Transanal endoscopic microsurgery in the treatment of patients with benign rectal tumors and early rectal cancer

Introduction. Transanal endoscopic microsurgery (TEM) is a method that allows the specialists to clearly visualize a tumor and bimanually remove the tumor using a set of special instruments. For a number of patients with a good tumor response to chemoradiation therapy (CRT), TEM is used as an advanced biopsy technique for tumor verification. The purpose of the study was to analyze the results of TEM performed at A. Tsyb MRRC. Material and Methods. Between 2015 and 2020, 64 patients (men - 42.2 % and women - 57.8 %) underwent TEM. Forty patients had rectal cancer and 25 patients had benign rectal tumors. The indication for TEM in patients with rectal cancer was the evidence of Tis-T1 tumor by postoperative examination findings (MRI and endosonography). Eleven patients with stage II-III rectal cancer received chemoradiation therapy. The indication for performing TEM after RT in patients with rectal cancer was a good tumor response (MRI TRG1-2). For statistical processing, commercial biomedical packages Prism 3.1 and InStat (GraphPad Software, Inc., San Diego, USA) were used. The significance of the differences between the indicators was assessed using the Pearson x2 test. Differences were considered significant if the p value was less than 0.05. Results. The median duration of surgery was 110 minutes (30-385). The volume of blood loss did not exceed 40 ml. Postoperative complications were observed in 15 cases (23.4 %). Grade 3 complications according to the Clavien-Dindo classification were observed in 5 (7.8 %) cases. Postoperative complications occurred more frequently in patients after CRT (10.7 and 18.2 %; p=0.603), however, the differences were not statistically significant. At a median follow-up of 18 months (7-30), local relapses developed in 6 out of 26 (23 %) patients who underwent surgery alone. There were no signs of local recurrence in patients with adenocarcinomas after neoadjuvant chemotherapy and rectal adenomas. When comparing patients with the depth of tumor invasion Tis-T1sm2 and T1sm3-T2, local relapses occurred in 1 of 21 (4.7 %) and 5 of 12 (41.6 %) cases, respectively (p=0.015). Conclusion. The analysis of the results of TEM interventions in patients with rectal neoplasms allows us to conclude that this method of treatment is a priority for patients with benign rectal neoplasms and early rectal cancer. The method can also be used after RT or CRT in patients with tumor invasion >T1sm3, provided a complete or almost complete tumor response to the treatment.