Brain edema after carotid revascularization: benign syndrome or prelude to hemorrhage?

Brain edema (BE) post carotid revascularization (CR) is considered a benign presentation of the hyperperfusion syndrome. Its physiopathology has been related to production of vasogenic edema that tends to progressive spontaneous resolution. Its relation with post-CR hemorrhage remains unclear. Three cases of BE post-CR are described and compared to controls. Clinical evolution, medical management, and plain-CT and perfusion-CT (PCT) results are analysed. Two cases of BE had a benign course, with a progressive resolution of edema and disappearance of neurologic deficits. Effective blood pressure control was achieved in these patients. The third case suffered massive hemorrhage 24h after initial BE and died. This patient reached peak systolic levels of 220 mmHg before conversion to hemorrhage. Plain-CT and PCT findings were similar in the three patients with BE. CT showed signs of hemispheric brain swelling ipsilateral to CR. PCT showed low MTT and high CBF values on the hemisphere ipsilateral to CR compared to the contralateral hemisphere, with symmetric CBV values. Plain-CT and PCT in controls showed no abnormalities. BE post CR can be reversible but may also herald a hemorrhagic complication. A common physiopathology of post-CR BE and hemorrhage is suggested by PCT findings, related to failure of auto-regulation and secondary blood-brain-barrier dysfunction. Spontaneous resolution of BE post-CR should not be routinely expected in clinical practice. Conversion to hemorrhage might be related with deficient blood pressure control and secondary rupture of the already damaged vessel wall.