"Transanal endoscopic microsurgery" with a flexible colonoscope (F-TEM): a new endoscopic treatment for suspicious deep submucosal invasion T1 rectal carcinoma

Background: Endoscopic techniques allow resections of deep submucosal invasion rectal carcinoma, but mostly are facing issues such as costs, follow-up care or size limit. Our aim was to design a new endoscopic technique, which retains the advantages over surgical resections while eliminating the disadvantages mentioned above.

Patients and methods: We propose a technique for the resection of the superficial rectal tumours, with highly suspicious deep submucosal invasion. It combines steps of endoscopic submucosal dissection, muscular resection and edge-to-edge suture of the muscular layers, finally performing the equivalent of a "transanal endoscopic microsurgery" with a flexible colonoscope (F-TEM).

Results: A 60-year-old patient was referred to our unit, following the discovery of a 15 mm distal rectum adenocarcinoma. The computed tomography and the endoscopic ultrasound examination revealed a T1 tumour, without secondary lesions. Considering that the initial endoscopic evaluation highlighted a depressed central part of the lesion, with several avascular zones, an F-TEM was performed, without severe complication. The histopathological examination revealed negative resection margins, without risk factors for lymph node metastasis, no adjuvant therapy being proposed.

Conclusion: F-TEM allows endoscopic resection of highly suspicious deep submucosal invasion T1 rectal carcinoma and it proves to be a feasible alternative to surgical resection or other endoscopic treatments as endoscopic submucosal dissection or intermuscular dissection.