Medial shifting of the canine vocal cord by injection of isolated chondrocytes.

In the search for new materials to fill the unilaterally paralysed vocal cord, auto- and allogeneic chondrocytes were isolated from costal cartilage, and were injected into the canine vocal cord. The produced cartilage caused a thickening and shift of the treated cord towards the median line of the glottis. Such changes occurred in all autogeneic transplants, and persisted for the period of observation (up to 6 weeks). In allogeneic transplants, the effect was present after 6 and 12 weeks, but disappeared after 18 weeks. Cartilage produced by the autogeneic chondrocytes persisted at the site of injection without any signs of resorption. In contrast, allogeneic cartilage became surrounded by infiltrating cells and was slowly resorbed to disappear completely between the 12th and 18th weeks of observation. Immunosuppressive treatment of some of the allogeneic chondrocyte recipients reduced the lymphocytic infiltrations occurring, and inhibited the resorption of the reconstructed cord cartilage. Discontinuation of the immunosuppression, however, resulted in subsequent graft loss.