Pulsed Doppler intraoperative flow assessment and midterm coronary graft patency.

BACKGROUND: This study was designed to assess the value of hemodynamic measurements taken intraoperatively in predicting midterm patency of coronary bypass grafts. METHODS: A pulsed Doppler flowmeter was routinely used during operation to determine the hemodynamic parameters of coronary bypass grafts. During a 7-year period, 85 patients underwent angiographic evaluation. As a result, a thorough hemodynamic assessment of 214 grafts (89 arterial and 125 venous) at initial operation was available for analysis. RESULTS: The overall patency rate was 88.3%. The mean flow measured intraoperatively in 168 intact grafts was 60+/-3 mL/min (range, 9 to 230 mL/min), and the resistance was 1.8+/-0.1 peripheral resistance units (range, 0.3 to 9.0 peripheral resistance units). The mean flow was 36+/-5 mL/min (range, 2 to 107 mL/min), and the resistance was 5.9+/-2.0 peripheral resistance units (range, 0.6 to 46.0 peripheral resistance units) in 25 grafts found occluded at angiographic evaluation. Multivariate analysis identified three independent variables associated with a reduced patency rate: increased resistance as measured in the graft (p = 0.012), increasing interval of control angiography (p = 0.006), and preoperative cardiogenic shock (p = 0.040). CONCLUSIONS: The prognosis for midterm patency of aortocoronary bypass grafts depends on the intraoperative hemodynamic status