Nico C. Grossmann

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.

Pure bipolar plasma vaporization of the prostate: the Zürich experience.

INTRODUCTION AND OBJECTIVES Bipolar plasma vaporization (BPV) has been introduced as an alternative to transurethral resection of the prostate (TURP). Promising short-term results, but inferior mid-term results compared to TURP have been reported following first-generation bipolar electrovaporization. Outcome data following second-generation BPV are still scarce. The aim of this investigation was to evaluate the intra- and postoperative outcomes of contemporary BPV in a center with long-standing expertise on laser vaporization of the prostate. METHODS A consecutive series of 83 patients undergoing BPV in a tertiary referral center was prospectively evaluated. The investigated outcome parameters included the maximum flow rate (Qmax), postvoid residual volume, International Prostate Symptom Score (IPSS)/quality of life (Qol), and prostate-specific antigen (PSA) tests. Follow-up investigations took place after 6 weeks, 6 months, and 12 months. The Wilcoxon signed-rank test was used to compare pre- and post-treatment parameters. RESULTS The median (range) preoperative prostate volume was 41 mL (17-111 mL). The preoperative IPSS, Qol, Qmax, and residual volume were 16 (2-35), 4 (0-6), 10.1 mL/s (3-29.3 mL/s), and 87 mL (0-1000 mL), respectively. One third of the patients were undergoing platelet aggregation inhibition (PAI). No intraoperative complications occurred. Postoperatively, 13 patients (15.7%) had to be recatheterized. Three patients (3.6%) had clot retention and 28 patients (34%) reported any grade of dysuria. After 6 weeks, all outcome parameters improved significantly and remained improved over the 12-month observation period [IPSS: 3 (0-2); Qol: 1 (0-4); Qmax: 17.2 mL/s (3.2-56 mL/s); residual volume 11 mL (0-190 mL)]. The PSA reduction was 60% at study conclusion. Three patients (3.6%) developed a urethral stricture and four patients (4.8%) bladder neck sclerosis. Re-resections were not necessary. CONCLUSIONS Contemporary BPV is a safe and efficacious treatment option even for patients undergoing PAI. Early urinary retention and temporary dysuria seem to be specific side effects of the treatment. Bleeding complications are rare. Long-term follow-up is needed to confirm these promising short-term results.

MP02-02 PURE BIPOLAR PLASMA VAPORIZATION OF THE PROSTATE: 5-YEAR FOLLOW-UP FROM A PROSPECTIVE 3D ULTRASOUND VOLUMETRY STUDY

INTRODUCTION AND OBJECTIVES: Pure bipolar plasma vaporization (BPV) has been established as low-morbidity alternative to conventional transurethral resection of the prostate (TURP). Low intraand postoperative morbidity as well as excellent functional short-term results have been reported. However, long-term outcome is still lacking. The extent of prostate tissue removal, which impacts the durability of postoperative functional improvements, is also unknown after BPV. The aim of the present study was to investigate the long-term functional outcome and associated prostate volume changes following pure BPV of the prostate. METHODS: A consecutive series of 75 patients treated by pure BPV in a tertiary care academic center was prospectively investigated. Prostate volume was assessed using planimetric volumetry following transrectal 3D-ultrasound of the prostate. Prostate volume and clinical parameters were recorded preoperatively and regularly after BPV (after catheter removal, 6W, 6M, 1, 3 and 5Y). RESULTS: Median (interquartile range; IQR) preoperative prostate volume was 41 ml (26.8ml), IPSS 16 (10), QoL 4 (2), Qmax 10.1ml/s (8ml/s), PVR 91ml (140ml) and PSA 2.57ng/ml (3.5ng/ml). A significant relative prostate volume reduction (RVR) of 33.3% (IQR: 22.3%; p<0.001) was already detectable at the time of catheter removal. Relative volume reduction increased significantly up to 12M (6W: 45.9% (17.4%; p<0.001), 6M: 50.5% (16.1%; p<0.001) and 12M 52.2% (17.4%; p1⁄40.014). After 12M the RVR remained stable with 50.6% (14.3%; p1⁄40.58) after 3Y and 52.6% (14.1%; p1⁄40.59) after 5Y. Postoperatively, all investigated clinical parameters improved significantly and remained stable during the 5Y follow-up [5Y results (IQR): IPSS: 3 (8), QoL: 1 (1), Qmax: 16.3ml/s (13.7ml/s), PVR 20ml (46.5ml)]. Median PSA reduction after 5Y was 55% (36.2%). During the observation period 9 urethral strictures (12%) were detected of which 7 were de novo strictures. Bladder neck incisions for postoperative bladder neck stenosis were performed in 6 patients (8%). Median prostate volume in these patients was 30.6ml (18.2ml). Re-resections for regrown adenoma were not necessary. CONCLUSIONS: Low intraand postoperative morbidity in combination with excellent functional outcome and durable prostate volume reduction confirm the role of contemporary BPV as a minimally invasive alternative to conventional TURP. However, postoperative bladder neck stenoses appeared rather frequent after BPV and might be a procedure-specific drawback.

Re: Sophia C. Kamran, Thomas Seisen, Sarah C. Markt, et al. Contemporary Treatment Patterns and Outcomes for Clinical Stage IS Testicular Cancer. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2017.06.013

We read with interest the article by Kamran and colleagues [1] and the editorial by Østergren and colleagues [2]. This is the largest published investigation on oncological safety of active surveillance (AS) among patients with stage IS germ cell tumors (GCTs). However, the results should be interpreted with caution and should not trigger a change in which AS becomes the standard approach for patients with stage IS GCTs. Although the different subgroups investigated were reasonably large (227–441 patients), it remains questionable whether the study had enough power (95% confidence interval 0.27–1.61) and sufficient follow-up time to exclude a clinically meaningful difference in survival between patients treated upfront versus those that were followed on AS. The number of patients with stage IS seminoma and nonseminoma tumors who underwent observation in the cohort (39% and 53%, respectively) is surprisingly high, particularly given the fact that clinical guidelines did not generally recommend surveillance for stage IS GCTs between 2004 and 2012. Hence, there is some doubt that all of these GCTs were truly stage IS. It has been found that incorrectly coded tumor marker (TM) levels (eg, preorchiectomy levels, TMs still elevated early after orchiectomy) resulting in an incorrect clinical stage were as high as 71% in the Surveillance, Epidemiology and End Results database [3]. Thus, it is likely that several patients with stage IA/B GCTs (for which AS is a recommended treatment option) were also incorrectly coded as stage IS in the National Cancer Data Base (NCDB). The treatment type and intensity would have given some insight into the true disease stage. However, these data are not part of the NCDB and thus could not be used to further characterize the cohort investigated. The high number of lymph node metastases (up to 87%) found after retroperitoneal lymph node dissection in patients with stage IS disease underlines that many of these patients still harbor viable disease and do not benefit

MP71-19 LOSS OF POWER OUTPUT IS FREQUENTLY DETECTABLE DURING LASER VAPORIZATION OF THE PROSTATE USING THE 180-WATT 532 NM LASER IN COMBINATION WITH MOXYTM LASER FIBERS

INTRODUCTION AND OBJECTIVES: The objective was to measure the penetration depth after PhotoVaporization of the Prostate (PVP) by Enhanced Contrat UltraSonography (ECUS). METHODS: It is a forward-looking study about twelve patients operated by a PVP performed by the GREENLIGHT XPS laser. Ethical committee gave its aproval (EUDRACT N : 2012-001451-39). ECUS was performed (B-mode then contrast mode after injection of 2,4mL of suphur hexafluoride micro bubbles) preoperatively and immediately after the PVP and at 1 month. With ultrasound were measured: width, prostatic volume and diameter of the cavity of vaporization (DC) with the B-mode; then in contrast mode MicroFlow Imaging (MFI): the prostatic width and the NonVascularized cavity diameter (DD). The necrotic depth was measured using the formula: NC 1⁄4 (DD-DC)/2) (Figure 1). RESULTS: The characteristics of the patients were : a median age of 70 years old [57-81], median prostatic volume of 65 cc [40-110], median maximal urinary flow of 7,2 mL/s [2, 9-15,2], median post mictional residual volume of 90 cc [0-213], median IPSS score of 19 [8-24] and a median PSA rate of 4 ng/mL [1,6-7,9]. The results found with ultrasound performed pre and post operatively are summarized in table 1. All the patients had their bladder catheter removed and then discharged the hospital at day 1, except one patient who had an acute retention treated at day 8 by an indwelling catheter. CONCLUSIONS: The use of ECUS showed an unexpected necrotic depth up to 16,5 mm in the immediate post-operative ultrasound. This necrotic depth persisted at 1 month and was measured up to 13 mm. At one month we measured a 26% decrease of the prostatic volume and a 23% of the necrotic depth. These results are to be considered to performe securely PVP without any rectal complication. The continuing follow-up at 6 and 12 months will probably precize the necrotic depth evolution and the potential correlation with the occurrence of irritative voiding dysfunction. Table 1 : Ultrasonography results

MP71-20 ABSORPTION OF IRRIGATION FLUID IS FREQUENTLY DETECTABLE DURING 180W 532-NM LASER VAPORIZATION OF THE PROSTATE: RESULTS FROM A PROSPECTIVE INVESTIGATION USING BREATH ETHANOL MEASUREMENTS

INTRODUCTION AND OBJECTIVES: Laser vaporization (LV) of the prostate using the 532-nm laser is a recommended treatment option for patients with prostatic bladder outlet obstruction and particularly for those with significant cardiovascular comorbidities. Despite the excellent coagulation properties of the laser, fluid absorption was frequently detectable during 120W LV of the prostate. For the nextgeneration 180W laser, a better coagulation technology has been announced. If fluid absorption occurs during LV using this improved but also more powerful laser is unknown. METHODS: Intraoperative fluid absorption was investigated during routine LV using the 180W Greenlight XPS laser (AMS, USA) in 32 consecutive patients. For this purpose intraoperative irrigation was performed using saline containing 1% ethanol. Measurements of breath ethanol were performed every 10 minutes during the operation with a conventional alcometer. The volume of fluid absorption was calculated from these results. Intraoperative changes in hemoglobin (Hb), hematocrit (Hct), venous pH and serum Na, K, Cl, HCO3 were also recorded. Statistical analysis was done using Mann Whitney U test and Wilcoxon signed-rank test. RESULTS: Median age was 73 y (range: 56 85 y), median prostate volume 50 ml (20 99 ml). The median operative time was 60 min (30-150 min), the intraoperative irrigation volume 21 L (6 42 L), and the applied laser energy 175 kJ (70 e 544 kJ). 17 patients (53%) had a positive ethanol test. The median calculated absorption volume in these patients was 827 ml (138 e 4808 ml). In the absorber group, a significant decrease in Hb, Hct, HCO3, pH (p1⁄40.001, 0.004, 0.002 and 0.02, respectively), and a significant increase in serum Cl (p1⁄40.007) were detectable. The changes in Hb, Hct, Cl and HCO3 were significantly greater compared to the non-absorber group (p1⁄40.005, 0.02, 0.001 and 2000ml) were prolonged metabolic acidosis and somnolence, hypothermia, jugular venous distension and significant postoperative weight gain. CONCLUSIONS: Intraoperative fluid absorption occurs in a significant proportion of patients during 180W LV of the prostate. Fluid absorption can be excessive and thus clinically relevant. Early identification of fluid absorption using the ethanol breath test enables timely interventions. If ethanol monitoring is not available, changes in Hb, Hct, pH, HCO3 and Cl can be used to detect potentially dangerous fluid absorption.