OBJECTIVES AND IMPORTANCE: Although controversial, revascularization of the distal posterior cerebral artery (PCA) may become necessary in treating complex PCA aneurysms before proximal parent vessel sacrifice. The revascularization of the distal PCA territories of two patients with peripheral PCA aneurysms is presented.
Clinical presentations: One patient had an aneurysm of the P2-P3 segment and failed a selective P2 balloon occlusion test by developing homonymous hemianopia before planned parent vessel sacrifice. The other patient with a giant P2 segment aneurysm presented with visual field deficits.
Technique: The distal segment of PCA was revascularized before the aneurysms were trapped by surgical clipping or coil occlusion of the distal P2 segment, proximal to the aneurysms. In both cases, the occipital artery was used as the "donor" vessel. Temporary occlusion times were 22 and 20 minutes, respectively. Both grafts were patent on postoperative angiography, and both patients had full visual fields at the time of their follow-up examinations.
Conclusion: De novo distal P2 sacrifice, advocated for treating peripheral PCA aneurysms, leads to visual field deficits in some patients. Revascularization of the distal segment of the PCA, less technically demanding than bypass to other PCA segments, preserves blood flow, thus sparing vision in this subset of patients.