Partial ileal bypass for hypercholesterolemia. 20- to 26-year follow-up of the first 57 consecutive cases.

Between 1963 and 1968, 57 patients underwent partial ileal bypass (PIB) at the University of Minnesota for primary hypercholesterolemia. Preoperative total plasma cholesterol (TC) was 363.3 +/- 136.8 mg/dL (mean +/- SD) in these patients. Baseline and follow-up TC results demonstrated highly significant (p less than or equal to 0.001) TC reduction, 34% (n = 48), 28% (n = 49), 35% (n = 26), 35% (n = 11), and 30% (n = 25) at 1, 2 to 5, 6 to 10, 11 to 15, and more than 20 years, respectively, after PIB. In 21 patients with baseline, 1-year, and more than 20-year results TC decreased 33% by 1 year and remained 29% less than baseline more than 20 years after surgery (p = NS versus 1 year). Plasma triglyceride results were available in fewer patients, and no statistically significant changes developed after PIB. Two patients (3.5%) underwent PIB reversal, one for intractable diarrhea and one for recurrent nephrolithiasis. In the 25 nonreversed, long-term survivors, no statistically significant weight change was noted. Twenty-four per cent had 0 to 2, 52% had 3 to 5, and 24% had more than 5 bowel movements per day. Subsequent cholecystectomy was required in eight patients, and nephrolithiasis developed in 10 (40%). During 20 to 26 years, most survivors developed clinically apparent atherosclerosis: angina (60%), myocardial infarction (16%), or coronary artery bypass (28%). Coronary heart disease was the predominant cause of death among nonsurvivors (80%). Overall survival rates were 95% 88%, 75%, 59%, 53%, and 41% at 1, 5, 10, 15, 20, and 25 years, respectively, after PIB. Partial ileal bypass leads to highly significant TC reduction, which is sustained, essentially unchanged, more than 20 years after operation. In comparison to available epidemiologic and clinical trial data, these results support the hypothesis that TC reduction has a beneficial effect in patients with hypercholesterolemia.