Percutaneous Extrahepatic Portacaval Shunt with Covered Prostheses: Feasibility Study

Abstract

To assess the anatomic feasibility of creating a percutaneous extrahepatic portosystemic shunt (PEPS) between the main portal vein (MPV) and the inferior vena cava (IVC) in patients with cirrhosis and to evaluate the feasibility of this approach in an animal model. In human studies, computed tomographic (CT) scans from 34 patients with cirrhosis were reviewed to assess the distance and anatomic structures found between the MPV and IVC. The MPV was divided into upper, middle, and lower thirds for analysis. In the experimental model, PEPS were created in 10 beagle dogs by placing between the MPV and IVC a tubular polyurethane-covered prosthesis with flared ends designed for this study. Different approaches, devices, and prostheses were assayed. In human studies, the shortest mean distance between the IVC and the MPV was found in the lower third of the MPV (1.18 cm +/- 0.6). The lower third, the nearest to the confluence of splenic and superior mesenteric veins, also presented fewer intervening structures, and the spatial relationship between the veins at this level was predictable. In the experimental model, direct portography was performed, with a small mesenteric vein catheterized through a minilaparotomy and a transjugular access to the IVC. A needle was advanced from the MPV to the IVC, and a polyurethane cone-shaped covered prosthesis was placed to bridge the path between the veins. Six of 10 animals died from bleeding that occurred either because several punctures were made during the procedure or because the prosthesis became dislodged when the mesentery was moved before suturing the minilaparotomy. The remaining four were kept alive for 1, 5, 60, and 90 days after the procedure. PEPS creation in patients with cirrhosis is anatomically possible. The lower third of the MPV should be the most suitable level at which to create the shunt. Preliminary studies carried out in beagle dogs support the feasibility of this approach. However, further work is needed to improve the efficacy of this technique.