Loss of selectivity of Warren shunt in long-term observation.

Sixty patients who underwent distal splenorenal shunt were followed up from one to ten years, with an average of 5.6 years. Postoperative portography through the superior mesenteric artery was carried out in 58 of these patients and the remaining two were studied at autopsy. The diameter of the portal vein was unchanged in 65 per cent of the patients within 30 postoperative days, but it decreased remarkably in size one year after the surgery in one third of the patients, and it was observed in about half of the patients at 5 years after the surgery. Numerous collaterals had developed around the pancreas and stomach in the majority of cases presenting narrowing of the portal vein. Enormously dilated pancreatic veins directed to non-isolated distal splenic vein were identified in the autopsied cases. These findings strongly suggest that pancreatic veins connecting to the distal vein may play a leading role in production of malcirculation of the portal system after distal splenorenal shunt.