The Efficacy Evaluation Of Rifapentine Polylactic Acid Microspheres On The New Zealand Rabbits With Spinal Tuberculosis

Objective: To determine the Rifapentine polylactic acid microspheres short-term local drug dose,which can prevent relapse in the successful model of the New Zealand rabbits after debridement. Methods: A total of 75 model of New Zealand rabbits with spinal tuberculosis were randomly divided into 5 groups(A, B, C, D, E, 15 rabbits in each group).were handled with partial decalcified allograft bone with different doses of Rifapentine polylactic acid microspheres in each group(group A : 3mg; group B : 6mg;group C :12mg; group D: blank microspheres; group E: 15mg) full filled the bone defect.General observation, iconography, pathology and bacteriology were checked at different postoperative time.Different doses of Rifapentine polylactic acid microspheres in each group with partial decalcified allograft bone full filled the bone defect after debridement of the model’s lesion, group A –E treated with doses of Rifapentine polylactic acid microspheres 3mg, 6mg, 12 mg, blank microspheres and 15 mg respectively. Then observe the activity, radiological films, pathological and bacteriological changes in different points postoperatively. Results: All of the 75 rabbits’ model survived during the experiment, 6 of them occurred paraplegia after operation. 15 days and 30 days later after debridement, the X-ray films could be found the clear damage in lumbar4, 5 vertebral body and intervertebral space. Sixty days later after operation, bone destruction could be seen in the X-ray films of lumbar 5 vertebral in different groups, 4 rabbits in group A(30.7%), 4rabbits in group B(30.7%), 2 rabbits group C(14.2%), 5 rabbits in group D(35.7%).15 rabbits in group E were not found clear changed in 8 weeks after the operation. In the recurrent rabbits after operation, the pathological and histological examination in group A,B, C, D showed pus cells and epithelioid cells, collected from vertebral body andparavertebral soft tissue sections with hematoxylin eosin(HE) staining, but In group E,there was no mycobacterium tuberculosis, only with many fibroblasts and lymphocytes.Conclution: In our experiment, the smallest dose of 15mg/3kg Rifapentine polylactic acid microspheres could prevent recurrence in the New Zealand rabbits with spinal tuberculosis after debridement shortly.