Clival tumors present challenging entities regarding their treatment options. Due to their proximity to critical neurovascular structures, the operative goal of gross total tumor resection is rendered more difficult by a high risk of neurological deficits. Retrospective cohort study of patients treated for clival neoplasms through a transnasal endoscopic approach between 2009 and 2020. Assessment of preoperative clinical status, length of operation, number of approaches, pre- and postoperative radiotherapy, and the clinical outcome. Presentation and clinical correlation with our new classification. In total, 59 transnasal endoscopic operations were performed on 42 patients over 12 years. Most lesions were clival chordomas; 63% of the lesions did not reach the brainstem. Cranial nerve impairment was present in 67% of the patients, and 75% of the patients with cranial nerve palsy improved after surgical treatment. Interrater reliability for our proposed tumor extension classification showed a substantial agreement (Cohen's κ = 0.766). The transnasal approach was sufficient to achieve a complete tumor resection in 74% of the patients. Clival tumors exhibit heterogeneous characteristics. Depending on clival tumor extension, the transnasal endoscopic approach can present a safe surgical technique for upper and middle clival tumor resection, with a low risk of perioperative complications and a high rate of postoperative improvement.
© 2023. The Author(s).