Rufus Baretti

Circulating endothelin in patients undergoing coronary artery bypass grafting

Increased synthesis of endothelin, (a powerful physiological vasoconstrictor), is a uniform response to endothelial injury and has been associated with myocardial ischemia and reperfusion. This study tests the hypothesis that coronary artery bypass grafting (CABG) affects endothelin plasma concentrations in various vascular beds. Twenty-four CABG patients were included in this study. Endothelin was determined in multiple plasma specimens obtained from superior vena cava, aortic root and coronary sinus (CS). Venous endothelin plasma concentrations collected in CABG patients before surgery were 1.16 +/- 0.18 pg/ml. They increased after sternotomy (1.71 +/- 0.12 pg/ml) and during (2.97 +/- 0.27 pg/ml) and after cardiopulmonary bypass (CPB, 2.72 +/- 0.21 pg/ml). There is no net release of endothelin from the coronary circulation before (aorta 2.26 +/- 0.13 pg/ml vs CS 2.44 +/- 0.17 pg/ml, not significant (n.s.), during (cardioplegia 2.55 +/- 0.17 pg/ml vs CS 2.45 +/- 0.15 pg/ml, n.s.), and after aortic cross-clamping (aorta 2.95 +/- 0.23 pg/ml vs coronary sinus 2.71 +/- 0.18 pg/ml, n.s.). Pulmonary endothelin clearance is preserved on partial bypass (aorta 2.26 +/- 0.13 pg/ml vs vena cava 2.86 +/- 0.18 pg/ml, P < 0.003), but remains inhibited even 10-30 min after release of the aortic cross-clamp (aorta 2.95 +/- 0.23 pg/ml vs vena cava 2.97 +/- 0.27 pg/ml, n.s.). Two out of 24 patients had severe myocardial ischemia. These patients showed particularly high endothelin concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of different routes of flush perfusion on the distribution of lung preservation solutions in parenchyma and airways

OBJECTIVE The present study was performed to investigate the influence of different routes of perfusion on the distribution of the preservation solutions in the lung parenchyma and upper airways. METHODS Pigs were divided into four groups: control (n = 6), pulmonary artery (PA) (n = 6), simultaneous PA + bronchial artery (BA) (n = 8), and retrograde delivery (n = 6). After preparation and cannulation, cardioplegia solution and Euro-Collins solution (ECS) for lung preservation were given simultaneously. After removal of the heart, the double lung bloc was harvested. Following parameters were assessed: total and regional perfusion (dye-labeled microspheres), tissue water content, PA, aorta, left atrial and left ventricular pressures, cardiac output and lung temperature. RESULTS Our data show that flow of the ECS in lung parenchyma did not reach control values (9.4+/-1.0 ml/min per g lung wet weight) regardless of the route of delivery (PA 6.3+/-1.5, PA + BA 4.8+/-0.9, retrograde 2.7+/-0.9 ml/min per g lung wet weight). However, flow in the proximal and distal trachea were significantly increased by PA + BA delivery (0.970+/-0.4, respectively, 0.380+/-0.2 ml/min per g) in comparison with PA (0.023+/-0.007, respectively, 0.024+/-0.070 ml/min per g), retrograde (0.009+/-0.003, respectively, 0.021+/-0.006 ml/min per g) and control experiments (0.125+/-0.0018, respectively, 0.105+/-0.012 ml/g per min). Similarly the highest flow rates in the right main bronchus were achieved by PA + BA delivery (1.04+/-0.4 ml/min per g) in comparison with 0.11+/-0.03 in control, 0.033+/-0.008 in PA, and 0.019+/-0.005 ml/min per g in retrograde group. Flows in the left main bronchus were 0.09+/-0.02 ml/min per g in control, 0.045+/-0.012 ml/min per g in PA, and 0.027+/-0.006 ml/min per g in retrograde group. The flow rates were significantly (P = 0.001) increased by PA + BA delivery of the storage solution (0.97+/-0.3 ml/min per g). CONCLUSIONS Our data show that the distribution of ECS for lung preservation is significantly improved in airway tissues (trachea and bronchi) if a simultaneous PA + BA delivery is used.

Submitral left ventricular tuberculoma.

A 62-year-old woman suffered from increasing dyspnea and an impaired general condition. Chest roentgenograms and echocardiogram showed a dense mass at the left atrioventricular junction resulting in the preoperative working diagnosis of a myocardial myxoma. Intraoperatively, an isolated tuberculoma was found caudal to the posterior leaflet of the mitral valve. This case report describes the successful surgical and postoperative medical treatment of an isolated myocardial tuberculoma.

Heart valve operations in solid organ recipients: an 18-year single-center experience.

Background. We retrospectively analyzed the outcome of heart valve operations in solid organ recipients, who were referred for operation to our institution. Methods. Over an 18-year period, 23 heart (group 1) and 16 renal (group 2) transplant recipients in New York Heart Association (NYHA) classes III and IV underwent valve operation. The mean interval from the time of transplantation to cardiac surgery was 77.9 months with a mean follow-up time of 34.6 months in group 1 and 87.2 months with a mean follow-up time of 39.2 months in group 2. Results. Group 1 underwent tricuspid valve replacement (n=12), tricuspid valve reconstruction (n=7), aortic valve replacement (AVR, n=3), and mitral valve replacement (MVR, n=1). In group 2, mechanical valve replacement was performed in 14 patients (9 AVR, 3 MVR, 2 AVR and MVR) and tricuspid or mitral valve reconstruction in two patients. There was no operative death. During hospitalization, multiorgan failure due to sepsis was the main cause of mortality (2 in both groups). In the mean follow-up period of 41.2 months, there were four late non-cardiac-related deaths in group 1. Currently 29 surviving transplant recipients (16 heart, 69.6% and 13 renal, 81.3%) are in NYHA classes I and II. Conclusion. In heart and renal recipients, valve operations can be performed effectively and safely with acceptable mortality, low cardiac morbidity, and excellent clinical results, although infection is the most serious complication.

Myocardial rewarming mirrors intraoperative mammary artery graft function.

Abstract  Background: The internal mammary artery (IMA) bypass graft provides a satisfactorily long‐lasting blood supply to the myocardium. However, its initial flow capacity can be insufficient with subsequent regional myocardial ischemia. We evaluated a method to assess the IMA graft function intraoperatively. Methods: Twenty‐five patients with three‐vessel coronary artery disease underwent coronary artery bypass grafting on cardiopulmonary bypass. The in situ IMA was grafted to the left anterior descending coronary artery (LAD) in combination with two saphenous vein grafts to the left circumflex and right coronary artery. Distal anastomoses were performed during cold intermittent blood cardioplegia. After unclamping of the aorta and of the grafted IMA, the temperature at the cardiac anterior and posterior side was measured during the first 5 minutes of warm reperfusion. Results: A sufficient IMA graft function was expressed by a typical rise in temperature: the cardiac anterior and posterior sides showed a parabolic and exponential course, respectively. The rewarming velocity expressed as the first derivative of temperature over time led to a sharp and early peak for the anterior side, and a smaller and delayed peak for the posterior side. Insufficient IMA graft function could be recognized by an atypical temperature course. Conclusions: Temperature measurement of the heart during warm reperfusion after hypothermic cardioplegia can help to assess the effectiveness of the IMA‐LAD graft function.