Transanal Endoscopic Operation Versus Conventional Transanal Excision for Rectal Tumors: Case-Matched Study with Propensity Score Matching

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.

An evaluation of trans-anal rectoscopic-assisted minimally invasive surgery (ARAMIS): a new platform for transanal surgery

PURPOSE

The study aimed to evaluate the feasibility and safety of a new trans-anal rectoscopic-assisted minimally invasive surgery (ARAMIS) platform to treat rectal lesions.

METHODS

ARAMIS was first compared with two transanal minimally invasive surgery platforms (SILS Port and GelPOINT Path) on human cadavers. Surgeons with different experience performed running sutures at different distances, at four quadrants, using the three platforms and gave a score to visibility, safety, and maneuverability. ARAMIS was then utilized on patients affected with rectal neoplasia who met the inclusion criteria. Patients and tumor characteristic and results were prospectively collected. The follow-up examinations included proctoscopy at 3, 6, and 12 months.

RESULTS

According to surgeons' scores, ARAMIS improves visibility and safety with respect to other platforms for distances beyond 10 cm. The procedure, which lasted an average of 59 min, was successfully carried out in 14 patients. No intraoperative or postoperative complications were reported. The mean tumor size was 3 cm; they were located a mean of 11 cm from the anal verge. Complete removal of the lesion was possible in 13/14 patients. There was one case of adenoma recurrence at follow-up.

CONCLUSION

Study results showed that ARAMIS, which is equipped with an adjustable rectoscope, can be considered a safe, effective platform for transanal surgery. The rectoscope protects the rectum during the procedure, a particularly important consideration when proximal rectal lesions are being treated. Further clinical studies are warranted to confirm these encouraging results.