What is the treatment approach for Small Bowel Obstruction (SBO)?

Treatment Approach for Small Bowel Obstruction (SBO)

Non-operative management should be the initial approach for all patients with small bowel obstruction unless there are signs of peritonitis, strangulation, or bowel ischemia. 1

Initial Assessment and Decision Making

Immediate Evaluation

• Assess for signs requiring urgent surgery:
  • Peritonitis
  • Signs of strangulation
  • Bowel ischemia
  • Closed loop obstruction
  • Free fluid on imaging
  • Pneumatosis intestinalis or portal venous gas

Diagnostic Imaging

• CT scan with oral and intravenous contrast is the preferred imaging technique 1
  • Helps differentiate complete vs. partial obstruction
  • Identifies location of obstruction
  • Detects concerning features: closed loop, ischemia, free fluid
  • Can assess for alternative causes of obstruction

Predictors of Need for Surgery

Four key features strongly predict need for operative intervention 2:

• Free intraperitoneal fluid on CT
• Mesenteric edema on CT
• Absence of "small bowel feces sign" on CT
• History of vomiting

Non-operative Management

Non-operative management is effective in approximately 70-90% of patients with SBO 1 and should include:

1. Bowel rest: Nil per os (NPO)
2. Decompression: Nasogastric tube placement
3. Fluid resuscitation: Correction of dehydration and electrolyte abnormalities
4. Water-soluble contrast agents (WSCA): Consider administration of 100ml Gastrografin within 24 hours of admission 1
   • Reduces failure rate of non-operative management (17% vs 50%) 1
   • Helps predict need for surgery

Duration of Non-operative Trial

• A 72-hour period is considered safe and appropriate 1
• Continuing beyond 72 hours with persistent high output from decompression tube remains debatable

Surgical Management

Indications for Urgent Surgery

• Peritonitis
• Signs of bowel ischemia or strangulation
• Clinical deterioration
• Failure of non-operative management after 72 hours

Surgical Approach

• Laparotomy: Traditional approach, especially with signs of ischemia 1
• Laparoscopy: Consider in selected patients 1
  • Benefits include less adhesion formation and earlier return of bowel function
  • Higher rate of negative explorations reported with laparoscopy (40%) 1
  • Conversion to open may be needed for complex cases

Intraoperative Considerations

• Careful adhesiolysis
• Assessment of bowel viability
• Resection of non-viable segments
• Consider adhesion barriers to reduce recurrence 1

Long-term Outcomes

• Surgical management results in lower rates of SBO symptom recurrence (34.8% vs 57.4%) and fewer hospitalizations for recurrent SBO (14% vs 29.4%) compared to conservative management 3
• However, the need for surgical management of recurrent SBO episodes is similar between groups (7.4% vs 7.1%) 3

Special Considerations

Malignant Bowel Obstruction

• Poorer prognosis (median survival 26-192 days) 4
• Consider palliative options including:
  • Surgical bypass
  • Endoscopic stenting
  • Parenteral nutrition in select patients with good functional status 4

Small Bowel Obstruction in Virgin Abdomen (SBO-VA)

• Can be treated according to the same management algorithms as other SBO patients once adhesive etiology is established by CT 1
• Consider other etiologies: internal hernias, malignancy, inflammatory conditions

Pitfalls to Avoid

1. Delayed surgical intervention: Delays beyond 72 hours in patients with unresolved obstruction increase morbidity and mortality 1

2. Missing strangulation: Carefully monitor for signs of ischemia including:

   • Peritonitis
   • Elevated serum lactate
   • CT findings of closed loop, pneumatosis, or portal venous gas 2

3. Inadequate resuscitation: Ensure proper fluid and electrolyte replacement before surgery

4. Overlooking alternative diagnoses: Consider differential diagnoses including:

   • Postoperative ileus
   • Narcotic bowel syndrome
   • Colonic pseudo-obstruction
   • Mesenteric ischemia 5