Dependency on bypass circulation: a case study.

In a case of consecutive occlusion of both internal carotid arteries bilateral STA-MCA anastomoses were established. Since a series of angiographic examinations were undertaken, dynamics and probable efficacy of both natural and artificial collateral circulations could be followed up in a two-year period. Objectively in the evaluation of anastomoses was enhanced by direct percutaneous STA-angiography (STAG), in order to delineate the vascular territory irrigated exclusively by the anastomosis. By demonstrating exactly the functional capacity of anastomoses in correlation with the clinical course, dependency on bypass circulation could be assessed.