Comparing the ultrastructural effects of two different cardiac preparation- and perfusion-techniques in a porcine model of extracorporal long-term preservation.
OBJECTIVE
In heart transplantation a well-preserved myocardial ultrastructure is an important precondition for functional regeneration. Aim of the study is to optimize the conditions in this new established model of extracorporeal cardiac perfusion.


METHODS
(I) In six pigs, hearts were arrested with Bretschneider Histidine-Tryptophan-Ketoglutarate cardioplegia and cold ischemia, explanted and connected to a circulating constant pressure Langendorff system (80-90mmHg) and perfused with leukocyte depleted autologous blood. (II) Beating hearts of seven pigs were explanted and connected immediately to the Langendorff system (40-50mmHg). Myocardial biopsies (n=55) were taken in situ and during the following 12h of reperfusion, and were prepared for electron microscopy.


RESULTS
Cardioplegia and hypothermia (group I) induced mitochondrial edema and myofibrillar degeneration in cardiomyocytes and severe endothelial edema. During 4h of reperfusion, mitochondrial edema, myofibrillar, and sarcolemmal damages in cardiomyocytes increased. Moderate endothelial degeneration, interstitial edema, and bleedings appeared. In contrast, in group II after 6h of reperfusion endothelia showed only mild alterations. Cardiomyocytes showed myofibrillary but not mitochondrial degeneration. Interstitial edema and bleedings were mild.


CONCLUSIONS
Avoiding cardioplegia and hypothermia, and using lower perfusion pressure resulted in a better preservation of the ultrastructure in explanted hearts at the Langendorff system.
Aupperle
Heike
H
Institute of Pathology, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 33, 04103 Leipzig, Germany. aupperle@rz.uni-leipzig.de
Garbade
Jens
J
Ullmann
Chris
C
Schneider
Katja
K
Krautz
Christian
C
Dhein
Stefan
S
Gummert
Jan Fritz
JF
Schoon
Heinz-Adolf
HA
D000818:Animals; D006324:Heart Arrest, Induced / Q000009:adverse effects; D016027:Heart Transplantation; D008929:Mitochondria, Heart / Q000648:ultrastructure; D009200:Myocardial Contraction; D015428:Myocardial Reperfusion Injury / Q000473:pathology* / Q000503:physiopathology; D009206:Myocardium / Q000648:ultrastructure*; D032383:Myocytes, Cardiac / Q000648:ultrastructure; D009926:Organ Preservation / Q000379:methods*; D019188:Organ Preservation Solutions; D013552:Swine; D013997:Time Factors
D019188:Organ Preservation Solutions