Biomedical subjects

H Nettelblad

Publications and source records attributed to H Nettelblad.

27 records · Page 2Linked to original sources

PubMed1985

Short-term response of a skeletal growth plate to heterotopic microvascular transfer.

The capacity of the epiphyseal growth cartilage from the dog fibula to retain its growth potential after heterotopic transfer to a distal radial defect was investigated and compared to orthotopically transferred controls. Autoradiographs of the physes cultured in 3H-thymidine indicated continued proliferation of the growth cartilage in all revascularized transfers at the time of death, six weeks postoperatively. However, the nonvascular orthotopic controls did not incorporate the radioactive label. Fluorescent bone labels were incorporated in parallel bands in the metaphyseal bone, demonstrating linear bone growth in the revascularized transfers. Additional evidence for the viability of the transferred growth cartilage was obtained with histologic sections stained with hematoxylin and eosin and safranin-O. Roentgenograms and volume measurements showed a tendency toward hypertrophy of the heterotopic transfers.

Animals↗

PubMed1985

Vascularized bone allograft transplantation in a genetically defined rat model.

A heterotopic subcutaneous model for experimental vascularized bone allograft transplantation has been presented. This model uses genetically defined rats and allows serial assessment of graft viability. The reliability of this model has been proven by successful isograft transplantation. This model was used to study the effect of matching at the major histocompatibility complex on vascularized bone allograft survival. Whereas grafts transplanted across a minor histocompatibility barrier survived until sacrifice, grafts transplanted across a major histocompatibility barrier were victims of an acute rejection process. This study, therefore, showed genetic disparity to be a critical determinant of vascularized bone allograft survival. It indicates that primary vascularized bone allografts are as susceptible to rejection as heart and kidney allografts. For these reasons, it can be anticipated that genetic matching will be important in clinical vascularized bone allograft transplantation. The model used in this study should be useful for obtaining further fundamental immunologic information concerning vascularized bone allograft transplantation.

Animals↗

PubMed1985

Molded vascularized osteoneogenesis: a preliminary study in rabbits.

The clinical application of free vascularized bone grafting techniques in reconstructive surgery has limitations with respect to available donor sites and configuration of the graft. In this study, we were able to produce a vascularized bone graft with a predetermined size and shape by the use of titanium chambers implanted into the groins of rabbits. Forty adult New Zealand white rabbits were included in this study. In all animals, bone fragments were harvested from the iliac crests and placed within a titanium chamber. The chamber was positioned in the groin with the saphenous vessels passing through the chamber longitudinally in contact with the bony fragments. In half the animals, a segment of periosteum was harvested from the tibia and sutured around the vessels with the cambium layer facing the bone fragments. Sacrifices were performed at 4, 8, 12, and 16 weeks to examine the chamber contents. At all time periods, the contents completely filled the chamber, and the saphenous vessels remained patent. Histologic evaluation showed remodeling of the bone fragments as early as 4 weeks concomitant with a sprouting vascular network demonstrable with microangiography. Fluorochrome bone labels documented new bone formation within the chamber. These changes were progressive to week 12, but the 16-week specimens appeared to be undergoing resorption.

Angiography↗

PubMed1984

Physiologic isolation of the canine proximal fibular epiphysis on a vascular pedicle.

In order to create a model for epiphyseal growth plate transplantation by microvascular technique, a well-defined donor site was established. Dissection of latex-injected adult and juvenile dogs established the vascular supply to the proximal canine fibula. By isolating 7 cm of proximal fibula on the popliteal vessels, the nutrient supply to the epiphyses, metaphysis, and diaphysis is retained. This preserves the nutrient arterial supply to the fibula originating from the cranial tibial artery, the caudal tibial artery, and the small blood vessels from these to the epiphysis. Perfusion of the graft through the defined vascular pedicle was confirmed using 141Ce-labeled microspheres. These results showed a perfusion of the established graft that was as great as or greater than the control, unoperated side. It is concluded that the technique described for isolation can be used for developing a model for vascularized transplantation of epiphyseal growth cartilage in canines.

Animals↗

PubMed1984

Free microvascular epiphyseal-plate transplantation. An experimental study in dogs.

To evaluate the feasibility of transplanting vascularized epiphyseal plates while maintaining normal growth in the recipient site, twenty-two puppies from known, large breeds were divided into one control and three experimental groups of four animals each and one long-term group of six animals. The control group underwent insertion of a radiopaque marker in the fibular metaphysis bilaterally, and, in addition, a fibular osteotomy was performed on one side. In the experimental groups, a fibular switch was carried out, selecting one fibula as a vascularized graft and the other as a non-vascularized graft. Both the controls and the experimental groups were evaluated using serial roentgenograms, histological examination, fluorescent bone-labeling, and microangiography. One week, six weeks, three months, and seven months postoperatively, animals from each group were killed. Continuous growth was observed in the vascularized epiphyseal transplants and in the controls, with no statistical difference noted, whereas the non-vascularized transplants exhibited considerably less or no growth. Vascularized transplants demonstrated an average 21.2-millimeter increase in length while non-vascularized transplants showed a 6.6-millimeter increase. Histological examination, fluorochrome bone-labeling, and microangiography confirmed the continued viability of the vascularized epiphyseal transplants in contrast to the non-vascularized transplants.

Angiography↗

PubMed1984