[Light- and electronmicroscopical findings of CO2-laser induced alterations of blood- and lymph-vessels. A contribution to the problem of intraoperative tumor cell propagation (author's transl)].

The CO2-laser induced vessel alterations of the colon transversum of rats are analyzed with the light- and electron-microscope. In the superficial carbonization zone the vessels are irreversibly closed up to an diameter of about 250 mu. In the following "necrobiotic zone" we see a partial homogenisation of the walls of the vessels, which are in a whole contracted. The endothelial cells are either ruptured or at least swollen. Only occasionally we found obliteration of the vessels by intravasal thrombosis. On the contrary to the lased animals show those being operated on by conventional methods massive bleeding into the operating-field and into the submucous layer of the colon. The immediate sealing of the vessels in the "carbonization zone" impedes the initial step of forming metastases, i.e. the intravascular tumor cell propagation. The meaning of intravascular tumor cells in respect of following metastases is discussed.