Triple-Layer Reconstruction Technique for Large Cribriform Defects after Endoscopic Endonasal Resection of Anterior Skull Base Tumors

Introduction: Endoscopic endonasal transcribriform resection of anterior skull base tumors results in large skull base defects that extend the entirety of the cribriform plate, from the frontal sinuses to the tuberculum sellae anteroposteriorly, and from one medial orbital wall to the other horizontally. Endoscopic repair of these large cribriform defects can often be challenging. We describe our reconstruction technique for large skull base defects after endoscopic endonasal transcribriform resection of anterior skull base tumors. This triple-layer technique is comprised of autologous fascia lata, acellular dermal allograft, and a vascularized pedicled nasoseptal flap (NSF). The technique is described, and CSF leak rate is evaluated.

Methods: Retrospective review of a prospective database over a 2-year period identified nine patients who underwent a purely endoscopic endonasal transcribriform approach for resection of anterior skull base tumors. Patients who underwent combined cranionasal approaches and those treated for anterior skull base encephaloceles were excluded from this study. Lesions included two olfactory groove meningiomas, two esthesioneuroblastomas, one olfactory schwannoma, one sinonasal small cell neuroendocrine carcinoma, one melanoma, one adenoid cystic carcinoma, and one recurrent osteoblastoma. After tumor resection, all patients underwent triple-layer reconstruction using autologous fascia lata and acellular dermal allograft followed by a vascularized pedicled NSF to reconstruct a large cribriform skull base defect. No postoperative lumbar drainage was used in these cases.

Results: Postoperative CSF leak rate was 0% without the use of postoperative lumbar drainage. Overall mean follow-up period for all cases was 5.4 months (range, 1 to 13 months).

Conclusion: The triple-layer reconstruction technique using autologous fascia lata, acellular dermal allograft and a pedicled NSF is effective in reconstructing large anterior skull base defects after endoscopic resection of the cribriform plate. We feel that the use of postoperative lumbar drainage is not necessary when using this repair technique, which may result in earlier mobilization and shorter hospital stays.