Comparison of trans-anal endoscopic operation and trans-anal excision of rectal tumors

Management of early rectal cancer; current surgical options and future direction

Rectal cancer is the second commonest cause of cancer death within the United Kingdom. Utilization of national screening programmes have resulted in a greater proportion of patients presenting with early-stage disease. The technique of transanal endoscopic microsurgery was first described in 1984 following which further options for local excision have emerged with transanal endoscopic operation and, more recently, transanal minimally invasive surgery. Owing to the risks of local recurrence, the current role of minimally invasive techniques for local excision in the management of rectal cancer is limited to the treatment of pre-invasive disease and low risk early-stage rectal cancer (T1N0M0 disease). The roles of chemotherapy and radiotherapy for the management of early rectal cancer are yet to be fully established. However, results of high-quality research such as the GRECCAR II, TESAR and STAR-TREC randomised control trials may highlight a wider role for local excision surgery in the future, when used in combination with oncological therapies. The aim of our review is to provide an overview in the current management of early rectal cancer, the surgical options available for local excision and the future multimodal direction of early rectal cancer treatment.

Comparison of the transanal surgical techniques for local excision of rectal tumors: a network meta-analysis

BACKGROUND

In order to assess the various surgical modalities for local resection of rectal tumors, a systematic review of the current literature and a network meta-analysis (NMA) was designed and conducted.

METHODS

The present study adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions principles. Scholar databases (Medline, Scopus, Web of Science) were systematically screened up to 23/12/2019. A Bayesian NMA, implementing a Markov chain Monte Carlo analysis, was introduced for the probability ranking of the available surgical methods. Odds ratio (OR) and weighted mean difference (WMD) of the categorical and continuous variables, respectively, were reported with the corresponding 95% confidence interval (95%CI).

RESULTS

Overall, 16 studies and 2146 patients were introduced in our study. Transanal minimal invasive surgery (TAMIS) displayed the highest performance regarding the overall postoperative morbidity, the perioperative blood loss, the length of hospitalization, and the peritoneal violation rate. Transanal endoscopic microsurgery (TEM) was the most efficient modality for resecting an intact specimen. Although transanal local excision (TAE) had the highest ranking considering operative duration, it was associated with a significant risk for positive resection margins and tumor recurrence.

CONCLUSIONS

In conclusion, TEM and TAMIS display superior oncological results over TAE. Due to several limitations, validation of these results requires further RCTs of a higher methodological level.