High-pressure balloons can be designed to perform several tasks at once. For procedures
that require the balloon to perform multiple functions, such as occlusion and device
positioning, a high-pressure balloon performs very well.
A treatment for benign prostate hyperplasia (BPH) involves the application of thermal
energy to the prostate with a microwave antenna inside a balloon. Microwave energy
is emitted through the walls of the balloon, heating the prostate from the inside
out as the microwaves penetrate the tissue. The antenna must be cooled during the
procedure to keep it from overheating. That is achieved with a cooling fluid that
also cools the lining of the urethra protecting it from thermal damage. As an added
function, a small side lumen is added to the cooling balloon that positions a thermal
sensor precisely relative to the curve of the catheter and holds it against the
tissue being treated. The sensor can be used to control the energy level of the
microwave antenna and cut off power if the temperature gets too high.
This photograph shows the cooling balloon and the sensor
side lumen used in the treatment of BPH. The small black dot shown close-up is a
temperature sensor.