Current status of colonic stent for obstructive colorectal cancer in Japan; a review of the literature

Colorectal cancer is the most common cancer in Japan. Approximately 10%-20% of the patients with colorectal cancer present with large bowel obstruction, and those who present with malignant colonic obstruction (MCO) require urgent decompression because MCO can cause electrolytic fluid imbalance, colonic necrosis, bacterial translocation, and death. Placement of colonic stents (self-expandable metallic stents) for MCO is a major and standard endoscopic treatment that has been available since 2012 in Japan. This review presents the current conditions and future prospects of this procedure based on the literature. The current indication of colonic stent placement is malignant colorectal stenosis. One of the purposes of using stents is palliative treatment; further, its advantages over emergency surgery with colostomy include avoidance of colostomy, relief of obstruction, shorter hospitalization, and better quality of life. In addition, stent placement can also be used as a bridge to surgery since the duration of the hospitalization is shorter and postoperative complications, colostomy rates, and mortality rates are lower with elective than with emergency surgery. Although recent studies have reported low complication rates related to colonic stents, complications may still occur, highlighting the importance of good preparation, adequate staffing, backup systems, and informed consent. The current major problem related to colonic stents is the lack of evidence on patients' long-term prognoses for bridge to surgery purposes, awaiting the results of ongoing clinical research.