Histopathologic study of transjugular intrahepatic portosystemic shunts.

A detailed histopathologic analysis of intrahepatic portosystemic shunts was performed following liver transplantation in five patients. Gross examination revealed that all stents were patent and unchanged in size, shape, and position from initial placement. Histologic examination at 4 days revealed an irregular luminal surface with liver parenchyma protruding between the stent wires and a single, patchy layer of endothelial cells lining the shunt surface. By 3 weeks, the stent wires were covered by a pseudointima of granulation tissue, and the luminal surface was lined with a contiguous layer of endothelial cells. Excessive pseudointimal proliferation resulted in shunt occlusion at 3 months in one patient whose shunt was subsequently reopened percutaneously.