Is there a limit to transanal endoscopic surgery? A comparative study between standard and technically challenging indications among 168 consecutive patients

AIM: To assess the surgical outcome of transanal endoscopic surgery (TES) for rectal neoplasms in technically challenging indications. METHOD: All patients who underwent TES for a rectal neoplasm from 2007 to 2014 were included. Technically challenging indications included a tumour with (i) diameter ≥ 5 cm, (ii) involving ≥ 50% of the rectal circumference and (iii) located ≥ 10 cm from the anal verge. Patients were divided into three groups according to how many of these features they had, as follows: Group 1, none; Group 2, one; Group 3, two or more. RESULTS: Of the 168 patients (80 benign and 88 malignant tumours) included in the study, 73 (44%) were in Group 1, 46 (27%) in Group 2 and 49 (29%) in Group 3. There was no difference between Group 1 and Group 2 with regard to peritoneal perforation (P = 0.210), severe postoperative morbidity (P = 0.804), length of hospital stay (P = 0.444), incomplete resection (P = 0.441), piecemeal resection (P = 0.740), locoregional recurrence (P = 0.307) and long-term symptomatic rectal stenosis (P = 0.076). Conversely Group 3 showed significantly impaired results compared with Group 1 with regard to peritoneal perforation (P = 0.003), piecemeal resection (P = 0.005), incomplete resection (P = 0.025), locoregional recurrence (P = 0.035) and long-term symptomatic rectal stenosis (P < 0.001), but no difference in severe postoperative morbidity (P = 0.328). CONCLUSION: Transanal endoscopic surgery for rectal neoplasms appears to be safe and effective, even in patients presenting with a technically challenging tumours. Although the short- and long-term outcomes after TES are worse in patients with highly challenging tumours, nevertheless the technique should still be considered in patients at high risk of requiring a proctectomy.