Anterior Skull Base Reconstruction in Multiportal Approaches: Insight into Vascularized Flap Techniques

<b>Background/Objectives</b>: To evaluate the outcomes of anterior skull base (ASB) reconstruction using single versus double vascularized flap techniques following multiportal cranio-endoscopic approaches (CEA), based on a 12-year experience. <b>Methods</b>: A retrospective analysis was conducted on 46 patients who underwent ASB reconstruction after a CEA at our department between 2010 and 2022. Patients were divided into two groups: Group 1 received a pericranial flap (PF) reinforced with a fascia graft, while Group 2 underwent multiple flap reconstruction with PF, fascia graft, and nasoseptal flap (NSF). The primary outcome measured was the incidence of cerebrospinal fluid (CSF) leakage and the impact of adjuvant radiotherapy (RT) on reconstruction. <b>Results</b>: Group 1 (86.9%) demonstrated no significant postoperative CSF leaks, showing that the PF, combined with multilayer techniques (including underlay sealing matrix and overlay fascia graft), effectively repaired ASB defects. Group 2 (13.1%), employing both PF and NSF, showed similar outcomes, with the dual flap approach particularly beneficial in cases of post-traumatic fistulas or when the nasal septum was spared by disease. No significant differences were observed in complications or flap necrosis, even in patients receiving adjuvant RT. <b>Conclusions</b>: The PF is a reliable and versatile option for ASB reconstruction, often sufficient as a single-flap technique. The addition of an NSF can be beneficial in specific cases, particularly in post-traumatic conditions or tumors with unilateral endonasal invasion. However, PF alone, when combined with a multilayer approach, minimizes the risk of CSF leakage and long-term flap necrosis, underscoring the importance of tailored surgical strategies for optimal outcomes.