Oncological Skull Base Reconstruction with Microvascular Tissue Transplantation in Advanced Relapsed Cases

Abstract

Introduction: Tumors involving the skull base are real challenges to reconstructive surgeons. Many articles have been published about these reconstructions, especially in primary cases. In tumor relapses after previous surgeries or irradiation, the surgical options for reconstruction are extremely narrowed and is our opinion that microvascular autologous tissue transplantation is specially indicated in those patients, even though it requires a technically demanding procedure. Materials and Methods: We analyzed retrospectively all patients treated at our institution between March 2014 and December 2018 and that met all the inclusion criteria: 1) oncological surgery for a tumor involving the skull base; 2) previous surgical treatment for that tumor; 3) cranial base bone resection; 4) dural exposure or defect; 5) reconstruction done with a free flap. The patient's age, comorbidities, number of previous surgeries and/or irradiation, oncological excisional procedures, type of defect, type of reconstruction, postoperative complications and mortality were reviewed. Results: Fifteen flaps were used in the 14 patients that met all the inclusion criteria. The used flaps were: Anterolateral Thigh (ALT) perforator or chimeric ALT/Vastus Lateralis (VL) (n=6), profunda artery perforator (n=3), muscular Rectus Abdominis (n=2), Vertical Rectus Abdominis Myocutaneous (VRAM) (n=2), chimeric osteomuscular scapular tip/Latissimus Dorsi (LD) (n=1) and radial forearm (n=1). Dural defects were reconstructed with Pericranial or fascia Lata grafts in 7 patients. No total flap failures or vascular thrombotic events were noted and just one case of partial flap necrosis was registered (treated conservatively). There was one case of cerebrospinal fluid leakage, one diffuse cerebral edema and one donor site wound dehiscence, all successfully treated with conservative measures. The only complication that required a second operation was a cranioplasty prosthetic exposure that required a second free flap. One patient had a tracheostomy bleeding followed by a pneumothorax and died 8 weeks postoperatively with a nosocomial pneumonia. In the follow-up period, one patient died 19 months postoperatively with a local relapse and another with a metastatic disease (at month 15). Conclusion: Secondary or multiple relapsed cases in the skull base require reconstructions that are technically demanding and the defects are often extensive. The surgical options are extremely reduced by previous treatments and if the basic concepts of cranial base reconstruction were strictly respected, the microsurgical free flaps can offer the best chance to avoid severe complications. However, it is not without some postoperative complications and mortality can be significant in the follow-up because of the advanced stage of the oncologic disease.