Stents for LBO

Selecting a stentable lesion

• Best between splenic flexure and rectosigmoid
• Rectum beyond rectosigmoid junction generally causes unbearable tenesmus, and carries a high risk of stent migration
• Areas of acute angulation (flexures) are hard in general
• Proximal colon is hard, but theoretically feasible by specialists

Indications (generally only malignant indications at this stage)

• Palliation for patients not fit for resection, or with widespread metastases
• Pre-operative decompression
  • Clinical stabilisation
  • Allow bowel prep
  • Pre-op colonoscopy to exclude synchronous lesions
  • Allows one-stage resection and anastomosis
  • Operate 5-10 days later

Equipment

• Covered vs uncovered
  • Covered are less likely to get tumour ingrowth (3.8% vs 14.5%)
  • Uncovered are less likely to migrate (1.8% vs 21.1%)
  • Uncovered are generally preferred
• Generally deployed through the scope

Preparation

• In partial obstruction, prep gently with PEG
• In complete obstruction, consider giving an enema
• Prophylactic Abx
• If in doubt about ability to traverse and stent, give a contrast enema - if contrast won't pass, neither will the guidewire

Technique

• Try to pass the lesion
• Don't dilate the lesion
• Pass a guidewire
• Confirm placement with fluoroscopy
• Pass stent over the top and expand in 1-2cm increments with fluoroscopy guidance

Post-procedure

• Low-residue diet
  • Avoid vegetables, fruits and whole grains
• Stool softeners

Efficacy

• Technical success - 97%
• Able to decompress colon through stent within 96 hours - 97%
• For palliation, rate of reintervention is 20%

Complications

• Perforation (<5%)
  • Immediate or delayed (erosion)
  • High-risk with bevacizumab or radiation
• Migration 11%
  • High risk
    • Benign lesions (doesn't embed)
    • Stent too small
    • Tumour shrinks after therapy
• Rectal bleeding - significant bleeding is rare
• Recurrent obstruction
  • Tumour can grow in at ends of stent or through the stent - can be treated by argon photocoagulation or laser or another stent