The role of extra and intracranial bypass in the treatment of complex aneurysms.
The availability of Flow Diverters and new endovascular techniques has greatly reduced the need and indications for bypass surgery. Nevertheless, there are situations where a bypass is the best option for a complex cerebrovascular problem. Generally typical indications are giant aneurysms with a wide neck and / or partially calcified aneurysms with main branches or perforating arteries arising directly from the sac or from the neck itself, or fusiform aneurysms, partially calcified aneurysms. In this chapter we discuss the following issues as they apply to the modern use of bypass techniques. In case of fusiform aneurysms involving the proximal bifurcations of the media or the internal carotid artery combined and coordinated evaluations and efforts by a Team which includes neurosurgeons and endovascular specialists is essential. Treatment with bypass alone may not be sufficient and the combination of one or more bypasses with an endovascular treatment of occlusion, partial aneurysm embolization or flow diversion may be the best strategy. Addressing complex and fusiform aneurysm surgery requires a problem solving attitude and in this lies both the challenging and the fun side of this surgery.