Intraoperative angiography during coronary artery bypass grafting.

INTRODUCTION: The aim of this study was to evaluate the incidence rate of technical failure of graft patency while performing intra-operative angiography after coronary artery bypass grafting. METHODS: This prospective pilot study included 50 patients with multi-vessel coronary artery disease who underwent coronary artery bypass grafting, in addition to intra-operative angiographic graft assessments, on open-chest. Overall, 144 grafts and 160 distal anastomoses were assessed in a hybrid operating room. RESULTS: Intra-operative angiography allowed the identification of 23 angiographic defects (15.9% of all grafts) in 22 patients (44%): three graft defects (2% of all grafts), 17 anastomotic defects (10.6% of all distal anastomoses), and three target artery errors (1.8% of all grafted arteries). Ten re-interventions (43.4%) were performed based on the angiographic defects detected. During the follow-up period, computed tomography angiography of the attached grafts at a mean of 224 days (range, 80-318 days) showed that all repaired grafts were patent. During surgery, the total mean dose of radiation was 1.848 ± 0.54 mSv (range, 0.78-3.4 mSv) per patient and investigation time was 19.4 ± 4.94 minute (range, 9-31 minute). CONCLUSIONS: Intra-operative angiography is a powerful tool allowing the identification of graft defects, anastomotic defects and target vessel errors. Assuming relatively low level of exposure to radiation and short investigation time, intra-operative angiography could be included in routine practice as safe procedure improving surgery quality.

Correlation between Preoperative Coronary Artery Stenosis Severity Measured by Instantaneous Wave-Free Ratio and Intraoperative Transit Time Flow Measurement of Attached Grafts.

Background and Objectives: To assess the correlation between the degree of target coronary artery stenosis measured by instantaneous wave-free ratio (iFR) and the intraoperative transit time flow measurement (TTFM) of attached grafts as well as evaluate flow competition between the native coronary artery and the attached graft according to the severity of stenosis. Materials and Methods: In total, 89 grafts were subjected to intraoperative transit time flow measurement after coronary artery bypass grafting (CABG) in 25 patients with multivessel coronary artery disease (CAD). The iFR was evaluated for all coronary arteries with grafts. The coronary artery stenoses were divided into three groups based on the iFR value: iFR < 0.86 (group 1); iFR 0.86-0.90 (group 2); and iFR > 0.90 (group 3). Results: The mean graft flow (MGF) was 46.9 ± 18.4 mL/min for group 1, 45.3 ± 20.9 mL/min for group 2, and 31.3 ± 18.5 mL/min for group 3. A statistically significant difference was confirmed between groups 1 and 3 (p = 0.002) and between groups 2 and 3 (p = 0.025). The pulsatility index (PI) was 2.49 ± 1.20 for group 1, 2.66 ± 2.13 for group 2, and 4.70 ± 3.66 for group 3. A statistically significant difference was found between groups 1 and 3 (p = 0.006) and between groups 2 and 3 (p = 0.032). Backward flow was detected in 7.5% of grafts for group 1, in 16.6% of grafts for group 2, and in 16% of grafts for group 3. A statistically significant difference was found between groups 1 and 2 (p = 0.025) and between groups 1 and 3 (p = 0.029). Conclusions: The iFR is a useful tool for predicting the impact of competitive flow observed between a native artery and an attached graft. The effect of competitive flow significantly increases when the graft is attached to a vessel with mild coronary stenosis. In a coronary artery where the iFR was not hemodynamically significant, the MGF was lower, the PI was higher, and a larger proportion of grafts with backward flow (BF) was detected compared to when there was significant stenosis (iFR < 0.86).