ABSTRACT
Objective@#This study aims to establish a model of prefabricated flaps on the back of rabbits, with the purpose to explore the optimal concentration of lead oxide suspension for microangiography.@*Methods@#Twenty clean grade male New Zealand white rabbits, with the weigh at 3.5-4.0 kg, were selected for the prefabricated flap model, pedicled with thoracodorsal vascular bundles, through 2-staged surgeries. Traditional flap model was established on the back of 2 rabbits. Small pieces of flap were taken for HE stain at 7th and 14th day after initial surgery. The time of second operation was determined by this result. Prefabricated flap models were established on the remained 18 rabbits, and divided into 9 groups. Nine different concentrations of lead oxide suspension (60%, 50%, 40%, 37%, 33%, 30%, 27%, 23%, and 20%) were injected through the aorta for each group, on 7 days after the 2nd surgery. The microangiographic results of gross specimen and prefabricated flap were observed by X-ray imaging.@*Results@#Microvascular lumens were observed by HE stain, on 14 days after the initial surgery. The number of microvessels in each 200× high power field, increased from 1-2 on day 7 to 10-20 on day 14. The vascularization process was mature. These suggest the prefabricated flap is ready for second surgery. Lead oxide perfusion angiography showed that there was non-development of tertiary arteries at 60% and 50% concentration. Tertiary arteries were not well developed at 40%, 37% or under 30% concentration. Clear arteriole development could only be obtained at 33% and 30% concentrations.@*Conclusions@#In this study, a rabbit model of prefabricated flap pedicled with thoracodorsal vascular bundles was successfully constructed by 2-staged surgeries. The microvasculature of the flap could be clearly displayed using lead oxide suspension with the concentration of 30%-33%.
ABSTRACT
The results of living iliac bone graft with microvascular anastomosis in 12 dogs were studied with microangiographic examination. Another 8 dogs with iliac bone graft without vascular anastomosis were also observed as the control. In 11 dogs with patent anastomosed vessels, microvessels were found to have distributed in the grafts two weeks after surgery. The majority of the microvessels in the newly formed bone which connected the graft and the host bone came from the graft and its periostium, only a small part of those originated from the host bone. This indicated that the bone grafts were surviving and participated in the healing process. In the dogs grafted without anastomosis, no microvessel was found in the specimens in the first four weeks after operation, only after 8 weeks, was a scanty amount of microvessels seen to have grown into the grafts from the surrounding soft tissues. This again proves that the "creeping substitution" of the vessels in the grafted bone which occurs in the conventional method of bone graft is very slow.
ABSTRACT
The structure and the blood supply of perichondral ring of human being and rabbits in developing period were studied by microangiographic and histological methods. Perichondral ring is situated around the epiphyseal disc and metaphysis and consists of osseous ring, zone of mesenchymal cell, which contains fairly abundant blood vessels derived from the metaphyseal periosteum and perichondrium. The perichondrium is thick and also contains abundant vessels which connect epiphyseal and metaphyseal circulations in the extra-osseous and part of which passes through the zone of mesenchymal cell to supply the epiphyseal disc. Role of perichondral ring in the development period of bones were discussed.
ABSTRACT
The distal femoral epiphyses of 18 human foetus and 10 children were studied by microangiographic and histological methods. The results showed that only the articular cartilage is avascular. Characteristic of vascularity in the chondroepiphyses is that the blood vessels coming from inter-condylar fossa are distributed in the center of chondroepiphyses, those coming from medial and lateral aspects of the condyles are distributed in the outer part of the condyles and those closing to epiphyseal plate mainly come from the area superior to the patellar surface and the area superior to the inter-condylar fossa. The secondary center of ossification first takes place around cartilage canal. The increase of the ossification center is faster in the areas adjacent to blood vessels than the areas far from blood vessels. The blood vessels within cartilage canals in the chondroepiphyses transform to epiphyseal vessels which remained as the blood supply to the ossification center during ossification process. Before 2 years of age, the blood vessels supplying the ossification center are 3-5 vessels coming from inter-condylar fossa. After 2 years of age, the blood vessels coming from the area superior to the patellar surface begin to supply the ossification center. After 5 years of age, the blood vessels coming from lateral aspects of the condyles also take part in the supply of the ossification center.
ABSTRACT
Cartilages of 19 human fetuses were studied by microangiographic and histological methods. Blood vessels were enclosed in a special structure, the cartilage canal which were present in individual cartilages from 2～3 months of the fetus. The cartilage canals developed either from the superficial blood vessels which was gradually embedded in the cartilage as it grew, or blood vessels in the cartilage canal grew and divided themselve progressively and penetrated into the deeper part of the cartilage. In addition to the nutritional supply for the centers of the growth of cartilage, the cartilage canal participates directly in the osteogenesis of the secondary centers of ossification.