Procedures

Endoscopic reduction of volvulus. This procedure is indicated for sigmoid volvulus when peritoneal signs are absent, which would imply dead bowel or perforation. It also is indicated when evidence of mucosal ischaemia is not present upon endoscopy. An experienced person should perform the procedure. A rigid sigmoidoscope may be used if a flexible instrument is not available. The endoscopist must have sufficient experience with this technique. Reduction of a volvulus does not imply cure.

The sigmoid usually revolvulizes if definitive treatment is not carried out. These patients generally are admitted, subjected to mechanical bowel preparation, and managed surgically by sigmoid resection, unless contraindications are present.

Barium enema for reduction of intussusception. This is useful and often successful in children in whom a pathological leading point for the intussusception is unlikely. It should be performed by an experienced radiologist because the risk of perforation is significant. In adults, typically a pathologic leading point for the intussusception is present. Success is far less likely, and patients still require surgery to deal with their pathology.

Cleansing enemas. Perform these if obstipation is suspected rather than true large bowel obstruction. Also perform them to prepare the distal colon for endoscopic evaluation.

Endoscopic dilation and stenting of colonic obstruction This procedure is indicated for colonic near total obstruction through which some small amount of lumen remains. The procedure may be palliative in a high-risk patient with an unresectable malignancy, accepting a risk of reobstruction of the stent, or preparatory to surgical resection. In cases in which the stent is deployed prior to surgery, it permits relief of the acute obstruction, resuscitation of the patient, and mechanical bowel preparation prior to a one-stage colonic resection and reanastomosis, thus avoiding temporary or permanent colostomy. The procedure should be performed only by an endoscopist experienced in such procedures. Surgical consultation and backup should be available, as the risk of perforation is increased during attempts at such procedures, with a potentially catastrophic result.

Medical Care

It involves resuscitation, correction of fluid and electrolyte imbalance, and nasogastric decompression to temporarily treat the obstruction and prevent vomiting and aspiration.

Surgical Care

Surgical care is directed at relieving the obstruction. In most patients, the obstructing lesion is resected. Because the colon has not been cleansed, anastomosis often is risky. After resection, most surgeons perform a proximal colostomy if the obstruction is on the left side or ileostomy if it is on the right side.

In patients with substantial comorbidity and surgical risk or in the presence of an unresectable tumor, a diverting proximal colostomy or ileostomy may be performed without resection.

A diverting transverse loop colostomy may be the least invasive procedure for a very ill patient with a left colonic obstruction. It permits relief of the obstruction and further resuscitation without compromising chances for a subsequent resection.

A sigmoid colostomy without resection may be employed in patients with rectal obstruction that cannot be managed without a combined abdominoperineal approach.

Cecostomy should not be performed because the diversion is inadequate.

In younger patients some surgeons would consider primary anastomosis, rather than ileostomy, in the right colon, assuming no intraoperative hypotension, blood loss, or other complications are present.

If resection and proximal colostomy or ileostomy is performed, a mucous fistula generally is extracted from the distal end, unless the obstruction is rectosigmoid, in which case the distal end may be oversewn or stapled and left to drain transanally.

If the cause of the obstruction can be relieved nonsurgically, through procedures such as decompressign a volvulus, or if the obstruction is only partial, deferring surgery temporarily and supporting the patient while the large bowel is cleansed so that primary anastomosis may be performed more safely is preferable.