Imaging Sciences Interesting Cases
Case 58
David Tuttle, MD
Clinical Presentation: Patient is a 56-year-old female with idiopathic liver failure and chronic ascites. She underwent transjugular intrahepatic portal system shunt (TIPS) placement with subsequent development of hyperammonemia and mental status changes. She now presents for a TIPS revision.
Imaging Findings: Fluoroscopic exam with injection of IV contrast taken after TIPS demonstrated a widely patent shunt (Fig. 1).
Fluoroscopic exam with injection of IV contrast taken after TIPS revision demonstrated stenosis of the shunt, created by placement of a self-expanding stent adjacent to a shorter balloon expandable stent (Fig. 2).
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| Figure 1:Fluoroscopic image taken after TIPS. |
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| Figure 2: Fluoroscopic image taken after TIPS revision. |
Diagnosis: TIPS related Encephalopathy
Discussion: TIPS is followed by encephalopathy in 20% to 40% of patients, manifesting as alterations in consciousness, intellectual deterioration, personality changes, flapping tremor, and asterixis. Pathogenesis is believed to be secondary to cerebral toxins that bypass the liver by means of the shunt, such as ammonia, mercaptans, and γ-aminobutyric acid. Ammonia is believed to be the main cerebral toxin, although the severity of encephalopathy does not correlate well with blood ammonia levels.
Management of encephalopathy includes restriction of dietary protein, treatment of any active infection, and discontinuation of all sedatives. Pharmacologic treatment includes neomycin and lactulose, which are believed to decrease the amount of intestinal ammonia as well as inhibit its absorption. Some patients improve after TIPS interruption or revision (decreasing the shunt).
References:
- Townsend C. Sabiston Textbook of Surgery. 17th ed., WB Saunders/Elsevier, 2004.