A new technique of intracranial interarterial anastomosis between distal anterior cerebral arteries (ACA) for ACA occlusion and its indication (author's transl)

Abstract

The author developed a new technique of intracranial interarterial anastomosis between distal anterior cerebral arteries (ACA). In 1974, a case was encountered where clipping of the aneurysmal neck was difficult because the left A2 arose from the big dome of an anterior communicating artery (Aco) aneurysm. Before clipping of the aneurysmal neck, the left A2 was cut off and anastomosed to the right A2 as an end-to-side anastomosis. By this method, a new flow route to a left peripheral ACA territory was obtained via the right A2, just as in the case of “artificial azygos anterior cerebral artery”. Thereafter, this operative technique was modified to an easier procedure. In this report, the operative technique, its indication and its operative results are described in detail. Bifrontal craniotomy followed by the interhemispheric approach should be performed. The anastomotic techniques were theoretically divided into four types as follows; 1) A2 A, end-to-side or 2) side-to-side anastomosis at the origin of distal ACA. 3) A3-A3 end-to-side or 4) side-to-side anastomosis at the knee portion of ACA. Among them, A2-A2, anastomosis is relatively difficult with respect to in the suturing technique because the operating field is very narrow and deep. However, A3-A3 anastomosis is easy for microsuturing because the operating field is situated superficially. By A3-A3 end-to-side anastomosis, reflow will be obtained to the proximal and to the peripheral vessels from the anastomotic part. Inter-ACA anastomosis was applied to two cases with Aco-aneurysms and three cases with spontaneous occlusion of one sided ACA. In postoperative angiography, only I case with ACA occlusion, in which this technique was used 5 months after occlusion of a vessel, lacked patency. The operative indication is proposed as follows; 1) in cases with occlusion of one ACA—especially A1 occlusion combined with hypoplasia of the Aco or A2-A3 occlusion—, and 2) in cases with a big or giant Aco-aneurysm, which causes occlusion of an A1 or A2. By this new technique, it becomes relatively easy to operate on cases with a big or giant Aco-aneurysm, where the direct surgical approach has, until now, been considered as difficult.