Convective Water Vapor Energy (WAVE) is a unique, natural and powerful thermal therapy technology with the potential to treat a variety of endourology conditions.
A Unique Form of Thermal Therapy
WAVE technology begins with a few drops of sterile water which are heated, converted into vapor (steam), and delivered into targeted areas of tissue. As the vapor condenses back to its liquid state, a vast amount of stored thermal energy is released into the tissue, causing the cell membranes in the treatment area to rupture. Over time, this ablated tissue is almost completely absorbed by the body’s natural healing response, reducing the volume of tissue.
Delivering Thermal Energy in the Form of Water Vapor
In a hand-held delivery device connected to a generator, a few drops of sterile water is heated to approximately 103ºC. As the sterile water is transformed from liquid into steam, or vapor, the volume expands by almost 1,700 times and stores 540 calories of thermal energy for every milliliter (mL). Currently, a typical WAVE technology treatment uses less than 0.5 mL of sterile water for each treatment.
A precise dose of water vapor thermal energy is delivered into the targeted tissue using a small needle with multiple emitter holes to ensure controlled and uniform vapor dispersion. The vapor is delivered into the targeted tissue at slightly above interstitial pressure, convectively driving the water vapor through tissue interstices, where it condenses and transfers the stored thermal energy directly to the targeted tissue. This convective heat transfer is what differentiates WAVE technology from other ablative thermal therapies that rely on the slower, less precise and less efficient process of conduction to heat tissue.
Convective transfer of vapor thermal energy to tissue is fast but also self-limiting. Vapor condenses back into its liquid state as it is dispersed through tissue, so the energy travels no further than its intended area of treatment. The prostate is comprised of three separate zones or regions and the enlarged tissue that causes BPH is located in two of them – the transition zone and the central zone. The tissue separating these zones provides a natural anatomical barrier that contains the vapor within the intended treatment areas.
The WAVE technology’s thermal energy transfer occurs only at the point of condensation. This energy release within the targeted area causes almost instantaneous death of tissue cell membranes, including the nerves, as well as collapse of the blood vessels. The body’s natural healing response then resorbs and removes the treated tissue, reducing the obstructive condition.
WAVE technology offers a unique and efficient means for thermal energy transfer and is currently being used to treat BPH and assessed for use in other endourology conditions.