SYSTEMS, METHODS, AND CATHETERS FOR ENDOVASCULAR TREATMENT OF A BLOOD VESSEL

Systems for forming a fistula between two blood vessels are provided. In embodiments, the system may include a catheter having a housing and a treatment portion coupled to the housing. The treatment portion may include a thermoelectric generator comprising an exposed surface exposed outside of the housing and a concealed surface opposite and electrically connected to the exposed surface. The thermoelectric generator may be configured to produce a temperature differential between the exposed surface and the concealed surface when an electric current is applied to one of the exposed surface and the concealed surface thereby producing the temperature differential between the exposed surface and the concealed surface such that the exposed surface is heated to a temperature greater than the concealed surface to weld the two blood vessels together.