Effect of gastric resection, Roux-en-Y diversion and vagotomy on gastric emptying in the rat.

Solid and liquid gastric emptying studies were conducted in 61 male Wistar rats. In 20 animals a two-thirds Pólya-type gastric resection was performed and 21 had a similar resection with a 10-cm Roux-en-Y diversion. In nine of the Roux diversions truncal vagotomy was also carried out. Twenty animals acted as controls: ten unoperated and ten that received laparotomy only. Body-weight and gastric emptying were measured weekly for 4 weeks and monthly for 4 months after surgery. Animals subjected to gastrectomy revealed a weight loss of approximately 16 per cent after operation. Weight gain was slower after Roux reconstruction than after Pólya-type anastomosis and slowest in animals with vagotomy and Roux drainage (P < 0.05). Gastric emptying was unchanged in unoperated controls. Animals in which a laparotomy was performed had delayed solid and liquid emptying for the first 4 weeks after operation (P < 0.05). Following Pólya-type gastrectomy, liquid emptying was delayed for 4 months. Solid emptying was unchanged, with no evidence of the delay present in animals with a laparotomy. Animals subjected to Roux-en-Y diversion showed a greater delay in liquid emptying than those with a Pólya resection; solid emptying was also delayed (P < 0.05). Severe gastric retention of liquids and solids occurred in the early postoperative phase when vagotomy was added to the Roux diversion (P < 0.01). Emptying of solids adopted a relatively normal linear pattern after this initial retention. Emptying of liquids, however, remained abnormal, appearing to adopt a biphasic pattern.