V56 - Robotic Abdominoperineal Resection with Robotic Harvest of VRAM Flap for Low Rectal Cancer: A Video Abstract

Purpose/Background: For low rectal cancer, surgery after neoadjuvant treatment may include abdominoperineal resection (APR), which can carry significant postoperative morbidity with a high risk of perineal wound complications. Robotic APR can be performed to reduce the morbidity of laparotomy, among other benefits. However, when a myocutaneous flap is required for perineal coverage, an open vertical rectus abdominis muscle (VRAM) flap is commonly used, which requires a laparotomy and significant open dissection. To reduce the morbidity of VRAM harvest, a novel strategy of performing the intra-abdominal VRAM dissection robotically has been reported. When implemented, the robotic dissection is usually performed by the plastic surgery (PRS) service. We present a video abstract where the robotic VRAM harvest was performed by the colorectal surgery service in close collaboration with the PRS service.

Methods/Interventions: A 56-year-old male diagnosed with stage IIIC (T4aN2M0) obstructing rectal cancer invading the pelvic floor underwent diverting loop colostomy. His postoperative course was complicated by Fournier's gangrene prompting serial perineal debridements. He received consolidation total neoadjuvant treatment and re-staging MRI demonstrated thickening in presacral space. A biopsy was negative for malignancy, but the decision was made to pursue robotic APR with robotic VRAM harvest.

In lithotomy position, the anticipated VRAM incisions were marked out, trocars were placed, and the operation began with conversion of loop colostomy to end colostomy. High ligation of the IMA & IMV was performed, the sigmoid colon was freed from attachments, and rectal mobilization commenced. Near the low anterior rectum, the tumor demonstrated fibrosis, perforation, and scarring, prompting an en bloc partial prostatectomy with dissection to the pelvic floor. The perineal portion required wide excision of the perianal margin to include previous Fournier's gangrene and scarring.

Then, PRS joined bedside for collaboration during VRAM harvest. Transabdominal needles were introduced to mark out the intraperitoneal borders of the anticipated VRAM flap. The peritoneum and posterior rectus sheath were longitudinally opened vertically towards the pelvis. The rectus sheath envelope was dissected circumferentially, and the vascular pedicle of the VRAM was preserved throughout. The posterior sheath was closed. Then, PRS performed the superficial abdominal wall dissection down to the anterior fascia. The superior border of the rectus muscle was transected, the flap was placed intraperitoneal, and the remaining posterior sheath window was closed.

Insufflation was reintroduced to visualize placement of the VRAM flap in the pelvis, confirming a comfortable lay. A drain was placed, the flap was inset in layers, and the anterior abdominal fascia was closed after a right component separation. Trocars were removed, skin was closed, colostomy stitch was removed, and the stoma appeared healthy.

Results/Outcomes: The patient was discharged home on post-operative day 3 and the perineal and abdominal wounds were healing well at 2-week follow up. Final pathology demonstrated ypT3N0 with negative margins.

Conclusion/Discussion: This case demonstrates the first reported robotic intra-abdominal VRAM harvest performed by the colorectal service in close collaboration with PRS. This technique utilizes colorectal surgeons' robotic expertise while overcoming the learning curve for PRS to learn robotic dissection.