小型猪减压性骨坏死病理及血液流变学改变

目的 通过反复加减压建立小型猪减压性骨坏死模型并观察其血液流变学改变.方法 12头小型香猪,每周2～3次暴露于0.45 MPa加压舱内,每次6 h,1 min匀速减至常压.用锥板式黏度计测定全血黏度,光镜下血小板计数,反复加减压3个月后进行股骨同位素发射计算机扫描(ECT)及组织病理学检查.结果 ECT检查发现,动物股骨头同位素聚集增加,骨病理检查发现股骨发生缺血性坏死改变,血小板计数随加压次数增多而进行性降低,低剪切率下全血黏度则进行性升高.结论 减压性气泡引起的血小板消耗、血黏度增高是骨缺血坏死的原因之一.

Changes of histopathology and blood viscosity in mini pigs with dysbaric osteonecrosis

Objective To develop the dysharie osteonecrosis (DON) model in mini pigs induced by rapid decompression, following repeated hyperbaric exposures and observe changes in blood rheology in DON. Methods Twelve male mini pigs were exposed to compressed air of 0.45 MPa for 6 hours twice to three times a week and were then brought to the surface with linear decompression at a rate of 0.35 MPa/min. Blood viscosity was measured with cone-plate type viscosimeter, platelet count was made under the light microscope. Emission of computed tomography (ECT) and pathologic examination were performed for the evaluation of accumulated rate of 99Tc in the femur, following 3 months of repeated compression and decompression. Results ECT showed an increased accumulation of isotope in the femur, when a comparison was made between the experimental animals and the control. Osteopatholngy revealed changes of osteonecrosis in the femur. Platelet count decreased progressively with frequencies of pressure exposures, and meanwhile blood viscosity also increased progressively at a low shear rate. Conclusions Dysharie osteronecrosis was usually accompanied with bone ischemia. Platelet consumption and increased blood viscosity induced by decompression bubbles could be attributed to decreased blood flow in the bone, resulting in osteonecrosis.