 Aim was to evaluate the amount of absorbed saline irrigation fluid during transurethral therapy of benign prostatic hyperplasia BPH. We want to differentiate two different methods of the surgical therapy: the TransUrethral Resection in Saline TURiS and the Photoselective Vaporisation of the Prostate PVP. Both methods using saline irrigation. To measure the amount of absorbed saline irrigation fluid, we added pure Ethanol to the Irrigation fluid resulting in am 0,02 ethanol containing saline irrigation fluid. The conventional TransUrethral Resection of the Prostate TUR method is using electrolyte free irrigation. In the literature this method is well known for the occurence of the transurethral resection syndrome TUR syndrome. This is caused by absorption of electrolyte-free irrigating fluid, followed by a hyponatraemic hyperhydration, and consists of symptoms from the circulatory and nervous Systems. 