2025 Proffered Presentations
S047: MICROVASCULAR FREE TISSUE TRANSFER FOR RECONSTRUCTION OF ANTERIOR SKULL BASE DEFECTS
Thomas G Townes, MD; Matheus Sewastjanow; Matthew Hanasono; Edward Chang; Shirley Su; MD Anderson Cancer Center
Background: Traditionally, many anterior skull base defects are treated with locoregional flaps, such as nasoseptal or pericranial flaps. These provide adequate coverage for a large subset of defects, but there are certain instances such as extensive resections or failure of previous local flaps in which free tissue transfer provides a better reconstructive option. Our goal was to analyze outcomes from a single institution’s experience with microvascular free tissue reconstruction of anterior skull base defects.
Methods: Reconstructive outcomes were analyzed by performing a retrospective review of medical records for patients undergoing microvascular free tissue transfer for anterior skull base defects at our center from 2015-2024.
Results: 30 patients underwent free flap reconstruction in this period. Repair of skull base defects at the time of neoplasm resection was the most common indication (23 patients), though a significant subset of patients underwent repair for osteoradionecrosis or other treatment-related complications after previous repair. Anterolateral thigh cutaneous perforator with chimeric vastus lateralis muscle free flaps were most commonly utilized. The facial artery and vein were most frequently used for pedicle anastomosis, with the superficial temporal system next in frequency. Greater saphenous vein grafts were used to extend the pedicle in 12 patients. One patient (3.3%) had flap failure and was salvaged with a second free flap successfully. The majority of patients had undergone prior oncologic treatment with a variable combination of surgery (20 patients), radiation (21 patients), and systemic therapy (12 patients). Prior reconstructions had been attempted in 11 patients. Recipient site complications occurred in 15 patients (50%). Tumor pathology included squamous cell carcinoma (5 patients), adenoid cystic carcinoma (5 patients), meningioma (5 patients), and melanoma (3 patients), among others. Most patients (18/30) are alive with no evidence of disease at the time of most recent follow up, with a median follow-up time since surgery of 22 months.
Conclusions: Our center’s experience shows that free microvascular tissue transfer is an important salvage reconstructive option for complex defects of the anterior skull base after treatment with surgery, chemotherapy, or radiation, or when prior locoregional reconstructive attempts have failed. These procedures can be performed safely and with low serious complication rates. The anterolateral thigh cutaneous perforator with chimeric vastus lateralis muscle free flap provides versatility, with ability to fill volume deficits with muscle, in addition to repairing skin or mucosal defects with skin. In our experience this flap has provided excellent soft tissue coverage and led to good success rates, even in cases of complex treatment history.