Hemodynamic Outcome of Successful Bypass Surgery in Patients with

Purpose: The aim of the study was to evaluate the hemodynamic changes after successful bypass surgery in patients with atherosclerotic stenosis in ICA using 99mTc-ECD SPECT. Materials and Methods: Fourteen patients (M:F=8:6, mean age; 60±9 years) who underwent STA-MCA anastomosis for unilateral atherosclerotic cerebrovascular disease were enrolled. 99mTc-ECD basal/acetazolamide perfusion SPECT studies were performed before, 10 days and 6 months after bypass surgery. Perfusion reserve was defined as the % changes after acetazolamide over rest image. Regional cerebral blood flow and perfusion reserve were compared preoperative, early-postoperative and late-postoperative scans. Results: The mean resting perfusion and decrease in perfusion reserve in affected ICA territory on preoperative scan was 52.4±3.5 and-7.9±4.7%, respectively. The resting perfusion was significantly improved after surgery on early-postoperative scan (mean 53.7±2.7) and late-postoperative scan (mean 53.3±2.5) compared with preoperative images (p<0.05, respectively). Resting perfusion did not showed further improvement on late-postoperative scan compared with early-postoperative scan. The perfusion reserve was-3.7±2.6 % on early-postoperative scan, and-1.6±2.3 % on late-postoperative scan, which was significantly improved after surgery. Additionally, further improvement of perfusion reserved as observed o