Bipolar RF systems, such as the Vessix V2, deliver energy using the electrical phenomena of ohmic resistive heating to the adjacent tissue and deliver electrical energy between two electrodes, which in the case of the V2 catheter are within a few millimetres of each other.  The V2 confines its energy delivery to an area very close to the two electrodes and moreover, thermistors mounted at each electrode pair allow for precise monitoring and temperature control at each independent electrode pair.  This delivery of energy causes thermal heat to perfuse through the artery wall into the adventitia layer of the artery and results in denervation of the target renal sympathetic nerves. The RF energy treatment, in effect, denervates the renal sympathetic nerves surrounding the renal artery without creating any flow limiting stenosis or any other deleterious effects to the renal artery. Bipolar systems do not unnecessary dissipate energy into areas further away from the electrode, and thus use energy very efficiently.  Accordingly, the V2 bipolar System uses lower voltages and power to achieve necessary depth of penetration. 

In a clinical procedure, standard angioplasty techniques are employed to gain access to the renal artery. The RF generator provides visible images to guide the operator through setup and treatment steps. Next, the balloon catheter is then inserted and placed in the renal artery. The balloon is then inflated at very low pressure (3 atmospheres) and then activated to provide a low power RF energy treatment over the length of the renal artery for 30 seconds. Impedance is used to determine apposition of the balloon catheters electrodes to the artery wall and temperature is constantly monitored and RF energy delivery is regulated according to a predetermined temperature control algorithm. This delivery of energy causes thermal heat to perfuse through the artery wall into the adventitia layer of the artery and results in denervation of the target renal sympathetic nerves. The RF energy treatment, in effect, denervates the renal sympathetic nerves surrounding the renal artery without creating any flow limiting stenosis or any other deleterious effects to the renal artery or the kidney.

Key benefits of the Vessix approach to renal denervation include:

• Employing a balloon catheter that is quite familiar to interventionists thereby increasing the safety profile of the device

• Ability to deliver RF treatment that lasts only thirty (30) seconds per artery which, in turn, significantly reduces discomfort for the patient

• Fast RF treatment time greatly increasing the efficiency of the procedure and provides the benefit of lower exposure to radiation, lower amount of contrast dye and therefore lower renal toxicity to the patient.