W. Scott Helton, MD, FACS, Piero M. Fisichella, MD

ACS Surgery 2004. © 2004 WebMD Inc.
All rights reserved.

Offers a safe, efficient, stepwise approach for deciding whether to operate on a patient with intestinal obstruction and describes the management of patients with this problem. Clinical evaluation, investigative studies, mechanical obstruction, nonmechanical obstruction (including pseudo-obstruction), and cost considerations are described.

To Operate or Not to Operate

The combination of a thorough history, a carefully performed physical examination, and correctly interpreted abdominal radiographs usually allows one to identify the type of bowel obstruction present and to decide whether a patient requires immediate, urgent, or delayed operation (Table 1) or can safely be treated initially with nonoperative measures. To this end, it is particularly important and useful to stratify patients into those with mechanical obstruction and those with nonmechanical obstruction. In patients with mechanical bowel obstruction, an effort should be made to determine whether the obstruction is complete or partial. Except for a few clinical situations, patients with complete bowel obstruction require immediate operation; conversely, patients with partial bowel obstruction rarely do. Finally, an effort should be made to establish the level and cause of obstruction, because these factors often help guide therapy and affect the probability of success in response to specific therapeutic intervention. Patients with nonmechanical obstruction, which derives from ileus or pseudo-obstruction, do not require immediate operation.

When one is uncertain whether the obstruction is mechanical or not on the basis of the information at hand, additional diagnostic measures are immediately indicated. When large amounts of colonic air extend down to the rectum, flexible or rigid sigmoidoscopy will readily exclude a rectal or distal sigmoid obstruction. If sigmoidoscopy yields normal findings and if partial colonic obstruction is the most likely diagnosis, a barium enema with water-soluble contrast material should immediately be performed. Abdominal ultrasonography, though not as definitive as a contrast examination, is also able to diagnose suspected colonic obstruction in 85% of patients.

Abdominal radiographs can be entirely normal in patients with complete, closed-loop, or strangulation obstruction. Therefore, if the patient's clinical profile and the results of physical examination are consistent with intestinal obstruction despite normal abdominal radiographs, abdominal ultrasonography, CT scanning, or fast MRI should be performed immediately.^[1-3] All three modalities are highly sensitive and specific for intestinal obstruction when performed properly and interpreted by experienced clinicians.

Indications for Immediate Operation

All patients with complete bowel obstruction, whether of the small intestine or the large, should undergo immediate operation unless extraordinary circumstances (e.g., diffuse carcinomatosis, terminal illness, or sigmoid volvulus that responds to sigmoidoscopic decompression) are present. If one attempts to manage complete intestinal obstruction nonoperatively, one risks delaying definitive treatment of patients with intestinal ischemia and subjecting them to significantly increased morbidity and mortality should perforation or severe infection develop.

Immediate operation is also indicated when bowel obstruction is associated with peritonitis; incarcerated strangulated hernias; suspected or confirmed strangulation; pneumatosis cystoides intestinalis; sigmoid volvulus accompanied by systemic toxicity or peritoneal irritation; colonic volvulus above the sigmoid colon; or fecal impaction. These conditions will not resolve without operation and are associated with increased morbidity, mortality, and cost if diagnosis and treatment are delayed. The only time one would not operate immediately on any patient with one of these diagnoses is when the patient requires cardiopulmonary stabilization, additional resuscitation, or both. Whenever there is any doubt as to the presence of any of these conditions, additional diagnostic tests (e.g., ultrasonography, CT, or contrast studies) are indicated to confirm or exclude them.

The Role of Laparoscopic Adhesiolysis

Several clinical reports have demonstrated that laparoscopic adhesiolysis for acute small bowel obstruction is both feasible and safe.^[4,5] Laparoscopic or laparoscopic-assisted lysis of adhesions relieves bowel obstruction in more than 50% of patients and is associated with lower morbidity, earlier return of bowel function, quicker resumption of normal diet, and a shorter hospital stay than open operative lysis.^[4] To minimize the risk of bowel injury at the beginning of the operation, the first trocar is inserted under direct vision by means of an open technique, and the incision is placed well away from any previous scars.^[6]

At present, there are no prospective, randomized, controlled clinical trials comparing laparoscopic with open adhesiolysis. Perhaps the best study published to date on this issue is a retrospective, matched-pair analysis from 2003 that used an intention-to-treat analysis.^[4] In this study, 52% of the patients in the laparoscopic group underwent conversion to open lysis of adhesions either for completion of adhesiolysis or for management of complications. No perforations or recurrent obstructions were missed. Perforations were more common overall in the laparoscopic group than in the open group, though this difference was largely eliminated when patients from the laparoscopic group who underwent conversion to open lysis were not considered. Patients with two or more previous laparotomies had a higher incidence of intraoperative complications than those with fewer laparotomies. Accordingly, the authors recommended against laparoscopic adhesiolysis in patients with two or more previous laparotomies. The high conversion rate in this study notwithstanding, the laparoscopic group as a whole (including conversions) experienced an overall reduction in postoperative complications.

Another potential advantage of laparoscopic adhesiolysis is that it results in fewer intra-abdominal adhesions than open laparotomy and thus may reduce the risk of recurrent bowel obstruction. However, a 1998 study found that despite a reduction in median length of stay, patients treated laparoscopically were at increased risk for early unplanned reoperation as a consequence of either incomplete relief of obstruction or complications.^[7] In fact, bowel perforation in the course of laparoscopic adhesiolysis often is not detected during the procedure and presents in a delayed fashion. Many such injuries are attributable either to insertion of the initial trocar or to delayed perforation of a thermal injury. When laparoscopic adhesiolysis fails to identify and relieve an obvious point of obstruction or when adhesiolysis is inadequate or unsafe, conversion to an open approach is indicated.

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