Angioscopy-assisted aneurysm clipping

OBJECTIVE: To test the concept that endovascular angioscopy can assist surg ical intracranial aneurysm clipping by providing an endoluminal view of the aneurysm-parent vessel complex. METHODS: A carotid bifurcation aneurysm was surgically created in a dog at the lingual artery origin. A balloon catheter was inflated proximal to the aneurysm to block proximal blood flow and allow endoluminal visualization. A flexible angioscope connected to a video monitoring system and to a high- intensity light source was then advanced within the catheter lumen and posi tioned immediately distal to the catheter tip. The aneurysm neck was clippe d, and the clip was repositioned several times along the neck, with or with out distal parent vessel compromise. Each time, the endovascular image on t he monitor was interpreted by an observer blinded to the position of the cl ip. Clip position and image interpretation were communicated independently to a third person, who analyzed the correlation between them. RESULTS: Angioscopy allowed clear visualization of the extent of aneurysm n eck occlusion (complete, incomplete, residual "dog ear") after clip applica tion, as well as the presence or absence of distal parent vessel compromise . Aneurysm neck configuration, size, presence of thrombus, and suture line definition were depicted. Critical structures external to the aneurysm-pare nt vessel complex were transilluminated by the high-intensity lamp. CONCLUSION: Although acknowledged as the treatment of choice for intracrani al aneurysms, surgical exclusion can be accompanied by significant morbidit y related to perforator occlusion, parent artery compromise, and/or persist ent residual aneurysm. The availability of a device allowing visualization of an aneurysm from an endoluminal perspective theoretically could reduce t he incidence of these complications. Angioscopy has the potential to become a useful adjunct during intracranial aneurysm clipping because it provides real-time endoluminal viewing of the aneurysm-distal parent vessel complex , which is sometimes obscured to the surgeon.