Preoperative transcranial and carotid Doppler study in coronary artery bypass graft patients

OBJECTIVE: To assess the correlation of postoperative neurologic complications with preoperative transcranial and carotid Doppler study findings of coronary artery bypass graft (CABG) patients.

METHODS: In a descriptive, analytic, follow up study we prospectively studied 201 patients undergoing elective and isolated CABG surgery during a 12 month period from October 2003 to September 2004 at Madani Hospital of Tabriz Medical Sciences University, Iran. Neurologic examination, intracranial cerebral arterial study using transcranial Doppler (TCD) and carotid duplex were performed preoperatively. Intraoperative and postoperative complications were followed up for one month.

RESULTS: Two hundred and one patients (158 male, 43 female) with a mean age of 57.29+/-9.67 were studied. Out of these, 131 patients had 3 coronary vessels disease, 64 had 2 vessels, 5 had one vessel, and one patient had diffuse coronary disease. A TCD was performed in 183 patients and disclosed abnormalities in 22 patients and was normal in 161 cases. The total number of involved arteries was 34. Among 154 carotid duplex studied patients, 102 had plaque, inducing <50% stenosis in 99, 50-74% stenosis in one, and 75-90% stenosis in 2 cases. Postoperative neurologic complication occurred as follows: 4 stroke, 7 delirium, and 3 amnesia. One of the operated patients died. Nine of 161 patients with normal TCD (5.6%) and 5 of 22 (22.7%) with intracranial cerebral arterial disease (ICAD) showed central nervous system (CNS) complications (p=0.015). There were significant correlations between number of involved cerebral arteries and post CABG CNS complications (p=0.0001), including stroke (p=0.007), and between diabetes mellitus history with these complications (p=0.012).

CONCLUSION: Our results suggest that lCAD is an independent risk factor for CNS complications after CABG surgery. Hence, we recommend pre-CABG evaluation of the cerebral arteries by TCD, for the risk assessment of CABG surgery.