Revisiting the normal perfusion pressure breakthrough phenomenon in the era of endovascular treatment of cerebral arteriovenous malformations.

Post-operative cerebral edema and hemorrhage are common after resection of cerebral arteriovenous malformations. This has traditionally been attributed to normal perfusion pressure breakthrough, a phenomenon of pathologic vasoreactivity in the surrounding brain caused by chronic oligemia from the nearby shunt. As endovascular techniques for arteriovenous malformation treatment have advanced, more arteriovenous malformations are being treated without open surgery, even to the point of cure. Here we revisit the concept of normal perfusion pressure breakthrough as applied to the hemodynamic changes after arteriovenous malformation embolization, which we propose is responsible for the persistent rate of hemorrhagic complications seen after these procedures.