A Study to Determine the Feasibility of Transanal Robot-assisted Resection of Distal Colorectal Lesions Using the Medrobotics Flex® System


About this study

The purpose of this study is to assess the rates of complete en bloc resection and adverse events of the Flex Robotic System for distal colorectal lesions.


Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Age > 22 years (minimum age approved for use).
  • Polypoid (0-Is) and non-polypoid (0-IIa, 0-IIb and 0-IIc) lateral spreading lesions according to Paris classification.
  • Colorectal lesions situated between 5 and 15 cm from the dentate line.
  • Colorectal mucosal lesions ranging from 1.5 to 7 cm in maximum diameter.
  • Colorectal subepithelial lesions < 2 cm in size.
  • Absence of uncorrectable bleeding disorder or coagulopathy (platelet count > 50,000 and INR < 1.5).
  • Ability to give informed consent.

Exclusion Criteria:

  • Inability to receive general anesthesia.
  • Presence of medical conditions for which a transanal approach is contraindicated (e.g., anal stricture, radiation proctopathy).
  • Excavated (0-III) colorectal lesions according to Paris classification.
  • Suboptimal colon preparation.
  • Clinical discretion of the provider.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Louis Wong Kee Song, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information


Publications are currently not available

Additional contact information

Cancer-related trials contact form

Phone: 855-776-0015 (toll-free)

International patient clinical studies questions