Myocardial protection: a forgotten modality.

The goals of a cardiac surgical procedure are both technical excellence and complete protection of cardiac function. Cardioplegia is used almost universally to protect the heart and provide a quiet bloodless field for surgical accuracy. Yet, despite the importance of myocardial protection in cardiac surgery, manuscripts or dedicated sessions at major meetings on this subject have become relatively rare, as though contemporary techniques now make them unnecessary.

Studies of isolated global brain ischaemia: I. A new large animal model of global brain ischaemia and its baseline perfusion studies.

Objectives: Neurological injury after global brain ischaemia (i.e. sudden death) remains problematic, despite improving cardiac survival.

Studies of isolated global brain ischaemia: III. Influence of pulsatile flow during cerebral perfusion and its link to consistent full neurological recovery with controlled reperfusion following 30 min of global brain ischaemia.

Objective: Brain damage is universal in the rare survivor of unwitnessed cardiac arrest. Non-pulsatile-controlled cerebral reperfusion offsets this damage, but may simultaneously cause brain oedema when delivered at the required the high mean perfusion pressure. This study analyses pulsatile perfusion first in control pigs and then using controlled reperfusion after prolonged normothermic brain ischaemia (simulating unwitnessed arrest) to determine if it might provide a better method of delivery for brain reperfusion.

Studies of isolated global brain ischaemia: II. Controlled reperfusion provides complete neurologic recovery following 30 min of warm ischaemia - the importance of perfusion pressure.

Objectives: Neurologic injury after sudden death is likely due to a reperfusion injury following prolonged brain ischaemia, and remains problematic, especially if the cardiac arrest is unwitnessed. This study applies a newly developed isolated model of global brain ischaemia (simulating unwitnessed sudden death) for 30 min to determine if controlled reperfusion permits neurologic recovery.

Methods: Among the 17 pigs undergoing 30 min of normothermic global brain ischaemia, 6 received uncontrolled reperfusion with regular blood (n = 6), and 11 were reperfused for 20 min with a warm controlled blood reperfusate containing hypocalcaemia, hyper-magnesemia, alkalosis, hyperosmolarty and other constituents that were passed through a white blood cell filter and delivered at flow rates of 350 cc/min (n = 3), 550 cc/min (n = 2) or 750 cc/min (n = 6).

Studies of isolated global brain ischaemia: I. Overview of irreversible brain injury and evolution of a new concept - redefining the time of brain death.

Despite advanced cardiac life support (ACLS), the mortality from sudden death after cardiac arrest is 85-95%, and becomes nearly 100% if ischaemia is prolonged, as occurs following unwitnessed arrest. Moreover, 33-50% of survivors following ACLS after witnessed arrest develop significant neurological dysfunction, and this rises to nearly 100% in the rare survivors of unwitnessed arrest. Although, whole body (cardiac) survival improves to 30% following recent use of emergency cardiopulmonary bypass, sustained neurological dysfunction remains a devastating and unresolved problem.

Resuscitation after prolonged cardiac arrest: effects of cardiopulmonary bypass and sodium-hydrogen exchange inhibition on myocardial and neurological recovery.

Objective: To determine if cardiopulmonary bypass (CPB), together with inhibition of the sodium-hydrogen exchanger (NHE), limits myocardial and neurological injury and improves recovery after prolonged (unwitnessed) cardiac arrest (CA), as NHE inhibition improved recovery after deep hypothermic circulatory arrest.

Methods: Twenty-seven pigs (31-39 kg) underwent 15 min of prolonged (no-flow) CA followed by 10 min of cardiopulmonary resuscitation-advanced life support (CPR-ALS). Subjects with restoration of spontaneous circulation (ROSC) during CPR-ALS received either no drug (n=6) or an inhibitor of the NHE (HOE-642; n=5).

Resuscitation after prolonged cardiac arrest: role of cardiopulmonary bypass and systemic hyperkalemia.

Background: The purpose of this study was to determine (1) the role of emergency cardiopulmonary bypass (CPB) after prolonged cardiac arrest and failed cardiopulmonary resuscitation, and (2) the use of systemic hyperkalemia during CPB to convert intractable ventricular fibrillation (VF).

Methods: Thirty-one pigs (34 +/- 2 kg) underwent 15 minutes of cardiac arrest after induced VF, followed by 10 minutes of cardiopulmonary resuscitation-advanced life support. Peripheral CPB was used if cardiopulmonary resuscitation failed to restore stable circulation.

WITHDRAWN: Influences of Perfusion Pressure and Pulsatile Flow on Cerebral Flow Reserve and Oxygenation in the Isolated Perfused Swine Brain under Normothermia.

This article has been removed at the request of the Editor-in-Chief. Please see Elsevier Policy on Article Withdrawal: (http://www.elsevier.

Sudden cardiac death: directing the scope of resuscitation towards the heart and brain.

Background: The fundamental goal of cardiopulmonary resuscitation (CPR) is recovery of the heart and the brain. This is best achieved by (1) immediate CPR for coronary and cerebral perfusion, (2) correction of the cause of cardiac arrest, and (3) controlled cardioplegic cardiac reperfusion. Failure of such an integrated therapy may cause permanent brain damage despite cardiac resuscitation.

Cerebral monitoring with transcranial Doppler ultrasonography improves neurologic outcome during repairs of acute type A aortic dissection.

Objective: Neurologic complications after repair of acute type A aortic dissection remain significant. The use of power M-mode transcranial Doppler monitoring to verify cerebral blood flow during these repairs might decrease cerebral ischemia by correcting malperfusion. The purpose of this study was to analyze the use of power M-mode transcranial Doppler monitoring during repairs of acute type A dissection with regard to neurologic outcome.

Staged repair of extensive aortic aneurysms: long-term experience with the elephant trunk technique.

Objective: This paper reports our experience of a large series of elephant trunk patients accumulated over 12 years.

Summary Background Data: Extensive aneurysms of the ascending/arch and descending thoracic or thoracoabdominal aorta are significant surgical problems that have potential for great morbidity. We adopted a staged approach known as the elephant trunk procedure in 1991, and we have used it with some modifications since that time.

Pediatric myocardial protection: a cardioplegic strategy is the "solution".

This article describes the experimental infrastructure and subsequent successful clinical application of a comprehensive cardioplegic strategy that limits intraoperative injury and improves postoperative outcomes in pediatric patients. The infant heart is at high risk of damage from poor protection as a result of preoperative hypertrophy, cyanosis, and ischemia. These factors may also make the immature (pediatric) heart more sensitive to cardioplegic arrest compared with the mature (adult) heart.

Conditioned blood reperfusion markedly enhances neurologic recovery after prolonged cerebral ischemia.

Objectives: To determine whether controlled reperfusion using conditioned leukodepleted blood can substantially limit cerebral reperfusion injury following prolonged ischemia.

Methods: Eighteen pigs (25-35 kg) underwent 90 minutes of hypothermic circulatory arrest (19 degrees C) to produce brain ischemia. At the start of rewarming, 10 pigs received uncontrolled reperfusion with unmodified (normal) blood.

Experience with an alternative technique for the management of anomalous left coronary artery from the pulmonary artery.

Background: Several operative approaches are utilized for the management of anomalous origin of the left coronary artery from the pulmonary artery, each with some limitation. The long-term results of a technique that facilitates direct and tension-free implantation of the anomalous artery to the aorta in all patients are described.

Methods: From January 1, 1992 through August 30, 2000, 10 consecutive patients with anomalous left coronary artery underwent operation using this technique.

Distal aortic perfusion and cerebrospinal fluid drainage for thoracoabdominal and descending thoracic aortic repair: ten years of organ protection.

Objective: To report the long-term results of our experience using cerebrospinal fluid drainage and distal aortic perfusion in descending thoracic and thoracoabdominal aortic repair.

Summary Background Data: Repair of thoracoabdominal and thoracic aortic aneurysm by the traditional clamp-and-go technique results in a massive ischemic insult to several major organ systems. Ten years ago, we began to use distal aortic perfusion and cerebrospinal fluid drainage (adjunct) to reduce end-organ ischemia.

The clinical significance of the reoxygenation injury in pediatric heart surgery.

Significant advances have been made in the technical performance of operations for infants and neonates with congenital heart disease. However, postoperative organ dysfunction is a frequent problem, particularly in hypoxic (cyanotic) infants. We review both our experimental and subsequent clinical experience with the injury caused by abrupt reoxygenation of the hypoxic patient and examine the modalities of gradual reoxygenation and leukodepletion in limiting this injury, thereby improving operative outcomes for cyanotic lesions.

Deep hypothermic circulatory arrest and global reperfusion injury: avoidance by making a pump prime reperfusate--a new concept.

Objective: We sought to determine whether damage after deep hypothermic circulatory arrest can be diminished by changing pump prime components when reinstituting cardiopulmonary bypass.

Methods: Fifteen piglets (2-3 months old) were cooled to 19 degrees C by using the alpha-stat pH strategy. Five were cooled and rewarmed without ischemia (control animals), and the other 10 piglets underwent 90 minutes of deep hypothermic circulatory arrest.

Pericardial tissue valves and Gore-Tex conduits as an alternative for right ventricular outflow tract replacement in children.

Background: There is still no perfect conduit for reconstruction of the right ventricular outflow tract (RVOT) in children. Homografts are not always available in the appropriate size, and degenerate in a few years. This study evaluates the pericardial valve with Gore-Tex conduit as an alternative for RVOT construction.

The role of leukodepletion in limiting ischemia/reperfusion damage in the heart, lung and lower extremity.

This article describes the experimental infrastructure and subsequent clinical application of a comprehensive reperfusion strategy to limit the injury following ischemia, resulting in an improvement in post operative organ function. In particular, it examines the role of luekodepletion in minimizing damage and improving functional outcome in the heart, lung and lower extremity. During cardiothoracic procedures, various organs can be subjected to temporary ischemia, particularly the heart (cardioplegic arrest), lung (transplant), and lower extremity (femoral canulation, IABP).

Intermediate results of the anatomic repair for congenitally corrected transposition.

Background: Anatomic repair of congenitally corrected transposition of the great arteries has several advantages over the traditional approach but lacks long-term evaluation.

Methods: The data on 12 patients who had the procedure between January 1989 and June 2000 were retrospectively reviewed. Associated lesions included ventricular septal defect in 12 patients, pulmonary stenosis in 10 patients, and moderate to severe tricuspid valve regurgitation in 4 patients.