耳鼻科領域における形成用硬性資材, 特に保存同種骨に関する実験的研究

抄録

The author conducted an experimental study of the preserved homogeneous bone as part of a series of experiments of grafting materials in the field of otolaryngology.
Sixty-two rabbits were divided into two groups, one consisting of 18 rabbits and the other of 44 rabbits. The rabbits of the first group was further divided into three groups, rabbits grafted with a preserved homogeneous bone, rabbits grafted with fresh autogeneous bone and rabbits grafted with a fresh homogeneous bone.
An iliac bone was grafted upon the bridge of the nose after the periostium had been removed. The grafted bone was histologically examined by H-E stain and PAS-stain at 2, 4, 8 and 24 weeks. Serum protein fractions were also examined to study the effect of the transplantation upon the rabbits. Changes in eash fraction especially in γ-globulin, were also studied.
The rabbits of the second group were also divided into three groups and bone grafting was performed in the same manner as in the first group. To determine the biological stability of the grafted bones, they were removed at 3 days, 1, 2 and 4 weeks and grafted again on the same site of the nasal bone.
The changes in the grafted bones were histologically examined. Homogeneous bones were grafted after preservation in a refrigerator at -20°C for two weeks.
The following results were obtained from this experiment.
1) The preserved homogeneous bones showed much the same satisfactory results as the autogeneous bones. Satisfactory bone fusion occured in two months after grafting, and osteogenesis also appeared. Although it was unable to confirm whether the new bone developed from the preserved bone or from the recipient, the author presumed that the preserved bone possesses such osteogenetic potency that activates the host to such an extent as to promote osseous fusion.
2) Absorption and substitution by the connective tissue were slower in the preserved homogeneous bone than in the autogeneous bone. This tendency was by far more marked after regrafting.
3) Histological and serological examination revealed the difference in biological characteristic between the preserved homogeneous bone and fresh homogeneous bones.
4) In the group of rabbits grafted with a fresh homogeneous bone, many developed sequestrum or abscess, whereas the group of rabbits grafted with a preserved homogeneous bone showed much the same biological stability as the group of rabbits grafted with autogeneous bone. This difference was by far more marked after regrafting.
5) The serum protein fractions, especially, γ-globulin, changed with time in the group of rabbits grafted with a fresh homogeneous bone. On the other hand, there was little or no difference between the group grafted with a preserved homogeneous bone and the group grafted with autogeneous bone.
6) Although it was difficult to demonstrate the antigenicity of the bone, the preserved frozen bone was as excellent as the autogeneous bone in this experiment. It may therefore be reasonable to presume that the antigenicity of the bones was reduced during their preservation in a refrigerator. Successful osseous grafting with the homogeneous or heterogeneous bone, largely depends upon immunological factors.
7) The author concluded that local blood circulation, proper fixation of the graft and prevention of infection were the prerequisite for a successful grafting of the bone.