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

purposeThis 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.

methodsForty-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.

resultsNo 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).

conclusionsThe 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.