| It has been estimated that about 8 to 13% of patients with advanced colorectal cancer may present acutely as malignant large bowel obstruction. This is a surgical emergency and urgent colonic decompression is needed. Options include oncologic resection, surgical diversion, and the use of colonic self-expandable metallic stent (SEMS) as a bridge to surgery (BTS). The concept of BTS for curative cases is attractive because it transforms an emergency surgery to an elective one, allowing time for patient stabilization, full preoperative staging, adequate preoperative bowel cleansing and facilitating a single stage minimally invasive surgery. Randomized studies and meta-analyses have demonstrated that BTS achieved a higher primary anastomosis rate, lower overall morbidity, shorter length of stay and lower complication rates compared to emergency surgery for curative cases. Most outcome data are derived from left sided obstruction, but the available data would suggest that despite the potential technical challenges in right sided obstruction, similar efficacy can be achieved. There had been some uncertainty about the impact of colonic stenting on long term oncologic outcomes, due to concerns about SEMS-induced shear forces on the tumor leading to increased circulating cancer cells and aggressive pathological characteristics, including perineural and lymphovascular invasion, and SEMS related perforation increasing the local recurrence rate. However, the limited long-term data demonstrated no difference in terms of overall and disease free 5-year survival between BTS and emergency surgery groups. Colonic stenting related complications include perforation, stent failure, migration, and re-obstruction, and can be immediate or delayed. To reduce such risks, colonic stenting should be performed by experienced endoscopists and there must be meticulous attention to technical details, and one must be prepared to abandon the procedure early in context of technical challenges in favor of surgery, rather than to persist and increase the risk of perforation and peritoneal soilage. Post stenting, early scheduling of curative surgery, preferably at two weeks, would reduce the risk of delayed complications and stent malfunction. BTS has now gained widespread acceptance and is able to facilitate minimally invasive curative surgery with good surgical outcomes. |
