What is the treatment for acute intestinal obstruction?

Treatment of Acute Intestinal Obstruction

Surgery is mandatory for acute intestinal obstruction when there is evidence of bowel ischemia, perforation, peritonitis, hemodynamic instability, or failure to resolve with conservative management within 12-24 hours. 1

Initial Management Approach

Immediate Resuscitation and Assessment

• Intravenous fluid resuscitation with correction of electrolyte derangements is the first priority in all patients with acute intestinal obstruction 2, 3
• Nasogastric decompression should be initiated immediately to decompress the bowel and prevent aspiration 2, 3
• Laboratory evaluation must include complete blood count, metabolic panel, and serum lactate level to assess for ischemia 2
• Antibiotic coverage against gram-negative organisms and anaerobes is indicated if fever, leukocytosis, or signs of peritonitis are present 2

Diagnostic Imaging

• CT scan is the preferred imaging modality to determine the level of obstruction, whether it is complete or incomplete, identify the cause (adhesions, malignancy, hernia, stricture), and detect signs of ischemia or perforation 4, 2, 3
• Plain abdominal radiography may be used initially but has lower sensitivity and specificity 3

Conservative vs. Surgical Management Decision Algorithm

Conservative Management (Bowel Rest)

Conservative management is appropriate for uncomplicated obstruction without signs of ischemia or perforation 2, 5, 3:

• Intravenous fluids and electrolyte correction 2, 3
• Nasogastric decompression 2, 3
• Bowel rest (NPO) 2, 3
• Serial clinical examinations by experienced surgeons to detect deterioration 4
• Reassessment within 12-24 hours for resolution 1

Indications for Immediate Surgical Intervention

Proceed directly to surgery without delay in the following scenarios:

Absolute Indications (Emergency Surgery)

• Hemodynamic instability despite aggressive resuscitation 1
• Signs of peritonitis (guarding, rigidity, rebound tenderness) 1, 5
• Radiological evidence of pneumoperitoneum (free air indicating perforation) 1
• Clinical or radiological signs of bowel ischemia: markedly elevated lactate, severe continuous pain, bloody bowel movements 1, 2
• Complete obstruction with vascular compromise 2, 3

Relative Indications (Surgery within 12-24 hours)

• Persistent symptoms after 12-24 hours of adequate conservative management 1
• Fibrotic strictures not amenable to endoscopic dilatation (particularly in Crohn's disease) 1
• Internal hernia (especially post-bariatric surgery) with persistent abdominal pain 1
• Closed-loop obstruction on imaging 3

Surgical Approach

Choice of Surgical Technique

• Laparoscopic approach is preferred in hemodynamically stable patients without signs of perforation or extensive peritonitis, if local expertise exists 1
• Open laparotomy is mandatory for hemodynamically unstable patients, those with free perforation and generalized peritonitis, or toxic megacolon 1

Intraoperative Management

• Assessment of bowel viability is critical—resect clearly nonviable segments 1
• Revascularization (embolectomy or bypass grafting) should be performed first if mesenteric ischemia is the cause, followed by reassessment of viability 1
• "Second-look" operations at 24-48 hours are recommended when bowel viability is questionable to avoid excessive resection or missed nonviable segments 1
• Indocyanine green (ICG) fluorescence angiography may assist in determining bowel viability and anastomotic perfusion when available 1

Specific Surgical Procedures

• Limited intestinal resection with primary anastomosis for segmental ischemia in stable patients 1
• Damage control surgery with open abdomen for extended ischemia/peritonitis in unstable patients 1
• Adhesiolysis for adhesive obstruction 1
• Closure of mesenteric defects with non-absorbable suture if internal hernia is found 1

Special Considerations

Malignant Obstruction

• Endoscopic stenting may be considered in stable patients with malignant colorectal obstruction as a bridge to elective surgery or for palliation 6, 5
• Self-expanding metal stents may offer better outcomes than emergency surgery in selected cases 4
• For patients with recurrent cancer and poor prognosis (<2 months life expectancy), medical management with opioids, antispasmodics, antiemetics, and antisecretory agents may be more appropriate than surgery 4

Post-Bariatric Surgery Obstruction

• Endoscopy is the first-line diagnostic and therapeutic tool for proximal obstruction after sleeve gastrectomy or gastric bypass 1
• Exploratory laparoscopy within 12-24 hours is mandatory for small bowel obstruction after Roux-en-Y gastric bypass with persistent pain and inconclusive imaging 1

Mesenteric Ischemia

• Arteriography is indicated if nonocclusive mesenteric ischemia is suspected and the patient does not improve rapidly with treatment of underlying shock 1
• Transcatheter vasodilator therapy may be attempted in nonocclusive ischemia before surgery 1
• Mortality remains approximately 70% despite treatment when diagnosis is delayed 1

Critical Pitfalls to Avoid

• Delaying surgery when signs of ischemia or perforation are present leads to significantly increased mortality 1, 2
• Failure to perform serial examinations by experienced surgeons can miss the window for timely intervention 4
• Attempting conservative management in complete obstruction with closed-loop configuration risks rapid progression to ischemia 3
• Premature revascularization of infarcted bowel can cause sudden release of endotoxins leading to cardiovascular collapse—control venous outflow first 1