THE CLINICAL-SIGNIFICANCE OF ADHESIONS - FOCUS ON INTESTINAL-OBSTRUCTION

Postoperative adhesions occur after almost every abdominal surgery and are the leading cause of intestinal obstruction, accounting for more than 40% of all cases and 60% to 70% of those involving the small bowe l. This contrasts with earlier experience in the Western World and cur rent practice in the Third World, where abdominal operations are infre quent, hernias remain untreated, and strangulated hernia is common. Th ese are among the findings of prospective and retrospective studies on adhesions conducted at the Westminster Medical School, University of London, London, UK, and of other published studies on the clinical con sequences of postoperative intra-abdominal adhesions and resultant int estinal obstruction. In an analysis of 210 patients who had undergone at least one previous abdominal operation, 92.9% had postsurgical adhe sions. This is not surprising, given the extreme delicacy of the perit oneum and the fact that apposition of two injured surfaces nearly alwa ys results in adhesion formation. Problems resulting from postsurgical adhesions create a considerable workload. At Westminster Hospital ove r 24 years, intestinal obstruction accounted for 0.9% of all admission s, 3.3% of major laparotomies and 28.8% of cases of large or small bow el obstruction. A 1992 British survey reported an annual total of 12,0 00 to 14,400 cases of adhesive intestinal obstruction. In 1988 in the United States, admissions for adhesiolysis accounted for nearly 950,00 0 days of inpatient care. Risk factors, such as type of surgery and si te of adhesions, as well as timing and recurrence rate of adhesive obs truction, remain unpredictable or poorly understood. The type of surge ry most frequently leading to adhesive obstruction includes colonic, a nd especially rectal surgery, appendicectomy, and gynecological proced ures. Laparoscopy does not seem to eliminate the risk of adhesions and adhesive obstruction. Adhesions involving the small intestine occur l ess frequently than those involving the omentum, but are more likely t o become obstructive. Follow-up of over 2,000 laparotomies at the West minster Hospital demonstrated that 1% of patients developed adhesive o bstruction within one year of surgery, and half of these occurred with in the first postoperative month. However, obstruction may occur at an y time, and some 20% of cases appeared more than 10 years later. Recur rent obstruction following adhesiolysis is common, but actuarial table s still need to be constructed. Adhesive obstruction is clinically cha llenging, since there is no simple way to differentiate between adhesi ve and strangulated obstructions. Mortality rates escalate from 3% for simple obstructions to 30% when the bowel becomes necrotic or perfora ted.