Endoscopic endonasal approach for infradiaphragmatic craniopharyngiomas: a multicentric Italian study

Infradiaphragmatic craniopharyngiomas (ICs) represent a distinct subtype, harboring a sellar-suprasellar origin and generally growing in the extra-arachnoidal space contained by the diaphragma sellae. They have been considered ideal for surgical removal through the transsphenoidal approach since the 1960s. The authors present a multicentric national study, intending to selectively analyze IC behavior and the impact of the transsphenoidal endoscopic endonasal approach (EEA) on surgical outcomes.

Craniopharyngiomas that were intraoperatively recognized as infradiaphragmatic and removed with standard EEA between 2000 and 2021 at 6 Italian neurosurgical departments were included in the study. Clinical, radiological, and surgical findings and outcomes were evaluated and reviewed.

In total, 84 patients were included, with 45.23% identified as pediatric cases and 39.28% as having recurrent tumors. The most common presenting symptoms were endocrine (75%), visual (59.52%), and hypothalamic (26.19%) disorders. ICs were classified as extending below (6 intrasellar and 41 occupying the suprasellar cistern) or above (26 obliterating the anterior recesses of the third ventricle and 11 extending up to the foramina of Monro) the chiasmatic cistern. Gross-total resection (GTR) was achieved in 54 cases (64.28%). Tumor extension above the chiasmatic cistern and calcifications were associated with lower likelihood of GTR. The cumulative rate of postoperative complications was 34.53%, with CSF leak being the most common (14.28%). Endocrine, visual, and hypothalamic functions deteriorated postoperatively in 41/78 patients (52.56%), 5/84 (5.95%), and 14/84 (16.67%), respectively. Twenty-eight patients (33.33%) had recurrence during follow-up (mean 63.51 months), with a mean 5-year progression-free survival (PFS) rate of 58%. PFS was greater in patients who achieved GTR than patients with other extent of resection.

This is the largest series in the literature to describe ICs removed with standard EEA, without the need for additional bone and dural opening over the planum sphenoidale. EEA provides a direct route to ICs, the opportunity to manage lesions extending up to the third ventricle without breaching the diaphragma, and high rates of GTR and satisfactory clinical outcomes. Increased surgical complexity and morbidity should be expected in patients with extensive suprasellar extension and involvement of the surrounding vital neurovascular structures.