Complications and functional outcomes of high-risk patient with cardiovascular disease on antithrombotic medication treated with the 532-nm-laser photo-vaporization Greenlight XPS-180 W for benign prostate hyperplasia.

PURPOSE: To examine the complications and functional outcomes of high-risk patients on antithrombotic therapy (ATT) treated with photoselective vaporization of the prostate (PVP) using the Greenlight (GL) XPS-180 system. METHODS: A retrospective analysis of prospectively maintained institutional database was performed. Men with symptomatic LUTS related to BPH were treated with 523-nm GL PVP using the XPS-180 W system. They were stratified according to ATT status: group 1 (control group), group 2 (acetylsalicylic acid), group 3 (antiplatelet agents other than acetylsalicylic acid) and group 4 (anticoagulation agents). Postoperative adverse events at 30- and 90-days were prospectively recorded. Complications were stratified according to the Clavien-Dindo classification. Additionally, functional outcomes (IPSS, Qmax and PVR) were analyzed up to 48 months of follow-up after surgery. Multivariable logistic regression analyses were used to predict the effect of ATT on serious bleeding-associated complications that was defined as the sum of patients with hematuria Clavien grade ≥ 2, patients requiring transfusions and patient with postoperative hemoglobin drop ≥ 15 g/dl. RESULTS: 274 (63%), 87 (21%), 24 (6%) and 37 (9%) patients were included in groups 1, 2, 3 and 4, respectively. Patients on antiplatelet (group 3) and anticoagulant medication (group 4) were older (median age 60 vs. 68 vs. 77 vs. 76 years, p < 0.001) and had more comorbidities (ASA 3-4: 9.5 vs. 27.6 vs. 66.7 vs. 64.9%; p < 0.001) than their counterparts. The overall 30-day complications rates were 31, 28.7, 45.8 and 45.9% of patients included in groups 1, 2, 3 and 4, respectively (p = 0.4). Hematuria Clavien 1 events (p < 0.001), readmissions rates (p = 0.02), length of post-operative hospital stay (p < 0.001) and catheterization time (p < 0.001) were significantly higher in patients on antiplatelet and anticoagulation medication. In multivariable analyses, ATT status was not a predictor of serious bleeding events after surgery (p > 0.5). Finally, functional outcomes were significantly improved accross the four groups. CONCLUSION: GL PVP is safe and effective in treating high-risk patients on ATT. Although serious bleeding complications are rare and equivalent with non-high-risk patients, patients on antiplatelet and anticoagulation medication should be counseled on the increased risk of minor bleeding events and readmissions rates at 30 days after surgery.

Multicentre international experience of 532-nm laser photoselective vaporization with GreenLight XPS in men with very large prostates.

OBJECTIVES: To describe peri-operative results, functional outcomes and complications of laser photoselective vaporization, using the GreenLight system, of prostate glands ≥200 mL in volume. METHODS: Retrospective analysis of a prospectively maintained multicentre database was performed to select a subgroup of patients with very large prostates (volume ≥200 mL) treated with the GreenLight XPS laser. A subgroup of patients with prostate volumes 100-200 mL was used for comparison. International Prostate Symptom Score, maximum urinary flow rate, postvoid residual urine volume and prostate-specific antigen levels were measured at 6, 12, 24, 36 and 48 months. Durability was evaluated using benign prostatic hyperplasia re-treatment rate at 12, 24 and 36 months. Additionally, complications were recorded using Clavien-Dindo classification. RESULTS: A total of 33 patients (38%) had prostates ≥200 mL. Baseline characteristics were similar between patients with prostates ≥200 mL and those with prostates 100-200 mL. Patients with very large prostates (≥200 mL) had longer operating times (129 vs 93 min), less energy delivered, a greater number of fibres used (3 vs 2) and a higher conversion rate to transurethral resection of the prostate (16% vs 4%). In terms of complications and functional outcomes, we did not find any differences between the groups. Retreatment rate was also comparable. CONCLUSIONS: Our results show that PVP GreenLight XPS-180W is an acceptable technique for very large prostates (≥200 mL); however, operating times, energy delivery, fibres used and conversion to TURP are a concern in this particular subgroup. This should be used for patient counselling and surgery planning.

Does surgical delay for radical prostatectomy affect biochemical recurrence? A retrospective analysis from a Canadian cohort.

AIM: We sought to explore the impact of surgical wait time (SWT) to robot-assisted radical prostatectomy (RARP) on biochemical recurrence (BCR). METHOD: Retrospective review of a prospectively collected database between 2006 and 2015 was conducted on all RARP cases. SWT was defined as period from prostate biopsy to surgery. Primary outcome was the impact on BCR, which was defined as two consecutive PSA ≥ 0.2 ng/dl, or salvage external beam radiation therapy and/or salvage androgen deprivation therapy. Patients were stratified according to D'Amico risk categories. Univariable analysis (UVA) and multivariable analyses (MVA) with a Cox proportional hazards regression model were used to evaluate the effect of SWT and other predictive factors on BCR, in each D'Amico risk group and on the overall collective sample. RESULTS: Patients eligible for analysis were 619. Mean SWT was 153, 169, 150, and 125 days, for overall, low-, intermediate-, and high-risk patients, respectively. Multivariate analysis on the overall cohort did not show a significant relation between SWT and BCR. On subgroup analysis of D'Amico risk group, SWT was positively correlated to BCR for high-risk group (p = 0.001). On threshold analysis, cut-off was found to be 90 days. SWT did not significantly affect BCR on UVA and MVA in the low- and intermediate-risk groups. CONCLUSION: Increased delay to surgery could affect the BCR, as there was a positive association in high-risk group. Further studies with longer follow-up are necessary to assess the impact of wait time on BCR, cancer specific survival and overall survival.

Multicenter international experience of 532 nm-laser photo-vaporization with Greenlight XPS in men with large prostates (prostate volume > 100 cc).

PURPOSE: To evaluate the outcomes and durability of photoselective vaporization of the prostate (PVP) using the XPS-180 system in patients with a large prostate volume (PV) > 100 cc at 4 years of follow-up in a large, multicenter experience. METHODS: 438 men with pre-operative transrectal ultrasound (TRUS) PV > 100 cc were treated in eight experienced centers in Canada, USA, and in France with the Greenlight XPS laser using PVP for the treatment of symptomatic BPH. IPSS, Qmax, postvoid residual (PVR), and prostate-specific antigen (PSA) were measured at 6, 12, 24, 36, and 48 months. Durability was evaluated using BPH retreatment rate at 12, 24, and 36 months. RESULTS: Median PV and PSA were 121 cc and 6.3 ng/dl. Indwelling catheter at the time of surgery was observed in 37% of men. Median operative, laser time, and energy applied were 90 min, 55 min, and 422 kJ, respectively. Median energy delivery was 3.4 kJ/cc of prostate per case. Outpatient surgery was feasible with median length of stay at 24 h. IPSS, Qmax and PVR were significantly improved at all endpoints including at 48 months. Moreover, surgical BPH retreatment rates were 5.4 and 9.3% at 24 and 36 months. Interestingly, characteristics of retreated men include: energy delivery 2.4 vs. 3.4 kJ/cc of prostate (p = 0.02) and PSA reduction at 12 months 26 vs. 51% (p = 0.02). CONCLUSIONS: PVP using Greenlight XPS-180W can potentially provide durable improvements with regard to functional outcomes at 4 years. However, rising retreatment rates after 3 years is of concern. This highlights the imperative need of utilizing a standardized surgical technique (enucleation-like-defect) and an optimal energy density >3KJ/cc.

180W-LBO GreenLight XPS laser vaporization for benign prostatic hyperplasia: our experience with current markers of surgical proficiency for durable and reproducible outcomes.

INTRODUCTION: This study aims at analyzing the impact of reaching current markers of proficiency on intra and postoperative clinical outcomes of laser vaporization with 180W GreenLight XPS in the treatment of benign prostatic hyperplasia. MATERIALS AND METHODS: A retrospective analysis was conducted on a prospectively collected database of 328 consecutive patients who underwent photoselective vaporization of the prostate (PVP) using Greenlight XPS performed by a single experienced laser surgeon. A logarithmic model was used to evaluate the case number to attain benchmark criteria for durable treatment. We compared clinical outcomes before and after current markers of proficiency, defined as either an energy density of 4kJ/cm³ or a 6 month prostate-specific antigen (PSA) drop of = 50%, were attained. RESULTS: Energy delivered per prostate volume increased significantly with experience. The published benchmark values of 4kJ/cm³ and 6 month PSA drop of 50% were attained after 190 and 155 cases, respectively. There were no significant differences between groups in intraoperative complications or postoperative functional outcomes. However, the number of Clavien-Dindo category I adverse events significantly decreased with experience. Sub-analysis evaluating prostate volumes ≤ 80 cm³ and > 80 cm³ demonstrated comparable clinical outcomes before and after technical proficiency. CONCLUSION: In our experience, the case volume required to achieve consistent reference values related to durable clinical outcomes and surgical proficiency was > 150 cases. However, desirable clinical outcomes were attained before reaching current markers of proficiency, regardless of preoperative prostate size. This suggests that current thresholds of technical proficiency may not be a good predictor of satisfying clinical outcomes.

Assessment of energy density usage during 180W lithium triborate laser photoselective vaporization of the prostate for benign prostatic hyperplasia. Is there an optimum amount of kilo-Joules per gram of prostate?

OBJECTIVES: To assess the effect of energy density (kJ/mL) applied on adenoma during photoselective vaporization of the prostate (PVP) treatment for benign prostate hyperplasia (BPH) on functional outcomes, prostate-specific antigen (PSA) reduction and complications. PATIENTS AND METHODS: After exclusions, a total of 440 patients who underwent GreenLight (tm) laser XPS-180W lithium triborate PVP for the treatment of BPH were retrospectively reviewed. Data were collected from seven different international centres (Canada, USA, UK and France). Patients were stratified into four energy density groups (kJ/mL) according to intra-operative energy delivered and prostate volume as determined by preoperative transrectal ultrasonography (TRUS): group 1: <3 kJ/mL; group 2: 3-5 kJ/mL; group 3: 5-7 kJ/mL; and group 4: ≥7 kJ/mL. Energy density groups were chosen arbitrarily. PSA reduction and functional outcomes (International Prostate Symptom Score, quality of life, post-void residual urine volume, maximum urinary flow rate) were compared at 6, 12 and 24 months. Peri-operative complications and retreatment rates were also compared among the groups. RESULTS: The PSA reduction rates at 24 months after the procedure were 51, 61, 79 and 83% for the energy density groups <3, 3-5, 5-7 and ≥7 kJ/mL, respectively (P ≤ 0.01). This held true after accounting for baseline confounders. Energy density was not associated with higher complication rates, including haematuria, stricture formation, incontinence, refractory urinary retention, urinary tract infection and conversion to transurethral resection of the prostate. Functional outcomes at 2 years of follow-up were equivalent among the groups (P > 0.05 for all) and similar retreatment rates were observed (P = 0.36). CONCLUSION: Higher energy usage per cc of prostate was associated with a more significant reduction in PSA level (>50%) at 6, 12 and 24 months, suggesting increased vaporization of adenoma tissue; however, this did not translate into differences in functional outcomes at 2-year follow-up.

Erectile function recovery after robotic-assisted radical prostatectomy (RARP): long term exhaustive analysis across all preoperative potency categories.

INTRODUCTION: To evaluate erectile function recovery following robotic-assisted radical prostatectomy (RARP) according to preoperative sexual health inventory for men (SHIM) score stratification. MATERIALS AND METHODS: We prospectively collected data on 250 consecutive patients who underwent RARP by a single surgeon between October 2006 and October 2012. Thirty-six patients were excluded because of lack of preoperative SHIM score. All patients had a minimum follow up of 2 years. Patients were divided into four groups according to their preoperative SHIM score: group 1 with normal potency (SHIM 22-25), group 2 with mild ED (SHIM 17-21), group 3 with mild-moderate ED (SHIM 12-16) and group 4 with moderate-severe ED (SHIM 1-11). Patients were followed at 3, 6, 9, 12, 18, 24 months intervals and twice yearly thereafter. SHIM questionnaire and erection hardness scale (EHS) score were collected at each visit. Potency was defined as successful penetration during intercourse (EHS score 3-4) with or without phosphodiesterase type 5-inhibitor (PDE5-I). RESULTS: After exclusion, 214 patients were evaluated. The number of patients in group 1, 2, 3 and 4 were 95, 59, 26 and 34, respectively. At 3, 6, 9, 12, 18, 24 months, SHIM scores and potency rates were statistically different between groups 1 versus 2 versus 3 versus 4 (p < 0.01, at each time point). Patients in each group 1, 2 and 3 showed a statistically significant improvement in potency rates and SHIM scores at consecutive follow up visits up to 24 months (p < 0.01, for each potency group). Potency rates at 24 months for groups 1 to 4 were 83.3%, 54.5%, 50.0%, and 20.7%, respectively (p < 0.001). CONCLUSION: For proper patient counseling and better prediction of erectile function recovery after RARP, it is important to stratify patients according to preoperative SHIM scores. Setting realistic expectations may increase patient satisfaction.

Photoselective Vaporization of the Prostate for Benign Prostatic Hyperplasia Using the 180 Watt System: Multicenter Study of the Impact of Prostate Size on Safety and Outcomes.

PURPOSE: We evaluated photoselective vaporization of the prostate using the GreenLight™ XPS™ 180 W system for benign prostatic hyperplasia treatment in a large multi-institutional cohort at 2 years. We particularly examined safety, outcomes and the re-treatment rate in larger prostates, defined as a prostate volume of 80 cc or greater, to assess the potential of photoselective vaporization of the prostate as a size independent procedure. MATERIALS AND METHODS: A total of 1,196 patients were treated at 6 international centers in Canada, the United States, France and England. All parameters were collected retrospectively, including complications, I-PSS, maximum urinary flow rate, post-void residual urine, prostate volume, prostate specific antigen and the endoscopic re-intervention rate. Subgroup stratified comparative analysis was performed according to preoperative prostate volume less than 80 vs 80 cc or greater on transrectal ultrasound. RESULTS: Median prostate size was 50 cc in 387 patients and 108 cc in 741 in the prostate volume groups less than 80 and 80 cc or greater, respectively. The rate of conversion to transurethral prostate resection was significantly higher in the 80 cc or greater group than in the less than 80 cc group (8.4% vs 0.6%, p <0.01). I-PSS, quality of life score, maximum urinary flow rate and post-void residual urine were significantly improved compared to baseline at 6, 12 and 24 months of followup without significant differences between the prostate size groups. The re-treatment rate at 2 years reported in 5 of 411 patients was associated with the delivery of decreased energy density (2.1 vs 4.4 kJ/cc) in the group without re-treatment. CONCLUSIONS: Photoselective vaporization of the prostate using the XPS 180 W system is safe and efficacious, providing durable improvement in functional outcomes at 2 years independent of prostate size when treated with sufficient energy.

Photoselective laser ablation of the prostate: a review of the current 2015 tissue ablation options.

INTRODUCTION: Transurethral resection of the prostate (TURP) is still considered the gold standard to treat benign prostatic hyperplasia (BPH). However, photoselective vaporization of the prostate (PVP) has gained widespread acceptance as an alternative option requiring preoperative patient selection. Four laser systems are currently in use: holmium, thulium, diode and GreenLight. MATERIALS AND METHODS: The goal of this article is to review the physics and the basics behind laser prostatectomies, as well as to present the most current literature concerning the results, advantages, disadvantages and international recommendations for each vaporization procedure. RESULTS: Holmium laser ablation of the prostate (HoLAP) and GreenLight photoselective vaporization of the prostate are an alternative to TURP for small to medium-sized prostates, providing equivalent efficacy and safety. GreenLight is also safe and effective in large-sized prostates and especially beneficial in anti-coagulated individuals compared to TURP. Thulium vaporization of the prostate (ThuVAP) and diode vaporization both require additional randomized trials and long term studies before conclusion is made, despite promising initial results. Diode vaporization provides the best hemostasis overall, but at the cost of increased complication and re-treatment rate, and thus is not recommended except in severely anti-coagulated patients. CONCLUSION: Laser vaporization is a safe and effective alternative to TURP in the treatment of benign prostatic hyperplasia (BPH) for carefully selected patients. However, further research is still needed to assess the durability of each technology.

Robot assisted radical prostatectomy: how I do it. Part II: Surgical technique.

The introduction of the "da Vinci Robotic Surgical System" (Intuitive Surgical, Sunnyvale, CA, USA) has been an important step towards a minimally invasive approach to radical prostatectomy. Technologic peculiarities, such as three-dimensional vision, wristed instrumentation with seven degrees of freedom of motion, lack of tremor, a 10x-magnification and a comfortable seated position for the surgeon has added value to the procedure for the surgeon and the patient. In this article, we describe the 9 step surgical technique for robot assisted radical prostatectomy (RARP) that is currently used in our institution (University of Montreal Hospital Center (CHUM) - Hopital St-Luc). We use the four-arm da Vinci Surgical System. Our experience with RARP is now over 250 cases with the senior surgeon having performed over 1200 RARPs and we have continually refined our technique to improve patient outcomes.

Robot assisted radical prostatectomy: how I do it. Part I: Patient preparation and positioning.

Radical prostatectomy remains the standard treatment for long term cure of clinically localized prostate cancer, offering excellent oncologic outcomes, with cancer-specific survival approaching 95% at 15 years after surgery. The introduction of the "da Vinci Robotic Surgical System" (Intuitive Surgical, Sunnyvale, CA, USA) has been another important step toward a minimally invasive approach to radical prostatectomy. Technologic peculiarities, such as three-dimensional vision, wristed instrumentation with seven degrees of freedom of motion, lack of tremor, a 10x-magnification and a comfortable seated position for the surgeon has added value to the surgeon and patient. In this first part of a two article series, we describe preoperative patient preparation and positioning protocols for robot assisted radical prostatectomy (RARP) that are currently used in our institution (University of Montreal Hospital Center (CHUM)-Hopital St-Luc). We use the four-arm da Vinci Si Surgical System. Our experience with RARP is now over 250 cases with the senior surgeon having performed over 1200 RARPs and we have continually refined our technique to improve patient outcomes.

Short term outcomes of GreenLight vapor incision technique (VIT) of the prostate: comparison of outcomes to standard GreenLight 120W HPS vaporization in prostate volumes greater than 80 cc.

INTRODUCTION: To evaluate a hybrid technique involving GreenLight 120W HPS vapor incision tissue removal in prostate glands > 80 cc. MATERIALS AND METHODS: Vapor incision technique (VIT) was performed in 25 consecutive men with a prostate > 80 cc by a single surgeon from May 2010 until September 2010. VIT involved adenoma incisions at 5 and 7-o'clock positions followed by 3, 9 and 12 o'clock down to the surgical capsule. Side-fire vaporization along the capsule excised transurethral resection of the prostate (TURP) like tissue strips for later retrieval. Functional evaluations were performed at 1 and 3 months. Outcomes and complications were compared retrospectively to baseline and a size matched- cohort of 25 men who previously underwent standard vaporization-only photoselective vaporization prostatectomy (PVP). RESULTS: The VIT and control subgroups were comparable. Mean laser time, operative time and energy usage were reduced in the VIT group compared to controls (35 min versus 48 min; 63 min versus 80 min; and 227 k versus 325 kJ respectively; all p < 0.05). At 3 months the VIT subgroup demonstrated improved Qmax and post void residual (PVR) (197% versus 173%, 88% versus 72%; all p < 0.05) compared to control. VIT showed a 68% reduction in mean preoperative PSA at 3 months compared to 50% for the control group (p<0.01). Hospital stay, catheterization time and complication rates were comparable. CONCLUSIONS: Our data demonstrates that VIT provides superior short term outcomes to standard HPS-PVP in men with prostate volumes > 80 cc. VIT appears to be more time-efficient, consumes less energy and obtains tissue for pathological evaluation. Further follow up is required to assess the durability of GreenLight HPS-VIT to PVP vaporization-only for large prostate glands.

Mid term outcomes of initial 250 case experience with GreenLight 120W-HPS photoselective vaporization prostatectomy for benign prostatic hyperplasia: comparison of prostate volumes < 60 cc, 60 cc-100 cc and > 100 cc.

INTRODUCTION: The aim of this study was to compare the efficacy of GreenLight 120W-HPS (American Medical Systems, Minnetonka, Minnesota, USA) laser vaporization for men with obstructive benign prostatic hyperplasia (BPH) according to prostate volumes < 60 cc, 60 cc-100 cc and > 100 cc. MATERIAL AND METHODS: The clinical data of 250 men with symptomatic BPH who underwent photoselective vaporization prostatectomy (PVP) by a single surgeon between July 2007 and August 2009 were retrospectively analyzed. Prostate volumes were measured by using transrectal ultrasonography (TRUS). Functional evaluations were performed at 3, 6 and 12 months with a prostate-specific antigen (PSA) obtained at 6 months. All men were stratified into three groups according to TRUS volume. RESULTS: Among the 250 consecutive PVP patients, 134, 76 and 40 men had prostate volumes < 60 cc, 60 cc-100 cc and > 100 cc, respectively. Mean laser time and delivered energy were 31, 44 and 59 minutes; 163, 309 and 473 kJ respectively (p < 0.01 for all). At 1 year, mean International Prostate Symptom Score (IPSS) improved by 69%, 63% and 50%, Qmax increased by 194%, 175% and 162% and post void residual (PVR) decreased by 88%, 81% and 71%, respectively (p < 0.01 for all). Mean decrease in preoperative PSA at 6 months was 63%, 52% and 41% (p < 0.01), respectively. Hospital stay, catheterization time and complication rates were comparable between groups, however retreatment rates were significantly higher for prostates >100 cc (1.5% versus 2.6% versus 9%; p = 0.02). CONCLUSIONS: Although larger prostates require more time and energy delivery, PVP is safe and efficacious for patients with lower urinary tract symptoms (LUTS) regardless of prostate size. Laser vaporization for glands > 100 cc appears to have a reduced reduction in PSA and a higher 9% rate of retreatment indicating that PVP for larger prostates remains to be optimized.

Targeted inactivation of EGF receptor inhibits renal collecting duct development and function.

The ureteric bud (UB) expresses high levels of the EGF receptor (EGFR) during kidney development, but its function in this setting is unclear. Here, Egfr mRNA was abundant in medullary portions of the UB trunk but absent from the branching UB tips during embryogenesis. Homozygous Egfr knockout did not affect the pattern of UB arborization, but renal papillae were hypoplastic and exhibited widespread apoptosis of tubular cells. Because these EGFR-deficient mice die within 1 week of life, we targeted Egfr inactivation to the renal collecting ducts using Cre-lox technology with a Hoxb7-Cre transgene. This targeted inactivation of Egfr led to a thin renal medulla, and at 7 weeks of age, the mice had moderate polyuria and reduced urine-concentrating ability. At 30 to 33 weeks, water deprivation demonstrated a continued urine-concentrating defect despite similar levels of vasopressin between knockout mice and littermate controls. Taken together, these results suggest that unlike other tyrosine kinases expressed at the UB tip, EGFR functions primarily to drive elongation of the emerging collecting ducts and to optimize urine-concentrating ability.

Wilms tumor arising in a child with X-linked nephrogenic diabetes insipidus.

We report on a child with X-linked nephrogenic diabetes insipidus (NDI) who developed Wilms tumor (WT). Nephrogenic diabetes insipidus is caused by mutations of the arginine vasopressin receptor (AVPR2) or aquaporin-II (AQP2) genes. Wilms tumor is also genetically heterogeneous and is associated with mutations of WT1 (15-20%), WTX (20-30%) and other loci. The boy presented at 5 months with failure to thrive, polyuria, hypernatremia and abdominal mass. Analysis of leukocyte DNA showed a novel missense mutation (Q174H) of the AVPR2 gene, which was not present in his mother. In cells (WitS) isolated from the tumor, WTX mRNA expression and coding sequence were intact. However, we identified a 44-kb homozygous deletion of the WT1 gene spanning exons 4 to 10. The WT1 deletion was not present in leukocyte DNA from the patient or his mother. We also noted strong beta-catenin (CTNNB1) expression in the tumor cells and identified a heterozygote missense Ser45Cys mutation of exon 3 of CTNNB1. However, the mutation was absent both in the constitutional DNA of the patient and his mother. The concurrence of WT and NDI has not been previously reported and may be unrelated. Nevertheless, this case nicely illustrates the sequence of events leading to sporadic Wilms tumor.

A common RET variant is associated with reduced newborn kidney size and function.

Congenital nephron number varies five-fold among normal humans, and individuals at the lower end of this range may have an increased lifetime risk for essential hypertension or renal insufficiency; however, the mechanisms that determine nephron number are unknown. This study tested the hypothesis that common hypomorphic variants of the RET gene, which encodes a tyrosine kinase receptor critical for renal branching morphogenesis, might account for subtle renal hypoplasia in some normal newborns. A common single-nucleotide polymorphism (rs1800860 G/A) was identified within an exonic splicing enhancer in exon 7. The adenosine variant at mRNA position 1476 reduced affinity for spliceosome proteins, enhanced the likelihood of aberrant mRNA splicing, and diminished the level of functional transcript in human cells. In vivo, normal white newborns with an rs1800860(1476A) allele had kidney volumes 10% smaller and cord blood cystatin C levels 9% higher than those with the rs1800860(1476G) allele. These findings suggest that the RET(1476A) allele, in combination with other common polymorphic developmental genes, may account for subtle renal hypoplasia in a significant proportion of the white population. Whether this gene variant affects clinical outcomes requires further study.

The role of photovaporization of the prostate in small volume benign prostatic hyperplasia and review of the literature.

OBJECTIVE: Our objective was to characterize the safety and efficacy of the 180 W XPS-GreenLight laser in men with lower urinary tract symptoms secondary to a small volume benign prostatic hyperplasia (BPH). METHODS: A retrospective analysis was performed for all patients who underwent 180 W XPS-laser photoselective vaporization of the prostate (PVP) vaporization of the prostate between 2012 and 2016 at two-tertiary medical centers. Data collection included baseline comorbidities, disease-specific quality of life scores, maximum urinary flow rate (Qmax), postvoid residual (PVR), complications, prostate volume and prostate-specific antigen (PSA). The secondary endpoints were the incidence of intraoperative and postoperative adverse events. Complications were stratified using the Clavien-Dindo grading system up to 90 days after surgery. RESULTS: Mean age of men was 67.8 years old, with a mean body mass index of 29.7 kg/m2. Mean prostate volume as measured by transrectal ultrasound was 29 mL. Anticoagulation use was 47% and urinary retention with catheter at time of surgery was 17%. Mean hospital stay and catheter time were 0.5 days. Median follow-up time was 6 months with the longest duration of follow-up being 22.5 months (interquartile range, 3-22.5 months). The International Prostate Symptom Score improved from 22.8 ± 7.0 at baseline to 10.7 ± 7.4 (p < 0.01) and 6.3 ± 4.4 (p < 0.01) at 1 and 6 months, respectively. The Qmax improved from 7.70 ± 4.46 mL/s at baseline to 17.25 ± 9.30 mL/s (p < 0.01) and 19.14 ± 7.19 mL/s (p < 0.001) at 1 and 6 months, respectively, while the PVR improved from 216.0 ± 271.0 mL preoperatively to 32.8 ± 45.3 mL (p < 0.01) and 26.2 ± 46.0 mL (p < 0.01) at 1 and 6 months, respectively. The PSA dropped from 1.97 ± 1.76 ng/mL preoperatively to 0.71 ± 0.61 ng/mL (p < 0.01) and 0.74 ± 0.63 ng/mL at 1 and 6 months, respectively. No patient had a bladder neck contracture postoperatively and no capsular perforations were noted intraoperatively. CONCLUSION: The 180 W GreenLight XPS system is safe and effective for men with small volume BPH. PVP produced improvements in symptomatic and clinical parameters without any safety concern. It represents a safe surgical option in this under studied population.

Assessment of Learning Curves for 180-W GreenLight XPS Photoselective Vaporisation of the Prostate: A Multicentre Study.

BACKGROUND: The learning curve for photoselective vaporisation of the prostate (PVP) has never been assessed accurately. OBJECTIVE: To compare 180-W GreenLight XPS PVP learning curves for three surgeons with different levels of surgical experience and different institutional backgrounds. DESIGN, SETTING, AND PARTICIPANTS: A multicentre retrospective study of the first patients treated with PVP by three operators in three different centres (n=152 in group 1, n=112 in group 2, n=101 in group 3) was conducted. Surgeon 1 had performed >600 PVP procedures (120-W GreenLight HPS laser) since 2007, while surgeons 2 and 3 had no previous experience with GreenLight PVP. Surgeon 1 mainly treats both benign prostatic hyperplasia (BPH) and urologic oncology, surgeon 2 primarily focuses on urologic oncology, and surgeon 3 mostly treats BPH. Surgeon experience was analysed as a continuous variable in terms of consecutive procedures performed. INTERVENTION: PVP using a 180-W GreenLight XPS laser. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The learning curve was analysed in terms of changes over time for the following variables: operative time, the vaporisation time/operative time ratio, and the energy delivered/prostate volume ratio. The primary endpoint was a trifecta of (1) energy delivered >5kJ/ml of prostate, (2) vaporisation time/operative time ratio of 66-80%, and (3) no postoperative complications. RESULTS AND LIMITATIONS: Patient baseline characteristics differed significantly among the centres in terms of age, prostate volume, and International Prostate Symptom Score (IPSS). Most perioperative outcomes favoured group 1 over group 3 over group 2. Functional outcomes, such as a decrease in IPSS at 1 mo for the first 50 patients (-15 vs -13.6 vs -13.3; p<0.0001) and an increase in maximum flow at 1 mo for the first 50 patients (+14.2 vs. +7 vs. +9.4; p<0.0001), favoured group 1 over group 3 over group 2. The trifecta achievement rate was significantly higher in group 3 over group 1 over group 2 (26.7% vs 14.4% vs 5.4%; p<0.0001). In multivariate analysis adjusting for age, American Society of Anesthesiologists score, and preoperative prostate volume, the only factors predictive of trifecta achievement were surgeon experience (p<0.0001) and surgeon identity (p<0.0001). The study limitations include selection bias, short follow-up, and a lack of consensus regarding learning curve assessment and definition. CONCLUSIONS: More than 100 PVP procedures were required to reach an intraoperative parameter plateau regardless of surgeon expertise and institutional background. Both surgeon background and expertise seemed to influence perioperative outcomes during the GreenLight XPS PVP learning curve. PATIENT SUMMARY: Both surgeon background and expertise seem to influence perioperative outcomes during the learning curve when using a GreenLight XPS laser for photoselective vaporisation of the prostate.