Invited commentary

Abstract

This article [1Koshida Y. Watanabe G. Yasuda T. Tomita S. Kadoya S. Kanamori T. Portable coronary active perfusion system for off-pump coronary artery bypass grafting.Ann Thorac Surg. 2006; 81: 706-711Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar] describes a novel active coronary perfusion system for use in off-pump coronary artery bypass (OPCAB) procedures. The authors tested this system in normal in-situ porcine hearts. They demonstrated stable electrophysiologic and contractile function for 30 minutes in myocardium perfused by their pump, and there was no evidence of acute vascular injury from the intracoronary cannula.Other investigators have shown the potential for active coronary perfusion systems to diminish ischemic injury during OPCAB procedures. The advantage of the system described in this report is its simplicity and small size. There is no need for personnel dedicated only to running the pump. Presumably drugs (eg, nitroglycerine or adenosine) can be added to the blood perfusing the coronary artery. The limitations of this approach are as follows: first, the need for active perfusion devices and the indications for their use are not clearly defined. Should all OPCAB patients have active perfusion, or just specific subgroups? Second, this pump delivers a constant flow but does not monitor or modulate coronary pressure. If there is small vessel disease or atherosclerosis distal to the cannulation site, resistance to flow will be higher than usual with consequent high intracoronary pressures that may cause myocardial edema. The authors believe that high intracoronary pressure will increase backflow around the cannula, but this pop-off mechanism is imprecise. Third, the maximum flow of the pump (100 mL/min) may not be sufficient for feeding multiple grafts.Clinical data are needed to determine the usefulness and indications for this device in OPCAB surgery. Simplicity and low cost are important advantages in the operating room that will give this concept an edge over more complex systems if the aforementioned limitations can be minimized by design modifications. This article [1Koshida Y. Watanabe G. Yasuda T. Tomita S. Kadoya S. Kanamori T. Portable coronary active perfusion system for off-pump coronary artery bypass grafting.Ann Thorac Surg. 2006; 81: 706-711Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar] describes a novel active coronary perfusion system for use in off-pump coronary artery bypass (OPCAB) procedures. The authors tested this system in normal in-situ porcine hearts. They demonstrated stable electrophysiologic and contractile function for 30 minutes in myocardium perfused by their pump, and there was no evidence of acute vascular injury from the intracoronary cannula. Other investigators have shown the potential for active coronary perfusion systems to diminish ischemic injury during OPCAB procedures. The advantage of the system described in this report is its simplicity and small size. There is no need for personnel dedicated only to running the pump. Presumably drugs (eg, nitroglycerine or adenosine) can be added to the blood perfusing the coronary artery. The limitations of this approach are as follows: first, the need for active perfusion devices and the indications for their use are not clearly defined. Should all OPCAB patients have active perfusion, or just specific subgroups? Second, this pump delivers a constant flow but does not monitor or modulate coronary pressure. If there is small vessel disease or atherosclerosis distal to the cannulation site, resistance to flow will be higher than usual with consequent high intracoronary pressures that may cause myocardial edema. The authors believe that high intracoronary pressure will increase backflow around the cannula, but this pop-off mechanism is imprecise. Third, the maximum flow of the pump (100 mL/min) may not be sufficient for feeding multiple grafts. Clinical data are needed to determine the usefulness and indications for this device in OPCAB surgery. Simplicity and low cost are important advantages in the operating room that will give this concept an edge over more complex systems if the aforementioned limitations can be minimized by design modifications.