A Japanese prospective multicenter study of self-expandable metal stent placement for malignant colorectal obstruction: short-term safety and efficacy within 7 days of stent procedure in 513 cases

Background: Endoscopic self-expandable metal stent placement has been used as an alternative to surgery for malignant colorectal obstruction; however, factors affecting its clinical outcome are unclear. Objective: To clarify the short-term safety and efficacy of endoscopic self-expandable metal stent placement for malignant colorectal obstruction and to identify factors associated with its clinical and technical failure. Design: Prospective clinical cohort study. Setting: Fourteen academic centers and 32 community hospitals. Patients: A total of 513 consecutive patients with malignant colorectal obstruction. Intervention: Endoscopic self-expandable metal stent placement, sharing of stent placement methods among participating facilities. Main Outcome Measurements: The primary endpoint was clinical success, defined as symptom and radiological finding resolution within 24 hours. Secondary endpoints were technical success and adverse events. The follow-up period was 7 days. Results: The clinical and technical success rates were 95.5% and 97.9%, respectively. Major adverse events included perforation (2.1%), stent migration (1.0%), and stent occlusion (0.8%). The main causes of perforation were the procedure itself (0.8%) and comorbidities (obstructive colitis and impending perforation) not apparent before stent placement (0.6%). Extrinsic tumor origin was independently associated with the clinical failure after stent placement (odds ratio 4.23; 95% confidence interval, 1.21-14.79; P = . 02). Stricture marking trended toward a negative association with technical failure (P =.09). Limitations: Noncomparative study. Conclusion: Strict inclusion criteria and stricture marking may improve the technical and clinical success of stent placement.