First Results of Ultrasound Controlled Laserresection in Wilmstumors in Children

Abstract

The physiological characteristics of newborn children and small infants suit the laser method. These characteristics are the smallness of organs and the small diameter of the vessels and lymph channels. A number of technical possibilities have made operations on parenchymatous organs such as liver, spleen and especially kidney safer, with the loss of blood being considerably reduced. The interaction of the laser beam with tissue consists above all thermal effects. At moderate energy supply the heat being generated during absorption of laser radiation causes denaturation of proteins (2). At higher temperatures, the tissue is vaporized, thus a cutting effect being achieved. Cutting is therefore a combination of vaporization in the center and coagulation at the edges. A very important result of coagulation is the closing of vessels, thus the laser method allowing surgery with the low loss of blood. Histological and EM-investigations demonstrate the occlusion of the lymph passways and the zone of cellular destruction of parenchymatous tissue by the laser beam (3). During a period of 14 to 21 days a neocapsula developed thus being caused by fibroblast grafting. On an average, a necrosis seam on 5–7 mm formed. Thus a safe closure of the vessels situated in the tissue could be obtained (4, 5, 6).