Perforation into the peritoneal cavity during transanal endoscopic microsurgery for rectal cancer is not associated with major complications or oncological compromise

This study was designed to investigate short-term and long-term consequences from perforation to the peritoneal cavity during transanal endoscopic microsurgery (TEM) for rectal cancer, with special emphasis on local recurrence and complications. Data from TEM procedures with peritoneal perforations were collected from six prospective databases. Patient, procedure, and follow-up data were extracted. Participating centers were the United Kingdom TEM database, the German TEM database from Mainz, the National Danish TEM database, and databases from the three major Norwegian TEM centers. A total of 888 TEM procedures were registered, and 22 perforations were identified. Median age was 82 years. Tumor stages were 14 pT1, 4 pT2, 3 pT3, and 1 pTx. The mean tumor size was 4.1 cm. Radical resection was achieved in 17 patients. All perforations were handled endoscopically. There were no severe complications and no deaths related to the procedure. The mean time of observation was 37 (median 36; range 3-164) months. Local recurrence occurred in two patients, three patients died from the cancer (distant metastasis), and six died from other causes. Breaching the peritoneum during TEM is not associated with major short-term complications or long-term oncological consequences provided that primary endoscopic repair is undertaken.