Partial versus complete attenuation of single portosystemic shunts.

Twenty-two dogs with congenital single portosystemic shunts were treated by partial or complete ligation of the shunts. Intraoperative portal pressures before and after shunt ligation, and central venous pressures measured after 3 minutes of temporary shunt occlusion, were evaluated prospectively. Portal pressures after ligation, increases in portal pressure above baseline values, and decreases in central venous pressure during temporary occlusion were significantly greater in dogs that underwent partial portosystemic shunt ligation and in dogs that developed postoperative complications. Absence of arborizing intrahepatic vasculature in intraoperative mesenteric portograms did not indicate whether partial or complete shunt attenuation could be performed safely, but it was correlated with greater occurrence of post-operative complications.