The effects of cardioplegic arrest and reperfusion on the microvasculature of the heart
| Autor: | John Fenner, David J. Wheatley, A. R. McPhaden, Philip R. Belcher, J Morrison, W Martin, V L Pathi, McQuiston Am |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Pulmonary and Respiratory Medicine
Therapeutic effectiveness Vascular anatomy Swine Myocardial Reperfusion Injury Group A Lymphocyte Depletion law.invention Microcirculation law Coronary Circulation Cardiopulmonary bypass medicine Animals Whole blood Cardiopulmonary Bypass business.industry Myocardium Direct effects General Medicine medicine.disease Coronary Vessels Anesthesia Heart Arrest Induced Microscopy Electron Scanning Surgery Cardiology and Cardiovascular Medicine business Reperfusion injury |
| Zdroj: | European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. 11(2) |
| ISSN: | 1010-7940 |
| Popis: | Objecti6es: Despite laboratory evidence of leucocyte involvement in reperfusion injury, cardiac surgical clinical trials do not support the therapeutic effectiveness of leucocyte filtration. Furthermore, the direct effects of crystalloid cardioplegia and reperfusion on the capillaries of the heart have yet to be elucidated. We tested the effects of cardioplegic arrest and reperfusion both with and without leucocyte depletion, in a model of cardiopulmonary bypass that mimics clinical cardiac surgical conditions. Methods: Four groups of Landrace pigs were studied. Group A (n 6) underwent 30 min of hypothermic (28°C) cardiopulmonary bypass. Groups B (n 6), C( n6) and D (n6) also had 90 min of cardioplegic arrest. Group C was then reperfused with whole blood, while Group D was reperfused with leucocyte-depleted blood. Microvascular methylmethacrylate corrosion casts were made at the end of the experimental period. Myocardial vascular anatomy was defined by electron microscopy and capillary abundance derived from this and from the weight of casts from representative areas. Leucocyte deposition was assessed using radioisotope-labelled leucocytes. Ischaemic damage to tissues was graded according to light and electron microscopic findings. Results: In Group A the mean (9S.D.) vascular cast weight:volume of myocardium (density) was 1259 9m g :mm 3 . After cardioplegic arrest (Group B), it fell to 749 7m g :mm 3 (PB 0.0001) due to absence of capillaries, although arterioles, venules and non-nutritive bypass vessels remained patent. Following reperfusion with whole blood (Group C), capillary numbers partially recovered but luminal diameters were reduced with a cast density of 949 5m g :mm 3 (PB 0.0001 versus Group A and B). Leucocyte-depleted (87‐92%) reperfusion in Group D did not affect cast density (909 3m g :mm 3 ; P 0.17). Coronary vascular resistances in Groups C and D rose slightly, but not significantly, during reperfusion. Conclusions: Following cardioplegic arrest, microvascular changes are marked. These changes are partially reversed by 30 min reperfusion. Leucocyte depletion does not ameliorate these effects in this model. © 1997 Elsevier Science B.V. |
| Databáze: | OpenAIRE |
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