ETIOPATHOGENESIS OF HEMOLYTIC REACTIONS IN TOTAL ARTIFICIAL-HEART RECIPIENTS

Hemolysis in total artificial heart (TAH) recipients was analyzed, Fro m a total of 66 long-term experiments lasting from 30-314 days per-For med in the Bma Research Center, in 53 animals, tilt: total red blood c ell (RBC) count, hematocrit, total hemoglobin, and free plasma hemoglo bin were investigated, We could essentially divide the whole group of calves in 2 subgroups. The first subgroup was calves with hemolytic re actions, and the second subgroup tvas calves without any hemolytic rea ction at all, In the first subgroup, hemolysis occurred in 47% of the overall number of animals during extracorporeal circulation (ECC), in 15% during ECC and later periodically during the experiment, in 8% dur ing ECC and then continuously during the experiment, and finally in 10 % not during ECC but repeatedly during the experiment, In 20% of the a nimals from the overall number, hemolysis did not occur at all (second subgroup), These results testify to the great individual differences within 1 breed (Bohemian with a substantial component of Holstein). Th ese differences are further modified by exogenous and endogenous facto rs. First. the inborn resistance of the RBC membrane and also thrombi formation and the mineralization of the driving diaphragm are very imp ortant. The extreme situation of decreased RBC membrane resistance was proved using a calf from another breed, the slow growing Scottish Hig hland breed, which did not survive 22 days of pumping due to intractab le lethal hemolysis. These factors are also indicated by the hemolytic action of some drugs (e.g., Dopegyt) used during the experiment for a nother reason. Also important are the mechanical forces of pumping, su rface moieties of the biomaterial, mineralization of the driving diaph ragms, thrombi formation, infection, etc. Essentially, the hemolytic r eaction in the TAH recipient has a multifactorial character. Hemolysis is undoubtedly an important factor, which can have a profound impact on the length of survival. The experimental and clinical experiences m ust be continuously integrated, and conclusions valid for human TAW ap plication must be considered as very important for further TAI-I exper imental and clinical research.