INNOVATION IN COMPOSITE TISSUE TRANSPLANTATION

P. Petruzzo¹, L. Badet¹, J. Kanitakis², S. Boutray³, J. Pialat⁴, P. Bureau du colombier⁵, A. Gazarian⁶, J.M. Dubernard¹, E. Morelon^1
1Dept Transplantation, Hopital Edouard Herriot, Lyon/FRANCE, ²Dept Dermatology, Hopital Edouard Herriot, Lyon/FRANCE, ³Inserm Research Unit 403, Claude Bernard Lyon I University, Lyon/FRANCE, ⁴Dept Radiology, Hopital Edouard Herriot, Lyon/FRANCE, ⁵Department Of Vascular Explorations, Hopital Edouard Herriot, Lyon/FRANCE, ⁶8. chirurgie De La Main Et Du Membre Supérieur, Polyclinique Orthopédique de Lyon, Lyon/FRANCE

Body: Introduction
On the basis of clinical experience composite tissue allotransplantations (CTA) have shown little evidence of chronic rejection. Consequently, the course of chronic rejection on bones, joints,nerves, muscles, tendons and vessels may have yet undescribed implications.
Methods
In five bilateral hand allografted patients (10, 7, 3, 2 and 1 year of follow-up respectively) and in one facial allotransplantation (4 years of follow-up) all these structures were assessed byhistology, magnetic resonance imaging (MRI), ultrasonography, high resolution peripheral quantitative computed tomography scan (HR-pQCT) and nailfold capillary microscopy.
Results
None of the recipients showed macroscopic signs of rejection when the biopsies were performed. All the recipients presented normal skin structure without dermal fibrosis. In 3 hand grafted patients(seven, two and one year after transplantation) deeper biopsies were performed showing sparse interstitial lymphocytic infiltrate.
In the bilateral hand grafted patients MRI and HR-pQCT system were used to study some tissues of CTAs even though they showed some limits due to the artefacts caused by the presence of metallicmaterials.
HR-pQCT showed in male patients a decrease in trabecular density in recipient as well as in graft bones, while in graft radius the alterations involved also the cortices. The reported alterations ofbone structure seem to be correlated to several factors, such as nutrition and recipient BMI, immunosuppressive treatment (steroid dose), recipient and donor age.
Nerves and tendons did not show any specific alteration on MRI and ultrasonography in any hand grafted patients. Muscles were the only tissue that showed some modifications. Indeed, MRI evidenced avariable degree of muscular hypotrophy, particularly of intrinsic muscles, accompanied by fatty degeneration. These alterations were not considered as signs of chronic rejection.
In the facial transplantation no significant differences between recipient and graft soft tissues were detected by ultrasonography and MRI.
Vessels were patent, without thrombosis, stenosis or visible intimal hyperplasia. Ten years after the transplantation the first recipient performed an angiography, which did not detect any stenosisor alteration of arterial silhouette.
No specific alterations were detected in the nailfold capillaroscopy of the hand grafted patients.
In all bilateral hand transplantations an increase in the score system values over the follow-up period was noted, with no decrease in the sensorimotor recovery.
In the case of face transplantation the patient recovered normal opening and complete closure of the mouth, and disappearance of inferior lip hypotonus while orbicularis muscle recovery is stillimproving.
Conclusion
No signs of chronic graft rejection have been detected in these patients on triple drugs immunosuppressive regimen. However, the possibility that chronic rejection may develop in CTA exists,highlighting the necessity of close continuous follow-up of the patients.

Disclosure: All authors have declared no conflicts of interest.