Coronary Artery Bypass Surgery for Patients with Severe Cerebrovascular Atherosclerosis: Importance of Preoperative Assessment and Perioperative Management

Objective: Cerebrovascular atherosclerosis is known to play a crucial role in perioperative stroke in coronary arterial bypass grafting (CABG). This study is to identify the degree of severity of cerebrovascular lesions for which patients can still undergo CABG with an acceptably low risk in current techniques. Methods: Cerebrovascular atherosclerosis was evaluated and graded for 200 consecutive patients prior to CABG. Grading was initially based on the level of stenosis in carotid, vertebral, and cerebral arteries: grade-0: normal or mild stenosis in cerebral arteries or stenosis <50% in other arteries; grade-1: moderate in cerebral arteries or 50% 69% in others; grade-2: severe in cerebral arteries or 70% 89% in others; grade-3: occlusion in cerebral arteries or 90% 100% in others. The grading was finally adjusted to a risk of regional ischemia by considering symptoms, number of lesions, and brain perfusion in scintigram. Therefore, some patients were up-graded. Off-pump CABG was scheduled for all patients. The lowest systolic arterial pressure during surgery was differently controlled in each grade: grade-0: ≥70 mmHg; grade-1: ≥80 mmHg; grade-2: ≥80 mmHg with intra-aortic balloon pump (IABP); grade-3: ≥90 mmHg with IABP; grade-4: ≥90 mmHg with IABP and administration of thyamiral. Results: Grade-1 and -2 included 38 and 29 patients respectively. Grade-3 initially included 36 patients and 14 of them were up-graded to grade-4 (extremely high risk patients). Stroke was seen in one patient (0.5%), for whom mild speaking disturbance occurred on the fifth day from CABG. Conclusion: Patients with severe cerebrovascular atherosclerosis can undergo CABG with a low risk of stroke. Intraoperative management of blood pressure may be critical for stroke prevention in CABG.