The effect of cholecystectomy on plasma cholecystokinin.

Objective: Gallbladder removal is associated with an increased incidence of gastroesophageal reflux, but the mechanism is unclear. Cholecystokinin (CCK) release, which causes gallbladder contraction, is inhibited by bile in the duodenum. This study investigates the effect of cholecystectomy on meal-stimulated CCK secretion.

Methods: Three groups of patients were studied. Group 1 (n = 15) were normal controls. Group 2 (n = 27) were patients with symptomatic gallstones. Group 3 (n = 25) were patients who had undergone cholecystectomy. Meal-stimulated CCK levels were measured by radioimmunoassay at defined time points for 60 min after a standard corn oil-based meal.

Results: Fasting CCK levels were similar in all three groups. In postcholecystectomy patients, meal-stimulated plasma CCK levels were significantly elevated compared with controls: median (range) integrated CCK values for 60 min were 116 (28-209) in controls, 123 (20-501) in gallstone patients, and 176 (63-502) after cholecystectomy.

Conclusions: This study suggests that cholecystectomy causes an exaggerated meal-stimulated CCK response. Because CCK is known to relax the lower esophageal sphincter. these findings may help explain the increased incidence of gastroesophageal reflux seen after cholecystectomy.