Medical devices, namely, surgical devices that facilitate endovascular treatment of biologic tissues; Medical and surgical devices and instruments, namely, catheters for the endovascular ablation, ablation, cauterization and hemostasis of tissue; Medical and surgical devices and instruments, namely, ablation catheters for the endovascular ablation, cauterization and hemostasis of vascular structures; Medical and surgical devices and instruments, namely, catheters for the endovascular treatment, ablation, cauterization and hemostasis of tissue that comprise of an electrode in the catheter tip for generating thermal energy; Medical and surgical devices and instruments, namely, catheters for the endovascular treatment, ablation and isolation of tissues using an energy source located in the catheter system for generating ablative energy; Medical and surgical devices and instruments, namely, catheters for the endovascular treatment ablation, cauterization and hemostasis of biological tissue.