SUMMARYA consecutive series of 25 patients with chronic duodenal ulcer has been treated by highly selective vagotomy without a drainage procedure. The vagal fibres passing to the distal 5-7 cm. of the stomachthe nerves of Latarjet-were left intact, as were the hepatic and coeliac branches of the vagus. The object was to denervate only the parietal cell mass, while preserving normal gastric emptying and normal inhibition of gastric secretion from the antrum and duodenum. This operation should cure the ulcer as effectively as vagotomy with drainage does, and at lower cost in terms of side-effects such as dumping and diarrhoea.The insulin te,jt was negative in each case, suggesting that vagal denervation of the parietal cell mass was complete. Evidence provided by mucosal biopsies taken at operation does not fully support this view, however. Pentagastrin-stimulated acid output was reduced by 70 per cent, and pepsin output by 51 per cent, 3 months after operation. The volume of resting juice was halved and spontaneous acid output was reduced by 97 per cent at this time. Thus, highly selective vagotomy is as effective as truncal or bilateral selective vagotomy with drainage in reducing gastric acid output in the early months after operation.There have been no deaths. With 2 exceptions, the patients appear to be doing well clinically and few complain of side-effects, but the period of follow-up is only from 3 to 11 months.These results are encouraging. They suggest that a highly selective vagotomy, denervating the parietal cell mass but leaving the antrum innervated, may be all that is required to cure most patients who have a chronic duodenal ulcer.A CONSECUTIVE series of 25 patients with chronic duodenal ulcer has been treated by highly selective vagotomy without any form of drainage procedure. The vagotomy WBS confined to the acid-and pepsinsecreting area, the distal 5-7 cm. of the stomach being left innervated. This operation is thought to possess two specific advantages over truncal or bilateral selective vagotomy with drainage. First, gastric emptying should be almost normal and as a result dumping should be eliminated, because the antropyloroduodenal segment remains normal anatomically and its extrinsic vagal nerve-supply is kept intact. Secondly, the neurohumoral inhibitory mechanisms in the antrum and duodenum, which 'apply the brake' to gastric secretion, are preserved. Thus, postoperatively, inhibition is still lively, whereas maximal acid output is only 30 per cent of its former level. This should be enough to ensure that the ulcer heals and remains healed. Table I) who have been treated during the period February to October, 1969. I n each case the diagnosis of duodenal ulceration was made clinically, radiologically, and at operation. The series is consecutive, except that patients with pyloric stenosis and emergency cases were excluded. I n an attempt to detect patients with early pyloric stenosis, special attention was paid to symptoms such as vomiting, acid regurgitation, or heartburn, and to the natur...