[The bladder-stone punch--a new principle of visual lithotripsy (author's transl)].

Description of a bladder-stone lithotriptor which works similarly to a punch resectoscope. This 24 French instrument can be used in simultaneously with electrohydraulic lithotripsy (Urat I), i.e., stones of the size of a cherry can be simply punched, while all larger stones may be destroyed first by electrohydraulic lithotripsy and then cut into smaller pieces for removal with the punch. The instrument, with irrigation qualities and a sight like a resectoscope, allows a quick operation, so that lithotripsy and TUR of the prostate may be performed opportunely.