Auto-enxerto percutâneo de medula óssea em coelhos: I. Coleta, preparo e aplicação

Thirty six White New Zealand male rabbits, that weighed 3.5kg, aged between 5 and 6 months were used for studying the harvesting, processing and percutaneous administration of bone marrow autograft. In 20 anesthetized rabbits, a needle for bone marrow collection was inserted in the iliac crest and marrow was aspirated with a 20 ml heparinized syringe. The 20 samples were processed in 2 ways, 10 samples each way: 1) whole marrow: after 1-ml-harvest the sample was homogenized and in the case of coagulation, the sample was discarded; 2) centrifuged marrow: after 2-ml-harvest, the marrow was centrifuged for 10 minutes, then the supernatant was discarded and 1m of the sediment was homogenized. In both proceedings the samples were submitted to nucleated cell count. In order to evaluate the percutaneous administration of the bone marrow, in the 16 remaining rabbits an 1-cm osteal-periosteal segmental osteotomy in both radii was produced. Five days after surgery, the 16 rabbits were set apart in groups I and II, anesthetized and prepared for grafting. Each animal of group I received 1.0m of whole bone marrow in one radius (treatment), immediately after harvesting and 1.0m of physiological saline in the contralateral radius (control). In group II each animal received 1.0 of concentrated marrow in one radius (treatment) and 1.0m of physiological saline solution in the contralateral radius (control). Because of the physical characteristics of medulla, its harvesting was a simple proceeding with minimal trauma. It was necessary to heparinize the syringe, there was no damage to the osteogenic potential of the samples. In relation to sample processing, it was observed wide individual variation of the cellular count in both proceedings. Medullary concentration did not negatively interfere on the osteogenic potential. Percutaneous marrow grafting was a simple method, with no need of surgical approach and no introducing of devitalized tissue, reducing this way risk of infection and interference of bone repair. Radiographic evaluation of the operated limbs demonstrated bone marrow grafting effectiveness in osseous formation.