Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Blunt Abdominal Trauma: Injury to the Epigastrium Mária Némethy, Harvard Medical School, Year III Gillian Lieberman, MD
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Blunt Abdominal Trauma (BAT) • Trauma is the leading cause of death in the United States in persons under 45 years of age • Because it primarily affects the young, trauma causes more lost years of productive life than cancer and cardiovascular disease combined • Blunt trauma accounts for 2/3 of all injuries • Majority of abdominal injuries are due to blunt trauma; 10% of trauma fatalities are due to abdominal injury 2
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Mechanisms of injury • Compression: direct blow or against a fixed object (seat belt, spinal column) – Generally results in tears or subcapsular hematomas in solid organs – Increased intraluminal pressure can cause rupture of hollow organs
• Deceleration: stretching and linear shearing between fixed and movable structures – Rupture of supporting elements at junction between fixed and free segments of organs – Thrombosis of vessels contained within supporting elements 3
http://www.emedicine.com/EMERG/topic1.htm
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Injuries resulting from blunt abdominal trauma • Common: – Liver – most commonly injured in all abdominal trauma (blunt and penetrating) – Spleen – most commonly injured organ in blunt trauma – Kidney – increasing frequency (increased detection) – Bladder (extraperitoneal)
• Rare: – Pancreas – Bowel
Adrenal Bladder (intraperitoneal) 4
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
First, a brief review of retroperitonal anatomy. Note the crowding of the numerous soft organs in the epigastrium, with little bony protection. Unlike small bowel, these organs are fixed in place, and so cannot move out of the path of blunt traumatic forces. 5
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Abdominal Retroperitoneum Inferior vena cava
Abdominal aorta
Pancreas Duodenum (retroperitoneal) Left kidney Right kidney
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Netter FH. Atlas of Human Anatomy, 2nd ed.
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Epigastric region IVC Right adrenal
Abdominal aorta
Right kidney
Left adrenal
Pancreas
Duodenum
Left kidney
Transverse colon
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Netter FH. Atlas of Human Anatomy, 2nd ed.
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Options for evaluating BAT • Plain film – Difficult to evaluate soft-tissue injury – May reveal free intraperitoneal air or signs of bowel obstruction
• Deep peritoneal lavage – Rapid detection of hemoperitoneum – Invasive – Risk of visceral and vascular injury 8
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Options for evaluating BAT • CT – gold standard for BAT evaluation – MDCT: high-resolution images and reconstructions allow improved detection and management of softtissue injury, hemorrhage, etc
• Ultrasound – increasing use – Safe for unstable patients; decreased costs – Limitations: fluid-filled bowel versus hemoperitoneum; extraperitoneal fluid versus intraperitoneal fluid; cystic masses can look like fluid collections; obesity
• MRI – not used in initial evaluation of BAT 9
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Our Patient JO, a 23-yr-old woman kicked in the stomach by a horse ● Imaging at outside hospital suggested pancreatic injury; JO was transferred to BIDMC for more complete evaluation 10
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Initial plain films were normal
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Images from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT: the diagnostic modality of choice in initial evaluation of blunt abdominal trauma
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT: pre-contrast Mesenteric hematoma Blood attenuation in duodenal wall
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Images from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Post-contrast: Pancreatic injury
Blood surrounding pancreatic head
Fluid surrounding pancreas
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Images from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Pancreatic injury in BAT • Epi: uncommon – seen in 0.2-12% of blunt trauma – associated visceral injuries are very common (50-90% of patients)
• Mechanism: – compression against vertebral column – shear across pancreatic neck
• Sequelae: Ductal leakage pancreatitis, which can lead to pseudocysts, fistulas and abscesses (20% mortality) • Grading: based on injury to main pancreatic duct: – minor injuries usually heal spontaneously and are treated conservatively – injuries involving main pancreatic duct require surgical 15 intervention
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT findings in pancreatic injury • CT sens/spec for pancreatic injury over 80%; dependence on interpreter experience and timing of evaluation • Contusion: areas of low attenuation with heterogeneous foci and diffuse enlargement of pancreas • Laceration: areas of linear, irregular low attenuation within normal parenchyma • Nonspecific: thickening of anterior pararenal fascia; blood/fluid tracking along mesenteric vessels; fluid in lesser sac; fluid between pancreas and splenic vein 16
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Renal injury Extravasation of IV contrast
Ischemic kidney 17
Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Renal injury Left kidney
Right kidney
Ischemic kidney 18
Images from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Renal injury in BAT • Epi: Seen in 10% of trauma patients; blunt trauma accounts for 80% of renal injuries – Left-sided predominance (1.3:1) – thought to be due to anatomic protection of right renal artery beneath inferior vena cava and duodenum
• Mechanism: – sudden deceleration/direct blow can cause renal dislocation – stretching of renal arteries can cause immediate avulsion or delayed thrombosis
• Sequelae: 80% are contusions/minor lacerations that heal spontaneously; persistent bleeding or complete infarction require surgical intervention
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT findings in renal injury • CT important in both diagnosis and patient management: provides both functional and morphologic information • Absence of contrast nephrogram reveals devascularized areas • Helical CT can image specific renal artery injury • Contusion: delayed and non-homogenous excretion of contrast material • Laceration: linear or wedge-shaped hypodensity • Fracture: involvement of full depth of renal parenchyma + disruption of collecting system 20
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Duodenal hematoma
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Duodenal injury in BAT • Epi: Bowel injury seen in 4-5% of major BAT; associated non-bowel injuries in 50% – Retroperitoneal duodenum most common site of injury – Duodenal hematomas are very uncommon!
• Mechanism: – Compression between spine and impacting body; – Shearing at fixed points (e.g. ligament of Treitz)
• Sequelae: – Duodenal hematoma: resolves in 1-3 weeks – Duodenal perforation: surgical intervention required
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT findings in duodenal injury • Nonspecific (perforation vs. hematoma): – Thickening of duodenal wall – Presence of fluid in right anterior pararenal space
• Specific to perforation: Extraluminal gas and/or oral contrast in right anterior pararenal space • Duodenal hematoma: – Initial heterogeneous, high attenuation region in duodenal wall due to blood accumulation – Isodensity, then hypodensity as clot resolves 23
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Intraperitoneal bleeding Uterus
Intraperitoneal blood in Douglas’ pouch (HU = 50)
Air in rectum 24
Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Intraperitoneal fluid in BAT • Is often sole finding on CT in blunt abdominal trauma • Tracks down right and left paracolic gutters into pelvic reflection of peritoneum • Large amounts of blood can accumulate in pelvis without significant hemoperitoneum apparent in upper abdomen 25
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
CT: detection of intraperitoneal fluid • CT very sensitive for detecting even small amounts of intraperitoneal fluid or hemorrhage • “Sentinel clot” sign: with multiple sites of hemoperitoneum, blood with highest CT attenuation is in proximity of site of hemorrhage • Blood attenuation on CT: – Free blood: 20-45 HU – Clotted blood: 40-100 HU – Active bleeding: within 10 HU of contrast density inside adjacent major vessel
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
How extensive was the pancreatic injury? …The role of MRI… 27
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
MRI: characterization of soft tissue injury • MRI is more sensitive for soft tissue anatomy and pathology • No advantage over CT in initial evaluation, but can be invaluable in characterization of subtle soft tissue injury, as in the pancreas • Role of MRCP: evaluate damage to pancreatic duct – key factor in surgical versus conservative treatment 28
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Pancreatic injury: characterization with MRI Lacerations in head of pancreas
Pancreatic head contusion Laceration in body of pancreas Images from PACS, BIDMC
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Duodenal hematoma on MRI
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Sequelae • JO was admitted to BIDMC one day after the injury • Her intra-abdominal injuries were managed conservatively (MRCP did not show laceration of pancreatic duct) • PICC line was placed on day two post-injury; initial inappropriate placement corrected on day three • Follow-up CT imaging was performed 10 days after initial CT – the findings…? 31
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
10-day follow-up: Pancreatic pseudocyst Pseudocyst
Pancreatic tissue
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Pancreatic pseudocyst
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Why did the kidney not infarct completely?? • Initial work-up demonstrated ischemic lower pole in left kidney • Extravasation of IV contrast into peritoneal cavity would suggest transection of renal artery • Follow-up CT indicated improved perfusion of lower renal pole • Interesting anatomy…
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Bilateral accessory renal arteries
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Accessory renal arteries • Transection of inferior accessory renal artery originating from common iliac artery, leading to contrast extravasation and infarct of inferior renal pole • Development of collateral perfusion from main renal artery and remaining accessory renal artery 36
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Our patient’s course • JO had a stable hospital course, and was discharged home 13 days after admission • Incidental note: JO received a PICC line for parenteral nutrition. Initial follow-up CXR revealed inappropriate positioning of the line…. 37
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
PICC line terminating in L jugular vein
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
The PICC line was repositioned, and subsequently revealed some more interesting anatomy….
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
A Left-sided SVC!
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Image from PACS, BIDMC
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
Acknowledgements • • • •
Michael Goldfinger, MD Gillian Lieberman, MD Pamela Lepkowski Larry Barbaras, Webmaster
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Mária Némethy, HMS III Gillian Lieberman, MD November 2004
References • • • • • • • • • •
Becker CD, et al. Blunt abdominal trauma in adults: role of CT in the diagnosis and management of visceral injuries. Eur Radiol 1998;8:772-80. Bradley EL III, et al. Diagnosis and initial management of blunt pancreatic trauma. Ann Surg 1998;227(6):861-9. Bruce LM, et al. Blunt renal artery injury: incidence, diagnosis, and management. Am Surg 2001;67(6):550-5. Dodds WJ, et al. Traumatic fracture of the pancreas: CT characteristics. J Comp Assist Tomography 1990;14(3):375-8. Fischer JH, Carpenter KD, O’Keefe GE. CT diagnosis of an isolated blunt pancreatic injury. AJR 1996;167:1152. Fuchs WA and Robotti G. The diagnostic impact of computed tomography in blunt abdominal trauma. Clin Radiol 1983;34:261-5. Klausner JM, et al. Intramural haematoma of the duodenum following blunt abdominal injury – the place for conservative treatment. Injury 1986;17:131-2. Kunin JR, et al. Duodenal injuries caused by blunt abdominal trauma: Value of CT in differentiating perforation from hematoma. AJR 1993;160:1221-3. Lupetin AR, Mainwaring BL, Daffner RH. CT diagnosis of renal artery injury caused by blunt abdominal trauma. AJR 1989;153:1065-8. McGehee M, et al. Comparison of MRI with postcontrast CT for the evaluation of 42 acute abdominal trauma. J Comp Assist Tomography 1993;17(3):410-3.
Mária Némethy, HMS III Gillian Lieberman, MD November 2004
References • • • • • • • • • •
McKenney KL. Ultrasound of blunt abdominal trauma. Radiol Clin N Am 1999;37(5):879-93. Mirvis SE and Shanmuganathan K. Abdominal computed tomography in blunt abdominal trauma. Sem Roentgen 1992;27(3):150-83. Netter FH. Atlas of Human Anatomy, 2nd ed. East Hanover, NJ: Novartis, 1999. Parker GD and Williams JAR. Massive intramural duodenal haematoma following blunt abdominal trauma: case report. Australas Radiol 1989;33:19204. Porter JM and Singh Y. Value of computed tomography in the evaluation of retroperitoneal organ injury in blunt abdominal trauma. Am J Emerg Med 1998;16(3):225-7. Sidhu MK, Weinberger E, Healey P. Intramural duodenal hematoma after blunt abdominal injury. AJR 1998;170:38. Shanmuganathan K. Multi-detector row CT imaging of blunt abdominal trauma. Sem Ultrasound CT MRI 2004;25(2):180-204. Shuman WP. CT of blunt abdominal trauma in adults. Radiology 1997;205:297306. Thomsen TW, Brown DFM, Nadel ES. Blunt renal trauma. J Emerg Med 2004;26(3):331-7. http://www.emedicine.com/EMERG/topic1.htm 43
