Purpose or Case Report: Portal hypertension in pediatric patients is rare, most commonly caused by extrahepatic portal vein (PV) occlusion. Complications include gastrointestinal bleeding. If obstruction recanalization or surgical shunt is not feasible, a transjugular intrahepatic portosystemic shunt (TIPS) can be placed. Risks of TIPS include encephalopathy, shunt stenosis, or thrombosis. Tipsitis is rare, occurring in less than 1% of TIPS patients, but is serious, with a mortality of 32%. Early diagnosis and treatment are key to preventing the need for liver transplantation, and imaging plays a key role in early detection. We present a case of tipsitis identified with FDG-PET/CT imaging.
A 16 year-old-male with prematurity, umbilical vein catheter, and heterozygous prothrombin mutation presented with hematemesis. Imaging identified chronic PV thrombosis. Due to the occlusion involving both the right and left PV, TIPS was placed. 5.5 months post-TIPS, he presented with fever and body aches. Investigations revealed Methicillin-Sensitive Staphylococcus aureus (MSSA) bacteremia and thrombosed TIPS. He completed a 6-week course of IV antibiotics, and the TIPS was revised.
Two weeks later, he was readmitted with recurrent MSSA bacteremia. FDG-PET/CT scan was performed, showing increased TIPS uptake, consistent with tipsitis. He completed an additional 8-week IV antibiotic course. Repeat FDG-PET/CT showed decreased but persistent TIPS uptake. IV antibiotics were extended, and he was placed on suppressive oral antibiotics with a plan for FDG-PET/CT in 3 months.
Tipsitis is rare, and early infection (<120 days) is associated with gram-positive bacteria caused by seeding during placement. In this case, later infection was suspected to be caused by Staph aureus superinfection during influenza. Low-grade symptoms include malaise, and high-grade symptoms include fever and rigors. Suspicious CT findings include peri-graft gas or fluid. Radiolabeled leukocyte uptake is specific to infection, but spatial resolution is limited. FDG-PET/CT with focal TIPS metabolic activity (SUV > 8.0) correlates with infection source (sensitivity 91-98%, specificity 64–91%).
Antibiotic therapy is successful in 53% of cases, and FDG-PET/CT can determine the degree of treatment success. Residual hypermetabolic activity signifies partial response. Aggressive antibiotics are recommended to prevent resistance and the need for liver transplant. FDG-PET/CT plays a vital role in diagnosis and management of tipsitis.
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