Extensive Anterior Cranial Base Fractures: Anatomic and Surgical Description of Combination Flaps

Introduction: Traditionally, cerebrospinal fluid (CSF) fistula repair following anterior skull base fractures has been accomplished with the use of exclusive anterior-based pericranial flaps. Over time, limitations have been identified with this technique. Persistent CSF leak rates following initial repairs are 12.5 to 17%, and could potentially be contributed to compromise blood supply resulting from initial cranial insult. In addition, glabellar tissue defects from placement of these flaps can result in poor cosmesis. The limited posterior reach of these flaps can hinder repairs in fractures with a substantial posterior extent. This has led to the addition of lateral temporoparital fascial flap and nasoseptal flap to our repair techniques. Methods: Retrospective chart review was preformed of patients with CSF fistula from anterior skull base fractures that were repaired utilizing any combination of anterior pericranial flap, lateral temporoparietal fascial flap, and/or nasoseptal flap. Nasoseptal flap repairs were utilized primarily during initial repair or as a salvage therapy in patients with persistent leaks following an initial repair. Additional anatomic studies were preformed using cadaveric specimen to help with flap design. Results: A total of 10 patients were identified. Nine had fractures extending back to the sphenoid bone, and one had fractures only spanning frontal and ethmoid bones. Nasoseptal flap was utilized as a salvage procedure in three patients. Two cases utilized all three flaps. One patient had combination anterior pericranial and nasoseptal flap, and the other four combined temporoparietal fascial and anterior pericranial flaps. There were no postoperative infections. There were no mortalities and one patient required wound revision for dehiscence. No patient had persistent CSF leak following repair with any combination of flap. Conclusion: Exclusive anterior-based pericranial flaps in comminuted anterior skull based fractures can be supplemented or replaced with temporoparietal fascial flaps and nasoseptal flaps to provide the greatest long-term functional and cosmetic outcome. The combined use of nasoseptal flaps, anterior pericranial flaps, and lateral temporoparietal fascial flaps allow for a comprehensive arsenal in anterior skull base repair and salvage therapy for extensive and severe fractures.