Source: {"pile_set_name": "USPTO Backgrounds"}

The present invention relates to a kidney-ureter catheter assembly particularly adapted to evacuate crumbled calculi. More specifically the invention is designed to be used to achieve the drainage of calculus fragments resulting from the destruction of renal calculi through modern techniques using shock waves, ultrasounds or the like.
At the present time calculus fragments obtained as a result of the above therapy are directly evacuated through ureter and urethra. However this solution can give rise to a series of complications because, above all when calculi of great sizes are concerned, the obtained fragments can obstruct ureter owing both to their relatively important dimensions and to the fact that they are numerous.
On the other hand, it is to be noted that at the present state of the art the evacuation of said fragments through drainage cannot be obtained in a satisfactory manner. This is essentially due to the fact that ureter is a very delicate canal and has a very reduced clearance, so that it is almost impossible to introduce catheters or probes of appropriate sizes thereinto without the risk of its tearing.
For the above reasons the modern and advantageous techniques consisting in "bombarding" calculi by means of ultrasounds or the like cannot be used when renal calculi have relatively important sizes.