[Show abstract][Hide abstract]ABSTRACT: To prolong the time of heart preservation, we modified the Wicomb's perfusion apparatus, in which oxygen flow acts as the source of power and provides oxygenation for the perfused myocardium. Ten adult porcine hearts which had been preserved for 24 hours were resuscitated successfully and continued to beat steadily for more than 1.5-3 hours after reperfusion. Myocardial ultrastructure was observed at the end of preservation and 15-120 minutes after reperfusion. The damages of the myocardial ultrastructure at the end of preservation were reversible.
[Show abstract][Hide abstract]ABSTRACT: The effect of infusing the M-cholinergic receptor blocker anisodamine during cardiopulmonary bypass (CPB) on granulocyte-mediated lung injury was evaluated in sixteen dogs undergoing CPB for 120 min with the aorta crossclamped for 90 min. The treated dogs (n = 8) received a total dose of 15 mg/kg anisodamine hydrochloride before and during CPB whereas the controls (n = 8) received saline only. A significantly reduced sequestration of granulocytes in the lungs was found in the treated dogs as indicated by a lower right-to-left atrium granulocyte gradient 15 minutes after pulmonary recirculation during CPB (p less than 0.05) and less granulocyte accumulation in the lung capillaries after CPB, as shown by histological examination (p less than 0.01). Moreover, oxygen free radical release as indicated by plasma malondialdehyde concentrations was significantly lower (p less than 0.05) in the treated dogs than in the controls towards the end of CPB. Finally, a significantly reduced lung-water content was found 30 min after CPB in the treated dogs as compared with the controls (p less than 0.01). These results suggest that anisodamine administration in this experimental model significantly inhibits pulmonary granulocyte sequestration in CPB and the consequent lung injury induced.
Article · Jul 1991 · The Thoracic and Cardiovascular Surgeon
[Show abstract][Hide abstract]ABSTRACT: The effect of blood activation on lung reperfusion injury during cardiopulmonary bypass was investigated in 20 dogs with the use of a bubble oxygenator (n = 10) or a membrane oxygenator (n = 10). In the bubble oxygenator group, significant leukocyte and platelet right to left atrium gradients were found 15 minutes after lung reperfusion (p less than 0.05, p less than 0.01) accompanied by a sharp increase in plasma malondialdehyde concentration 5 minutes after lung reperfusion, whereas no significant right to left atrium gradient of leukocytes or platelets nor significant increase in plasma malondialdehyde concentration was observed in the membrane oxygenator group. In both the bubble oxygenator and membrane oxygenator group, similar mild to moderate lung histological changes were found before lung reperfusion. After lung reperfusion, however, more endothelial cell swelling (p less than 0.05), leukocyte (p less than 0.01) and platelet (p less than 0.01) accumulation in lung capillaries, leakage of erythrocytes into the alveolar space (p less than 0.05), and type I cell damage (p less than 0.05) were found only in the bubble oxygenator group. Eventually, a significantly higher lung water content was found in the bubble oxygenator group than in the membrane oxygenator group (p less than 0.01) after cardiopulmonary bypass. This study indicated that lung injury during cardiopulmonary bypass starts mainly after lung reperfusion, which was correlated with lung leukocyte and platelet sequestration associated with different types of oxygenators.
Article · May 1991 · The Annals of Thoracic Surgery
[Show abstract][Hide abstract]ABSTRACT: From conception to realization, the design emphasis of the spiral vortex diaphragm pump has been on promoting efficient blood flow patterns in order to lower thrombogenicity. The tracer method was used to visualize flow patterns in this pump and the results were compared with those of a conventional diaphragm pump with paraxial inlet and outlet ports. During diastole, the flow through a 45 degrees angled inlet is tangential to the axis of the pump forming a continuous vortex central along the pump axis. During systole, the vortex converges to pass through the apically located outlet. No areas of turbulence or stasis could be found, whilst in the conventional pump only random flow with recirculation could be demonstrated. Dye washout tests confirmed good washout at the periphery of this pump with no signs of stasis. However, large areas of stagnation with incomplete washout at diaphragm-housing (D-H) junctions were observed in the conventional pump. The comparative in vitro haemolysis test revealed that the level of free plasma haemoglobin was doubled in a commercially available pump compared with that of the spiral vortex pump. No thrombus formed within the pump housing after up to 50 hours of pumping in five acute animal experiments without postoperative anticoagulants. However, thrombi were found at the D-H junction of this pump due to imperfect fabrication techniques in one of the four sheep that survived 14-21 days.(ABSTRACT TRUNCATED AT 250 WORDS)
[Show abstract][Hide abstract]ABSTRACT: To evaluate the effects of an RVAD on myocardial ischemic injury during right coronary artery (RCA) ligation, a pneumatically driven pusher plate pump was inserted between the right atrium and pulmonary artery, and the RCA was ligated at its origin for two hr. There were 18 sheep, of which nine each served as the control and RVAD groups. Hemodynamic parameters and blood samples were collected from the coronary sinus. Area at risk and area of infarct were detected by gentian violet injection and triphenyltetrazolium (TTC) staining. Hemodynamic parameters (left ventricular systolic pressure (LVSP), cardiac output (CO], and creatine kinase levels in coronary sinus blood tended to be beneficial, to some degree, in the RVAD group. Electron microscopic examination revealed chromatin clumping and mitochondrial destruction, however this ultrastructural damage was more severe in the control group. The ratio of area of infarct to area at risk in the RVAD group was significantly less than that in the control group, being 20.25 +/- 6.93% vs. 47.24 +/- 10.53% (p less than 0.05). The infarct size induced by RCA occlusion was significantly reduced by the RVAD, due to the right ventricular unloading via reduced myocardial oxygen demand.
Article · Jul 1990 · ASAIO transactions / American Society for Artificial Internal Organs