Endoscopic underwater detection and resection of anal squamous intraepithelial lesions in non-anesthetized patients - a feasibility study and comparison with standard surgical treatment.

Background: Anal squamous intraepithelial lesions (ASILs) correspond to premalignant changes preceding the development of anal squamous cell carcinoma.

Objective: To describe a new endoscopic technique to detect and remove ASILs in non-anesthetized patients and compare it with standard surgical treatment.

Methods: For endoscopic treatment, high resolution (HR) flexible endoscopes with a distal attachment were used.