J Reconstr Microsurg
DOI: 10.1055/s-0040-1718394
Original Article

Effects of VEGF on Prefabricated Vascularized Bone Allografts in Rats

1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
,
Yoshio Kaji
1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
,
Osamu Nakamura
1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
,
1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
,
Kunihiko Oka
1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
,
Tetsuji Yamamoto
1  Department of Orthopaedic Surgery, Kagawa University Faculty of Medicine, Miki-cho, Kita-gun, Kagawa, Japan
› Author Affiliations
Funding This study was supported by grant-in-aid for scientific research.

Abstract

Background Massive bone defects after wide resection of malignant bone tumors or a serious injury require treatment using vascularized bone grafts. Although cadaveric bone allografts combined with vascularized bone autografts are currently thought to be ideal in terms of size and durability, this treatment requires the scarification of healthy bone tissue. In a previous study, we attempted to improve this situation by prefabricating a vascularized bone allograft in recipient rats. In this study, we added vascular endothelial growth factor (VEGF)-containing hydroxyapatite/collagen composite (HAp/Col) to a prefabricated vascularized bone allograft to stimulate angiogenesis, which is known to be important for bone formation.

Materials and Methods Sprague Dawley rats (n = 50) were used as donors and Wistar rats (n = 50) as recipients. All rats were 9 weeks old. The recipient rats were divided into five groups according to the use of vascular bundles, HAp/Col, and an additive substance (VEGF). The bone allografts collected from the donors were transplanted into the thigh region of the recipients, and a saphenous vein and 10 μg HAp/Col with VEGF were inserted into the bone allografts through the slit. After 4 weeks, the transplanted bone allografts were harvested, and histologic and genetic evaluations were performed in relation to bone formation and resorption.

Results The results showed that, compared with the control group, the implantation of the vascular bundles and VEGF-containing HAp/Col significantly stimulated angiogenesis and bone formation in the rats with the bone allografts. However, histological and genetic evaluations of bone resorption revealed that resorption was not observed in any group.

Conclusion These results suggest that VEGF-containing HAp/Col effectively stimulates angiogenesis and bone formation, but not bone resorption, in prefabricated vascularized bone allografts. This method could therefore become a useful tool for treating large bone defects.



Publication History

Received: 14 January 2020

Accepted: 25 August 2020

Publication Date:
14 October 2020 (online)

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