Hyperperfusion syndrome: toward a stricter definition.

OBJECTIVE: Hyperperfusion syndrome is a rare and potentially devastating complication of carotid endarterectomy or carotid artery angioplasty and stenting. With the advent of new imaging techniques, we reviewed our experience with this phenomenon. METHODS: This report is a retrospective review of 129 consecutive cases of carotid endarterectomy performed between June 1, 2000, and May 31, 2002, and 44 consecutive cases of carotid artery angioplasty and stenting performed between January 1, 1997, and May 31, 2002. We specifically searched for examples of patients who developed postprocedural nonthrombotic neurological deficits that typified the hyperperfusion syndrome. RESULTS: Seven cases of hyperperfusion syndrome occurred, four after endarterectomy (3.1% of carotid endarterectomy cases) and three after stenting (6.8% of stenting cases). The cases of hyperperfusion were classified as presenting with 1). acute focal edema (two cases with stroke-like presentation, attributable to edema immediately after revascularization), 2). acute hemorrhage (two cases of intracerebral hemorrhage immediately after stenting and one case immediately after endarterectomy), or 3). delayed classic presentation (two cases with seizures, focal motor weakness, and/or late intracerebral hemorrhage at least 24 hours after endarterectomy). CONCLUSION: Hyperperfusion syndrome may be more common and more variable in clinical presentation than previously appreciated.