Medical devices and apparatus for cardiac ablation procedures, namely, introducer for venous access, dilator and guide wire, and parts and fittings therefor; cardiovascular catheters and stents; artificial vascular grafts, synthetic stent grafts, vascular stents; endovenous treatment devices for treating venous disease; medical instruments, namely, laser fiber for endovenous laser ablation of varicose veins; medical ultrasound apparatus, namely, medical devices with echogenic surfaces produced by coatings that enhance ultrasound imaging and ultrasound imaging in procedures; medical ultrasound apparatus, namely, medical devices with echogenic surfaces produced by mechanical roughening of the surfaces that enhance diagnostic ultrasound imaging and ultrasound imaging medical procedures; catheters; catheter components; medical devices, namely, percutaneous ultrasonically guided catheter introducers; medical apparatus, namely, ultrasound doppler guided needles used for vascular access for veins and arteries; multi-lumen central venous catheters; single-lumen central venous catheters; medical apparatus, namely, implantable ports; and medical guidewire introducers; medical devices, namely, doppler ultrasound and blood pressure computerized apparatus for measuring blood flow velocities and/or pressure gradients in coronary and peripheral vasculature; intravascular ultrasound catheter used to visualize coronary and peripheral vessels