Jean Junior, HMS IV Gillian Lieberman, MD
September 2015
The Common and the Uncommon: Abdominal Pain in a Child with a Ventriculoperitoneal Shunt Jean Junior, Harvard Medical School Year IV Gillian Lieberman, MD
Jean Junior, HMS IV Gillian Lieberman, MD
Outline • • • • • •
Our patient: Neonatal period Ventriculoperitoneal (VP) shunts Our patient: One month prior to presentation Our patient: Presentation with abdominal pain Diagnostic imaging for appendicitis in children Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Neonatal History • Intraventricular hemorrhage at birth of unknown etiology, which led to: – > Obstruction of cerebrospinal fluid (CSF) flow – > Hydrocephalus
• Ventriculoperitoneal (VP) shunt placed during neonatal period to relieve the hydrocephalus
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Jean Junior, HMS IV Gillian Lieberman, MD
Anatomy of Hydrocephalus: Ventricles
Image: Netter 2011.
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Jean Junior, HMS IV Gillian Lieberman, MD
Anatomy of Hydrocephalus: CSF Flow Direction of CSF Flow: --> Lateral ventricle --> Foramen of Monro --> 3rd ventricle --> Cerebral aqueduct --> 4th ventricle --> Foramina of Luschka and foramen of Magendie --> Subarachnoid space --> Arachnoid granulations --> Dural venous sinuses --> Systemic veins (e.g., internal jugular vein)
Image: Netter 2011.
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period • Ventriculoperitoneal (VP) shunts • Our patient: One month prior to presentation • Our patient: Presentation with abdominal pain • Diagnostic imaging for appendicitis in children • Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Function • Devices that drain CSF away from the ventricles, usually into the peritoneal cavity – > Helps relieve excess CSF build-up in the ventricles and prevent abnormally high intracranial pressure
Text and image: Campellone 2013.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Mechanics • Proximal catheter drains CSF from the ventricles (Campellone 2013) • Valve that controls how much CSF is removed from the ventricles per unit time (Lollis et al. 2010) • Distal catheter tunneled underneath the skin usually to the abdomen, where it inserts into the peritoneal cavity (Campellone 2013) – Extra catheter distance in peritoneal cavity allows for child’s growth (Khan 2015)
Text: Campellone 2013; Khan 2015; Lollis et al. 2010. 1st Image: Neuroanimations website; 2nd image: Campellone 2013.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Clinical Issues In technology-assisted children (e.g., with VP shunts or other devices), consider: • Common childhood illnesses unrelated to the device • Device infection • Device malfunction – For VP shunts: Obstruction, catheter disconnection, abnormal positioning, CSF over- or under-drainage Text: Fein et al. 2010.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Symptoms of Shunt Pathology • Neurologic – Altered mental status, headache
• Gastrointestinal – Abdominal pain, vomiting
Text: Fein et al. 2010.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Signs of Shunt Pathology • Fever • Cushing’s triad – Increased intracranial pressure --> Hypertension, bradycardia, abnormal respirations
• Sunsetting eyes – Compression of midbrain structures that mediate vertical gaze --> Upward gaze paresis
• Signs of cellulitis overlying catheter tract • Bulging fontanelle or increased head circumference • Abdominal tenderness • Abnormal neurologic exam or papilledema Text: Fein et al. 2010. Image: http://www.nurse.cmu.ac.th/webped/educate/lesson1/8.jpg
Sunsetting eyes
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunts: Radiological Work-Up • Suspected VP shunt malfunction almost always requires diagnostic imaging – But there is not consensus as to imaging tests of choice in suspected VP shunt malfunction
Text: DeFlorio et al. 2014.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunt Imaging: Cranial CT Scan • Has been the most commonly used imaging modality for suspected ventricular shunt malfunction (Boyle et al. 2014) • Cheaper than MRI – e.g., Patient charge of $1364 for a head CT versus $1428 for a rapid cranial MRI at one tertiary pediatric hospital (Boyle et al. 2014)
• Easier to access than MRI, especially at night (Boyle et al. 2014) • No risk of de-programming VP shunts – MRI can alter the rate of CSF drainage of certain brands of VP shunts that are magnetically programmed. These shunts need re-programming after MRI to prevent CSF over- or underdrainage (Lollis et al. 2010).
Text: Boyle et al. 2014; Lollis et al. 2010.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunt Imaging: Cranial MRI • No radiation exposure – Compared with adults, children are more sensitive to radiation, with a higher proportion of dividing cells and more life-years remaining in which cancer can develop (Brenner et al. 2007)
• Rapid cranial MRI technology now exists – Involves fewer MRI sequences with faster image acquisition time (as low as 8 seconds) (Woodfield et al. 2015) – Sedation generally unnecessary given minimal time in scanner (Woodfield et al. 2015) – Accuracy for diagnosing ventricular shunt malfunction is not inferior to that of cranial CT (Boyle et al. 2014) Text: Boyle et al. 2014; Brenner et al. 2007; Woodfield et al. 2015.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunt Imaging: “Shunt Series” Radiograph • Captures entire course of VP shunt from brain to peritoneal cavity • May not be needed if other cranial imaging is also obtained – When both a cranial CT and a shunt series are obtained, the shunt series alters decisions about the need for neurosurgery in only ~1.5% of cases Companion Patient #1: Example of a normal shunt series Text: Vassilyadi et al. 2010. Image: wikiRadiography website.
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Jean Junior, HMS IV Gillian Lieberman, MD
VP Shunt Imaging: Ultrasound Images ventricles through an open anterior fontanelle Shunt
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Companion Patient #2: Example Companion Patient #3: Example of a of an infant undergoing an shunt and enlarged ventricles (*) on ultrasound examination ultrasound 1st image: Meijler 2012; 2nd image: DeFlorio et al. 2014.
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period Ventriculoperitoneal (VP) shunts • Our patient: One month prior to presentation • Our patient: Presentation with abdominal pain • Diagnostic imaging for appendicitis in children • Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: One Month Prior to Presentation • 11-year-old female presented to emergency department 4 days after falling from a scooter and hitting her head. She had: – Headache – Pain and swelling behind ear over VP shunt site – No other symptoms or signs
• Given these symptoms and signs, there was concern for VP shunt malfunction and imaging was obtained 18
Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Enlarged Ventricles on Rapid Cranial MRI Frontal horns of lateral ventricles
Atria/trigones of lateral ventricles C- axial T2 head MRI from 2 months prior to presentation with ventricles at baseline size Images: Boston Children's Hospital.
C- axial T2 head MRI from 1 month prior to presentation with larger ventricles 19
Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: VP Shunt Discontinuity on Shunt Series Radiograph
Discontinuity
New 3 cm discontinuity in the VP shunt catheter in the left scalp region Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: VP Shunt Surgery • Given her VP shunt discontinuity, she underwent surgical revision of the shunt with placement of a new distal catheter – The surgery was uncomplicated
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period Ventriculoperitoneal (VP) shunts Our patient: One month prior to presentation • Our patient: Presentation with abdominal pain • Diagnostic imaging for appendicitis in children • Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Presentation with Abdominal Pain • 11 year-old female presented to emergency department with abdominal pain during the 4 weeks since her VP shunt surgery – Worst in right lower quadrant, exacerbated by movement, worse in the 3-4 days prior to presentation – No fever, anorexia, nausea, vomiting, or diarrhea; last bowel movement the day prior – Exam notable for an abdomen that: • Was soft, non-distended, diffusely tender (especially in the right lower quadrant) • Had rebound and positive psoas sign, but no guarding 23
Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Differential Diagnosis Differential was broad, and included: • Appendicitis • CSF pseudocyst – An abnormal, loculated CSF fluid collection at the tip of the VP shunt catheter in the peritoneal cavity – Fluid may become infected
• Renal/urinary and ovarian pathology 24
Jean Junior, HMS IV Gillian Lieberman, MD
Companion Patient #4: Example of a CSF Pseudocyst on Ultrasound
CSF pseudocyst
Ultrasound showing a CSF pseudocyst surrounding multiple shunt catheter loops (circled) Image: DeFlorio 2014.
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period Ventriculoperitoneal (VP) shunts Our patient: One month prior to presentation Our patient: Presentation with abdominal pain • Diagnostic imaging for appendicitis in children • Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Appropriateness Criteria for Appendicitis Diagnostic Imaging in Children
Table: ACR 2013.
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Jean Junior, HMS IV Gillian Lieberman, MD
Pediatric Appendicitis Imaging: Ultrasound • No radiation • Sensitivity of 88% and specificity of 94% (Doria et al. 2006) – Similar to CT sensitivity of 94% and specificity of 95% (Doria et al. 2006)
• Initial imaging of choice (ACR 2013)
Text: ACR 2013; Doria et al. 2006.
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Jean Junior, HMS IV Gillian Lieberman, MD
Pediatric Appendicitis Imaging: CT Scan • Among females ages 5-14 “a radiationinduced solid cancer is projected to result from every 300 to 390 abdomen/pelvis [CT] scans” (Miglioretti et al. 2013:700) • Consider obtaining a CT scan if ultrasound findings are equivocal (ACR 2013)
Text: ACR 2013; Miglioretti et al. 2013.
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Jean Junior, HMS IV Gillian Lieberman, MD
Pediatric Appendicitis Imaging: Abdominal Radiograph • Shows free air and obstruction (ACR 2013) • Shows findings that can be associated with appendicitis, e.g.: – An appendicolith (Lieberman 2005) – A sentinel loop of bowel, which is a focal ileus in an area of inflammation (Lieberman 2005)
Text: ACR 2013; Lieberman 2005.
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Jean Junior, HMS IV Gillian Lieberman, MD
Pediatric Appendicitis Imaging: MRI • Not commonly used, given availability, potential need for sedation, and cost
Text: ACR 2013.
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Jean Junior, HMS IV Gillian Lieberman, MD
Companion Patient #5: Example of Appendicitis with Hyperemic Appendiceal Wall on Doppler Ultrasound
Incompressible, blind-ended, fluid-filled structure, with diameter > 6 mm and thickened/hyperemic wall Image: Gaitini 2011.
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Jean Junior, HMS IV Gillian Lieberman, MD
Companion Patient #6: Example of Appendicitis with Appendicolith on Ultrasound
Appendicolith
Acoustic shadowing
Enlarged appendix with appendicolith apparent as an echogenic focus with adjacent acoustic shadowing (*) Image: Rybkin et al. 2007.
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period Ventriculoperitoneal (VP) shunts Our patient: One month prior to presentation Our patient: Presentation with abdominal pain Diagnostic imaging for appendicitis in children • Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Appendix Not Seen on Abdominal/Pelvic Ultrasound
Right lower quadrant view with appendix not visualized Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Other Findings on Abdominal/Pelvic Ultrasound • Large stool burden in rectum • Unremarkable kidneys, bladder, uterus, and ovaries • VP shunt tip not definitely identified, but no appreciable loculated fluid collection suggestive of CSF pseudocyst
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Clinical Reassessment • Patient’s status after her ultrasound – Afebrile with normal vital signs – Abdomen soft without rebound or guarding – Labs (CBC, chem-7, LFTs, amylase, lipase, urinalysis) unremarkable
• Clinical suspicion for appendicitis or other acute abdominal/pelvic pathology was low enough to defer CT scan • Abdominal radiograph was obtained mainly to evaluate further for obstruction, constipation, and VP shunt pathology 37
Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Abdominal Radiograph
There are 3 main findings on our patient’s upright and supine abdominal radiographs. Let’s look at these findings one by one.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: New VP Shunt Catheter on Abdominal Radiographs New catheter
New catheter
New VP shunt distal catheter placed 1 month prior, which does not have discontinuities or kinks. Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Old VP Shunt Catheter on Abdominal Radiographs Old catheter
Old catheter
There is a piece of the patient’s old VP shunt distal catheter, which does not appear to extend past the T8 vertebral level. This free piece of catheter was calcified and could not be removed during her surgery 1 month prior. Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Stool on Abdominal Radiographs
Fecal Matter
Fecal Matter
There is no bowel obstruction, but the right colon contained a moderateto-large amount of stool. Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Summary of Findings on Abdominal Radiographs Old catheter
New catheter
New catheter
Old catheter Fecal Matter
Fecal Matter
Images: Boston Children's Hospital.
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Jean Junior, HMS IV Gillian Lieberman, MD
Our Patient: Diagnosis and Outcome • She was discharged from the emergency department with a diagnosis of constipation and instructions for the outpatient treatment of this condition
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Jean Junior, HMS IV Gillian Lieberman, MD
Outline Our patient: Neonatal period Ventriculoperitoneal (VP) shunts Our patient: One month prior to presentation Our patient: Presentation with abdominal pain Diagnostic imaging for appendicitis in children Our patient: Imaging results and outcome
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Jean Junior, HMS IV Gillian Lieberman, MD
Summary of Learning Points We reviewed the: • Anatomy pertinent to hydrocephalus • Function and malfunction of VP shunts – And the warning signs of shunt malfunction
• Imaging options for diagnosing VP shunt malfunction – And the radiological appearance of VP shunt pathologies on ultrasound, radiograph, and cranial MRI 45
Jean Junior, HMS IV Gillian Lieberman, MD
Summary of Learning Points Continued We reviewed the: • Imaging options for diagnosing appendicitis – And the radiological appearance of appendicitis on ultrasound
Finally, we were reminded that common diagnoses (e.g., constipation) are indeed common. 46
Jean Junior, HMS IV Gillian Lieberman, MD
References • American College of Radiology (ACR). Right Lower Quadrant Pain—Suspected Appendicitis. ACR Appropriateness Criteria website. https://acsearch.acr.org/docs/69357/Narrative/. Updated 2013. Accessed September 13, 2015. • Boyle TH, Paldino MJ, Kimia AA, et al. Comparison of rapid cranial MRI to CT for ventricular shunt malfunction. Pediatr. 2014;134:e47–e54. • Brenner DJ and Hall EJ. Computed tomography — an increasing source of radiation exposure. N Engl J Med. 2007;357:2277-2284. • Campellone JV . Ventriculoperitoneal shunt – series. MedlinePlus website. https://www.nlm.nih.gov/medlineplus/ency/presentations/100123_4.htm. Updated October 29, 2013. Accessed September 10, 2015. • Campellone JV. Ventriculoperitoneal shunt – series. MedlinePlus website. https://www.nlm.nih.gov/medlineplus/ency/presentations/100123_5.htm. Updated October 29, 2013. Accessed September 10, 2015. • DeFlorio RM, Shah CC. Techniques that decrease or eliminate ionizing radiation for evaluation of ventricular shunts in children with hydrocephalus. Semin Ultrasound CT MR. 2014;35:365-373. • Doria AS, Moineddin R, Kellenberger CJ, et al. US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis. Radiology. 2006;241(1):83-94. • Fein JA, Cronan KM, Posner JC. Approach to the care of the technology‐assisted child. In: Fleisher GR, Ludwig S, eds. Textbook of Pediatric Emergency Medicine. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2010:1494-1514. • Gaitini D. Imaging acute appendicitis: state of the art. J Clin Imaging Sci. 2011;1(3):49. • http://www.nurse.cmu.ac.th/webped/educate/lesson1/8.jpg. Accessed September 13, 2015. 47
Jean Junior, HMS IV Gillian Lieberman, MD
References Continued • Khan RA. Introduction: the use of extrathecal CSF shunts, optional vs mandatory, unavoidable complications. In: Di Rocco C, Turgut M, Jallo G, Martínez-Lage JF, eds. Complications of CSF Shunting in Hydrocephalus: Prevention, Identification, and Management. Cham, Switzerland: Springer; 2015:75-80. • Lieberman G. Radiologic assessment of abdominal pain: Case 7. Lieberman's Primary Care Radiology website. http://eradiology.bidmc.harvard.edu/primarycare/abdominalpain.html. Updated 2005. Accessed September 27, 2015. • Lollis SS, Mamourian AC, Vaccaro TJ, Duhaime AC. Programmable CSF shunt valves: radiographic identification and interpretation. Am J Neuroradiol. 2010;31:1343–1346. • Miglioretti DL, Johnson E, Williams A, et al. The use of computed tomography in pediatrics and the associated radiation exposure and estimated cancer risk. JAMA Pediatr. 2013;167(8):700-707. • Netter FH. Atlas of Human Anatomy. 5th ed. Philadelphia, PA: Saunders Elsevier; 2011. • Radiography of VP Shunts. wikiRadiography website. http://www.wikiradiography.net/page/Radiography+of+VP+Shunts. Accessed September 13, 2015. • Rybkin AV, Thoeni RF. Current concepts in imaging of appendicitis. Radiol Clin N Am. 2007;45:411–422. • Meijler G. Neonatal Cranial Ultrasonography. 2nd ed. Berlin, Germany: Springer-Verlag; 2012. • Vassilyadi M, Tataryn ZL, Alkherayf F, Udjus K, Ventureyra ECG. The necessity of shunt series. J Neurosurg Pediatr. 2010;6:467-473. • What is a VP Shunt and what does it do? Neuroanimations website. http://neuroanimations.com/Hydrocephalus/Shunts/VP_Shunt.html. Accessed September 10, 2015. • Woodfield J, Kealey S. Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review. Pediatr Radiol. 2015;45:1271–1281. 48
Jean Junior, HMS IV Gillian Lieberman, MD
Acknowledgements • Radiology residents: Dr. Stella Lam, Dr. Walter Champion, and Dr. Catherine Wei • Fellow radiology students • Katie Armstrong and Dr. Gillian Lieberman
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