patient should include family history of pulmonary disease, profession, smoking history, previous bronchodilator use, functional capacity, presence of dyspnoea, cough, sputum and previous lower respiratory system infection history. Pulmonary auscultation findings are important especially if pathological findings are present.

Chest X-Ray Chest X-ray evaluation has no additional benefit in patients without risk factors and pathological physical examination but is valuable when post-operative complications occur in order to compare pre- and post-operative findings.

Arterial Blood Gas Analysis Arterial blood gas analysis is valuable in patients with chronic pulmonary disease. Previous studies established significantly higher post-operative morbidity rates in patients with pre-operative hypercapnia [9, 10]. Though hypercapnia is not a contraindication for surgery, post-operative meticulous follow-up is indicated.

Spirometry Performing pulmonary function test into all patients pre-operatively is controversial. Besides, pulmonary function testing results are not absolutely correlated to pulmonary complications. Post-operative complication rates increase in patients with FEV1 or FVC lower than 70 % and FEV1/FVC lower than 65 % of the predicted values. Pulmonary function test is not indicated in patients without history and symptoms of pulmonary disease and with normal physical examination. Also normal pulmonary function test results do not mean low post-operative

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complication risk. In addition, pre-operative testing was not found efficient in patients with older age, obesity, malnutrition and before abdominal surgery [11].

Post-operative Pulmonary Complications Depending on the type of surgery and patient’s characteristics, post-operative pulmonary complication incidence shows significant variations. Pulmonary complication rate is higher in patients with older age, smoking history, obesity and existing pulmonary disease. The most frequent pulmonary complication after surgery is atelectasis, which is treated with supplemental oxygen therapy. Long-standing atelectasis has high morbidity rates.

Post-operative Pulmonary Complications • • • • • • •

Infections Atelectasis Bronchospasm Exacerbation of chronic pulmonary disease Respiratory failure (prolonged mechanic ventilation (>48 h), reintubation) Pulmonary thromboembolism Obstructive sleep apnoea [12]

Risk Lowering Strategies Pre-operative risk lowering strategies are smoking cessation 8 weeks prior to operation, bronchodilator therapy in patients with symptomatic obstructive pulmonary disease, postponing surgery for antibiotic therapy in patients with lower respiratory tract infections and teaching lung expansion manoeuvres to the patient. Intraoperative strategies are shortening the duration of the surgery (less than 3 h), preferring epidural and spinal anaesthesia instead of general anaesthesia and laparoscopic surgery instead of open surgery. Deep breathing exercises using incentive spirometer, epidural analgesia and intercostal nerve blocking for pain, prophylaxis for deep vein thrombosis are important strategies for preventing complications in the postoperative period [13].

Editorial Comments for Patients Dr Omer Engin Colonoscopy has low complication rates when performed in experienced hands. Sedation for colonoscopy is performed via intravenous drug injections. However, intubation and general anaesthesia may be required if laparotomy is needed for any

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complication occurring during procedure. Condition of respiratory system becomes important in such a situation. Pulmonary diseases may cause serious problems; therefore, pre-procedural determination and treatment of them could help to decrease such risks. Especially, cessation of smoking is very important.

References 1. Demir T. KOAH’ da preoperatif değerlendirme. In: Saryal SB, Acıcan T, editors. Güncel bilgiler ışığında kronik obstrüktif akciğer hastalığı. Istanbul: Bilimsel; 2003. p. 321–31. 2. Alexander JI, Spence AA, Parikh RK, Stuart B. The role of airway closure in postoperative hypoxemia. Br J Anaesth. 1973;45:34–40. 3. Ali J, Weisel RD, Layug AB, et al. Consequences of postoperative alterations in respiratory mechanism. Am J Surg. 1974;128:376–82. 4. Meyers JR, Lembeck L, O’Kane H, Bauer AE. Changes in functional residual capacity of the lung after operation. Arch Surg. 1975;110:576–83. 5. Swenson ER, Swenson EW. Preoperative pulmonary evaluation. In: Albert RK, Spiro SG, Jett JR, editors. Clinical respiratory medicine. 2nd ed. Philadelphia: Mosby; 2004. p. 229–34. 6. Ferguson MK. Preoperative assessment of pulmonary risk. Chest. 1999;115:58S–63. 7. Mutlu B. Preoperatif değerlendirmede akciğer fonksiyon testleri. In: Yıldırım N, editor. Akciğer fonksiyon testleri: fizyolojiden klinik uygulamaya. Istanbul: Turgut; 2004. p. 154–67. 8. Wooddard FH, Jones M. Intensive care for the critically ill adult. In: Pryor JA, Webber BA, editors. Physiotherapy for respiratory and cardiac problems. 2nd ed. Edinburgh: Churchill Livingstone; 1998. p. 267–93. 9. Milledge JS, Nunn JF. Criteria of fitness for anaesthesia in patients with chronic obstructive lung disease. BMJ. 1975;3:670–3. 10. Stein M, Koota GM, Simon M, Frank HA. Pulmonary evaluation of surgical patients. JAMA. 1962;181:765–70. 11. Lawrence VA, Page CP, Harris GD. Preoperative spirometry before abdominal operations. A critical appraisal of its predictive value. Arch Intern Med. 1989;149:280–5. 12. Vintch JRE, Hansen JE. Chapter 6: Preoperative evaluation and relation to postoperative complications. In: Crapo JD, Glassroth J, Karlinsky J, King TE, editors. Baum’s textbook of pulmonary diseases. 7th ed. Philadelphia, USA: Lippincott Williams & Wilkins; 2004. p. 113–32. 13. Henzler D, Dembinski R, Kuhlen R, Rossaint R. Anesthetic considerations in patients with chronic pulmonary diseases. Minerva Anestesiol. Philedelphia USA. 2004;70(5):279–84.

5

Colonoscopy Omer Engin, Mebrure Evnur Uyar, Oguzhan Sunamak, and Fuat Ipekci

Colonoscopy is the process of investigating the entire lumen of the large intestine, from the rectum to the cecum, for diagnosis and treatment. Specially developed flexible tools, with a light and camera on the tip, are used. Although colonoscopy is an invasive intervention, today it is a reliable and indispensable diagnostic procedure when it is performed by an experienced person or team with good equipment. For the detection of colon polyps and malignancies, it is more sensitive and specific than double-contrast barium enema, computed tomography, and virtual colonoscopy. It is a gold standard in the diagnosis and treatment of many diseases, such as lower gastrointestinal bleeding, polyps, and colon tumors. Unlike tomography, it does not require large machines or facilities and can be performed in an office or an endoscopy center. The importance of colonoscopy has become increasingly evident from the first application to the present day. An increasing number of colonoscopies are being performed, and more people are benefiting from colonoscopic examination. Colonoscopy began to have greater importance in diagnosis as well as treatment as the tools have been modernized. As the quality increased, so did variety of the interventional procedures performed with colonoscopy. The following factors have lead to today’s extensive use of colonoscopy: an increased understanding of the importance of colonoscopy; more physicians are performing colonoscopies; of the use of

O. Engin, MD (*) Surgery Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey e-mail: [email protected] M.E. Uyar, MD Emergency Department, Buca Seyfi Demirsoy State Hospital, Izmir, Turkey O. Sunamak, MD Surgery Department, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey F. Ipekci, MD Surgery Department, Tepecik Training and Research Hospital, Izmir, Turkey © Springer International Publishing Switzerland 2015 O. Engin (ed.), Colon Polyps and the Prevention of Colorectal Cancer, DOI 10.1007/978-3-319-17993-3_5

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colonoscopy instruments has become more practical; advances in technology; lower-cost instruments resulting from competition among manufacturers; and public awareness of and demand for colonoscopy. Nevertheless, colonoscopy has still has not been made available to all patients at the desired concentration.

History Colorectal endoscopic procedures have been performed throughout history. Hippocrates (460–377 BC) used some type of speculum to perform anoscopy [1–3]. Colonoscopic examination after colotomy was proposed in 1953 by Deddish and Fairweather, and was applied by a few other surgeons [4]. In 1965, the first total colonoscopy was performed by Luciano Provenzale and Antonio Revignas in Sardinia, Italy [5]. Retrograde colonoscopy and excision of colon polyps began in 1969 [6], and Hiromi Shinya performed the first polypectomy that year [7]. In 1991, Edmonston divided the historical development of gastrointestinal endoscopy instruments into three periods [8]: 1. The era of rigid endoscopes (1805–1932) 2. The era of semi-flexible endoscopes (1932–1957) 3. The fiber optic era (1957 to present) Edmonston notes that the display area of the gastrointestinal tractus cavity increased with semi-flexible endoscopes and the entire cavity became visible with fiber optic instruments. Lau et al. divided the history of endoscopy into four phases [9]: Phase 1: Open tube system (1805–1879): The rectum was studied by candlelight passing through a tube (to be reflected in a mirror). Phase 2: Rigid telescopic instruments (1879–1936): A telescope system was added to the open tube system. Phase 3: Semi-flexible instruments (1936–1957) Phase 4: Flexible instruments (1957 to present): The modern era of endoscopy began with flexible fiber optic instruments.

The Definition of Colonoscopy Colonoscopy is an examination of the inside part of the large intestine. Before explaining this definition broadly, it would be useful to review briefly the colonic anatomy related to colonoscopy. The colon begins in the right iliac fossa at the end of the small intestine, which is called the cecum and is the widest part of the colon. The ascending colon extends from the cecum to the liver. Below the liver is the hepatic flexure. From there, the colon proceeds to the left to the spleen and forms the transverse colon. The flexure around the spleen is called the splenic flexure. The descending colon moves

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downward from the splenic flexure. After the descending colon, the parts are the sigmoid colon, rectum, anal canal, and anus. The examination of the entire large intestine is performed with colonoscopy by proceeding retrograde. With colonoscopic examination, only the inner face of the colon can be seen and evaluated. Information about lesions in the colon wall cannot be obtained with colonoscopy, but if a lesion grows and reaches a size that creates a mass in the colon mucosa, then it can be realized. However, it should be noted that mucosal lesion characteristics can be identified in colon cancer, but colonoscopy does not provide information about the concentration of colon wall involvement, the layers of the colon involved, or serosal involvement. Application of other imaging methods is necessary for these definitions [10–13].

Colonoscopy: Indications and Contraindications Colonoscopy is a process with both diagnostic and therapeutic features. It is an invasive process, which has a specific cost (expensive) and requires skill to perform. Therefore, it should be used selectively in patients [14]. Indications for colonoscopy include the following: iron-deficiency anemia, lower gastrointestinal system bleeding, lower abdominal symptoms (lower abdominal pain, chronic constipation), uncomplicated diarrhea, evaluation of known ulcerative colitis and Crohn’s disease, colorectal cancer screening in patients diagnosed with inflammatory bowel disease, follow-up after polypectomy, follow-up after colorectal cancer surgery, screening for colorectal cancer, mass lesions, pathologies inside the colon detected by other imaging techniques, unexplained weight loss, and other various reasons [15–17]. Contraindications are classified in the literature as absolute and relative contraindications. Absolute Contraindications Absolute contraindications include intestinal perforation, acute peritonitis, complete or high-grade intestinal obstruction, toxic megacolon, fulminant colitis, noncooperative patients, and patients without adequate sedation. Relative Contraindications Relative contraindications include bleeding disorders, thrombocytopenia, platelet function abnormalities, neutropenia, previous intestinal surgery, patients with bowel perforation risk (Ehlers-Danlos syndrome, Marfan syndrome), acute diverticulitis, previous cardiac infarction, pulmonary embolism, recent postoperative condition, large or abdominal aortic aneurysm, pregnancy (second or third trimester), and hemodynamic instability [17–19].

Issues Related to Colonoscopy Indications The indications are examined further below, as differential diagnosis and treatment options are better informed by understanding the issues faced with these indications.

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Colonoscopy in Iron-Deficiency Anemia According to the description of the World Health Organization (WHO), anemia is based on erythrocyte (red blood cell [RBC]) count and is present when the oxygencarrying capacity of erythrocytes is insufficient to meet the body’s physiological work. According to WHO, normal hemoglobin concentrations are ≥13 g/L in adult men and ≥12 g/L in women [20]. Specific physiological requirements vary with age, sex, and pregnancy. The most common cause of anemia is iron deficiency. Other common causes of anemia include insufficient intake of nutrition (folate, vitamin B12, vitamin A deficiency), acute and chronic inflammation, and parasitic infections. Malignancy is an uncommon but important cause of anemia that should not be overlooked. The hematocrit values accepted as normal are reported as 36–46 % for women and 38–48 % for men [21]. Normal adult RBC counts are given as 4.5–6.5 (×1012/L) for men and 3.9–5.6 (×1012/L) for women [22]. Anemia classification can be performed according to etiology and RBC parameters. It can be classified morphologically as normocytic, microcytic, and macrocytic. In etiologic classification, the groups include insufficient RBC production, hemolytic anemia, and anemia due to blood loss. Microcytic hypochromic anemia is often associated with decreased hemoglobin synthesis and is seen in iron-deficiency anemia and thalassemia. Normocytic normochromic anemia may result from acute blood loss. Macrocytic normochromic anemia is usually seen in vitamin B12 and folic acid deficiency. In etiologic classification, insufficient RBC production can be seen in nutritional deficiencies, immune-mediated neoplasms, and primary hematologic malignancies. Blood loss can be acute or chronic in anemia due to blood loss. In hemolytic anemia, hemolysis may develop depending on extrinsic factors, intrinsic factors, and defects in the erythrocyte itself. Many immunological reasons for hemolysis and synthesis errors can be considered [23–25]. Although the subject of this chapter is the large intestine and colonoscopy, we would like to briefly discuss pernicious anemia associated with malignancy. After oral administration, vitamin B12 combines in the stomach with an intrinsic factor produced in gastric parietal cells. The vitamin B12–intrinsic factor complex moves forward in the intestine, reaching the distal ileum, which is about 80 cm from the terminal ileum. Vitamin B12 is absorbed into the blood at the distal ileum. The anemia caused by vitamin B12 deficiency is called megaloblastic anemia. Gastrectomy and distal ileum resection are major causes of anemia due to vitamin B12 deficiency [26, 27]. The coexistence of pernicious anemia and atrophic gastritis has been recognized for a long time. Atrophic gastritis can be caused by autoimmune disorders (type A) [28]. It should be emphasized here that the risk of development of gastric carcinoma in patients with atrophic gastritis is high, and follow-up of these patients is important [29]. Autoimmune diseases can be found together, and clinical trials have indicated the coexistence of type 1 diabetes mellitus, autoimmune thyroid disease, autoimmune gastritis and/or pernicious anemia, celiac disease, Addison’s disease, and vitiligo [30–33].

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Given this brief discussion of anemia, the importance of anemia in indications for colonoscopy can now be defined. Anemia may be due to blood loss. With acute blood loss, the color of fresh blood may be noted with defecation. Chronic blood loss may develop intermittently; it may be seen macroscopically or it may be less visible. Bleeding that cannot be seen macroscopically can be determined by fecal occult blood test. Anemia is normochromic, normocytic in colonic bleeding that is seen in acute blood loss [34]. Bleeding due to chronic blood loss has a hypochromic microcytic property [35] that causes iron-deficiency anemia. In parallel with this, there is a decrease of serum iron and ferritin is determined in serum [36]. Iron-deficiency anemia has many causes, which is reviewed briefly below, along with the laboratory values for differential diagnosis. Iron-deficiency anemia is one of the most common diseases in the world, especially in women. Chronic fatigue is one of the main complaints. Hair loss and pica (eating of materials that are not food, such as soil and paper) are among the other symptoms. In prolonged iron-deficiency anemia, Plummer-Vinson syndrome, koilonychias, and chronic heart failure may be present classically. The causes of iron-deficiency anemia may be increased iron loss, reduction of dietary iron, decreased iron absorption, or increased need for iron. Increased iron loss is seen in bleeding and hemolytic states. Cancer should not be forgotten among the causes of bleeding. Reduced intake of dietary iron can be seen in vegetarian diets, malnutrition, chronic alcoholism, psychiatric disorders, and dementia. Decreased iron absorption can be seen in inflammatory bowel disease, antacid treatment, partial gastrectomy, excessive consumption of tea, and Whipple’s disease. An increased need for iron occurs during pregnancy and lactation [36–40]. Laboratory Values Indicative Iron-Deficiency Anemia In iron-deficiency, anemia is seen as microcytosis (mean corpuscular volume (MCV) is lower than the normal range). Serum ferritin concentration that is