Ex-vivo investigations on endoluminal laser therapy of varicosis – An optimization process

ObjectiveThis study was performed to compare the acute effects of different endoluminal heating procedures, by which obstruction of insufficient veins could be induced in an established standardized experimental ex-vivo model.MethodsThe model consists of the subcutaneous foot vein from recently slaughtered cows. Different energy sources (laser and radiofrequency), application devices and energy application parameters were compared in an iterative optimizing process. Following energy application the vein tissue was harvested and prepared for histology.ResultsBy means of the developed ex-vivo model reproducible conditions for the application of endoluminal thermal energy were enabled in each specimen. Radiofrequency-treated veins showed macroscopic shrinkage, contraction of vessels and induration of tissue. Histologically a circumferential and homogenous thickening of the vessel wall could be described. Dependent on the laser treatment protocol, in-situ dissection of the treated veins showed a broad spectrum of effects. These effects ranged from blood deposits in perivascular tissue and perivascular thermal lesions to transmural coagulated vein tissue inducing obstruction of the lumen.ConclusionThis standardized model is applicable to investigate acute effects of endoluminal treatment protocols. Changes in the protocol could be easily performed and investigated in order to develop optimized treatment protocols. These ex-vivo experiments indicate that endovenous laser treatment should be modified and needs treatment standardization to ensure a controlled homogenous circumferential thermal damage.