Microvascular Free Flap Reconstruction of Dural Defects

Objective: Surgical management of large mid-face lesions often requires orbital exenteration and cranial base resection resulting in complex defects. Free flap reconstruction is often the best reconstructive strategy to protect intracranial structures, prevent a cerebrospinal fluid (CSF) leak, replace tissue, maintain function such as swallowing, and achieve an acceptable cosmetic outcome. We present a series of twenty-nine consecutive patients who underwent mid-face resection including the osseus skull base as part of the oncologic resection. We reviewed the patient demographics, tumor type, free-flap used, incidence of post-operative CSF leaks, and early complications. We propose that free flap reconstruction of these defects is safe, provides the best tissue bulk and protects intracranial contents well.

Methods: After obtaining institutional review board approval, the electronic medical records for 55 consecutive patients who underwent free tissue transfer for complex orbito-facial defects at a tertiary medical center between September 2006 and July 2012 were reviewed. Follow-up of ≥ 3 months was available for 49 patients. Twenty-nine patients of this group were identified to have dural exposure and/or resection.

Results: Eighteen of twenty-nine patients (62%) had primary dural resection as part of the oncologic extirpation, of these eighteen patients eleven had a concomitant orbital exenteration. The mean age was 62 years and the majority of patients were male. Nine patients underwent extirpation for squamous cell carcinoma, 4 for adenocarcinoma, 6 for meningioma, 2 for adenoid cystic carcinoma, and 2 for osteoradionecrosis. Other pathologies requiring surgery included sarcoma, basal cell carcinoma, hemangiopericytoma, sinonasal undifferentiated carcinoma, malignant nerve sheath tumor and esthesioneuroblastoma. Twenty-three patients were reconstructed using an anterolateral thigh free flap, five with a radial forearm free flap, and one with a lattismus dorsi flap. Two patients had post-operative infections requiring removal of orbital implant, three patients had a post-operative CSF leak (10%) secondary to three flap-related complications. Five patients in the series underwent therapeutic sinus surgery for post-operative sinusitis.

Conclusion: Microvascular free tissue transfer for the reconstruction of complex skull base defects requiring dural repair has significant advantages compared with traditional techniques. The relatively long pedicle length and robust soft tissue bulk make it the ideal choice for dural reconstruction and reinforcement. While post-operative leak rates and infection rates remain low in our series, there was a significant incidence of post operative sinusitis. Intraoperative management of the sinuses to maintain sinus outflow is paramount in optimizing patient care.