Occult Hepatocellular Carcinoma Associated with Transjugular Intrahepatic Portosystemic Shunts in Liver Transplant Recipients.

INTRODUCTION Transplant eligibility for hepatocellular carcinoma (HCC) is determined by the imaging identification of tumor burden within Milan criteria. Transjugular intrahepatic portosystemic shunts (TIPS) reduce portal hypertension but may impact HCC visualization. It was hypothesized that the presence of pre-transplant TIPS would correlate with occult HCC and reduced survival. METHODS A single-center retrospective case control study was performed among liver transplant recipients with HCC (2000-2017). The primary endpoint was occult disease on explant pathology. Backward stepwise elimination of candidate variables was modeled with logistic regression (LR). Secondary endpoints included disease-free survival (DFS) and overall survival (OS), evaluated with Kaplan-Meier curves and Cox regression analysis. RESULTS 40 of 640 patients had TIPS and more frequently exhibited occult disease (80.0% vs. 43.1%, p<0.001, odds ratio [OR] 4.16, p<0.001). Explant tumor burden was equivalent between TIPS subgroups; accordingly, TIPS status was not independently associated with reduced DFS or OS. However, exceeding Milan criteria was associated with reduced DFS (hazard ratio 3.21, p=0.001), and TIPS status in patients with a single suspected lesion (N=316) independently correlated with explant tumor burdens beyond Milan criteria (OR 13.47; p=0.001). Equivalent explant tumor burdens between TIPS groups suggests that occult disease in TIPS patients was due to reduced diagnostic capacity by imaging. Portal venous thrombosis similarly correlated with occult disease, suggesting a mechanism through altered hepatic perfusion. CONCLUSION TIPS on pre-transplant imaging are associated with occult HCC on explant pathology. TIPS are not independently associated with reduced DFS or OS, but are associated with exceeding Milan criteria for patients with a single suspected lesion. The presence of TIPS may alter the sensitivity of imaging and necessitate a higher index of suspicion.