Adhesive Intestinal Obstruction

Adhesive small bowel obstruction results from postoperative or inflammatory fibrous bands that kink, compress or trap small bowel. It is the commonest form of small bowel obstruction after previous abdominal surgery.

Adhesions may cause a single transition point, multiple points of obstruction or a closed loop. The presence of previous surgery makes adhesions likely but does not justify attributing every obstruction to adhesions without excluding hernia, malignancy and other causes.

• Presentation is typical of small bowel obstruction with colicky pain, vomiting, distension and reduced stool or flatus.
• Previous abdominal or pelvic surgery is the major clue. Symptoms can occur weeks or decades after the original operation.
• Increasing continuous pain, focal tenderness, fever, tachycardia, peritonism or metabolic deterioration suggests strangulation rather than uncomplicated adhesive obstruction.

Assess full blood count, renal function, electrolytes and lactate.

CT abdomen and pelvis with IV contrast: demonstrates mechanical obstruction while excluding another cause; closed loop obstruction, ischaemia or free fluid should prompt early surgery.

Adhesions themselves may not be directly visible. Diagnosis is often inferred when a transition point is present without another structural cause in a patient with previous surgery.

Initial nonoperative management is preferred when there is no peritonitis, strangulation or bowel ischaemia. WSES reports successful conservative management in approximately 70 to 90 percent of appropriately selected adhesive obstructions.

Treatment consists of bowel rest, IV crystalloid, electrolyte correction, aspiration prevention and nasogastric decompression when vomiting or major distension is present.

A water soluble contrast challenge has both prognostic and possible therapeutic value. If contrast has reached the colon by 24 hours, spontaneous resolution is likely. Failure to reach the colon strongly predicts failure of conservative management.

Do not allow a planned conservative strategy to obscure deterioration. Operate for:

• Peritonitis
• Strangulation or ischaemia
• Closed loop obstruction
• Perforation
• Progressive pain or physiological deterioration
• Failure of a monitored conservative trial

Approximately 72 hours is generally considered a reasonable conservative trial in a stable patient. Prolonged treatment beyond this point with persistent obstruction may increase morbidity and should trigger senior surgical reassessment.

At operation, perform the minimum adhesiolysis necessary to relieve obstruction while avoiding unnecessary bowel handling. Identify all transition points before closure.

A single band obstruction is particularly suitable for laparoscopic adhesiolysis. Multiple dense adhesions, severe distension or suspected necrosis make laparotomy more appropriate.

Resect bowel only when viability is irreversibly compromised or enterotomy makes repair inappropriate. Adhesion barriers can reduce subsequent adhesive obstruction after selected operations, although they do not eliminate recurrence.