The da Vinci™ surgical robotic system with its increased instrument stability, tridimensional view, and dexterity with 7 degrees of wristed motion offers a distinct surgical advantage over traditional laparoscopic instruments. This advantage is mainly in the deep pelvis where the limited working space and visibility makes distal rectal dissection extremely challenging. Additionally, the complete control of the surgeon over the stable surgical platform allows fine and accurate dissection in this area.
An abdominoperineal resection (APR) involves the excision of the rectum with a total mesorectal excision (TME), and excision of the anus with an adequate circumferential resection margin (CRM). In a conventional open or laparoscopic approach, the rectal dissection is performed down to the level of the pelvic floor, after which the perineal approach is used to excise the anus and to cut the pelvic floor muscles circumferentially to allow for ‘en bloc’ tumor removal. However, as the pelvic floor is frequently very deep from the skin surface, dissection is technically challenging due to poor visualization, often leading to blind dissection. As a result, many APR specimens suffer from the problem of “waisting” and a positive CRM at the level of the levator ani muscle. In order to solve this problem, some units practice extralevator APR – however, in those cases, the patient ends up with a large perineal defect which frequently needs to be closed with either mesh or flap reconstruction.
With the da Vinci™ robotic system, this problem can potentially be minimized. The robotic system can be used to access deep into the pelvic cavity and make an incision in the puborectalis sling down to the ischiorectal fat. This incision, once completed, allows for easy access from the perineal approach to enter the pelvic cavity and complete the dissection, preventing any blind dissection and facilitating a CRM-clear specimen to be excised.
This video features a totally robotic approach to an abdominoperineal resection for a poorly differentiated anorectal adenocarcinoma, with intraperitoneal incision of the puborectalis sling to facilitate subsequent perineal dissection and specimen extraction.
A 79-year-old female patient presented with a perianal lump and discomfort. Colonoscopy revealed a 2cm mobile adenomatous polypoid lesion at the anorectal junction. Excision biopsy showed a poorly differentiated adenocarcinoma.
CT-scan of the thorax, abdomen and pelvis did not show any distant metastases, and MRI of the rectum did not show any significant locoregional disease. A robotic abdominoperineal resection was performed.
The da Vinci™ Si™ robotic system was used, and a dual docking approach was chosen.
The patient was placed in a Lloyd-Davies position. Robotic ports (8mm) were placed in the epigastrium, left flank, suprapubic region, and in the right iliac fossa respectively. A 12mm trocar is inserted into the right flank for assistance and stapling.