Tuesday, November 5, 2002
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Canine Hemifacial Composite Tissue Transplantation by Local Immunosuppression

Ergin Er, MD, Selçuk Işık, MD, Murat Yarim, PhD, Hüsamettin Gül, MD, and Mustafa Şengezer, MD.

In this experimental study, canine hemifacial allogeneic composite flaps were harvested and transferred on their vascular pedicles. Besides, a local immunosuppressive strategy was accomplished by intra-arterial slow-delivering miniostotic pumps and the effect of this system was investigated. This study was achieved on 12 dogs, two of them being cadaveric study ( 12-15.5kg., 10-16 months-old). 2 groups were consructed between MHC mismatched dogs (N:5). Hemifacial allogeneic composite flaps were harvested in both groups on external carotid artery and external jugular vein pedicle and transferred by microvascular technique under general anestesia. Local immunosuppression was achieved in experimental group for 15 days. No immunosuppression was given to control group. Flap rejection was observed macroscopic and microscopic examinations.Tissue CsA levels were measured in tissue biopsies of experimental group on 6th day postoperatively. Statistical analysis was performed by Mann-Whitney-U test. All the dogs were survived at postoperative period. Allograft rejection time was 3,8±0,8 days in control group and 22,2±1,4 days in experimental group respectively. (p<0.005). Mean CsA concentrations were as follows:1636±104 ng/gr tissue in allograft skin and 282±12 ng/gr tissue in the skin of other side of the face, 818,4±11 ng/ gr. tissue in allograft muscle and 284±20 ng/gr.tissue in other side’s facial muscle, 1184±74 ng/gr tissue in flap mucosa and 530±25 ng/gr tissue in the other side (p<0.001). Systemic CsA level was 87,2±6.7 ng/ml. Microscopically, acute rejection morphology was observed at postoperative 4th day in control group. In the experimental group, the tissue biopsies obtained at 6th and 15th days postoperatively revealed minimal inflamation . As a result, in this experimental study hemifacial composite tissue transplantation was achieved in a big animal model by local immunosuppressive strategy, which is the first report in scientific literature. We think facial reconstruction can be achieved by successful clinical hemifacial transplantations in the future
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