Endoscopic Endonasal Transcribriform Approach for Anterior Skull Base Lesions Involving the Cribriform Plate: Indications, Techniques, and Results in 24 Patients

Introduction: Lesions involving the anterior skull base (ASB) have traditionally been treated with a transcranial or craniofacial approach. The endoscopic endonasal transcribriform approach (EEA-TC) is an extracranial approach that provides direct visualization and exposure of the ventral ASB without brain retraction or manipulation of neurovascular structures. In this study, we reviewed our experience with EEA-TC.

Methods: A retrospective review of a prospective database of endoscopic skull base procedures revealed 24 patients who underwent EEA-TC for ASB lesions involving the cribriform plate, all of which were through a pure endonasal approach. The pathologies included olfactory groove meningioma (five), esthesioneuroblastoma (four), encephalocele (four), sinonasal melanoma (two), olfactory schwannoma (two), small cell neuroendocrine carcinoma (two), inflammatory pseudolesional lesion (one), osteoblastoma (one), renal cell metastasis (one), adenoid cystic carcinoma (one), and nonspecific adenocarcinoma small blue cell type (one). All patients underwent careful reconstruction of large cribriform skull base defects via a triple layer repair with a pedicled nasoseptal flap.

Results: Gross total resection was achieved in 95.8% (23 cases), and near-total resection was achieved in 4.2% (one case). Postoperative complications occurred in three patients, including a postoperative hematoma and delayed brain abscess in one, a single postoperative CSF leak, and a delayed hypertension hemorrhage. Mean follow-up was 20 months (range, 2 to 48 months).

Conclusion: The EEA-TC is a safe and viable approach for resection of benign and malignant ASB lesions involving the cribriform plate. Meticulous triple layer repair with a pedicled nasoseptal flap can minimize the risk of CSF leakage.