Medical vagotomy: an assessment.

Abstract

Attempts have been made to predict the secretion of gastric acid after surgical vagotomy with a drainage procedure, by blocking the vagus nerves with atropine and hexamethonium or with propantheline in preoperative tests (McArthur, Tankel, and Kay, 1960;Gillespie and Kay, 1961;Checketts, Gillespie, and Kay 1966). These workers carried out two tests on their subjects before operation: the first was an augmented histamine test (Kay, 1953); in the second hexamethonium bromide 50 mg. and atropine 0.325 mg., or propantheline 30 mg., were given before the injection of histamine. If this drug-induced or " medical " vagal blockade in the second test brought about a large decrease in the response to histamine a similar large reduction in secretion was to be expected after surgical section of the vagi. On the other hand, in some patients the response to histamine was reduced by only a small amount (<35 %) after medical vagotomy, and some of these subjects also had a small reduction in secretion after surgical vagotomy. It was suggested that a minority of patients with duodenal ulcer had "antral dominance " over the production of gastric acid, the vagi playing a lesser part; that it might be possible to pick them out before operation by the " medical vagotomy " test; and that they would be better treated by vagotomy and antrectomy than by vagotomy and drainage alone.Our study is a critical examination of the above hypothesis, designed to answer the following questions: (1) (Lawrie, Smith, and Forrest, 1964), injecting atropine and hexamethonium when maximal levels of secretion have been attained after 90 to 105 minutes. The subjects were male patients with duodenal or gastric ulceration, hiatus hernia, dyspepsia without any abnormality on barium-meal examination, and normal individuals. After an overnight fast a 16 F.G. duodenal tube with a metal tip was passed transnasally into the stomach, the contents of which were aspirated by continuous suction wit'' an electric motor. The antihistamine mepyramine maleate (Anthisan) was given in a dose of 50-100 mg. intramuscularly at the start of the test. The histamine infusion was then set up, with either a paediatric drip set or a constant-infusion pump, to deliver 0.4 pg. of histamine acid phosphate per kg. per minute intravenously throughout the test. The gastric secretion was aspirated by continuous suction, and separate samples representing 15-minute periods were collected.After 90 to 105 minutes, when a steady rate of gastric secretion had been achieved, the medical vagotomy injection was given. Atropine sulphate 1.3 mg. (1/50 gr.) and hexamethonium bromide (C6) 50 mg. were given together intramuscularly. Gastric secretion was then collected for a further two hours (in 74 tests) or four hours (28 tests). The "maximal" acid secretion was taken as the mean of the two or three 15-minute collections immediately before the injection of atropine and hexamethonium, while "acid output after medical vagotomy" was taken as the mean of the two or three lowest consecutive readings, which...

Gastroenterostomy and vagotomy for chronic duodenal ulcer.

“…J., 1968), and controlled clinical trials of selective vagotomy are indicated to assess these points. Johnston, Goligher, and Duthie (1966) have claimed that complete vagotomy will prevent jejunal ulceration regardless of the initial acid secretion, and our experience supports this. However, in patients with an initial high acid secretion, an incidence of incomplete vagotomy of 35% would expose too many of these patients to a high risk of jejunal ulceration.…”

“…The lowest residual (post-vagotomy) secretion in the latter group was 17 HCl (m-equiv/hr), and the lowest pre-vagotomy secretion was 22 HCl (m-equiv/ hr) in the post-histamine hour. The reason for this finding is obscure, but preferential interference with the inhibitory or protective mechanism in the duodenum is a possible explanation (Johnston, Goligher, and Duthie, 1966).…”

Psychological factors, operative procedures, and results of surgery for duodenal ulcer.

“…The insulin test is used to evaluate the completeness of surgical vagotomy but interpretation of the results has been the subject of recent controversy (Johnston, Goligher, and Duthie, 1966). There is general agreement that a complete vagotomy has been carried out if the acid concentration rises less than 20 m-equiv/1.…”

Factors affecting maximal acid secretion

“…Recently screening of the tube was omitted in some studies (Johnston, Goligher & Duthie, 1966) w-hich, of course, is a retrograde step. Aspiration Continuous aspiration is recommended in order to avoid the effect of gastric emptying on total collection.…”