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Clinical strategies for minimizing reperfusion-related injury following falled angioplasty
J Mol Cell Cardiol
R28
22 (Supplement
V) (1990)
NYOCARDIAL PRESERVATION FOR TBANSPLANTATION: Bruce Beitz, Medicine, Baltimore, Maryland
M.D.,
Johns Hopkins
School
of
The increasing number of patients receiving cardiac transplants, and the number of centers performing the operation, emphasizes the importance of better methods for preeervation. Since cardiac donora are the limiting factor, any method that extends cardiac preservation will allow better utilization, and other issues, such as potential tissue matching of donor and recipient would also become possible if extended preservation were available. Despite this need, and all of advances that have been made in myocardial preservation, current clinical practice in the majority of transplant centers involves simple crystalloid flush with cardioplegia solutions and cold storage. This traditional approach results in satisfactory function after ischemic times of up to 6-7 hours, with the majority of transplants performed with an ischemic time of 3.5 hours. Current experimental approaches consist of either standard cardioplegic flush with various electrolyte solutions and static storage, the use of low pressure, low flow perfusion, either antegrade or retrograde, or continuously working and autoperfusing preparations at near normothermic temperatures. Abjunctive techniques for any of these methods includes the use of leukocyte depletion, oxygen free radical scavengers post reperfusion, or substrate enhancement during warm cardioplegic reperfusion. Many of these for 24 hours. adjunctive techniques appear promising for extending preservation Eventual clinical utilization will depend upon the practical usefulness of the technique, with an emphasis on simplicity and reliability. This presentation will review current clinical practice and the multiple experimental techniques mentioned above.
MYOCARDIAL PRESERVATION FOR THORACIC AORTIC ANEURYSM Christian Cabrol, Alain Pavie, Iradj Gandjbakhch. Department of Cardiovascular Surgery, Hospital la Piti6, Paris - France. Safe myocardial preservation during thoracic aortic aneurysm surgery is of special concern ; due to the usual long duration of the ischemic time during such operations. In our unit, cardiac arrest was induced with a cold hyperkaliemic blood cardioplegia. This technique needs a specific circuit with a separated heat exchanger of easy use for the surgeon and the perfusionnist. The infusion was started through an aortic catheter in case of aneurysm. In case of dissection, the solution was infused directly in the coronary ostia. Reperfusion of half dose of blood solution without potassium was performed each following 20 minutes. The body temperature was lowered to 31°C. In patients in whom aortic replacement included the aortic aorch, hypothermie at 22°C used with partial circulatory arrest and carotid arteries perfusion at a flow rate of 1 liter/minute. Warm blood cardioplegia reperfusion was started at the end of the suture. This warm reperfusion used the same volume as the initial perfusion. It contained a small amount of Potassium, glutamate to restore the energetic level of the myocardium and Trinitrine to facilitate spontaneous defibrillation. This technique provided a significant improvement in cardiac function and post operative recovery of our patients.
R30
Clinical
Strategies
For Minimking
RepeHusion-Ftelsted
Injury Followhg
Failed Angioplasty
Marc S. Visner, University of Massachusetts Medical Center, Worcester, Massachusetts Coronary artery occlusion is becoming an increasingly rare complication of percutaneous transluminal coronary angioplasty (FTCA). However, when an artery subserving a substantial area of myocardium is acutely occluded, potentially life-threatening ventricular dysfunction and arrhythmias may occur. There are several strategies available to the cardidogist and cardiac surgeon for sustaining myocardiaf function and viability through this crisis until the patency of the occluded vessel can be re-established. It Is now clear, however, that following brief periods of coronary occlusion, the precise circumstances of reperfusion can Influence the extent of recovery of ventricular function and the incklence of ventricular arrhythmias. Emerging experimental evidence suggests that reperfuslon-related injury can be minimized by: 1) maintaining mechanical quiescence of the injured region, 2) establishing an electrochemical environment that permits extrusion of lntramyocardlal calcium. and 3) limiting exposure to oxygenderlved free radicals. The mechanical properties of regional contractile arrest and the electrochemical derangements that occur during brlef perfods of lschemia and reperfusion will be discussed. New strategies for modifying the conditions of repetfuslon following failed F’TCA will be considered. s.47
R28
22 (Supplement
V) (1990)
NYOCARDIAL PRESERVATION FOR TBANSPLANTATION: Bruce Beitz, Medicine, Baltimore, Maryland
M.D.,
Johns Hopkins
School
of
The increasing number of patients receiving cardiac transplants, and the number of centers performing the operation, emphasizes the importance of better methods for preeervation. Since cardiac donora are the limiting factor, any method that extends cardiac preservation will allow better utilization, and other issues, such as potential tissue matching of donor and recipient would also become possible if extended preservation were available. Despite this need, and all of advances that have been made in myocardial preservation, current clinical practice in the majority of transplant centers involves simple crystalloid flush with cardioplegia solutions and cold storage. This traditional approach results in satisfactory function after ischemic times of up to 6-7 hours, with the majority of transplants performed with an ischemic time of 3.5 hours. Current experimental approaches consist of either standard cardioplegic flush with various electrolyte solutions and static storage, the use of low pressure, low flow perfusion, either antegrade or retrograde, or continuously working and autoperfusing preparations at near normothermic temperatures. Abjunctive techniques for any of these methods includes the use of leukocyte depletion, oxygen free radical scavengers post reperfusion, or substrate enhancement during warm cardioplegic reperfusion. Many of these for 24 hours. adjunctive techniques appear promising for extending preservation Eventual clinical utilization will depend upon the practical usefulness of the technique, with an emphasis on simplicity and reliability. This presentation will review current clinical practice and the multiple experimental techniques mentioned above.
MYOCARDIAL PRESERVATION FOR THORACIC AORTIC ANEURYSM Christian Cabrol, Alain Pavie, Iradj Gandjbakhch. Department of Cardiovascular Surgery, Hospital la Piti6, Paris - France. Safe myocardial preservation during thoracic aortic aneurysm surgery is of special concern ; due to the usual long duration of the ischemic time during such operations. In our unit, cardiac arrest was induced with a cold hyperkaliemic blood cardioplegia. This technique needs a specific circuit with a separated heat exchanger of easy use for the surgeon and the perfusionnist. The infusion was started through an aortic catheter in case of aneurysm. In case of dissection, the solution was infused directly in the coronary ostia. Reperfusion of half dose of blood solution without potassium was performed each following 20 minutes. The body temperature was lowered to 31°C. In patients in whom aortic replacement included the aortic aorch, hypothermie at 22°C used with partial circulatory arrest and carotid arteries perfusion at a flow rate of 1 liter/minute. Warm blood cardioplegia reperfusion was started at the end of the suture. This warm reperfusion used the same volume as the initial perfusion. It contained a small amount of Potassium, glutamate to restore the energetic level of the myocardium and Trinitrine to facilitate spontaneous defibrillation. This technique provided a significant improvement in cardiac function and post operative recovery of our patients.
R30
Clinical
Strategies
For Minimking
RepeHusion-Ftelsted
Injury Followhg
Failed Angioplasty
Marc S. Visner, University of Massachusetts Medical Center, Worcester, Massachusetts Coronary artery occlusion is becoming an increasingly rare complication of percutaneous transluminal coronary angioplasty (FTCA). However, when an artery subserving a substantial area of myocardium is acutely occluded, potentially life-threatening ventricular dysfunction and arrhythmias may occur. There are several strategies available to the cardidogist and cardiac surgeon for sustaining myocardiaf function and viability through this crisis until the patency of the occluded vessel can be re-established. It Is now clear, however, that following brief periods of coronary occlusion, the precise circumstances of reperfusion can Influence the extent of recovery of ventricular function and the incklence of ventricular arrhythmias. Emerging experimental evidence suggests that reperfuslon-related injury can be minimized by: 1) maintaining mechanical quiescence of the injured region, 2) establishing an electrochemical environment that permits extrusion of lntramyocardlal calcium. and 3) limiting exposure to oxygenderlved free radicals. The mechanical properties of regional contractile arrest and the electrochemical derangements that occur during brlef perfods of lschemia and reperfusion will be discussed. New strategies for modifying the conditions of repetfuslon following failed F’TCA will be considered. s.47