Non-Strangulating Distal Ileal Obstruction

Abstract

Avoluminous literature is available dealing with many of the experimental and clinical aspects of intestinal obstruction. Relatively little effort, however, has been made experimentally to evaluate pre-obstruction base-line factors that might influence the gross changes occurring in the intestinal tract following obstruction. In addition, the emphasis in the radiologic literature has been on the clinical aspects of obstruction, with only scattered articles reporting experimental observations. It is proposed at this time to present the first of a series of studies on intestinal obstruction. Specifically, an attempt will be made to evaluate the role of hydration in the rate of development, the extent of the gross dilatation, and the nature of the luminal contents occurring in experimentally produced, complete, non-strangulating obstructions of the distal ileum. The radiologic findings will be correlated with the gross anatomic patterns. Method of Study Obstruction was produced by essentially the same method in 60 mongrel dogs. Under intravenous 2 per cent Surital sodium (thiamylal sodium) anesthesia and sterile conditions, a midline abdominal incision was made. The ileocecal junction was identified and a point in the ileum roughly 30 cm. proximal to this was selected for the obstruction site. A small rent was made in the avascular portion of the mesentery close to the bowel wall, and a strip of gauze was placed completely around the circumference of the intestine. A tight ligature of stainless steel was then placed over the gauze, thus producing complete, non-strangulating obstruction. The abdominal incision was closed in layers, following which recumbent antero-posterior and postero-anterior, as well as erect postero-anterior, radiographs of the abdomen were obtained. No animal received anything by mouth during the entire postoperative period. The 60 dogs used in the study were divided into three groups of 20 each, as follows. Group I: The animals were allowed nothing by mouth for twenty-four hours prior to surgery. Starting with the induction of anesthesia and extending over the next sixty to ninety minutes, normal saline was given intravenously, 60 c.c. per kilogram of body weight. Group II: The animals were given nothing by mouth for twenty-four hours preoperatively, with no fluid supplement at the time of surgery. Group III: The animals received nothing by mouth for forty-eight hours preoperatively, and no fluid supplement at the time of surgery. Each group was further subdivided according to the length of time the animals were followed after surgery. In each of the three groups 10 dogs were followed for six hours, and 10 for twenty-four hours (Table I). At the completion of each experiment (either six or twenty-four hours) the dog was again anesthetized with intravenous Surital sodium and a repeat series of recumbent and erect radiographs was obtained.