Prostate volume reduction following pure transurethral bipolar plasma vaporization and conventional transurethral resection of the prostate: a prospective investigation using transrectal 3D ultrasound volumetry.

PURPOSE: To evaluate and compare postoperative changes in prostate volume and clinical outcome after bipolar plasma vaporization (BPV) and conventional transurethral resection of the prostate (TURP). PATIENTS AND METHODS: Consecutive series of patients undergoing BPV or TURP were included in this prospective, nonrandomized study. Planimetric volumetry after transrectal three-dimensional ultrasound of the prostate was performed preoperatively and postoperatively after 6 weeks, 6 months and 12 months. Additionally, changes in clinical outcome parameters were assessed and compared between the groups. The reduction ratio and analysis of covariance were used to compare volume changes between BPV and TURP. Multiple regression analysis was performed to assess a possible interaction between preoperative prostate volume and effect of therapy. RESULTS: A total of 157 patients were included (BPV: n = 68, TURP: n = 89). Median preoperative prostate volume was 43.1 ml in the BPV group and 45.9 ml in the TURP group (p = 0.43). Postoperatively, the prostate volumes decreased significantly in both groups. After catheter removal, the relative residual prostate volume was significantly higher in the BPV group (66.6 vs. 60.8 %; p = 0.02). Thereafter, significant differences were not detectable anymore (12 months: 46.6 vs. 47.1 %; p = 0.82). Regression analysis revealed that tissue ablation after BPV was superior to TURP in prostates <45 ml but inferior in prostates >45 ml. All clinical outcome parameters improved significantly and were not significantly different between the groups. CONCLUSIONS: Volume reduction and short-term clinical outcome following pure BPV was excellent and comparable to conventional TURP. However, volume reduction seems to be limited in patients with larger prostates.

Absorption of irrigation fluid occurs frequently during high power 532 nm laser vaporization of the prostate.

PURPOSE: Absorption of irrigation fluid was not detected during GreenLight™ laser vaporization of the prostate using the first generation 80 W laser. However, data are lacking on intraoperative irrigation fluid absorption using the second generation 120 W high power laser. We assessed whether fluid absorption occurs during high power laser vaporization of the prostate. MATERIALS AND METHODS: We performed this prospective investigation at a tertiary referral center in patients undergoing 120 W laser vaporization for prostatic bladder outlet obstruction. Normal saline containing 1% ethanol was used for intraoperative irrigation. The expired breath ethanol concentration was measured periodically during the operation using an alcometer. The volume of saline absorption was calculated from these concentrations. Intraoperative changes in hematological and biochemical blood parameters were also recorded. RESULTS: Of 50 investigated patients 22 (44%) had a positive breath ethanol test. Median absorption volume in the absorber group was 725 ml (range 138 to 3,452). Ten patients absorbed more than 1,000 ml. Absorbers had a smaller prostate, more capsular perforation, higher bleeding intensity and more laser energy applied during the operation. Three patients (13%) had symptoms potentially related to fluid absorption. Hemoglobin, hematocrit and serum chloride were the only blood parameters that changed significantly in the absorber group. The changes were significantly different than those in nonabsorbers. CONCLUSIONS: Fluid absorption occurs frequently during high power laser vaporization of the prostate. This should be considered in patients who present with cardiopulmonary or neurological symptoms during or after the procedure.

Ablative efficiency of 532-nm laser vaporization compared to transurethral resection of the prostate: results from a prospective three-dimensional ultrasound volumetry study.

PURPOSE: To assess and compare postoperative prostate volume changes following 532-nm laser vaporization (LV) and transurethral resection of the prostate (TURP). To investigate whether differences in volume reduction are associated with differences in clinical outcome. METHODS: In this prospective, non-randomized study, 184 consecutive patients undergoing 120 W LV (n = 98) or TURP (n = 86) were included. Transrectal three-dimensional ultrasound and planimetric volumetry of the prostate were performed preoperatively, after catheter removal, 6 weeks, 6 and 12 months. Additionally, clinical outcome parameters were recorded. Mann-Whitney U test and analysis of covariance were utilized for statistical analysis. RESULTS: Postoperatively, a significant prostate volume reduction was detectable in both groups. However, the relative volume reduction was lower following LV (18.4 vs. 34.7 %, p < 0.001). After 6 weeks, prostate volumes continued to decrease in both groups, yet differences between the groups were less pronounced. Nonetheless, the relative volume reduction remained significantly lower following LV (12 months 43.3 vs. 50.3 %, p < 0.001). All clinical outcome parameters improved significantly in both groups. However, the maximum flow rate (Q max) and prostate-specific antigen (PSA) reduction were significantly lower following LV. Subgroup analyses revealed significant differences only if the initial prostate volume was >40 ml. Re-operations were necessary in three patients following LV. CONCLUSIONS: The modest but significantly lower volume reduction following LV was associated with a lower PSA reduction, a lower Q max and more re-operations. Given the lack of long-term results after LV, our results are helpful for preoperative patient counseling. Patients with large prostates and no clear indication for the laser might not benefit from the procedure.