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Updated: Aug 9, 2026

The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors
Published on: February 13, 2026
[Transsphincteric surgery of rectal lesions: a report of 120 cases]
Hui-zhong Qiu1, Guo-le Lin, Bin Wu
1Department of Surgery, Peking Union Medical College Hospital, Beijing 100730, China.
Objective:
To generalize the clinical use of transsphincteric operation (Mason operation) for rectal lesions.
Methods:
Clinical data of 120 patients with middle and lower rectal lesions who underwent Mason operation from Aug. 1990 to Aug. 2005 were analyzed retrospectively.
Results:
There were 61 cases with villous adenoma including 26 with cancerization, 25 cases with rectal cancer including 16 cases with early rectal cancer, and 17 with submucosal tumor. Of the 103 patients with rectal tumor, 98 underwent partial rectectomy, 5 segmental rectectomy. The postoperative complications included incision infection in two cases (1.6%), fistula in 4 cases (3.3%). Three patients (3.0%) had postoperative local recurrence. 90.2% of the rectal cancer patients (46/51) survived more than five years after Mason operation.
Conclusion:
Mason operation is satisfactory because of good exposure and simple access to the rectum, which is suitable for those lesions that could be locally resected on the mid and low rectum.
