Microsurgical management of large and giant paraclinoid aneurysms

Abstract 

Background

Because of the complex topographic anatomical relationship between vascular, dural and bone structures, paraclinoid aneurysms, especially those of larger size, remain a great challenge for vascular neurosurgeons. We present our microneurosurgical experience of 51 consecutive patients with large and giant paraclinoid aneurysms to scrutinize our personal strategies related to surgical treatment.

Methods

Fifty-one patients with large or giant paraclinoid underwent micorneurosurgical aneurysm treatment. Operative strategies were planned according to preoperative state-of-the-art imaging studies, and a pterional-transsylvian approach was routinely used. Proximal control of the internal carotid artery (ICA) was achieved by exposure of the cervical portion of the vessel. Intraoperative electroencephalogram and somatosensory evoked potential monitoring, indocyanine green (ICG) videoangiography and/or microvascular Doppler ultrasonography (MDU) were regularly used. A postoperative digital subtraction angiography or computed tomography angiography was performed to verify the efficacy of treatment.

Results

Forty-three large and giant paraclinoid aneurysm necks (84%) were directly clipped, seven unclippable aneurysms (14%) were trapped with extra-intracranial high-flow revascularization, and one aneurysm (2%) was treated with only ICA proximal Hunterian ligation. Two patients (4%) died in the early postoperative period. In 84% of the patients, the Glasgow Outcome Scale score was 4 or 5 at discharge. At the 6-month follow-up examination, the Rankin Outcome Scale score was 0-2 in 90% of patients.

Conclusions

Temporary parent vessel occlusion, retrograde suction decompression, endoaneurysmectomy, parent vessel clip reconstruction, and bypass vascular anastomosis are essential techniques to treat complex paraclinoid aneurysms. The combined use of electrophysiological monitoring, MDU, intraoperative ICG videoangiography, and endoscopy can substantially improve microsurgical outcome.

Abbreviations: ACP, Anterior Clinoid Process, BTO, Balloon Test Occlusion, CSF, Cerebrospinal Fluid, CT, Computed Tomography, CTA, Computed Tomography Angiography, DSA, Digital Subtraction Angiography, EEG, Electroencephalogram, ICA, Internal Carotid Artery, ICG, Indocyanine Green, MCA, Middle Cerebral Artery, MDU, Microvascular Doppler Ultrasonography, PComA, Posterior Communicating Artery, SSEP, Somatosensory Evoked Potential, STA-MCA, Superficial Temporal Artery to Middle Cerebral Artery

Keywords: Large aneurysm, Giant aneurysm, Paraclinoid aneurysm, Clipping, Bypass, Microsurgical management, Outcome