New Developments in Urology Probes

Urology probes are used for treating a variety of disorders including prostate, renal and urinary tract cancers, and urinary and renal obstructions. They are also used for imaging the urinary tract.

Cryoablation probes are used to treat prostate cancer in a minimally invasive technique that has entered wider use in recent years. In cryoablation, an extremely small cryoprobe (2.4mm-.36 mm) and a thermoprobe are inserted through the perineum and are used to freeze the prostate gland in a controlled process that destroys the cancer at the molecular, cellular and tissue levels. The procedure is often used as a second tier treatment in cases where radiation treatment fails or when the cancer recurs following radiation. The freezing process is monitored via a transrectal ultrasound probe.

Various types of lithoscopy probes are used to break up and remove biliary and urethral stones. Electrohydraulic lithotripsy (EHL) probes are comprised of two electrodes, with insulation between them. A spark is generated at the end of the probe by activating an electric current between the electrodes, vaporizing a drop of fluid that is at the end of the probe. The cavitation bubble that results from vaporization of the fluid expands rapidly, creating shock waves that cause the stone to fragment. Each disposable EHL probe is used for just one patient.

Ultrasonic lithotripsy probes are positioned percutaneously via a rigid endoscope. The procedure differs from electrohydraulic lithotripsy in that the probe must form a straight channel through which ultrasound waves can reach the stone, since deflection results in significant decrease in power. Mechanical and ballistic lithotripsy probes are inserted via endoscope as well, and use pneumatically propelled projectiles to break up the calculi. In recent years, physicians have come to prefer laser-equipped lithotripsy probes that fragment stones effectively and result in fewer complications.

Urology probes are used in additional cystoscopy procedures such as viewing the inner surfaces of the urinary tract and treating a variety of urinary conditions via microsurgery.

In recent studies, optical coherence tomography (OCT) probes have been proven effective at imaging cross-sections of the upper urinary tract at resolutions of 10 to 20 µm. The probe was inserted through a cytoscope and urinary catheter. In the studies, physicians were able to distinguish between the different layers of the urinary tract and identify urothelial cancers in vivo.