In 50 consecutive patients portal blood flow was determined using computed liver perfusion scintigraphy preoperatively and at 6, 12, 24, 36, 48, 60, 72, and 84 months postoperatively between 1 January 1983 and 1 January 1990. All 25 subjects had undergone placement of a distal splenorenal shunt (DSRS) and 25, insertion of low-diameter PTFE mesocaval interposition shunt (LDMIS) between 15 January 1983 and 1 January 1988. Indications for shunt operation included recurrent variceal hemorrhage in spite of long-term endoscopic sclerotherapy, a Child-Pugh classification of A or B, a sonographically determined liver volume of between 1000 and 2500 ml, exclusion of the activity and progression of liver disease by biopsy and stenosis of the hepatic artery or coeliac trunk. DSRS was performed when the portal perfusion index (PPI) was greater than 30% (normal values 56 +/- 5%) and LDMIS was carried out when the PPI was 10% to 30%. In all cases the underlying disease was liver cirrhosis of alcoholic (n = 34, 68%) or hepatic (n = 12, 24%) etiology. Five patients who underwent LDMIS had originally scheduled for DSRS at a PPI of greater than 30%; because the DSRS would have been technically difficult due to severe chronic pancreatitis, a LDMIS was performed. One in-hospital death due to liver failure had occurred in each group by 1 January 1990. One patient in the DSRS group and two in the LDMIS group died later, and in each group one patient was lost to follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)