Therapeutic strategies for patients with internal carotid or middle cerebral artery occlusion complicated by severe coronary artery disease.

BACKGROUND/OBJECTIVES: Ischemic stroke is one of major complications of cardiac surgery. Although a current American Heart Association (AHA) guideline states that carotid endarterectomy is probably recommended before or concomitant to coronary artery bypass grafting (CABG) for the carotid stenosis, there is no report that analyzed optimal strategies in cardiac surgery for patients with total occlusion of the internal carotid artery (ICA) or the middle cerebral artery (MCA). Therefore, this preliminary study was aimed to clarify whether preoperative blood flow measurements and prophylactic superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis could reduce the incidence of perioperative ischemic stroke during cardiac surgery in patients with total occlusion of the ICA or MCA.

METHODS: This prospective study included eight patients who were admitted to undergo cardiac surgery including CABG. All of them had total ICA or MCA occlusion on preoperative magnetic resonance (MR) examinations. Preoperative cerebral blood flow and its reactivity to acetazolamide were quantitatively determined in all eight patients using single photon emission computed tomography or positron emission tomography.

RESULTS: Preoperative blood flow measurements revealed that two (25%) of eight patients had normal cerebral hemodynamics because of well-developed collaterals. They safely underwent cardiac surgery. However, a marked impairment of cerebral perfusion reserve was identified in six (75%) of eight patients in the ipsilateral hemispheres. Of these, four patients underwent prophylactic STA-MCA anastomosis prior to CABG. Subsequently, they safely underwent CABG without perioperative ischemic stroke.

CONCLUSION: This is the first report suggesting that preoperative identification of hemodynamic compromise and prophylactic STA-MCA anastomosis may reduce perioperative ischemic stroke during cardiac surgery in patients with ICA or MCA occlusion, although further studies are needed to assess the validity.