From 1958 to 1990, elective therapeutic portal-systemic shunt (PSS) procedures were performed for recurrent bleeding esophagogastric varices in 162 children and adults with extrahepatic portal hypertension (EHPH) resulting from portal vein thrombosis (PVT). The onset of EHPH was in childhood for at least 74% of patients. Of the 162 patients, 147 were eligible for and received 5 years of follow-up (100%), and 117 were eligible for and received 10 years of follow-up (100%). The longest follow-up was 35 years. The cause of PVT was unknown in 68%, neonatal omphalitis in 12%, umbilical vein catheterization in 8%, peritonitis in 6%, trauma in 4%, and thrombotic coagulopathy in 2%. The number of variceal bleeding episodes ranged from 2 to 18 (mean, 5.6). None of the patients had clinical, biochemical, or liver biopsy evidence of liver disease. Esophageal varices were demonstrated by endoscopy, and/or contrast x-rays, and/or angiography in all patients. Visceral angiography was always used to demonstrate the extent of portal obstruction and the veins available for shunting. Before referral, the following procedures had failed: endoscopic sclerotherapy (68 patients), splenectomy alone (32 patients), central splenorenal shunt with splenectomy (10 patients), transesophageal varix ligation (12 patients). Three types of PSS were used: (1) central side-to-side splenorenal without splenectomy (75 patients, 46%); (2) central end-to-side splenorenal with splenectomy (34 patients, 21%); and (3) mesocaval (end-to-side cavomesenteric) (53 patients, 33%). PSS reduced the mean corrected portal pressure from 292 to 28 mm saline. All patients survived the procedure and left the hospital (100%). The actuarial survival rate for 5 years is 99%, and for 10 years is 96%. Three of the 6 deaths were unrelated to EHPH or PSS. Shunt patency for up to 35 years was demonstrated in 98% of patients by angiography and/or ultrasonography. In four patients (2%), all of whom had end-to-side splenorenal shunts, shunt thrombosis and rebleeding developed 3, 4, 4, and 6 years (respectively) after PSS. There were the only patients who experienced rebleeding. A diligent and repeated effort was made to detect portal-systemic encephalopathy (PSE), and no instance of PSE was found during 3 to 35 years of follow-up. Liver function and morphology remained normal, and hypersplenism was corrected in all patients. Quality of life was good in 98% of patients, and 5 years after PSS 96% were gainfully employed, engaged in full-time homemaking, or attending school.(ABSTRACT TRUNCATED AT 400 WORDS)