A 64-year-old male presented to his gastroenterologist with a history of portal hypertension and esophageal varices. His past medical history was remarkable for an episode of deep venous thrombosis. He also had a history of ulcerative colitis for which a colectomy and ileostomy had been performed. The patient had no history of hepatitis B or C, nor did he report any alcohol abuse.
Based on clinical concern for primary biliary cirrhosis, a percutaneous liver biopsy was performed. The patient tolerated the biopsy well and was discharged without any obvious immediate postbiopsy complications. The results of the biopsy were essentially unremarkable, revealing no evidence of either fibrosis or cirrhosis .
Following the biopsy, an MRI of the liver demonstrated a new geographic focus of increased T2 signal in the region of the biopsy (Fig. 1A). This region demonstrated decreased signal on both in- and opposed-phase imaging (Figs. 1B, 1C). However, no difference in signal was seen between these two T1-gradient sequences.
T1, fat-saturated, 3D-gradient, arterial-phase imaging demonstrated contrast opacification of the anterior branch of the right portal vein at the same time as the right hepatic artery (Figs. 2A, 2B). During this phase however, there was no main portal-vein enhancement. The main and left portal veins did opacify as expected in the portal phase of imaging (Figs. 2C, 2D). These findings suggested an iatrogenic fistulous communication between the right hepatic artery and the anterior branch of the right portal vein.
No intervention was performed as this time, but rather a watchful management approach was taken. One month later, a triple-phase CT demonstrated a nonenhancing filling defect with the right portal vein, with extension into adjacent portions of the anterior and posterior branches (not shown). A subsequent MRI demonstrated complete occlusion of the main portal vein, with cavernous transformation. The prominent early filling of the anterior branch of the right portal vein seen on the previous MRI examination was no longer present, indicating that the arterioportal fistula had resolved (Fig. 3).
The hepatic veins were patent and showed no evidence of thrombus, but there were an increased number of small veins around the anterior branch of the right portal vein, indicating the development of collateral venous flow. As in the previous MRI, prominent esophageal varices were seen in the distal esophagus. As a result, elective endoscopic band ligation was performed for treatment. The patient was also referred for a hematologic evaluation and anticoagulation treatment, but the hematological workup was surprisingly negative for hypercoagulable states.