Cadaveric and clinical study of endoscope-assisted microneurosurgery for cerebral aneurysms using angle-type rigid endoscope.

Highly advanced optical equipment enables endoscopic surgery to be performed in neurosurgery. We developed an angle-type rigid endoscope having an angled shaft, and has performed endoscope-assisted surgery in neck clipping of 50 cerebral aneurysms. Anatomical study concerning the perforating branch was made through a pterional approach using 3 cadavers. By using endoscope, we can observe the posterior communicating artery and anterior choroidal artery behind the internal carotid artery without retract the internal carotid artery and the surrounding structures. Furthermore IIIrd~VIIIth cranial nerve in opposite side and basilar artery in the posterior fossa can be observed. As the clinical study, we used endoscope in 50 clipping of cerebral aneurysms (29 Internal carotid artery aneurysms, 6 anterior communicating artery aneurysms, 2 anterior cerebral artery aneurysms, 7 middle cerebral artery aneurysms, 5 vertebral artery-posterior inferior cerebellar artery aneurysm, and basilar bifurcation aneurysms). The endoscopic image showed in incomplete clipping in 2 cases, where additional clipping was then performed. In all subject, complete clipping was performed using both microscopic and endoscopic view. Use of the angle-type rigid endoscope together with Doppler ultrasound, should increase the feasibility of complete clipping procedure, resulting in reduced complication rate.