Evidence-based Clinical Management of Acute Malignant Colorectal Obstruction.

Acute malignant colorectal obstruction (AMCO) is an emergency associated with colorectal cancer (CRC). Emergency surgery is standard therapy for AMCO, and 1-stage surgery without colostomy is preferable, but it is occasionally difficult in the emergency setting. A self-expandable metallic stent (SEMS) enables noninvasive colonic decompression and subsequent 1-stage surgery, which has been widely applied for CRC with AMCO. However, recent accumulation of high-quality evidence has highlighted some problems and the limited efficacy of SEMS for AMCO. In palliative settings, SEMS placement reduces hospital stay and short-term complication rates, whereas it increases the frequency of long-term complications, such as delayed perforation. SEMS placement does not seem compatible with recent standard chemotherapy including bevacizumab. As a bridge to surgery, while SEMS placement provides a lower clinical success rate than emergency surgery, it can facilitate primary anastomosis without stoma. However, evidence regarding long-term survival outcomes with SEMS in both palliative and bridge to surgery settings is lacking. The efficacy of transanal colorectal tube placement, another endoscopic treatment, has been reported, but its clinical evidence level is low due to the limited number of studies. This review article comprehensively summarizes the current knowledge about surgical and endoscopic management of CRC with AMCO.