Evaluation of Anterior and Posterior Clinoid Process Pneumatization with Sphenoid Sinus Types

Abstract

INTRODUCTION: Anterior clinoid process (ACP) and posterior clinoid process (PCP) are usually excised for access to lesions in the surgery of sellar and parasellar tumors or aneurysms. Anatomical variations of these structures should be well known for a safe clinoidectomy. This study aimed to investigate the variations in pneumatization of ACP, PCP, and the sphenoid sinus. METHODS: The study was conducted by evaluating the images acquired by axial, coronal, and sagittal plane reconstructions of cranial computed tomography (CT) of 500 (245 female and 255 male) patients aged 15-93 years. Evaluating ACP, PCP, and sphenoid sinus pneumatization and pneumatization patterns, the concurrent occurrence of these variations was examined. RESULTS: ACP pneumatization was identified in 24% of the patients, with 8.8% being on the right, 6.4% on the left, and 8.8% bilaterally. PCP pneumatization was observed in 7% of the patients, with 2.2% being on the right, 2.2% on the left, and 2.6% bilaterally. The prevalence of concurrent CP and PCP pneumatization was 5.8%. ACP and PCP pneumatization was most frequently noted in patients with postsellar sphenoid sinus pneumatization, with rates of 19.2% and 6.6%, respectively. DISCUSSION AND CONCLUSION: The knowledge of variations in pneumatization of ACP, PCP and sphenoid sinus prevents neurovascular injuries that may occur during clinoidectomy and the formation of post-clinoidectomy cerebrospinal fluid (CSF) fistulas. These structures should be evaluated with preoperative cranial CT. Clinoidectomy should be avoided in order to prevent the formation of CSF fistulas, especially in cases of type 3 ACP and PCP pneumatization.

Keywords

• anterior clinoid process
• posterior clinoid process
• sphenoid
• pneumatization