Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms

The vicinity of carotid-ophthalmic aneurysms to the roof of the cavernous sinus, to the anterior clinoid process, and to the optic nerve or the optic chiasm requires well-defined surgical techniques. Although microsurgical techniques with ipsilateral direct approaches to these aneurysms have been described in detail, studies about contralateral strategies for the microsurgical treatment of carotid-ophthalmic aneurysms are rare and are mainly confined to case reports. The aim of this study is to describe how to decide on the ipsilateral and contralateral microsurgical approaches to such aneurysms and to demonstrate the surgical techniques for the ipsilateral and contralateral exposure of carotid-ophthalmic aneurysms.

In a series of 51 patients with 58 aneurysms of the ophthalmic segment of the internal carotid artery, nine patients with 10 aneurysms (4 large aneurysms, 6 small aneurysms) were treated via a contralateral microsurgical approach after careful preoperative planning. Preoperative planning was based on the analysis of clinical and radiographic data, including cranial computed tomography, magnetic resonance imaging, magnetic resonance angiography, and conventional cerebral angiography.

The postoperative results were good in 38 (75%) of the patients, fair in 2 (4%), and poor in 3 (6%); 8 (15%) of the patients died after surgery. The postoperative follow-up was 4 months to 10 years. Postoperatively, 15 of 19 patients with uni- or bilateral visual deficits or visual field defects improved, 3 of the 19 patients experienced postoperative impairment of visual function, and 1 of the 19 patients had an unchanged visual field deficit. Visual impairment or unchanged visual function was observed in patients who underwent ipsilateral approaches, which was possibly caused by inappropriate intraoperative retraction of the optic nerve or chiasm. In all patients presenting with preoperative visual deficits who were treated via contralateral approaches, visual function improved in the postoperative course.

Giant carotid-ophthalmic aneurysms that are eligible for surgical treatment as well as small and large aneurysms dislocating the optic nerve or the chiasm superomedially or medially should be approached via ipsilateral craniotomies. It is recommended that small and large aneurysms of the carotid-ophthalmic segment originating medially, superomedially, or superiorly, displacing the optic nerve or the chiasm superiorly, superolaterally, or laterally, be approached via contralateral craniotomies.