Planum-Clival Angle Classification: A Novel Preoperative Evaluation for Sellar/Parasellar Surgery

Objective Endonasal approaches are increasingly used to treat sellar pathologies, leading to increased interest in achieving maximal safe resection. We propose a tool-the planum-clival angle (PCA)-and explore its surgical implications for sellar pathology resections. Design Retrospective analysis. Participants Consecutive patients with pituitary lesions between 2003 and 2013. Outcome Measures The PCA and suprasellar extension ratios; head position and extent of surgical resection. Results We enrolled 89 patients (ages 21-88 years). There were 15 type A patients (17%), 13 with suprasellar extension (89%) and ratios between 0.12 and 0.70. There were 61 type B patients (70%), 49 with suprasellar extension (81%) and ratios from 0.09 to 0.66. Finally, there were 13 type C patients (13%), 10 with suprasellar extension (73%) and ratios from 0.21 to 0.76. Type B was treated with a sphenoidectomy and neutral head positioning, type A with 10 to 20 degrees of flexion and an additional posterior ethmoidectomy with or without posterior planum resection, and type C with 10 to 20 degrees of extension and an additional superior clival resection. Conclusions Sellar anatomy and PCA influence the growth patterns of sellar lesions. Thus PCA should allow for better surgical planning and thereby improve surgical efficacy.