Introduction: Endonasal approaches are increasingly popular for management of sellar pathologies, leading to greater interest in achieving maximal safe resection. We propose classifying the planum-clival angle into 3 types, with their surgical implications.
Methods: Ethical approval was obtained. Our analysis included all consecutive patients with sellar/suprasellar lesions requiring first-time endonasal transsphenoidal surgery between 2003 - 2013. The planum-clival angle (PCA) was obtained by measuring the mid-sagittal CT scan angle between the planum and the posterior clival base. PCA was then classified. Type A (“horizontal sella”) = 121°. Type B (“normal sella”) = 105 to 120°. Type C (“vertical sella”) = 104 degrees. Suprasellar extension ratio was measured. All data were analyzed using SAS version 9.1 and Excel 2007.
Results: 114 consecutive patients were enrolled, 54 male (47%), 60 female (53%). Age ranged from 16 - 88 years. Most common diagnosis was pituitary adenoma (89 patients (78%)). Remaining diagnoses were craniopharyngiomas, meningiomas, etc. There were 32 type A patients (28%). 26 type A had suprasellar extension (81%), with ratio from 0.12 - 0.82. There were 74 type B patients (65%). 60 type B had suprasellar extension (81%), with ratio from 0.09 - 0.76. There were 8 type C patients (7%). 7 type C had suprasellar extension (88%), with ratio from 0.21 - 0.60.
Conclusions: Type B PCA only requires a standard sphenoidectomy, and neutral head positioning. Type A PCA requires an additional posterior ethmoidectomy, +/- posterior planum resection, with 10-20 degrees of flexion. Type C requires an additional superior clival resection, with 10-20 degrees of extension to facilitate exposure.
Patient Care: It will help surgeons to better plan their transsphenoidal surgeries. This should translate in better positioning of the patient, better exposure of the sellar/parasellar lesion for safer maximal resection, shorter duration of surgery.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) understand the sellar anatomy and its relationship with the skullbase, 2) recognize the most common sellar/parasellar pathologies