Abstract
In young, growing white New Zealand rabbits the third, fourth, and fifth intercostal nerves were resected anteriorly on the right side. Six months later the animals developed structural left convex scoliosis, with a Cobb angle ranging from 15 to 31Β°. The vascular structure changes of the anterior chest wall were evaluated by measuring surface temperature and fluorescein intensity of the pectoral muscles, and the capillary density of the pectoral and intercostal muscle and periosteal parts of the ribs after angiography. In five normal control rabbits there was neither scoliotic deformity nor significant differences in the examined vascular variables between the right and left sides. In the animals undergoing resection, the temperature of the pectoral muscle on the side of the denervationβthe right sideβwas significantly increased (p < 0.05), but the difference was not correlated to the degree of scoliosis. The fluorescence index was significantly greater (p < 0.05) on the right than on the left side, this difference being fairly strongly correlated to the degree of scoliosis. The capillary densities of the costal periosteum and the intercostal and the pectoral muscle were significantly greater (p < 0.05) on the right than on the left side, and the difference was positively correlated to the degree of scoliosis. The volume density of the periosteum of the ribs was likewise significantly greater on the right. These results demonstrate that unilateral resection of the intercostal nerves significantly increase the vascularity of the structures on the denervated side of the thorax. This development may account for the greater longitudinal growth of the ribs on this side and for the development of the scoliosis observed in earlier studies.