Non-conventional applications for transanal endoscopic microsurgery. A single center experience and a systematic review of literature.

[INTRODUCTION] Transanal endoscopic microsurgery (TEM) and transanal endoscopic operation (TEO) have been initially described for local excision of rectal adenomas and selected cases of rectal carcinomas. In the past decade, however, several new indications raised, and others could raise in the future. The aim of this review was to evaluate, both in the literature and in our personal experience, the use of TEM and TEO for non-conventional applications, different from rectal tumors.

[EVIDENCE ACQUISITION] We conducted a systematic review of published papers and we selected articles reporting patients who underwent endoscopic surgery for other medical reason than polyp cancer resection, with TEM or TEO. PubMed, MEDLINE, EMBASE and bibliographies of the selected studies were searched for articles in English published up to May 2020 to identify all relevant articles. We excluded articles reporting TEM and TEO used for classical indications. We finally report our experience of non-conventional use of TEO in 5 patients with different diseases.

[EVIDENCE SYNTHESIS] The research revealed 800 papers and among them we selected 52 articles for a total of 697 patients. Of all patients, only 52 had intraoperative or postoperative complications, with only 10 patients requiring major surgery.

[CONCLUSIONS] Our study suggests that TEM and TEO may be valid alternatives to traditional surgery in situations other than its classical indication. These findings can positively impact on the care of patients, who could benefit from less invasive surgical procedures associated with lower morbidity.