Annular pancreas: a new classification and clinical observations.

Seven cases of annular pancreas are described. In all the diagnosis was confirmed at autopsy or at operation. This study provides a new, original classification for annular pancreas. Two distinct subtypes are described: type 1, extramural and type 2, intramural. In type 1 the presenting symptoms are those of high gastrointestinal obstruction. In type 2 the symptoms are those of duodenal ulceration. For extramural obstructing annuli surgical intervention, if indicated, should be a bypass procedure; for intramural types with duodenal ulcer, subtotal gastrectomy with or without vagotomy is the procedure of choice.