Topographic Anatomy and Pneumatization of the Posterior Clinoid Process in Chiari Type I Malformation

• Published in: World neurosurgery Vol. 185; pp. e767 - e773
• Main Authors: Alpergin, Baran Can, Eroglu, Umit, Zaimoglu, Murat, Kılınç, Mustafa Cemil, Özpişkin, Ömer Mert, Erdin, Engin, Beger, Orhan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2024
• Subjects: Adolescent; Adult; Arnold-Chiari Malformation - diagnostic imaging; Chiari type I malformation; Dorsum sellae; Female; Foramen Magnum - anatomy & histology; Foramen Magnum - diagnostic imaging; Humans; Male; Middle Aged; Posterior clinoid process; Posterior clinoidectomy; Sella turcica; Skull Base - anatomy & histology; Skull Base - diagnostic imaging; Sphenoid Bone - anatomy & histology; Sphenoid Bone - diagnostic imaging; Tomography, X-Ray Computed; Young Adult; Posterior clinoid process; Posterior clinoidectomy; Dorsum sellae; MRI; CIM; Dis-PCP-ACP; Chiari type I malformation; ACP; Dis-PCP-SOF; Sella turcica; CT; Dis-PCP-FO; CIIM; Dis-PCP-FR; Dis-PCP-FM; PCP; Dis-PCP-CG
• ISSN: 1878-8750; 1878-8769; 1878-8769
• DOI: 10.1016/j.wneu.2024.02.130

This study aimed to examine pneumatization and topographic location of the posterior clinoid process (PCP) in Chiari type I malformation (CIM) for skull base approaches. Computed tomography images of 52 (23 males/29 females) CIM subjects aged 23.87 ± 16.09 years and 71 (26 males/45 females) healthy subjects aged 42.48 ± 21.48 years constituted the study universe. The distances of PCP to the foramen magnum (P = 0.037), superior orbital fissure (P < 0.001), foramen rotundum (P < 0.001), and foramen ovale (P < 0.001) were smaller, but the distance of PCP to the crista galli (P = 0.038) was greater in CIM patients, compared with normal subjects. In CIM, the fusion between PCP and the anterior clinoid process was observed in 9 sides (8.70%), while in controls it was observed in 12 sides (8.50%). PCP pneumatization was observed in 40 sides (38.50%) in CIM patients, while it was observed in 28 sides (19.70%) in normal subjects. These data displayed that PCP pneumatization was affected by CIM (P < 0.001). The distances of PCP to the crista galli and foramen magnum indicate the anterior fossa length and the posterior fossa depth, respectively; thus CIM patients have a longer anterior fossa and a shallow posterior fossa. In addition, the distances of PCP to the superior orbital fissure, foramen rotundum, and foramen ovale indicate the middle fossa width; hence CIM patients have less middle fossa width than normal individuals. CIM patients have an approximately 50% higher PCP pneumatization rate, and this may increase the risk of complications such as cerebrospinal fluid fistula during the application of posterior clinoidectomy.