骨移植における血管像の変化に関する実験的研究 形態学的研究およびマイクロスフェアー法による血行動態測定

Abstract

Vascularization of grafted bones has been the title of a number of morphological studies. However, there are few published papers following up dynamic changes of blood flow in process of vascularization. In view of these facts, I investigated a morphological study concerning vascularization of grafted bones and also diurnal dynamic changes of blood flow in grafted bones using the microsphere technique.MethodsUsing male wister rats as test animals, autologous tibia (about 1 cm) was grafted into the bipedicle tubed abdominal flap (4×2cm) established on the abdominal wall. The animals were sacrificed at 3 days, 1, 2, 3 and 4 weeks after the bone graft, and pathological preparations and transparent preparations were prepared. Then, microsphere 125I was injected into the left venticle immediately and at 3 days, 1, 2, 3 and 4 weeks after the operation, and radioactivities were counted by Beckman Ganma Radiation Counter. By using a Mutoh Desitizer, the bone reconstruction rate was determined.Group A...Tibia without periosteumGroup B...Longitudinally-cut tibia without periosteum and marrowResults1. Vascularization in the bone grafted into the flap1) In both Groups A and B vascularity appeared at day 3 after the operation.2) Vascularization in the cortical bone of the grafted bone appeared earlier in Group B as compared to Grooup A.3) In Group A, the medullary vascularization almost completed in about 3 weeks, at which period vascularization in the cortical bone exceeded that observed in Group B.4) Changes in blood flow determined by the microsphere technique showed almost similar patterns for both Groups A and B: Namely, the blood flow showed an increasing tendency to reach its peak at week 2, followed by a decrease at week 3 and slight increase at week 4.2. Bone reconstruction associated with vascularization1) Bone reconstruction appeared at week 1 after the operation and it occurred in the region where accelerated vascularization was seen.2) In Group B, bone reconstruction started in the earlier stage and progressed gradually in the entire grafted bone. Until week 2, the bone reconstruction in Group B was superior to that in Group A.3) In Group A, the bone reconstruction exceeded that of Group B from week 2. In particular active bone reconstruction was seen in the medullary cavity where pronounced vascularization was observed.