Cirugía mínimamente invasiva transanal (TAMIS): Técnica y resultados de la experiencia inicial

Background: Transanal endoscopic surgery, a recently described minimally invasive approach, provides superior exposure and access to the entirety of rectal lesions and has lower risks of compromising resection margins, lower recurrence rates and lower morbidity and mortality than do conventional transanal excision and endoscopic removals. Objectives: The aim of this study is to describe our initial experience and with minimally invasive transanal surgery (TAMIS) and its results in terms of complete resections and complications possibly related to the procedure. Materials and methods: This is a series of TAMIS cases with prospective follow-ups. We analyzed the results of 27 patients who underwent the procedure at several centers in Medellin, Colombia, between January 2012 and December 2016.  Twenty patients had Single Incision Laparoscopic Surgery while the GelPOINT path transanal access platform was used for the other six patients. Laparoscope optics provide support for 16 procedures while the more recently introduced flexible endoscope supported eleven procedures. Results: Twenty-seven TAMIS procedures were performed and evaluated. Ten patients were women (37%), and 17 were men. On average, patients were followed up for 32 months, but none less than 12 months. Average patient age was 68 years (52 to 83 years). The average tumor size was 5.3 cm (2 to 9 cm) and the average distance from the anal margin was 7 cm (5 to 9 cm). Postoperative complications occurred in six cases (22%). In one case, a rectal perforation was corrected laparoscopically during the procedure. Another perforation was corrected by the same transanal route. A rectal stenosis was managed with digital dilatation, there was one case of minor rectal bleeding, one case of urinary retention and one patient developed advanced rectal cancer with a positive microscopic margin (4%) three months after resection. There were no readmissions. There were no deaths due to the intervention. Pathology reported low grade adenomas in three cases (11%), high grade adenomas in 11 cases (41%), in-situ adenocarcinoma in six cases (22%), neuroendocrine tumors in five cases (19%), and one case each of cicatricial fibrosis (4%) and leiomyoma (4%). Limitations: The results cannot be extrapolated to the general population because of the limited number of interventions and performance of procedures by only two authors. Conclusions: Our initial experience shows TAMIS to be a minimally invasive procedure with low postoperative morbidity which is curative for benign lesions and for selected patients with early cancer.