Reconstructing the Anterior Skull Base After Oncologic Resection: A Comprehensive Systematic Review of Open Techniques and Outcomes.
INTRODUCTION Anterior skull base (ASB) oncologic resection can create composite defects involving bone, dura, sinonasal cavities, orbit, and soft tissue. Although endoscopic techniques have expanded, open reconstruction remains essential for extensive tumors with intracranial, orbital, or craniofacial involvement. We systematically reviewed techniques and outcomes after open ASB reconstruction following oncologic resection. METHODS Following PRISMA guidelines, PubMed, Embase, Cochrane Library, and Web of Science were searched through December 2025. Eligible studies included English-language original reports of patients undergoing oncologic tumor resection requiring open ASB reconstruction, with reported reconstructive technique and at least one clinical or surgical outcome. Data were extracted on study characteristics, surgical approach, flap or graft strategy, dural closure, structural support, adjuncts, and outcomes. Complications were categorized using a structured framework. RESULTS Twenty-seven studies comprising 554 cases/procedures were included: 17 retrospective studies (13 cohorts and 4 case series) and 10 case reports. Tumor histologies were heterogeneous, with meningioma, esthesioneuroblastoma, and squamous cell carcinoma among the most frequently reported pathologies. Reconstruction strategies included pedicled regional flaps in 12 studies, free (microvascular) flaps in 7, non-vascularized free grafts in 4, a mixed local-and-free-flap strategy in 2, artificial dural grafts in 1, and an autologous fascia-muscle-fat composite in 1. Dural patch grafts were used in 18 studies, while watertight closure was explicitly reported in 12. Bone grafts were used in 12 studies, and titanium mesh in 7. Flap survival was reported in 20 studies, with 9 failures across the series. CSF leak was reported in 26 studies; 17 reported no leaks, while 9 documented leaks, with the highest cohort rate of 11.8%. Revision surgery was reported in 24 studies and occurred in 10. Complications included infectious, CSF-related, flap-related, and donor-site events. CONCLUSION Open anterior skull base reconstruction has been reported as feasible across heterogeneous clinical series; however, the predominantly retrospective evidence does not support comparative conclusions regarding reconstructive superiority. Recurring practices included defect-specific multilayer closure, vascularized tissue coverage in compromised fields, and structural reconstruction when required.