Ureteroscopy is needed to remove a stone/stones from the kidneys, which have not been able to normally pass through the ureter (connection between the kidney and the bladder).
Ureteroscopy involves the passage of a small fibroptic instrument called a ureteroscope through the urethra and the bladder into the ureter. This 3 mm diameter optical instrument is connected to a light source, sterile water irrigation and a camera. It also contains a working channel through which various instruments are introduced, such as metal guides, laser fibers and basket probes. As such, Dr Marois can actually look into the ureter, find the stone and remove it.
The manipulation of the instruments is done under direct vision and by fluoroscopic guidance (by X-rays).