Transanal drainage tubes vs metallic stents for acute malignant left-sided bowel obstruction A systematic review and meta-analysis

Background: The surgical management of acute malignant left-sided bowel obstruction is associated with high morbidity and mortality. Recently, transanal drainage tubes (DTs) and metallic stents (MSs) used as a "bridge to surgery" have become widely used decompression methods compared with emergency surgery. This study aims to evaluate the efficacy and safety of DTs and MSs for the decompression of acute left-sided malignant colorectal obstruction. Methods: All studies were acquired from PubMed, Medline, Embase, CNKI and the Cochrane Library. The data were extracted by two of the coauthors independently and were analyzed with RevMan5.3. Mean differences (MDs), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The Cochrane Collaboration's risk of bias tool and the Newcastle-Ottawa scale were used to assess the risk of bias. Results: Eleven studies, which included three randomized controlled trials (RCTs) and 8 observational studies, were assessed. The methodological quality of the trials ranged from low to moderate. The pooled results of the technical success rate showed that the difference was not statistically significant between the2 devises. The differences in clinical success rate, operative time and complications were statistically significant between MSs and DTs, and MSs were associated with a better clinical success rate, increased operative time and fewer complications. Sensitivity analysis proved the stability of the pooled results, and the publication bias was low. Conclusion: MS insertion for acute left-sided malignant bowel obstruction is effective and safe with a better technical success rate and with fewer complications than decompression using a DT, and MS insertion can avoid stoma formation. Moreover, MS insertion appears to be a useful treatment strategy for malignant colonic obstruction even if the lesion is located in the right colon. More large-sample, multicenter, high-quality RCTs are needed to verify the outcomes of this meta-analysis.