Robotic Abdominoperineal Resection (APR) with Bilateral Gracilis Muscle Flaps

Robotic abdominoperineal resection (APR) with reconstruction of the pelvic floor of the perineum is a crucial surgical procedure for patients with advanced rectal cancer, especially those with metastatic disease.^1,2

The use of robotic technology in APR allows for greater precision and control during surgery. This minimally-invasive approach results in less blood loss, reduced postoperative pain, and faster recovery times compared to traditional open surgery.^3–5 Robotic assistance provides surgeons with enhanced 3D visualization and magnification, which is particularly beneficial when working in the confined pelvic space and dealing with complex anatomical structures. By combining tumor resection with immediate reconstruction, this procedure addresses both oncological and functional needs, reducing the risk of complications and improving overall outcomes.

The patient presented in this video is a 52-year-old male with metastatic rectal cancer. Initially presenting with bone, liver, and lung metastases, he underwent chemotherapy, experienced some progression, and was subsequently placed on a clinical trial, which resulted in an impressive response. For the past two years, his condition has been under control, but there has been a recent progression of symptoms. Consequently, a resection of his primary tumor is planned as a palliative measure.

This video is a comprehensive step-by-step demonstration of the complex surgical procedure described above. It starts with a physical examination of the rectum, during which a locally advanced rectal tumor was identified. The tumor was found to be situated quite low, involving the anterior rectal wall and the right wall. Subsequently, during the flexible sigmoidoscopy, the tumor was visualized, further confirming its presence and location.

The surgical process involved specific port placements and robot docking. Initially, the anterior superior iliac spines and the rectus muscle were marked. The colostomy site was preoperatively marked. A line from the apex of the anterior superior iliac spine to the midclavicular line was drawn to guide the port placements. Ports were marked approximately 6–8 cm apart to avoid limiting dissection. The camera port, bipolar port, scissors port, and assist port were positioned accordingly.

The initial entry was made using the direct optical trocar access, as called the Optiview technique, involving a small incision through the anterior rectus fascia. The rectus muscle and posterior fascia were visualized, ensuring safe access to the abdominal cavity. The right lower quadrant port was placed first, followed by the other ports, spaced a handbreadth apart. Proper positioning was verified to avoid collisions during pelvic dissection. The robot arms were then carefully docked to their respective ports, ensuring secure connections and optimal positioning for the procedure.

The pelvic dissection was initiated by positioning the patient in approximately 18 degrees of Trendelenburg on the robotic system. Tension was created above the operating area while critical structures such as the hypogastric nerves and ureter were preserved. The total mesorectal excision (TME) dissection was performed posteriorly, extending to the levator plates. Gentle retraction and tension-counter tension techniques were employed for precise dissection throughout the procedure.

The inferior mesenteric artery (IMA) pedicle was initially left intact to provide ventral tension during dissection. The dissection progressed along the left side, following the curve of the pelvis, and proceeded anteriorly guided by TME principles.⁶

Careful attention was paid to staying in the correct plane during dissection, particularly in challenging areas such as around the seminal vesicles and prostate. The parasympathetic nerves on the pelvic sidewalls were preserved, while the integrity of the mesorectum was maintained. Lateral dissection, often the most challenging part due to unclear planes, was approached with caution to avoid entering the mesorectum.
Edema resulting from the patient's prior chemoradiotherapy was noted and managed throughout the procedure by keeping the field dry and using careful dissection techniques. This allowed for better visualization of anatomical structures.

The dissection was continued towards the pelvic floor, with efforts made to avoid coning in too much and compromising margins. The camera angle was frequently adjusted, and tension was maintained to ensure clear dissection lines. The pelvic floor muscles were identified, confirming the depth of the dissection. The IMA pedicle and lymph nodes were then addressed, with careful attention paid to the ureter's position. Double ligation was performed to secure the vessels.

Various techniques were employed to maintain proper tension and create sufficient space in the narrow pelvis. These included angling the robotic arms and wrists and using continuous motion to pull up and straighten the dissection line. Circular movements and upward sweeping motions were used to even out tension and define the avascular plane.

As the procedure neared completion, focus was placed on reaching the levator area for perineal dissection. Hemostasis was checked, and the IMA pedicle was secured. Finally, a 19 French silicone drain was prepared and correctly placed, secured to the sigmoid stump.

The colostomy creation involved careful handling to prevent hernias and maintain proper orientation. The posterior fascia was crucial, and a cruciate incision was made. Muscle bleeding was controlled, and the colostomy was delivered with care, avoiding mesenteric tears.

Ensuring proper stoma formation, the mesentery was checked for any twisting. The drain was positioned correctly, and hemostasis was confirmed. Sutures were placed to secure the colostomy, ensuring proper perfusion and positioning. A 0 Vicryl suture was used to secure the drain, with a preference for maintaining the sigmoid orientation.

The abdominal closure involved ensuring a proper seal and avoiding contamination. The stoma was matured, ensuring a well-perfused appearance. The robotic portion concluded with meticulous attention to detail, ensuring all steps were followed for a successful outcome. The final steps involved ensuring proper placement of the colostomy and securing all components before moving to the prone position for further procedures.

As the robotic APR progressed, the second surgical team simultaneously performed the gracilis muscle flap harvest. This concurrent approach optimized surgical efficiency and prepared for comprehensive closure of the surgical site.

The gracilis muscle flaps were bilaterally harvested from the medial thighs. Preoperative marking was performed, and the incision was placed slightly posteriorly to the traditional two fingerbreadths below the adductor tendon, allowing direct access to the gracilis muscle.

The initial incision was made through the skin and subcutaneous tissue. The gracilis muscle was located beneath the deep fascia of the medial thigh. Circumferential dissection was carried out, with an initial focus on the distal portion. The dominant pedicle from the medial femoral circumflex vessel, was located 9 cm from the muscle insertion, as is typical. The nerve supply, originating from the obturator nerve, was found proximal to the dominant pedicle.

Minor pedicles were ligated or cauterized during the dissection. Once freed circumferentially, a Penrose drain was placed around the muscle for easier manipulation. A secondary distal incision was made to access the tendinous part of the gracilis. The muscle was disinserted distally and passed through to the proximal incision.

Following the robotic portion of the APR, the perineal dissection was performed with the patient in a prone position. A circular incision was made around the anus, entering the ischiorectal fat while staying outside the external sphincter. Dissection was carried posteriorly towards the coccyx, laterally along the levator muscles, and anteriorly with careful attention to avoid injury to the prostate and urethra.
The specimen was removed, ensuring adequate mesorectal excision. The quality of the TME was assessed visually, and frozen section analysis of the anterior margin was performed to ensure negative margins.

For the gracilis muscle flap inset, tunnels were created from the thigh incisions to the perineal defect. The gracilis muscles were passed through these tunnels, oriented to naturally fill the pelvic defect taking care to ensure the pedicles were not kinked or twisted. The muscles were inset with absorbable sutures, recreating the pelvic floor sling with healthy, non-irradiated tissue at the level of the levator muscles.
The proximal thigh incisions were closed in layers. The perineal incision was closed in layers over the muscles to close the dead space and take tension off the skin closure. A running reverse suture technique was employed for skin closure, providing closure of dead space and eversion of skin edges. At the time of closure, the legs were brought closure to midline to ensure no added tension was present at the perineal closure. Given the limited required skin excision this was not an issue in this patient. Additionally this is why a skin paddle was not harvested with the flap. Drains were placed as needed.

This gracilis flap technique offers several advantages over alternatives such as vertical rectus abdominis myocutaneous (VRAM) flaps, including avoiding additional abdominal incisions and preserving core musculature.^7,8 The use of gracilis flaps provided healthy, vascularized tissue to promote healing in the irradiated field, contributing to improved surgical outcomes and patient recovery. Given that this portion of the procedure can be done in tandem with the robotic tumor resection the total operative time was greatly reduced. The patient presented in this video and article had an uneventful recovery with no wound healing complications or infections.

In summary, robotic APR with bilateral gracilis flap reconstruction is a vital procedure for managing advanced and metastatic rectal cancer. It offers a precise, minimally-invasive approach that addresses both tumor removal and functional reconstruction, providing significant benefits for patients requiring complex oncological and reconstructive surgery. This step-by-step video guideline is crucial for advancing surgical techniques in complex rectal cancer treatment. It serves as a vital educational resource for surgeons at all levels, demonstrating the combination of APR with gracilis flap reconstruction. The video's importance lies in its ability to standardize the procedure, showcase innovative techniques, and highlight critical aspects that are difficult to convey through text alone. Providing detailed visual instruction on navigating challenges helps prevent complications and improve patient outcomes.

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.