Safety and efficacy of endoscopic colonic stenting as a bridge to surgery in the management of intestinal obstruction due to left colon and rectal cancer: a systematic review and meta-analysis.

Introduction: Colorectal carcinoma can present with acute intestinal obstruction in 7%-30% of cases, especially if tumor is located at or distal to the splenic flexure. In these cases, emergency surgical decompression becomes mandatory as the traditional treatment option. It involves defunctioning stoma with or without primary resection of obstructing tumor. An alternative to surgery is endoluminal decompression. The aim of this review is to assess the effectiveness of colonic stents, used as a bridge to surgery, in the management of malignant left colonic and rectal obstruction.

Methods: We considered only randomized trials which compared stent vs surgery for intestinal obstruction from left sided colorectal cancer (as a bridge to surgery) irrespective of their size. No language or publication status restrictions were imposed. A systematic search was conducted in Medline, Cochrane Central Register of Controlled Trials and the Science Citation Index (from inception to December 2011)

Results: We identified 3109 citations through our electronic search and 3 through other sources. Initial screening of the titles and abstracts resulted in the exclusion of 3104 citations. A further 5 citations were excluded after detailed screening of full articles. Three published studies were included in this systematic review. A total of 197 patients were included in our analysis, 97 of them had colorectal stent vs 100 who had emergency surgery. Clinical success has been defined in different manners. In included trials the clinical success rate was significantly higher in the emergency surgery group (99%) compared with the stent group (52.5%) (p < 0.00001). There was no difference in the overall complication rate in the stent group (48.5%) vs emergency surgery group (51%) (p = 0.86). There was no difference in 30-days postoperative mortality (p = 0.97). The overall survival was analyzed in none trial. When used as a bridge to surgery, colorectal stents provide some advantages: the primary anastomosis rate was significantly higher in the stent group (64.9%) vs emergency surgery group (55%) (p = 0.003); the overall stoma rate was significantly lower in the stent group (45.3%) compared with the emergency surgery group (62%) (p = 0.02). There were no significant differences between the two groups as to permanent stoma rate (46.7% in stent group vs 51.8% in surgical group, p = 0.56), anastomotic leakage rate (9% in stent group vs 3.7% in surgical group, p = 0.35) and intra-abdominal abscess rate (5.1% in stent group vs 4.9% in surgical group, p = 0.97).

Conclusion: Although colonic stenting appears to be an effective treatment of malignant large bowel obstruction, the clinical success resulted significantly higher in the emergency surgery group without any advantages in terms of overall complication rate and 30-days postoperative mortality. On the other hand, the colonic stenting as a bridge to surgery provides surgical advantages, as higher primary anastomosis rate and a lower overall stoma rate, without increasing the risk of anastomotic leak or intra-abdominal abscess. However, these results should be interpreted with caution because few studies reported data on these outcomes. Due to the small and variable sample size of the included trials, further RCTs are needed including a larger number of patients and evaluating long term results (overall survival and quality of life) and cost-effectiveness analysis.