Extended full-thickness transanal local excision to treat ultra-low rectal cancer: an initial clinical exploration.

Objective: To investigate the feasibility of extended full-thickness transanal local excision for rectal cancers invading anorectal junction.

Methods: Four patients with small (size ≤3cm) unfixed rectal cancer, which extended into the upper anal canal, were submitted to transanal local excision with a dissection plane extended to the striated muscle layer around the upper anal canal, so that a portion of striated muscle beneath or around the tumor was excised en bloc with the anorectal wall. The defect in the anorectal wall was laid open to granulate and epithelize.

Results: The mean operative time was 28±6 min, with no related mortality. Postoperative pathological examination confirmed clear resection and revealed 1, T2, 2, T1, and 1 Tis carcinomas. The median follow-up was 3.2 months (range, 1.5-13.0 months). Minor soiling with flatus incontinence was common during the first postoperative month. Two patients with a follow-up longer than 3 months had perfect anal continence. No local recurrence was observed.

Conclusion: Extended full-thickness transanal local excision for rectal tumors lying at the anorectal junction is safe and simple. Patients with partial excision of striated muscle around the upper anal canal may still enjoy good anal continence. Further studies on extended full-thickness transanal excision are worthwhile.