Insulin testing after truncal and selective vagotomy

Abstract

Summary In 1969 at the Repatriation General Hospital, Concord, N.S.W., the completeness of truncal vagotomy was determined using the criteria of Ross and Kay for interpretation of the insulin test. This revealed a failed or early positive response rate of 30 per cent (35 of 118 patients). This finding led some of the surgical staff members to adopt Tanner's technic of bilateral selective vagotomy in an attempt to improve the rate of complete section. Three hundred twenty patients were subjected to insulin testing more than three months after surgery. The results show an improvement in the rate of early positive responses from 30 to 21 per cent (56 of 273 patients). If the original 118 cases are excluded from this figure, the early positive response rate falls to 13.5 per cent (21 of 155 patients). The early positive response rate after selective vagotomy was similar to that of the original series, that is, 36 per cent (18 of 47 patients). We conclude therefore that the change to selective vagotomy, as performed in an initial group of forty-seven patients, has not improved our rate of complete vagal section whereas an awareness of the difficulty in obtaining complete vagotomy by the truncal technic has led to a good improvement in results.