Perforation in the peritoneal cavity during transanal endoscopic microsurgery for rectal tumors: a real surgical complication with a challenging prognosis?

Background: Perforation in the peritoneal cavity during transanal endoscopic microsurgery represents a major challenge. It is usually treated by primary suture, though some authors propose laparoscopic repair with or without ostomy. It is unclear whether perforation increases the risk of tumor dissemination.

Aim: The purpose of the study is to assess the safety of primary suture of peritoneal perforation and the long-term risk of dissemination, also, to determine risk factors for perforation and to propose a predictive model for lesions with risk of perforation.

Method: This is an observational study with prospective data collection at Parc Taulí University Hospital, Sabadell, of patients undergoing transanal surgery with perforation into the peritoneal cavity from June 2004 to September 2017. The main variable is postoperative morbidity and mortality. The long-term follow-up of local recurrence and peritoneal tumor dissemination is described, and a quantitative predictive model for peritoneal cavity perforation is proposed.

Results: Forty-five patients out of 686 (6.6%) presented perforation into the peritoneal cavity. Ten patients (22.2%) in the perforation group had morbidity, a rate similar to the non-perforated group. There was no peritoneal dissemination in patients with adenoma or with carcinoma treated with curative intent. In the quantitative predictive model, risk factors for perforation were proximal edge of tumor > 14 cm from anal verge (6 points), size ≥ 6 cm (2), age ≥ 85 years (4), anterior quadrant (3) , and sex (2). Total scores of ≥ 6 points predicted perforation.

Conclusions: Primary suture after peritoneal cavity perforation during transanal surgery is safe and does not increase the risk of recurrence or peritoneal dissemination. Our predictive model provides guidance regarding the risk of perforation and the need to suture the defect after transanal surgery resection.