[Healing of free vascularized bone allotransplants: optimizing by short-term immunosuppression and host-derived neovascularization].
BACKGROUND
Living bone allotransplants (ATs) currently require long-term immunosuppression (IS), but this is impractical for extremity-preserving procedures. An alternative method to maintain viability of the transplant uses host-derived neoangiogeneic vessels combined with short-term IS.


METHODS
Diaphyseal femoral defects in Dutch-Belted rabbits were reconstructed with a free microvascular AT from New Zealand White rabbits. Additionally, a host-derived intramedullary pedicled fascial flap was placed and short-term IS administered to two of four groups. Neovascularization and bone healing were quantified by microangiography and a custom radiographic score.


RESULTS
Bone ATs with perfused fascial flaps achieved bone healing equivalent to autotransplant controls, even when they received IS only until host-derived neoangiogenesis replaced the original perfusion. Vascularized ATs without this combination achieved significantly inferior results.


CONCLUSIONS
This rabbit model demonstrated that increased bone turnover allows good healing but may temporarily weaken the allotransplant. However, by the more intense replacement of the graft with host-derived cells, this process may, in the long-term, ultimately result in a better transplant than an avascular graft.
Giessler
G A
GA
Klinik für Hand, Plastische und Rekonstruktive Chirurgie, Schwerbrandverletztenzentrum, BG Unfallklinik Ludwigshafen, Ludwigshafen am Rhein, Germany. giesslerplasticsurgery@hotmail.com
Friedrich
P F
PF
Shin
R H
RH
Bishop
A T
AT
D016025:Bone Transplantation / Q000379:methods*; D017102:Fracture Healing / Q000187:drug effects; D050723:Fractures, Bone / Q000188:drug therapy* / Q000601:surgery*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D018919:Neovascularization, Physiologic / Q000187:drug effects; D000092464:Elbow Injuries
D007166:Immunosuppressive Agents