Anterior lesser curve seromyotomy and posterior truncal vagotomy versus truncal vagotomy and pyloroplasty in the treatment of chronic duodenal ulcer. In a prospective randomized controlled clinical trial, anterior lesser curve seromyotomy with posterior truncal vagotomy (AMPT, n = 77) has been compared with truncal vagotomy and pyloroplasty (TVP, n = 69) in 146 patients with chronic duodenal ulcer with a mean duration of symptoms of 7 years. The mean follow-up time was 4.5 years with a range of 2-7 years. One elderly patient died from a myocardial infarction in the TVP group. Acid secretory inhibition in response to insulin and pentagastrin stimuli was equal in both groups, indicating a similar degree of vagal denervation. Recurrent ulcers were more common after AMPT (five) than TVP (two) (P = 0.29, n.s.). Dumping and diarrhoea were significantly commoner (P less than 0.001) after TVP, with 31 instances as opposed to eight with AMPT. The mean operating time was increased by 6 min when AMPT was performed rather than TVP. The results of this study have shown that AMPT is associated with a lower incidence of dumping and diarrhoea and achieves better overall Visick grading. However, continued monitoring is required to assess the long-term incidence of recurrent ulceration after this procedure. 