Endoscopic endonasal approaches for resection of suprasellar pituitary neuroendocrine tumors: a novel classification based on the optic chiasm and operative nuances.

PURPOSE

Suprasellar pituitary neuroendocrine tumors (PitNETs) present surgical challenges due to their strong adherence to vital neurovascular structures, significantly affecting surgical strategies and outcomes. This study proposed a new classification for suprasellar PitNETs based on their relationship with the optic chiasm.

METHODS

We retrospectively reviewed 82 patients who underwent endoscopic endonasal approaches (EEAs) for suprasellar PitNETs between January 2018 and December 2021. Suprasellar PitNETs were classified into four types based on the relationship between the tumor and the optic chiasm: type I (prechiasmatic type), type II (infrachiasmatic type), type III (retrochiasmatic type), and type IV (mixed type). We assessed detailed operative techniques and outcomes across different suprasellar PitNETs types.

RESULTS

The overall gross total resection (GTR) rate for suprasellar PitNETs was 87.8%. GTR rates varied among different types of suprasellar PitNETs, with type IV exhibiting the lowest rate. Approximately 85.5% of patients with preoperative visual disturbances reported improvement after surgery, with type II suprasellar PitNETs showing the highest improvement rate and type IV suprasellar PitNETs showing the lowest. Cerebrospinal fluid (CSF) leakage occurred in 4 (4.9%) patients and was successfully treated using lumbar drainage or surgical repair. Meningitis was observed in 5 (6.1%) cases, with one fatality occurring in a patient with type I suprasellar PitNET.

CONCLUSION

The classification of suprasellar PitNETs into four types based on their relationship with the optic chiasm enhances our understanding of tumor growth patterns and aids in preoperative assessment. Consequently, determining individualized surgical strategies using EEAs for suprasellar PitNETs can lead to higher resection rates and better visual outcomes.