[A giant sacral chordoma resection and reconstruction with a gluteal perforator flap, a case report and literature review]

Anatomical Considerations and Plastic Surgery Reconstruction Options of Sacral Chordoma Resection

Introduction Chordomas are slow-growing malignant bone tumors arising from remnant embryonic notochord cells with predilection for the sacrum. They rarely metastasize, and early surgical resection with clear margins is the treatment of choice followed by plastic surgery reconstruction supplemented with adjuvant radiotherapy based on the local treatment protocol or in cases with a contaminated surgical field. Aim The aim of the present study is to present our experience in surgical management of sacral chordomas and propose a surgical reconstruction algorithm considering anatomical parameters after partial or total sacrectomy. Materials and methods  Twenty-seven patients with sacral chordomas were treated in our Orthopaedic Surgery Department between January 1997 and September 2022, and 10 of them had plastic surgery reconstruction. Patients were divided into groups based on the type of sacrectomy, sacrum anatomical vascular or neural variations, partial or total, and the type of soft tissue reconstruction. The postoperative complications and the functional outcomes in each patient were assessed. Results  Bilateral gluteal advancement flaps or gluteal perforator flaps are the first choice in patients with partial sacrectomy, intact gluteal vessels, and without preoperative radiotherapy followed by transpelvic vertical rectus abdominis myocutaneous flap or free flaps in those patients with near total sacrectomy and preoperative radiation therapy. Conclusion  There are four reliable options for patients after sacral chordoma resection: direct closure, bilateral gluteal advancement flaps, transpelvic vertical rectus abdominis myocutaneous flaps, and free flaps. Each time, tumor-free margins and a good reconstructive plan according to the defect and patient characteristics are mandatory.

Management of chordoma of the sacrum and mobile spine

Chordoma is a very rare, poorly known malignancy, with slow progression, mainly located in the sacrum and spine. All age groups may be affected, with a diagnostic peak in the 5th decade of life. Clinical diagnosis is often late. Histologic diagnosis is necessary, based on percutaneous biopsy. Specific markers enable diagnosis and prediction of response to novel treatments. New radiation therapy techniques can stabilize the tumor for 5 years in inoperable patients, but en-bloc resection is the most effective treatment, and should be decided on after a multidisciplinary oncology team meeting in an expert reference center. The type of resection is determined by fine analysis of invasion. According to the level of resection, the patients should be informed and prepared for the expected vesico-genito-sphincteral neurologic sequelae. In tumors not extending above S3, isolated posterior resection is possible. Above S3, a double approach is needed. Anterior release of the sacrum is performed laparoscopically or by robot; resection uses a posterior approach. Posterior wall reconstruction is performed, with an associated flap. Spinopelvic stabilization is necessary in trans-S1 resection. Total or partial sacrectomy shows high rates of complications: intraoperative blood loss, infection or mechanical issues. Neurologic sequelae depend on the level of root sacrifice. No genital-sphincteral function survives S3 root sacrifice. Patient survival depends on initial resection quality and the center's experience. Immunotherapy is an ongoing line of research.

[Anatomical basis of gluteus maximus and application as a pedicled cover flap for pelvic tumor resections]

OBJECTIVES

The resection of malignant bone tumors of the pelvis causes significant loss of substances making covering procedures difficult. The gluteus maximus pedicled flap allows some reconstructions, but its use in vascular sacrifice is not clearly established. The objective of our study was to study its vascularization in order to assess the possibility of vascular sacrifice during carcinological resection of a pelvic tumor.

METHOD

We first performed a vascular mapping of the gluteus maximus muscle using 3-dimensional (3D) models from CT angiography in patients with Leriche syndrome. These models were compared to a cadaveric dissection of 2 injected muscles. A second 3D modeling from postoperative scans was performed in patients who had a gluteus maximus flap after pelvic carcinological surgery.

RESULTS

Ten patients with Leriche syndrome had a 3D model from their scanners. Three distinct arterial systems were identified. Seven patients had a flap from the gluteus maximus muscle, including 3 cases of an Inverted pedicled Hemi Gluteus maximus flap (HGI). According to the modeling, the richness of the vascular network would allow the sacrifice of the superior gluteal pedicle without compromising the viability of this flap.

CONCLUSION

Our study made it possible to confirm the richness of the vascular network of the gluteus maximus muscle and to consider the theoretical possibility of sacrificing the superior gluteal pedicle without endangering an HGI pedicled muscle flap.