ABSTRACT
Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24). In the control group (n=6), the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group), the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.
Afecções ortopédicas em gatos são frequentes, podendo-se encontrar fraturas cominutivas, neoplasias ósseas ou não-uniões de fraturas. Uma opção para o tratamento dessas afecções é a utilização de enxerto ou implante ósseo. O objetivo deste trabalho foi avaliar implantes ósseos corticais alógenos conservados em mel, congelados ou liofilizados na substituição de segmento diafisário do fêmur de felinos. Foi confeccionada uma falha óssea na diáfise do fêmur de 24 felinos. Em seis felinos a falha foi preenchida com o próprio osso removido e nos outros 18 animais, com implantes ósseos corticais alógenos conservados em mel, congelados ou liofilizados. Os animais foram avaliados clínica, radiográfica e histologicamente durante 180 dias. A incorporação foi de 91,6% no grupo controle, com tempo médio para consolidação de 83,1 dias; no mel foi de 75%, com tempo médio de 105 dias; no congelado foi de 83,3% com tempo médio de 78 dias e no liofilizado foi de 25%, com tempo médio de 120 dias. A porcentagem de consolidação foi significativamente menor no grupo liofilizado em relação aos grupos congelado e controle. É possível concluir que os implantes ósseos autógenos e os conservados no mel e congelados são eficazes no preenchimento de defeito cortical em fêmur de felinos.
ABSTRACT
Transluminal coronary angioplasty is a routine therapeutic intervention in coronary heart disease. Despite the high rate of primary success, restenosis continues to be its major limitation. Porcine models have been considered to be the most adequate experimental models for studying restenosis. One limitation of porcine models is the need for radiological guidance and the expenses involved. The objective of the present study was to adapt an experimental model of angioplasty in the porcine carotid artery that does not require radiological equipment. Eight animals were used to develop the technique of balloon injury to the common carotid artery by dissection without radiological guidance. This technique was then employed in six other animals. Under anesthesia, the left common carotid artery was dissected and incised at the carotid sinus for insertion of an over-the-wire angioplasty balloon towards the aorta. Overstretch injury of the carotid artery was performed under direct visualization. After 30 days, the arteries were excised and pressure-fixated. Uninjured carotid arteries from 3 additional animals were used as controls. A decreased luminal area associated with intimal hyperplasia and medial reaction was observed in all injured arteries. Immunohistochemistry identified the intimal hyperplastic cells as smooth muscle cells. Computerized morphometry of the ballooned segments revealed the following mean areas: lumen 2.12mm2 (+ 1.09), intima 0.22mm2 (+ 0.08), media 3.47mm2 (+ 0.67), and adventitia 1.11mm2 (+ 0.34). Our experimental model of porcine carotid angioplasty without radiological guidance induced a vascular wall reaction and permitted the quantification of this response. This porcine model may facilitate the study of vascular injury and its response to pharmacological interventions.