Hippocrates, the father of medicine, recognized, described, and treated bowel obstruction many years ago. Praxagoras appears to have performed the earliest recorded operation for bowel obstruction circa 350 bc when he relieved the obstruction of a bowel segment by creating a decompressive, diverting enterocutaneous fistula.
Bowel obstruction continues to be one of the most common intra-abdominal problems faced by general surgeons in their practice. Independent of the underlying etiology, bowel obstruction remains a major cause of morbidity and mortality. Early recognition and aggressive treatment are crucial in preventing irreversible ischemia and transmural necrosis and thereby in decreasing mortality and long-term morbidity. Despite multiple recent advances in diagnostic imaging and marked advances in our treatment armamentarium, intestinal obstruction will continue to occur. The aim of this chapter is to review the etiologies, pathogenesis, diagnosis, and management in the current era with emphasis on early diagnosis and aggressive management, both operative and nonoperative.
Bowel obstruction occurs when the normal propulsion and passage of intestinal contents cannot occur for whatever reason. This obstruction can involve only the small intestine (small bowel obstruction), the large intestine (large bowel obstruction), or via systemic alterations in metabolism, electrolyte balance, or neuroregulatory mechanisms involving both the small and large intestine (generalized ileus). Mechanical obstruction is due to physical obstruction of the intestinal lumen either from something within the lumen in the wall of the intestine or from an extraluminal cause, while ineffective motility without any physical obstruction causes functional obstruction, also called “pseudo-obstruction,” or (paralytic) ileus. Classification can also be based on duration (acute vs chronic), extent (partial vs complete), and type of obstruction (simple vs closed-loop vs strangulation). Closed-loop and strangulation obstruction fall into the category of complicated obstruction and require emergent intervention.
Mechanical Bowel Obstruction
Mechanical bowel obstruction is defined as a physical blockage of the intestinal lumen. This blockage may be intrinsic or extrinsic to the wall of the intestine or secondary to luminal obstruction arising from the intraluminal contents (eg, an intraluminal gallstone or other foreign body) (Table 29-1). Partial obstruction implies that the intestinal lumen is narrowed, but some intestinal content still can transit aborally. In the presence of a complete obstruction, the lumen is obliterated, and no intestinal content can get beyond this point of obstruction. The risk of so-called strangulation, that is, vascular compromise of the intestine, is increased markedly in the presence of a complete obstruction, especially when caused by an extraluminal etiology such as a hernia defect of an adhesive band compressing the small bowel mesentery. Accordingly, complete obstruction can be categorized further into simple, closed-loop, and strangulation obstruction. A simple obstruction is an obstruction without any vascular compromise and the intestine can be decompressed proximally. Closed-loop obstruction occurs when both ends of the involved intestinal segment are obstructed (eg, volvulus or a compressive adhesive band), and results in increased intraluminal pressure secondary to increased intestinal secretion and accumulation of ...