Pylorus-preserving gastrectomy: Effect on resistance through the sphincter of Oddi compared to conventional distal gastrectomy in dogs

Bile stasis is an important etiologic factor in the high incidence of postgastrectomy gallstone disease (PGGD). Our previous study showed that duodenal, but not prepyloric, transection disturbed the motility of the sphincter of Oddi (SO) in anesthetized dogs. We had developed pylorus-preserving gastrectomy (PPG), in which the anal margin of the resected stomach is the prepyloric portion, not the duodenum. The present study evaluated the usefulness of PPG for reducing bile stasis, which may induce PGGD. We examined the resistance of bile flow through the SO using dogs that had undergone either PPG (n = 5) or conventional distal gastrectomy (B-I) (n = 5). Four weeks after gastrectomy we anesthetized the animals and compared the basal and volume load-induced pressure in the common bile duct (CBD) between groups with or without administration of cholecystokinin-8 (CCK8). Flow resistance of the SO was evaluated by measuring flow volume through the SO following a graded pressure load to the CBD. The basal pressure and the threshold pressure to open the SO were significantly lower in PPG dogs than in B-I dogs independent of CCK8 administration. There were no significant differences between groups in regard to volume load-induced pressure elevation or the resistance of the SO. These results indicate that PPG may be more useful for reducing the incidence of PGGD than conventional distal gastrectomy, possibly through attenuating resistance to bile flow.