Preliminary results on diode-laser assisted vaporization of prostate tissue

Abstract

<b>Introduction and objectives:</b> The aim was to identify the capability and the laser parameter of under water tissue vaporisation by means of a diode laser (1470 nm). Afterwards the feasibility and postoperative clinical outcome of vaporization of the prostate was investigated. <b>Method:</b> After acquiring suitable laser parameters in in-vitro experiments using a perfused tissue model patients (n=10) suffering from bladder outlet obstruction due to benign prostatic hyperplasia (BPH) were treated by diode laser. Their clinical outcome, in terms of acceptance and post-operatively voiding were evaluated. The diode laser emitted light of the wavelength of 1470 nm at 50 W (Biolitec GmbH) and delivered to the tissue by means of a side-fire fibre introduced through a 24F continuous-flow cystoscope. Normal saline was used for irrigation with an additive of 1% ethanol. The prostatic lobes (volume range 35-80ml) were vaporized within the prostatic capsular using sweeping and push and pull technique. The mean time of laser application was 2400 sec (1220-4000 sec) resulting in applied energies of 121 kJ in the mean (range: 61-200kJ). <b>Results:</b> During laser treatment none of the 10 patients showed any significant blood loss or any fluid absorption (no ethanol uptake). Foley catheters were removed between 18 and 168 hours postoperatively (mean: 49.8h&plusmn;46h). After removal of the catheter the mean peak urine flow rate increased from 8.9ml/s &plusmn; 2.9ml/s pre-operatively in comparison to 15.7ml/s &plusmn; 5 ml/s (p=0.049) post-operatively. 8/10 patients were satisfied with their voiding outcome. None of the patients showed appearance of urgency, dysuria, hematuria, or incontinence but two patients required re-catheterization. After a follow-up of 1month, 8/10 patients showed evidence of good results and are satisfied with the outcome. Two patients required consecutive TUR-P. After a follow-up of 6-month the 8 patients are still satisfied. <b>Conclusions:</b> This very early and limited experience using a 50W-Diode laser emitting at 1470 nm indicates a safe and effective treatment modality for quickly relieving bladder outlet obstruction due to BPH. Larger randomized clinical trials to compare this technique with standard transurethral resection of the prostate and increased follow-up data are needed to determine its long-term efficacy and durability.