Colonic self-expandable metal stents: Indications and placement techniques

Abstract

Self-expandable metal stents (SEMS) in the large bowel can be employed in malignant colorectal obstruction (MCRO), benign colorectal obstruction (BCRO), and rectocolonic fistulae (RCF). MCRO is the most frequent scenario. Endoscopic insertion of SEMS for colonic obstructions relies on crossing the stricture with a guidewire inserted through the working channel of an endoscope. Afterward, the undeployed SEMS is slid over the guidewire inside the working channel (through-the-scope or TTS insertion) or outside the scope (over-the-wire or OTW). The stent is finally opened up, bridging the entire stricture. Both endoscopic and fluoroscopic monitoring during the procedure are the best methods to achieve success. Insertion of colonic SEMS takes part in advanced therapeutic endoscopy, and special interventional skills are needed for the endoscopic team. For MCRO, an average of 93% in technical success and at least about 80% in clinical success has been reported. Patients can then either undergo scheduled surgery or have the stent left in place as a definitive palliative treatment. A complication rate up to 24 % can occur. Many are manageable endoscopically, but perforation (up to 9%) and death have been reported. Despite these drawbacks, initial treatment of MCRO by means of SEMS compares favorably with surgery. SEMS allow an earlier patients' recovery, shorter hospital stay, lower rate of early complications, less need for colostomy, and chemotherapy to be administered earlier; have no detrimental effect on morbidity and survival; and have long-term efficacy comparable to that with surgery.