Extent of anterior clinoidectomy for clipping of carotid-ophthalmic aneurysms predicted on three-dimensional computerised tomography angiography

Abstract

Aim of study. We aimed to verify the value of computerised tomography angiography (CTA) on predicting the extent of anterior clinoidectomy that is optimal for particular carotid-ophthalmic aneurysms (COAs).Clinical rationale for study. The anterior clinoid process (ACP) often impedes the complex microsurgery of COA. Complete removal of the ACP ensures safe clipping; however, it also may increase the risk of severe complications. The probability of performing a successful partial anterior clinoidectomy could be evaluated by preoperative CTA.Materials and methods. 28 patients with either a ruptured (n=4) or unruptured COA were included in this prospective, single--centre, observational study. One aneurysm was giant, two were large, and the rest were smaller. Successful aneurysm clipping was the aim in all cases. The anterior clinoidectomy was preoperatively planned on multiplanar three-dimensional reconstructions of CTA images (3D-CTA) which resembled the typical view of a frontotemporal craniotomy. Finally, the predicted clinoidectomy was compared to the extent of the actual clinoidectomy.Results. 21 aneurysms (75%) projected superolateral or superior. The ACP was completely and selectively resected in 25% (7 of 28) and 67.9% of patients (19 of 28) respectively. Optic nerve (ON) unroofing was always performed in the case of total anterior clinoidectomy, but accompanied only 8 of 19 selective clinoidectomies (p = 0.03). The extent of the actual clinoidectomy was predicted by the 3D-CTA-based preoperative planning in 17 of 27 cases (63.0%). Particularly, prediction of the osteotomy was correct in 85.7% of complete, 62.5% of selective lateral, and 57.1% of medial clinoidectomy. None of the radiological and clinical factors determined the correlation between the planned and the actual extent of ACP removal. There was one incomplete occlusion among 23 obtained follow-up CTAs. Conclusions.The predictive value of 3D-CTA on the extent of anterior clinoidectomy still remains unsatisfactory; it is limited by the individual variability of COA and its surrounding structures.Clinical implications: Currently, the role of 3D-CTA planning is restricted to educational purposes only.

Microsurgical strategies for small unruptured dorsal internal carotid artery aneurysms

“…This anatomical relationship significantly aided in deciding whether to remove the ACP in the surgical field. In some cases, 3D CTA with bone image enabled us to predict that aneurysm clipping could be performed without ACP removal and falciform ligament cutting [ 17 ]. If imaging showed that the aneurysm was located distal to the ACP, the aneurysm could likely be clipped without ACP removal.…”

How I do it: microsurgical clipping of carotid-ophthalmic aneurysms through minipterional approach with extradural resection of the anterior clinoid process

“…Using the combination of minipterional approach (keyhole approach) with extradural resection of the anterior clinoid process (ACP) -an element of skull base surgery -we can significantly expand the range of indications for this approach. The main indications are: paraclinoid aneurysms of the internal carotid artery in patients having contraindications for endovascular treatment; small lesions of the sella turcica, the area of the sphenoid bone wings, and the anterior clinoid process; optic nerve gliomas; pathologies requiring decompression of the optic canal [7][8][9][10].…”

Artificial Intelligence Segmentation Model-Based Computed Tomography Angiography Image in the Diagnosis of Congenital Aortic Constriction

“…Depending on the location and degree of stenosis, the symptoms of CAC may manifest as hypertension, lower extremity arterial ischemia, heart failure, intracranial aneurysm rupture, etc. [2,3]. e cause of aortic constriction is not yet fully understood.…”