Endoscopic endonasal approach for craniopharyngioma resection in 604 cases: tumor classification, treatment strategies, and surgical outcomes

OBJECTIVE: Craniopharyngiomas (CPs) pose significant surgical challenges due to their proximity to critical neurovascular structures and their high recurrence rates. The endoscopic endonasal approach (EEA) has emerged as a reliable alternative to craniotomy, offering unique advantages. This study aimed to summarize management experience by analyzing the largest single-team cohort of the EEA for CPs, providing insights for optimizing treatment and guiding surgical decision-making. METHODS: A retrospective analysis of 604 patients with CP (ages 2-76 years) treated via the EEA from 2019 to 2023 was conducted. A new tumor classification based on the relationship between the tumor and key anatomical interfaces in the EEA (sellar diaphragm and third ventricle floor) was proposed. Three surgical corridors were used: chiasm-pituitary, suprachiasmatic translamina terminalis, and transclival. Intraoperative visual evoked potential (VEP) monitoring was assessed for visual protection. Risk factors for complications and progression-free survival (PFS) were analyzed. RESULTS: Gross-total resection (GTR) was achieved in 89.7% of cases (93.7% in primary vs 78.8% in recurrent tumors). CSF leak rates declined from 7.35% in 2019 to 1.63% in 2023, with hypoalbuminemia and larger dural defects emerging as independent risk factors in adults. VEP monitoring reduced visual deterioration (6.74% vs 12.62%, p = 0.015). Recurrent tumors (odds ratio [OR] 5.397, 95% CI 2.984-9.763; p < 0.001), larger tumor volume (OR 1.038, 95% CI 1.018-1.06; p < 0.001), Puget grade II (OR 2.35, 95% CI 1.249-4.42; p = 0.008), and massive calcification (OR 2.541, 95% CI 1.333-4.841; p = 0.005) were independent risk factors for non-GTR (NGTR). Multivariate Cox analysis showed that NGTR (hazard ratio [HR] 9.181, 95% CI 5.143-16.392; p < 0.001), Puget grade I (HR 3.306, 95% CI 1.385-7.895; p = 0.007), Puget grade II (HR 2.918, 95% CI 1.260-6.755; p = 0.012), cystic tumor (HR 1.794, 95% CI 1.065-3.021; p = 0.028), and calcification (HR 2.249, 95% CI 1.206-4.195; p = 0.011) were independently associated with decreased PFS. Pediatric patients had higher GTR and lower CSF leak incidence rates than adults. CONCLUSIONS: The EEA could be considered the first-line surgical treatment modality for most adult and pediatric patients with CP. For large CPs invading the hypothalamus, the EEA allows for sharp dissection of the tumor from the hypothalamus under direct visualization, enabling complete resection while minimizing hypothalamic damage. Intraoperative VEP monitoring aids in reducing visual deterioration. The proposed tumor classification and experience can enhance surgical quality, reduce complications, and guide patient counseling.