Contralateral approaches to bilateral cerebral aneurysms: a microsurgical anatomical study

Abstract

In patients with bilateral supratentorial aneurysms, surgical clipping of all aneurysms via a unilateral approach would obviate the need for a second operation. The authors conducted a microsurgical study in human cadaver heads to examine the contralateral exposure for four common aneurysm sites in the anterior circulation: the ophthalmic artery (OA) origin, the posterior communicating artery (PCoA) origin, the internal carotid artery (ICA) termination, and the middle cerebral artery (MCA) bifurcation. Frontotemporal craniotomies were performed in 16 cadavers to evaluate the corridor for exposure of these sites from the contralateral side. Morphometric data, including lengths and diameters of major arterial segments and optic nerves, were documented for anatomical correlation. In this study, the contralateral OA origin was successfully exposed in 62% of specimens, the PCoA origin in 50%, the ICA bifurcation in 100%, and the MCA bifurcation in 62%. Exposure of the OA origin and, in some cases, the PCoA, required incision of the falciform ligament and mobilization of the contralateral optic nerve. Exposure of the MCA bifurcation was dependent on the length of the M1 segment, with successful exposure only when this segment was shorter than 14 mm. Implications for the contralateral approach to aneurysms at these sites are discussed and the microsurgical corridors for exposure are described. For correlation with the anatomical study, a brief clinical review of patients with bilateral supratentorial aneurysms treated at The Johns Hopkins Hospital between 1992 and 1995 is presented. Guidelines for the contralateral approach to aneurysms are discussed with reference to the anatomical study and the clinical review.

Fully Endoscope-Controlled Clipping Bilateral Middle Cerebral Artery Aneurysm Via Unilateral Supraorbital Keyhole Approach

“…The contralateral approach can be considered as a useful procedure to clip bMCA aneurysms; its use is not widely spread because of technical difficulty, the long dissecting distance, limiting view, and impaired the brain tissue. Oshiro et al 14 previously described the contralateral exposure for the most common sites of anterior circulation aneurysms. Several authors have reported clipping of bilateral aneurysms via unilateral craniotomy successfully in case series and clinical reports.…”

“…1–3 Surgical management of bMCA aneurysms is still controversial and considered a challenge procedure for neurosurgeons, although clipping all aneurysms in a single-stage operation is more preferred 2,4–6,7,8 to eliminate bleeding from unruptured aneurysm in perioperative period. 6,9,10,11 Despite the fact that unilateral management of bMCA aneurysms has been addressed in a few publications, 4,12–14 only one publication describes microscopy-assisted clipping of bMCA aneurysms via a unilateral supraorbital keyhole approach. 13 To our knowledge, there is no study in surgical management of patients with bMCA aneurysms by fully endoscope-controlled techniques.…”

Contralateral approach to a carotid bifurcation aneurysm in a case of multiple intracranial aneurysms: a case report

“…Previous studies have addressed the contralateral approach to the anterior circulation aneurysms, yet clarification of the very guidelines regarding microsurgical techniques and neuroanesthetic aspects is still evolving [2-4]. The present case is an example of contralateral pterional craniotomy used to clip an ICA bifurcation saccular aneurysm.…”

“…Successful management of such a malady via a single craniotomy, would be fruitful regarding the morbidity and mortality [1,2]. …”

Contralateral Approach to Paraclinoid Aneurysms: Angiographic Analysis and Surgical Results of 12 Patients

“…Since then, although some groups have reported their experience with clipping contralateral aneurysms, only a limited number of case reports are available. 2,[6][7][8][9][10][11][12] We emphasize the usefulness and advantages of the contralateral pterional approach for particular types of paraclinoid aneurysm.…”