A preclinical canine model for composite tissue transplantation

Area of Science:

• Regenerative Medicine
• Transplantation Immunology
• Surgical Innovation

Background:

• Composite tissue allografts (CTAs) like hands and faces are feasible but require immunosuppression.
• Chronic immunosuppression poses significant risks to transplant recipients.
• Achieving immune tolerance is crucial to mitigate these risks.

Purpose of the Study:

• To develop a large-animal model for composite tissue allografts (CTAs).
• To evaluate the utility of a myocutaneous rectus flap in a canine CTA model.
• To assess allograft survival without post-transplant immunosuppression.

Main Methods:

• Autotransplantation of four canine myocutaneous rectus flaps based on deep inferior epigastric vessels.
• Five CTA transplants between dog leukocyte antigen (DLA)-identical littermates without immunosuppression.
• Clinical monitoring and routine biopsies of allografts.

Main Results:

• Autotransplantation and flap dissection were successful, demonstrating dual perfusion (skin and muscle).
• Flaps could be transplanted as skin, muscle, or combined components.
• DLA-identical littermates rejected allografts within 15 to 30 days.

Conclusions:

• The myocutaneous rectus flap is a versatile component for creating canine CTA models.
• This model facilitates the study of allograft rejection in the absence of immunosuppression.
• Further research is needed to develop tolerance protocols for CTA transplantation.