Introduction: Flexible renoscopes offer access to almost all points within the collecting system. For stone workup, excellent visualization is mandatory. Therefore, irrigation flow is of critical importance. The aim of this study was to evaluate the effect of tools and probes on deflection angle and irrigation flow volume in the latest generation of flexible renoscopes. Methods: Five flexible renoscopes [Wolf (Viper), Storz (FlexX²), ACMI (DUR-8 Elite, DUR-D), Olympus (URF-P5)] were tested. Deflection angle, lowest diameter of the bent tip, and flow rates were measured. Recorded parameters were deflection angle and flow rate of the empty and loaded scopes. A laser probe (273 μm), biopsy forceps (2.4–3.0 French), and tipless nitinol baskets (1.5–2.4 French) were tested. Results: Deflection has no influence on flow rate. The size of the basket has no influence on the maximum angle of deflection. Introducing the laser fiber or the biopsy forceps leads to relevant loss of deflection (laser fiber: 4.44%–10.21%; biopsy forceps: 30.7%–57.8%). The inner diameter of the bent tip increases with introduction of a laser fiber (+1 to 3 mm) or the biopsy forceps (+13 to 34 mm). Flow rates are dependent on the size of the tool used. Loss of irrigation volume varies from 62.24% (1.5 French) to 99.1% (3.0 French). The use of a laser fiber leads to a decrease in irrigation volume of 53.7%. Conclusion: Irrigation flow, loss of deflection, and intraoperative visualization are dependent on the working tool used. The provided data, in awareness of the patient's anatomy, help to select scopes, probes, and tools correctly for successful ureterorenoscopy.

Tm:YAG vapoenucleation was introduced as a minimally invasive treatment in patients with benign prostatic obstruction. The efficiency and safety of Tm:YAG vapoenucleation must still be confirmed in large volume prostates to prove the size independence of this promising treatment option. We evaluated the safety and efficiency of Tm:YAG vapoenucleation in patients with a prostate volume of 80 cc or greater and benign prostatic obstruction during a 12-month followup. Included in this trial were 90 consecutive patients undergoing 90 W Tm:YAG vapoenucleation. Vapoenucleation was done using the 2 μm continuous wave Tm:YAG laser combined with a mechanical tissue morcellator. We analyzed patient demographic, perioperative and 12-month followup data. Complications were assessed. Mean preoperative prostate volume was 108.6 cc (range 80 to 200), mean International Prostate Symptom Score was 23.5 (range 8 to 35) and mean quality of life score was 4.3 (range 1 to 6). There was an 86% reduction (range 67% to 99%) in prostate volume on transrectal ultrasound by 12 months and an 88% decrease (range 58% to 100%) in prostate specific antigen. International Index of Erectile Function score remained stable. Peak urinary flow rate, International Prostate Symptom Score and quality of life improved significantly (p <0.001), as did post-void residual urine. The overall complication rate was manageable. Two patients required blood transfusion and 10 experienced early postoperative stress incontinence. During followup 7% of patients had symptomatic urinary tract infection and 2 had persistent grade I stress urinary incontinence. The reoperation rate due to urethral stricture was 1.8% during the 12-month followup. Tm:YAG vapoenucleation is a safe, effective and size independent treatment option for benign prostatic obstruction. As shown by reductions in transrectal ultrasound prostate volume and prostate specific antigen, complete removal of the adenoma can be achieved by this procedure.