Partial ileal bypass surgery in the treatment of heterozygous familial hypercholesterolemia: a review.

Partial ileal bypass (PIB) surgery is a method in the treatment of heterozygous familial hypercholesterolemia (FH). Since the first report in 1964 about 150 cases of FH who underwent the surgical procedure have been described. This number is very low when compared to other types of cholesterol-lowering treatment. On average, PIB decreases the level of plasma total cholesterol by 35% in FH patients, and the surgical procedure can be considered the most effective, single cholesterol-lowering method. PIB-induced reduction of plasma cholesterol is permanent. Further decrease of plasma cholesterol may be obtained in combination with an inhibitor of cholesterol biosynthesis. PIB specifically lowers plasma LDL cholesterol; the concentration of HDL cholesterol is not systematically influenced. The mechanism underlying the hypocholesterolemic action of PIB is discussed. Until now there is no evidence that PIB reduces atherosclerotic coronary death in FH patients. After PIB more patients experience improvement of angina pectoris rather than deterioration (15 versus 2 out of 41), but the number of patients is too small to allow solid conclusions. In 50% of FH patients PIB may cause regression of xanthomata. Out of 209 hyperlipidemic patients described, 14 patients had postoperative complications, which caused death in 3 patients. Diarrhea is the most common side-effect of PIB; out of 99 operated patients serious diarrhea troubled 38 patients, whereas 40 patients had minor complaints during the first year postoperatively. Diarrhea may persist as long as 10 years after PIB. There is no evidence that PIB enhances gallstone formation and severely impairs liver function, but PIB may increase the incidence of renal stones. It is suggested that PIB can be considered in the treatment of FH. However, in each individual case the disadvantages and possible advantages should be carefully weighed out, and this consideration should form the basis to decide whether or not surgery is indicated.