[Reparative regeneration of nerve fibers after sympathectomy: an experimental study]

The results of sympathectomies depend on the degree of regeneration of the sympathetic nerve trunk: the quicker the onset of regeneration the less remarkable the effect of operation. The aim of our experimental study WPS to examine the rate of regeneration of sympathetic nerve fibers softer different sympathectomy techniques (resection, electrocoagulation and cryodestruction of the part of the sympathetic nerve trunk) following 6 and 12 months. Nine random-bred rabbits were used (Central Research Laboratory, Urals State Medical Academy) to examine the rate of regeneration of the sympathetic nerve trunk contained by the vascular-nervous bundle of rabbit ear. Altogether 18 nerve sympathetic trunks were examined. The rate of regeneration was measured by morphometry. While examining the processes of reparative regeneration of the nerve fibers after resection, electrocoagulation and cryodestruction, account was taken of the changes in their quantity, diameter and degree of myelinization over time. The study of the morphologic picture during comparative analysis of regeneration made on different models of nerve derangement has demonstrated that after resection and electrocoagulation of the sympathetic trunk the process of regeneration proceeds most slowly. On cryogenic injury to the nervous tissue when only nerve fibers are damaged and connective tissue membranes preserve their anatomic integrity, there are created most favourable conditions for regeneration. Toward 12 months after cryodestruction the bundles of nerve fibers acquire an identical diameter, with predominance of the population of thick nerve fibers, and appear mature enough. After electrocoagulation the fibers contained by the bundles are different in diameter, with the predominance of medium-diameter fibers whereas the thick nerve fibers are not many. After resection the thick nerve fibers are lacking whereas the medium-diameter bundles contain myelinated nerve fibers, with the maintenance of the selective decay of the myelin membrane.