Introduction: Cerebral hyperperfusion syndrome (CHS) is a substantial complication of carotid endarterectomy (CEA). We sought to determine whether quantitative hemodynamic assessment can stratify CHS risk and guide the need for intervention.
Methods: In this prospective study, patients with ICA-stenosis were randomly selected for quantitative phase contrast MR Angiography (PC-MRA) before and after carotid endarterectomy. Assessment was standardized by a protocol including duplex sonography, CTA, PC-MRA of intra- and extracranial supplying arteries of the brain. Physiological and clinical parameters were documented. Blood pressure and end-tidal partial pressure of carbon dioxide (EtCO2) during PC-MRA studies were registered.
Results: Between November 2011 and July 2013, 25 out of 127 patients that underwent CEA for ICA stenosis were selected for PC-MRA. Data showed a significant post-operative increase of blood flow in the operated internal carotid artery (ICA) by 175 ± 31 ml/min (p<0.0001) and the middle cerebral artery (MCA) by 37 ± 13 ml/min (p=0.01). Four patients suffered from clinically manifest CHS. Postoperative ICA and MCA flow was significantly higher in those patients compared to patients without CHS (413 ± 198 ml/min; p<0.0002 and 133± 90 ml/min; p=0.0012, respectively), and ICA blood flow was more than double preoperative values.
Conclusions: Carotid endarterectomy increases blood flow in the operated ICA significantly, by 175 ml/min on average, as measured by quantitative MR flow technique. No clinical risk factor for CHS after CEA could be identified. An increase in blood flow of more than 413 ml/ min measured by PC-MRA in the ICA might indicate a risk for CHS and these patients may warrant closer monitoring in the perioperative setting.
Patient Care: Quantitative hemodynamic assessment may stratify CHS risk and these patients may warrant closer monitoring in the perioperative setting.
Learning Objectives: By the conclusion of this session, participants should be aware of the potential role for PC-MRA in the assessment of CHS.