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Findings: CT scan of the abdomen (Image #1) reveals a small liver with a large amount of ascites. A 1.5 cm round structure is identified in the right lobe of the liver demonstrating marked enhancement. The study also demonstrates rapid shunting from the arterial to portal venous systems consistent with fistula. Digital subtraction ateriogram (selective hepatic artery injection) (Images #2,3) reveals a small pseudoaneurysm off the distal aspect of the main right hepatic artery. There is also rapid shunting from hepatic artery to portal vein consistent with an arterioportal venous fistula. Percutaneous transcatheter embolization of the affected hepatic arterial branch was then undertaken. Multiple metallic coils were deposited in this branch both proximal and distal to the pseudoaneurysm and AV fistula. Follow-up arteriogram (Image #4) reveals occlusion of the distal hepatic artery and no evidence of filling of the pseudoaneurysm or arteriovenous shunting.
Diagnosis: Pseudoaneurysm and arterioportal venous fistula status post percutaneous liver biopsy.
Discussion: Iatrogenic hepatic arterial pseudoaneurysms and arterial portal venous fistulas may be the result of percutaneous biopsy, following percutaneous biliary drain placement or following surgical procedures. Similar findings may be seen following penetrating trauma to the liver. Patients may present with a wide spectrum of findings including abdominal pain, hemobilia or upper GI tract bleeding, intraperitoneal bleeding which may result in hemodynamic collapse. While surgical therapy was previously the treatment of choice, with the advent of microcatheters and newer embolization materials, transcatheter embolization is the treatment of choice. Advantages include precise localization of the site of origin of the pseudoaneurysm and fistula, access to sites deep within hepatic parenchyma that would be difficult to approach surgically and much more rapid recuperation. It is important to insure that the portal vein is patent prior to hepatic artery embolization, as catastrophic liver failure can result following embolization in patients with portal vein occlusion.
References:
Baker KS, Tisnado J, Cho S, Beachley MC. Splanchnic Artery Aneurysms
and Pseudoaneurysms: Transcatheter Embolization. Radiology 1987;163:135-139.
Beningfield SJ, Bornman PC, Krige JEJ, Terblanch J. Control of Hemobilia by
Embolization of a False Aneurysm and Arterioportobiliary Fistula of the Hepatic Artery.
AJR 1991; 156:1263-1265.
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