From the Guidelines
SEMS is a recommended treatment for bowel obstruction, particularly for palliative treatment of malignant colorectal obstructions or as a bridge to surgery, due to its ability to rapidly relieve obstruction symptoms and avoid emergency surgery with its associated high morbidity and mortality. The procedure involves endoscopic placement of a flexible, expandable metal mesh tube that opens to approximately 20-25 mm in diameter, pushing against the walls of the obstructed bowel to create a patent lumen 1. SEMS placement is typically performed under combined endoscopic and fluoroscopic guidance, usually requiring only moderate sedation rather than general anesthesia.
The main advantages of SEMS include:
- Rapid relief of obstruction symptoms (usually within 24-48 hours)
- Avoidance of emergency surgery with its associated high morbidity and mortality
- Allowing time for proper staging and treatment planning in cancer patients Potential complications of SEMS include:
- Perforation (1-4%)
- Stent migration (10-12%)
- Re-obstruction due to tumor ingrowth (7-15%)
- Bleeding
SEMS are contraindicated in cases of perforation, severe inflammation, or when the obstruction is very proximal in the small bowel where endoscopic access is limited 1. A study from 2021 found that SEMS had a technical success rate of 91.9% in SEMS placement as a bridge to surgery, with 71.7% of patients subsequently undergoing one-stage surgery 1.
In terms of outcomes, a meta-analysis of 7 randomized controlled trials with 382 patients found that the SEMS group had significantly higher rates of primary anastomosis and lower rates of permanent stoma and overall adverse events, with no difference in overall survival 1. Therefore, SEMS should be considered as a treatment option for bowel obstruction, particularly in patients with malignant colorectal obstructions, due to its ability to improve outcomes and quality of life.
From the Research
Definition and Purpose of SEMS for Bowel Obstruction
- Self-expanding metallic stents (SEMS) are used to palliate malignant stenoses of the gastric outlet, proximal small bowel, and colon in patients with bowel obstruction 2, 3, 4, 5, 6.
- The primary purpose of SEMS is to relieve obstruction and improve symptoms, allowing patients to resume oral intake and improving their quality of life.
Indications and Contraindications
- SEMS are indicated for patients with malignant bowel obstruction who are unfit for surgery or require a bridge to surgery 4, 5, 6.
- Contraindications for SEMS include patients with poor performance status, intra-abdominal carcinomatosis, and massive ascites 2.
Placement and Efficacy
- SEMS placement is a minimally invasive procedure that can be performed under endoscopic or radiologic guidance 3, 6.
- The technical success rate of SEMS placement is high, ranging from 92% to 92.5% 3, 6.
- Clinical success rates are also high, with improvement in symptoms reported in 75% to 86% of patients 3, 6.
Complications and Risks
- Common complications of SEMS include stent migration, obstruction, and perforation 3, 6.
- The risk of tumor seeding following SEMS placement is a concern, particularly in cases of perforation 4.
- Peri-interventional mortality rates range from 6.5% to 12% 3, 6.
Current Status and Future Prospects
- SEMS are considered a safe and effective alternative treatment for malignant bowel obstruction, both as a bridge to surgery and for palliative care 4, 5.
- The development of new interventional endoscopic techniques, such as endoscopic ultrasound-guided anastomotic techniques, may expand the applications of SEMS in the treatment of bowel obstruction 5.