A comparison of the technical and oncologic validity between robot-assisted and conventional open abdominoperineal resection.

PURPOSE: This study was to ascertain whether a robot-assisted (RA) approach to APR might facilitate a cylindrical APR by enabling a deeper pelvic dissection during an abdominal approach, concurrently comparing the feasibility and short-term oncologic outcomes.

METHODS: Forty-eight consecutive patients with lower rectal cancer who had undergone curative APR (21 RA vs. 27 open) were prospectively enrolled. The short-term operative outcomes and oncologic feasibility were evaluated and compared. A levator muscle excision was performed concomitantly with the abdominal procedure in the RA group and with the perineal procedure in the open group.

RESULTS: No patients in the RA group experienced intraoperative perforation or required conversion to open APR. Overall, a cylindrical APR was performed in 72 % of patients, and subtotal excision of the levator muscle, i.e., either one or both sides of the puborectalis and pubococcygeus muscles, was more likely in the RA group (P = 0.019). A positive CRM was exclusively identified in four open APR patients. The mean number of retrieved lymph nodes was greater in the RA group (20 vs. 16, P = 0.035). There was no difference in perineal morbidity between the two groups (P = 0.445).

CONCLUSIONS: The RA approach facilitates an efficient excision in the pelvic region than open APR during the abdominal procedure. The RA approach also demonstrated a trend toward improved oncologic outcomes with equivalent postoperative morbidities than with the open approach.