Effect of colectomy with ileo‐anal anastomosis on the biliary lipids

Abstract

Total colectomy with ileo-anal anastomosis is an effective treatment for ulcerative colitis and familial adenomatous polyposis. The absence of the colon and the coexistence of bile acid malabsorption may increase bile lithogenicity, but data on biliary lipid composition in patients with this operation is lacking. Our aim was to assess bile lithogenicity, bile composition and mass of biliary lipids within the gallbladder. We studied 11 patients with total colectomy and ileo-anal anastomosis and 16 healthy controls. We measured the percentage composition of conjugated bile acids and the masses within the gallbladder of the three main biliary lipids. This method, in contrast with measurement of cholesterol saturation index, can determine the cause of bile lithogenicity in terms of absolute modifications of the biliary lipids. There was no difference in the cholesterol saturation index between patients and controls. Colectomy patients had reduced masses of all three biliary lipids (medians and ranges, mmol): cholesterol 0.11 (0.03-0.24) vs. 0.36 (0.02-0.96), P < 0.02; bile acid 1.62 (0.75-5.21) vs. 3.95 (1.27-8.70), P < 0.01; phospholipids 0.35 (0.07-0.69) vs. 1.14 (0.14-3.00), P < 0.002. They also had reduced per cent deoxycholic acid: 3.8 (0.0-27.6) vs. 17.4 (6.4-44.7), P < 0.005, and increased percent cholic acid: 44.9 (23.3-71.4) vs. 34.3 (19.2-57.9), P < 0.05. We conclude that, despite having bile acid malabsorption, patients with colectomy and ileo-anal anastomosis have a normal cholesterol saturation index, caused by a concomitant reduction in the masses of all three biliary lipids. The reduced per cent biliary deoxycholic acid may help explain the reduced cholesterol and phospholipid masses in these patients. Total colectomy with ileo-anal anastomosis does not seem to predispose to the formation of cholesterol gallstones.

Biliary lipid composition in idiopathic bile acid malabsorption

“…Similar results were obtained from Einarsson’s group in patients with Crohn’s disease following ileal resection 25. Similarly, Koivisto and Miettilnen found cholesterol saturation of duodenal bile to be normal in patients with partial ileal bypass26 and we found this to be true also in patients with ileoanal anastomosis and total colectomy,27 who have bile acid malabsorption according to the 75 SeHCAT test 16…”

Kinetics of Primary Bile Acids in Patients after Proctocolectomy and Ileal Pouch-Anal Anastomosis

“…In two other studies, no increased cholesterol saturation of duodenal bile was observed [12,14], and a recent study, in which gallbladder bile was obtained by direct puncture of the gallbladder, revealed that biliary lipid composition and cholesterol saturation of bile may be normal after colectomy [13]. Biliary composition, cholesterol saturation and nucleation were not investigated in our study, but (presumably due to the loss of bile acids in the intestine) the fractional turnover of bile acids was markedly increased suggesting an impairment of the enterohepatic circulation of bile acids.…”

“…It was assumed that impaired intestinal bile acid absorption was followed by formation of a more lithogenic bile and an increased incidence of cholelithiasis [5,6]. Other studies in colectomized patients, however, found normal biliary cholesterol saturation, normal biliary lipid composition and normal nucleation time [12,13,14]. Thus, the present investigation, which for the first time directly studied bile acid kinetics in patients after proctocolectomy and IPAA, contributes to the understanding of bile acid metabolism under this condition and its potential pathophysiologic sequelae.…”

“…This has been attributed to an increased loss of bile acids [7,8] followed by an elevated cholesterol saturation and facilitated nucleation of cholesterol in gallbladder bile [9,10,11]. However, some studies in colectomized patients have found normal biliary cholesterol saturation, normal biliary lipid composition and normal nucleation time [12,13,14]. Thus, it is unclear whether increased fecal loss of bile acids after colectomy may lead to major alterations in bile acid metabolism and enterohepatic bile acid circulation.…”

Impact of Surgery on the Development of Duodenal Cancer in Patients with Familial Adenomatous Polyposis

“…19,20 Patients with IAA show a reduced biliary secretion of bile acids and reduced masses of cholesterol, bile acid, phospholipids. [21][22][23] In particular the deoxycholic acid is significantly reduced in patients with IAA. 20,24,25 This secondary bile acid is produced by the intestinal microflora containing 7a-dehydroxylase and it is considered as promoter of intestinal carcinogenesis.…”