eP205 - Vertical Rectus Abdominis Myocutaneous Flap Perineal Reconstruction After Extralevator Abdominoperineal Excision for Locally Advanced Rectal Cancer

Purpose/Background: Locally advanced rectal cancer management has evolvedto achieve the best oncologic outcome while improving patient quality of life. Approximately 10% of rectal cancer cases are locally advanced with extension distally to involve the levators, external sphincters, and perianal skin warranting an abdominoperineal resection (APR). The perineal wound after an APR poses a challenge due to difficulty in closing the defect and collaborationwith reconstructive surgeons may be necessary.Methods/Interventions: An elderly male presented with a bleeding right gluteal mass that measured 7 cm x 8 cm in size. Proctoscopy showed an obstructing rectal mass 4 cm from the anal verge. Biopsies of both masses showed adenocarcinoma.
Abdominal CT scan showed an irregular, lobulateddistal rectal mass extending to the right gluteal region involving the right external sphincter with multiple enlarged mesorectal lymph nodes and no distant metastasis. The clinical stage was IIIC (T4bN1M0) and a laparoscopic sigmoid loop colostomy was performed. The patient received total neoadjuvant therapy (TNT) following the RAPIDO protocol with short course radiotherapy followed by 6 cycles of oxaliplatin and capecitabine.Repeat imaging after TNT showeda decrease in the size of the rectal mass.However, the right gluteal mass extension progressed in size, now measuring 10 cm x 13 cm.
An extralevator abdominoperineal excision (ELAPE) with en bloc wide excision of the right gluteal mass was performed resulting in a 12 cm x 15 cm full thickness perineal defect. A vertical rectus abdominis myocutaneous flap (VRAM) was used for perineal reconstruction.A skin paddle was harvested with the right rectus abdominis muscle and flipped through the pelvis into the perineal defect and secured with subdermal sutures (Figure 1).Results/Outcomes: Histopathology showedmucinous adenocarcinoma, moderately differentiated with invasion to the perianal skin and sphincter muscles. No perineural and lymphovascular space invasion was identified and all resection margins were negative for tumor. One out of 13 lymph nodes and 1 tumor nodule were positive for tumor.
The patient was discharged after 6 days with an unremarkable postoperative course. He was followed-up at 2 weeks post-operatively, and was seen with a viable flap.Conclusion/

Discussion: ELAPE, a modification to the conventional APR achieves wider margins of resection resulting in improved oncologic outcomes and more cylindrical specimens as “waist”-ing is avoided. A patient isplaced in a prone jackknife position for betterperineal exposure. However, the patient was placed on lithotomy due to the planned reconstruction involving dissection of the rectus abdominis muscle.
The wider margins of ELAPE may result in a larger perineal defect. Thesedefects, especially those receiving radiation,are more aptly managed using flaps. VRAM provides more tissue bulk and has the advantage of using non-irradiated tissue resulting inlower wound complications.
Performing ELAPE may further decrease local recurrence rates after TNT and satisfactory TME. Collaboration with reconstructive surgeons within a multidisciplinary team is necessary in managing complex cases and in performing increasingly more radical surgeries.Figure 1.(A) The fungating gluteal mass that was an extension from a rectal adenocarcinoma. (B) Full thickness perineal defect after extralevator abdominoperineal excision measuring 12 cm x 15 cm. (C) Perineum after vertical rectus abdominis myocutaneous flap reconstruction. PGH, 2023.