An extraperitoneal isolated vascularized bone marrow transplant model in the rat

Abstract

An isolated vascularized bone marrow transplant (iVBMT) model was previously developed in the rat to specifically study the role of bone marrow and its environment in a composite tissue allotransplant. An extraperitoneal model was successfully created to avoid laparotomy and cross-clamping of the great vessels. The extraperitoneal iVBMT model consisted of a left donor femur that was harvested with its nutrient vessels, anastomosed to the right femoral vessels in a syngeneic host, and then placed subcutaneously in the abdominal wall. At explant, the graft vessels were grossly patent, and histology of the graft bones showed a viable marrow compartment. Polymerase chain reaction demonstrated peripheral chimerism in the recipients. This model is technically simple with minimal morbidity in the recipient animals. By using the iVBMT, future studies across semiallogeneic and allogeneic barriers will help define the role of the bone marrow compartment in composite tissue allotransplants to potentially induce immune tolerance.

Chimerism induction in vascularized bone marrow transplants augmented with bone marrow cells

“…Although only a few studies have presented the results of isolated femur allotransplantations, 12,19,21,22 researchers are familiar with this source because of limb allograft studies in which the femur is considered to be the VBM source. The femur receives its blood supply from four arteries: the medial and lateral circumflex arteries, the superior genicular artery, and the muscular branch.…”

“…In the donor rat, the femur (the source of bone marrow) was harvested from the right side as described by Tai et al 19 The whole hind limb and the inguinal regions were shaved and cleaned with an antiseptic iodine solution. The rat was anesthetized with an intraperitoneal injection of pentobarbital (40 mg/kg) and was placed in the supine position.…”

“…Because of these drawbacks, other possible bone marrow sources have been studied that are simple to access, do not include different type of tissues, and leave no deformity in the recipient. Two such models in rats involve transplanting the femur 19 and the sternum 20 as VBM sources.…”

Tunneled superficial inferior epigastric artery (SIEA) myocutaneous/vascularized femur chimeric flaps: A model to study the role of vascularized bone marrow in composite allografts

“…2, top). Vascularized femur dissection and transplantation proceeded as previously described by Suzuki et al, 16 later refined by Siemionow et al, 12 and further developed by Tai et al, 17 who placed the transplanted bone into a subcutaneous groin pocket. Briefly, the investing femoral musculature was dissected taking care to preserve both the periosteum and the nourishing vasculature (lateral femoral circumflex and superficial circumflex iliac vessels).…”

Chimerism and bone marrow based therapies in transplantation

“…Suzuki et al 113 described a vascularized femoral BM transplant model and concluded that it was more useful than limb and sternum transfers in VBMT; and because this model did not include any tissue as additional bone, it was comparatively simple. Tai et al 114 introduced some modifications in this surgical procedure. Instead of using the abdominal cavity of the recipient, Tai et al placed the femoral bone into a subcutaneous pocket created in the anterior abdominal wall of the recipient in order to circumvent the need for laporotomy.…”