Bilateral Pedicled Superior Gluteal Artery Perforator (SGAP) Flap for Double-Layer Closure and Reconstruction of Sacrococcygeal Defect After Chordoma Resection: A Case Report

Abstract

Chordomas are rare, slow-growing, locally aggressive malignant tumors arising from notochord remnants that commonly affect the sacrococcygeal area. Surgical resection with negative margins is crucial but often results in extended defects with exposed critical structures, necessitating complex reconstructions. The reconstruction techniques commonly employed and described in the literature often utilize musculocutaneous flaps, which are associated with higher donor site morbidity. Thus, the challenge remains to minimize donor site morbidity while ensuring effective reconstruction and long-term stability. This case report presents a novel technique for sacrococcygeal defect reconstruction after chordoma resection. This approach aims to help reconstructive surgeons to improve patient outcomes and broaden the range of available surgical strategies in this area while minimizing donor site morbidity. An 87-year-old male patient presented a sacrococcygeal chordoma measuring 51 × 41 × 58 mm, which caused the destruction of the coccygeal vertebrae and infiltrated the levator ani muscle. After a multi-disciplinary discussion, the patient underwent en-bloc tumor resection. The mass measured 11 × 8 cm and included the coccyx, the gluteus maximus insertion to the coccyx, and a portion of the levator ani muscle, leaving part of the rectum ampulla exposed. For the reconstruction, to create a strong barrier to minimize the risk of rectal herniation, obliterate the dead space, and cover the defect, we performed a bilateral advancement of the gluteus maximus and harvested two pedicled superior gluteal artery perforator (SGAP) flaps measuring 15 × 10 cm and centered on the perforator. The flaps were consequently tunneled below the gluteal skin, rotated 90°, and placed in the defect; one was de-epithelialized and buried into the defect, and the other was placed above it for surface coverage. The postoperative recovery was uneventful, and at a 1-year follow-up, the patient reported no motor dysfunction or problems during sitting, and no signs of rectal herniation were shown at the CT. The reconstruction with bilateral pedicled SGAP flaps arranged in a double-layer fashion could effectively address the key points of reconstruction of the sacrococcygeal area after chordoma resection, with several advantages since it causes minimal donor site morbidity and maintains the contour of the gluteal area with excellent functional outcomes. However, further studies are warranted to validate and refine this approach.