What is the management for a patient with a chronic segmental stricture of the proximal sigmoid colon with concerns for colonic obstruction?

Management of Chronic Segmental Stricture of Proximal Sigmoid Colon with Concerns for Colonic Obstruction

For patients with chronic segmental stricture of the proximal sigmoid colon with concerns for colonic obstruction, flexible endoscopic evaluation followed by surgical resection is the recommended management approach to prevent complications and reduce mortality risk.

Initial Diagnostic Approach

Imaging Studies

1. Plain Abdominal Radiographs

   • First-line imaging to assess for obstruction patterns
   • Look for "coffee bean" sign if volvulus is suspected 1
   • Helps detect presence of free air in case of perforation

2. CT Scan with IV Contrast

   • Indicated when diagnosis is uncertain or complications are suspected
   • Superior diagnostic performance (89% positive yield for sigmoid volvulus) 1
   • Helps identify:
     • Degree of obstruction
     • Cause of stricture (malignant vs. benign)
     • Presence of complications (ischemia, perforation)
     • Other diagnoses that may mimic colonic stricture

3. Water-Soluble Contrast Enema (if needed)

   • May show "bird's beak" sign at point of stricture
   • Caution: Strictly contraindicated if perforation is suspected 1
   • Always use water-soluble contrast, never barium, if perforation is possible

Endoscopic Evaluation

• Flexible colonoscopy/sigmoidoscopy is recommended for direct visualization of the stricture 1
• Allows for:
  • Assessment of stricture characteristics
  • Tissue biopsy to rule out malignancy
  • Evaluation of mucosal viability
  • Potential therapeutic intervention

Management Algorithm

Step 1: Assess for Emergent Conditions

• If signs of peritonitis, perforation, or severe obstruction are present, proceed directly to surgical management
• Check blood gas and lactate levels to evaluate for bowel ischemia, though normal values don't exclude ischemia 1

Step 2: Endoscopic Management

• For non-emergent cases without signs of ischemia or perforation:

  • Attempt endoscopic decompression and evaluation 1
  • Consider endoscopic dilation for benign strictures
  • Obtain biopsies to rule out malignancy 1

• Limitations of endoscopic management:

  • High recurrence rates (43-75%) with endoscopic treatment alone 1
  • Stenting for benign strictures has high complication rates, including migration 2

Step 3: Definitive Management

• Surgical resection is the definitive treatment for chronic sigmoid strictures that prevent passage of a colonoscope 3
• Surgical options include:
  • Segmental colectomy (preferred over total colectomy if no other colonic issues) 1
  • Resection with primary anastomosis for uncomplicated cases 1
  • Hartmann's procedure for high-risk patients 1

Special Considerations

Malignant vs. Benign Strictures

• Barium enema is a poor predictor of malignancy in strictures 3
• Even when diverticular disease is suspected, carcinoma must be excluded
• Up to 30% of sigmoid strictures initially thought to be diverticular may be malignant 3

Self-Expandable Metal Stents (SEMS)

• Can be used as a bridge to surgery in selected cases
• Higher complication rates in benign strictures compared to malignant ones 2
• Not recommended as definitive treatment for benign strictures due to high migration rates 2

Pitfalls and Caveats

1. Failure to exclude malignancy - Any stricture preventing passage of a colonoscope should be considered for resection when the cause is not apparent 3

2. Relying solely on conservative management - Patients with sigmoid strictures treated conservatively often continue to have significant symptoms 3

3. Delayed intervention - Waiting too long for definitive treatment increases risk of complete obstruction, perforation, and emergency surgery with higher morbidity and mortality

4. Inappropriate stent use - SEMS for benign strictures has high complication rates and should only be considered as a bridge to surgery when no other options are available 2