Peter Kleine

Venoarterial extracorporeal membrane oxygenation for treatment of cardiogenic shock: Clinical experiences in 45 adult patients

OBJECTIVE Venoarterial extracorporeal membrane oxygenation is an established treatment option in patients with cardiogenic shock. This report reviews our 3-year experience with this support system with respect to early and midterm outcome, as well as predictors of survival. METHODS From January 2003 until November 2006, 45 (0.8%) of 5750 patients undergoing cardiac surgery procedures required the following: temporary extracorporeal membrane oxygenation support coronary artery bypass grafting, n = 20; implantation of a left ventricular assist device, n = 5; heart transplantation, n = 1; heart and lung transplantation, n = 1; coronary artery bypass grafting plus repair of postinfarction ventricular septal defect, n = 3; coronary artery bypass grafting plus mitral valve repair, n = 5; aortic valve replacement, n = 2; coronary artery bypass grafting plus aortic valve replacement, n = 3; and other procedures, n = 5. Extracorporeal membrane oxygenation implantation was performed through the femoral vessels or axillary artery or through the right atrium and ascending aorta. Additional intra-aortic balloon pumps were used in 30 patients. RESULTS Average patient age was 60.1 +/- 13.6 years. There were 35 male patients. Average duration of extracorporeal membrane oxygenation was 6.4 +/- 4.5 days. Twenty-five patients could be successfully weaned from extracorporeal membrane oxygenation. The 30-day mortality was 53% (24/45 patients). The in-hospital mortality was 71% (32/45 patients). Thirteen (29%) patients could be successfully discharged. After a follow-up period of up to 3 years, 10 (22%) patients were still alive. CONCLUSIONS Extracorporeal membrane oxygenation offers sufficient cardiopulmonary support in adults with similar hospital and midterm survival rates to those of other mechanical support systems. Early indication, alternative peripheral cannulation techniques, and reduced anticoagulation to avoid perioperative bleeding could improve our results with increasing experience.

Orientation of tilting disc and bileaflet aortic valve substitutes for optimal hemodynamics

Procedures for implantation of mechanical aortic valves have to consider eccentric flow in the aortic root. We describe how to optimize orientation of tilting disc (Medtronic Hall) and bileaflet (St. Jude Medical) valves. In tilting disc valves, an asymmetric design faces an asymmetric flow. Hemodynamic performance of this valve type, regarding turbulence and pressure gradients, is close to normal physiology and superior to the bileaflet valve design. This difference is more pronounced the smaller the valve size.

Choice of Prosthetic Heart Valve in Today's Practice

In this update, current guidelines addressing prosthesis selection published by the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) are discussed, along with additional data that affect choices in valve prostheses. The case of a 50-year-old man undergoing aortic valve replacement is used to address anticipated operative mortality, risk of reoperation, and valve-related morbidity and mortality. The apparent advantages associated with the use of a bioprosthesis even in a relatively young patient help to explain current clinical trends toward the increasing use of tissue valves. We also provide a simplified algorithm that may be used to facilitate the choice of valve procedure in patients with heart valve disease. The outcomes after surgery for valvular heart disease in terms of survival, functional status, and quality of life are determined primarily by patient-related factors such as age, ventricular function, and other comorbidities.1 However, outcomes also are influenced by surgical factors; the best clinical outcomes often are associated with valve repair, although mitral repair is not always possible and aortic valve repair in adults remains the exception rather than the rule. For patients who require valve replacement, the valve prosthesis can significantly influence outcome. The ideal prosthetic valve that combines excellent hemodynamic performance and long-term durability without increased thromboembolic risk or the need for long-term anticoagulation does not exist. Hence, patients and their physicians need to choose between a mechanical and a tissue (bioprosthetic) valve. In general, the advantageous durability of mechanical valves is offset by the risk of thromboembolism and the need for long-term anticoagulation and its associated risk of bleeding. In contrast, bioprosthetic valves do not require long-term anticoagulation yet carry the risk of structural failure and reoperation.2,3 Two historic randomized clinical trials compared outcomes after valve replacement with a first-generation porcine heterograft …

Antegrade Cerebral Perfusion for Acute Type A Aortic Dissection in 120 Consecutive Patients

BACKGROUND Treatment of acute type A aortic dissection remains a surgical challenge because of prolonged operative times, bleeding complications, and a considerable risk of neurologic morbidity and mortality. The following study investigates clinical results after modification of perfusion technique for cardiopulmonary bypass as well as temperature management. METHODS Between January 2000 and August 2006, 120 consecutive patients underwent repair of acute type A dissection. Selective antegrade cerebral perfusion through the right subclavian artery combined with mild systemic hypothermia (30 degrees C) was used in all patients. RESULTS Mean cardiopulmonary bypass time was 144 +/- 53 minutes, and mean myocardial ischemic time was 98 +/- 49 minutes. Isolated cerebral perfusion was performed for 25 +/- 12 minutes. Mean core temperature amounted to 30.1 degrees +/- 2.2 degrees C. Chest tube drainage during the first 24 hours was 525 +/- 220 mL. Mean ventilation time was 54 +/- 22 hours. Elevation of serum lactate levels at 1, 12, and 24 hours postoperatively rose to 22 +/- 14, 18 +/- 11, and 19 +/- 8 mg/dL respectively. We observed new postoperative permanent neurologic deficits in 5 patients (4.2%) and TND in 3 patients (2.5%). The 30-day mortality rate was 5% (n = 6). After a mean follow-up period of 2.8 years, 104 patients (87%) were still alive. CONCLUSIONS Antegrade cerebral perfusion in combination with mild hypothermia offered sufficient neurologic protection in our patient cohort, provided adequate distal organ protection, and reduced perioperative complications in surgery for type A dissection. This perfusion strategy may help in reducing perioperative complications in this particular patient population.

Leukocyte filtration fails to limit functional neutrophil activity during cardiac surgery

Abstract. Objective and design: The beneficial effects of leukocyte filtration on the outcome of cardiac surgery with cardiopulmonary bypass (CPB) is probably due to the limitation of pathogenesis mediated by over-stimulated neutrophils. However, the influence of leukocyte filtration on the functional neutrophil activity has not been studied in detail. Therefore, by using different filtration timing strategies we determined neutrophil effector functions before and after the filter passage as well as blood surrogate markers for neutrophil activation.¶Methods: We randomly assigned 80 cardiac surgery patients to four groups (n = 20 each) without (I) and with three different filtration timing strategies (II–IV). As functional end points neutrophil phagocytic activity and oxidative burst upon ex vivo stimulation with E.coli were analyzed from blood of 31 patients whereas polymorphonuclear elastase (PMNE), myeloperoxidase, and malondialdehyde (MDA), a marker for lipid peroxidation was determined in plasma samples from 80 patients. Blood was harvested immediately before and behind the filter (Pall LG6) at different times during CPB.¶Results: We found that none of the filtration strategies either reduced the number of neutrophils capable of eliciting phagocytic activity and oxidative burst or the activity per cell. In contrast, PMNE and MPO levels in peripheral venous blood were found to be significantly increased in groups II–IV compared with group I throughout the entire filtration period in all patients. MDA was not enhanced in the filter groups.¶Conclusions: Our results show that the leukocyte depletion filter in the arterial line of the heart-lung machine failed to limit neutrophil stimulation but rather augmented PMNE plasma levels. We speculate that augmented PMNE and MPO levels mainly stem from neutrophils that are captured within the mesh of the leukocyte filter.

Perioperative biventricular pacing leads to improvement of hemodynamics in patients with reduced left-ventricular function--interim results.

Background: Cardiac resynchronization therapy (CRT) has been introduced as a new therapeutic modality in patients with chronic heart failure. However, most studies have investigated the hemodynamic effects in congestive, but not postoperative heart failure.

Downstream turbulence and high intensity transient signals (HITS) following aortic valve replacement with Medtronic Hall or St. Jude Medical valve substitutes

OBJECTIVE High intensity transient signals (HITS) representing microembolization to the brain have been found to contribute to cognitive impairment and psychoneurological dysfunction in patients carrying a mechanical aortic valve. It is unknown, whether HITS represent gaseous or solid emboli. This animal study evaluates the impact of valve orientation on HITS for two different mechanical valves with both valves implanted in their best and worst orientation, which has been defined in previous studies with respect to downstream turbulence. METHODS In four pigs a rotation device carrying either a Medtronic Hall (MH) or St. Jude Medical (SJM) valve size 23 mm was implanted. The device allowed rotation of the implanted valves without reopening of the aorta. Approximately 30 min after weaning from extracorporeal circulation, a Doppler probe was placed on both common carotid arteries. In different orientations of the implanted valves (best and worst position), HITS were detected by the Doppler probe and recorded for ten min by a transcranial Doppler sonography device (Medilab Inc., Estenfeld, Germany). RESULTS HITS showed significant change with rotation for both valve designs. With the major orifice of the MH oriented towards the non-coronary leaflet (optimum position) very low HITS-counts (0.8-1.7/min) were observed. In the worst orientation HITS rose to 43-66/min. For the SJM the HITS count in the optimum position was 23.4-24/min and in the worst orientation 38-48/min. CONCLUSIONS Valve orientation has an important impact on microembolization to the brain. In the optimum orientation (large orifice facing the non-coronary leaflet) the Medtronic Hall valve showed negligible incidence of HITS. The St. Jude Medical bileaflet valve showed less variation but demonstrated significant HITS counts at any orientation. As the MH in the worst position shows significantly higher turbulent stresses than the SJM but no higher incidence of HITS, a strong correlation between turbulence and HITS was not demonstrated by this study.

Biventricular pacing for weaning from extracorporeal circulation in heart failure

Resynchronization of the intra- and interventricular conduction by biventricular pacing has been suggested in patients with end-stage heart failure. We present a case in which extracorporeal circulation could only be weaned after placement of an additional left ventricular pacing wire. Biventricular stimulation led to normal motion of the anterior wall and a previously bulging interventricular septum; this improved the hemodynamic situation significantly.

Simplified technique for surgical ligation of the left atrial appendage in high-risk patients.

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Biventricular Pacing for Successful Weaning from Extracorporal Circulation in an Infant with Complex Tetralogy of Fallot

AbstractBiventricular pacing therapy is an innovative therapy for improving cardiac output in adult patients with severe heart failure. However, this technique is not yet used in infants with congenital heart disease. We present a six month old infant with tetralogy of fallot and atresia of the left pulmonary artery in which biventricular stimulation led to improved left ventricular function and successful weaning from extracorporeal circulation.