Vorobyov G.I., Tsarkov P.V., Talalakin A.I., Sorokin E.V. Moscow Of all the existing methods of cost-effective treatment of rectal neoplasms, the transanal endomicrosurgery technique proposed by Buess in 1973 undoubtedly offers the optimal balance between radicalism and minimal trauma. However, despite all the advantages of this method, the cost of a complete instrument set is quite high. In this regard, a modified transanal microsurgery technique was developed using an operating rectoscope with a laparoscopic stand and instrumentation, which reduces the initial cost of the equipment. Between 1999 and 2000, 24 patients were operated on at the State Scientific Center of Proctology using this technique, including 11 men and 13 women, with an average age of 56 years (range: 30 to 73). Twenty-two patients had villous tumors, including 12 broad-based tumors, 6 flattened tumors, and 4 pedunculated tumors. 14 tumors were primary, and 8 were recurrent. Two well-differentiated adenocarcinomas at stage T N M were treated. According to endorectal ultrasound examination, tumor invasion within the mucosa was detected in 14 cases of primary villous tumors; invasion of the mucosa and submucosa was detected in 8 cases of recurrent villous adenomas and 2 adenocarcinomas. Infected pararectal lymph nodes were not detected in any observation. Large, recurrent villous tumors and adenocarcinomas were excised through the full thickness of the intestinal wall. Pathological examination of the removed specimens revealed a discrepancy with the preoperative diagnosis in only one case: adenocarcinoma invasion of the circular muscle layer was noted. Therefore, the patient underwent radiation therapy. A 12-month follow-up examination revealed no signs of tumor recurrence. The other patients who underwent the procedure are alive and well with no signs of recurrence 1 to 20 months after the surgery. Blood loss during surgery averaged 35.8±13.2 ml. The average surgical time was 45 minutes (range 30 to 90 minutes). The average postoperative hospital stay was 3.5 days. When assessing the function of the rectal sphincter apparatus 1 month after surgery, there was no statistically significant difference compared to the preoperative profilometry data. The obtained preliminary results of the application of the modified transanal microsurgery system allow us to evaluate the technique as quite effective and cost-effective in the treatment of large benign epithelial neoplasms and early rectal cancer.