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Coronary bypass flow during use of intraaortic balloon pumping and left ventricular assist device
T Tedoriya1, M Kawasuji, N Sakakibara
1Department of Surgery (1), Kanazawa University School of Medicine, Japan.
Insights
Left ventricular assistance with intra-aortic balloon pumping (IABP) and left ventricular assist device (LVAD) significantly increases diastolic blood flow in coronary artery bypass grafts. Ascending aorta-coronary bypass grafts (ACB) show the greatest improvement, highlighting graft-specific hemodynamic responses.
Area of Science:
- Cardiovascular Surgery
- Medical Devices
- Hemodynamics
Background:
- Left ventricular support is crucial after coronary bypass grafting for severe coronary artery disease.
- Intra-aortic balloon pumping (IABP) and left ventricular assist devices (LVAD) are key interventions for low cardiac output.
- Coronary artery bypass grafts exhibit distinct hemodynamic properties affecting blood flow.
Purpose of the Study:
- To investigate the hemodynamic effects of IABP and LVAD on blood flow through different types of coronary artery bypass grafts.
- To compare the efficacy of ventricular assistance across various graft configurations.
Main Methods:
- A canine model was used to anastomose ascending aorta-coronary bypass graft (ACB), internal thoracic artery, and descending aorta-coronary bypass graft to the left anterior descending coronary artery.
- Blood flow through these three graft types to the same coronary bed was evaluated with and without ventricular assistance (IABP and LVAD).
Main Results:
- Diastolic flow, unlike systolic flow, varied among grafts, decreasing in the order: ACB, internal thoracic artery, descending aorta-coronary bypass graft.
- Both IABP and LVAD significantly increased diastolic blood flow compared to control.
- LVAD demonstrated a greater increase in diastolic flow than IABP.
- The ACB graft showed a significantly greater increase in diastolic flow with ventricular assistance compared to arterial grafts.
Conclusions:
- Diastolic flow augmentation during left ventricular assistance is graft-dependent, with ACB performing better than arterial grafts.
- Ventricular assistance strategies should consider the specific hemodynamic characteristics of coronary artery bypass grafts.
- Understanding these differences is vital for managing post-coronary bypass grafting complications.
Background:
Intraaortic balloon pumping (IABP) and left ventricular assist device (LVAD) are used for left ventricular support when low cardiac output occurs after a coronary bypass operation for serious coronary artery disease. There are hemodynamic differences in blood flow in various kinds of coronary artery bypass grafts, caused by their inherent physiologic characteristics. The hemodynamic effects of left ventricular assistance with IABP and LVAD on blood flow through various coronary artery bypass grafts were investigated.
Methods:
An ascending aorta-coronary bypass graft (ACB), an internal thoracic artery, and a descending aorta-coronary bypass graft were anastomosed to the left anterior descending coronary artery in a canine model. In this experimental model, the blood flow to the same coronary bed in the three types of grafts could be evaluated. Blood flow in the left anterior descending coronary artery through the three types of coronary bypass grafts was studied in this model during or in the absence of ventricular assistance.
Results:
In the control study, the systolic blood flow did not differ among the three types of grafts, but the diastolic flow decreased in the following order: with the ACB, the internal thoracic artery, and the descending aorta-coronary bypass graft. The systolic flow during IABP and LVAD was similar to the control flows. Use of IABP increased the diastolic flow by 75.3%+/-12.4% of the control value in the ACB, 37.9%+/-25.0% in the internal thoracic artery, and 21.2%+/-11.4% in the descending aorta-coronary bypass graft. The LVAD increased the diastolic flow by 97.7%+/-18.7% of the control value in the ACB, 64.5%+/-25.7% in the internal thoracic artery, and 63.0%+/-27.9% in the descending aorta-coronary bypass graft. The diastolic blood flows in the left anterior descending coronary artery and the three types of grafts were significantly greater with IABP than the control values, and significantly greater with LVAD than with IABP and the control values. The degrees of increase of diastolic flows in the left anterior descending coronary artery and the ACB with IABP and LVAD were significantly greater than in the arterial grafts (p < 0.01).
Conclusions:
The diastolic flows in the internal thoracic artery and descending aorta-coronary bypass graft increased less than in the native left anterior descending coronary artery and ACB during left ventricular assistance, particularly with IABP. It is important for the selection of tactics for the management of catastrophic status after coronary bypass grafting to consider the hemodynamic characteristics of the graft.