The pneumatisation of anterior clinoid process is not associated with any predictors that might be recognised preoperatively

Abstract

The anterior clinoid process (ACP) is usually removed during surgeries of proximalinternal carotid artery (ICA) aneurysms. However, some ACPs presentwith air cells originating from the sphenoid or/and ethmoid sinus. In surgeriescontaining a clinoidectomy of a pneumatised process, up to 40% of patients experience cerebrospinal fluid (CSF) rhinorrhoea. The aim of this study wasto explore the potential predictors of pneumatisation of the ACP, as well asto compare the occurrence of CSF rhinorrhoea between total and partialanterior clinoidectomies. This study comprised 2 different groups, with 2 differentanalyses. Firstly, the pneumatisation of the ACP was evaluated in 496 ACPs and was based on 248 computer tomography exams (CT). The c2 testand ROC curve comparisons were utilised in conjunction, to explore possiblepredictors of air cell accumulation in the ACP. The overall pneumatisation ratewas 9.7%, unilateral and bilateral aerial ACP was found in 4.4% and 2.6% of all patients respectively, while at least one pneumatised ACP was found in 14.1% of examined patients. The route of pneumatisation was establishedin 87.5% of cases. The side of the ACP, gender, and patient age were notsignificantly associated with both pneumatisation of ACP or route of pneumatisation.Secondly, a clinical group of 23 patients after operative securingof an ICA aneurysm were retrospectively assessed with regards to the extentof anterior clinoidectomy and the occurrence of CSF rhinorrhoea. A total of23 ACPs were removed, 17 ACPs were totally resected, and 6 underwent partialresection. CSF rhinorrhoea was not noted in any patients, thus the comparison between clinical groups was not valid. Moreover, we described a novelmethod of partial removal of the lateral aspect of ACP, which was applied in6 patients treated for an ICA — ophthalmic artery junction aneurysm.