Fluid dynamics within renal cavities during endoscopic stone surgery: does the position of the flexible ureteroscope and ureteral access sheath affect the outflow rate?

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.

Trends in the use of radiation protection and radiation exposure of European endourologists: a prospective trial from the EULIS-YAU Endourology Group.

INTRODUCTION: Due to the radiation exposure for the urology staff during endourology, our aim was to evaluate the trends of radiation protection in the operation room by endourologists from European centers and to estimate their annual radiation. METHODS: We conducted a multicenter study involving experienced endourologists from different European centers to evaluate whether the protection and threshold doses recommended by the International Commission on Radiation Protection (ICRP) were being followed. A 36-question survey was completed on the use of fluoroscopy and radiation protection. Annual prospective data from chest, extremities, and eye dosimeters were collected during a 4-year period (2017-2020). RESULTS: Ten endourologists participated. Most surgeons use lead aprons and thyroid shield (9/10 and 10/10), while leaded gloves and caps are rarely used (2/10 both). Six out of ten surgeons wear leaded glasses. There is widespread use of personal chest dosimeters under the apron (9/10), and only 5/10 use a wrist or ring dosimeter and 4 use an eye dosimeter. Two endourologists use the ALARA protocol. The use of ultrasound and fluoroscopy during PCNL puncture was reported by 8 surgeons. The mean number of PCNL and URS per year was 30.9 (SD 19.9) and 147 (SD 151.9). The mean chest radiation was 1.35 mSv per year and 0.007 mSv per procedure. Mean radiation exposure per year in the eyes and extremities was 1.63 and 11.5 mSv. CONCLUSIONS: Endourologists did not exceed the threshold doses for radiation exposure to the chest, extremities and lens. Furthermore, the ALARA protocol manages to reduce radiation exposure.

Non-papillary prone percutaneous nephrolithotomy for renal abnormalities: single-institution experience.

PURPOSE: To evaluate the effectiveness and safety of non-papillary prone PCNL for the treatment of patients with renal abnormalities. METHODS: An observational retrospective cohort study including PCNL cases of patients with renal abnormalities was performed. The following inclusion criteria were applied: renal stones > 1.5 cm with maximal diameter, anatomical malformations of affected kidney (malrotated kidneys, horseshoe kidneys and kidneys with complete duplicated systems, medullary sponge kidney), patients treated with standard (30Fr) PCNL or mini-PCNL (22Fr). The lithotripsy was performed using the Lithoclast Master or the Lithoclast® Trilogy (EMS Medical, Nyon, Switzerland). RESULTS: Overall, 57 patients, 35 males, and 22 females with any renal malformation underwent non-papillary prone PCNL. Our study included 25 patients with horseshoe kidneys, 21 with malrotated kidneys, 9 with kidneys with duplicated pelvicalyceal systems and 2 with medullary sponge kidneys. The mean cumulative stone size was 36 ± 1.4 mm and most of the stones were in the lower calyceal group (36.9%) and in the pelvis (27.2%). The stone-free rate (SFR) was 84.2% and the mean hospitalization time was 2.7 ± 0.7 days. In total, postoperative complications were developed in six patients (10.5%), half of them presenting fever and the other half requiring blood transfusion (Grade II). CONCLUSION: The PCNL is the method of choice for treating large stones in anomalous kidneys. The generally accepted panacea that only a papillary puncture is safe is questioned by our results. Based on our experience, a non-papillary puncture proved to be a safe and effective procedure.

Endoscopic management of encrusted ureteral stents: outcomes and tips and tricks.

PURPOSE: To report our experience in the management of encrusted ureteral stents (EUS) and provide technical insight of our endourological approaches for difficult scenarios posed by this entity. MATERIALS AND METHODS: A retrospective evaluation of a longitudinally collected database of 58 patients with encrusted US between December 2012 and May 2022 was performed. The ureteral stents were initially inserted due to obstructive uropathy, pyelonephritis or after a successful endoscopic procedure for urolithiasis. A combination of antegrade/retrograde treatment in single or multiple sessions took place for the retrieval of the encrusted stents. Non-contrast enhanced computer tomography was used for the follow-up of the patients at 1-month after the removal of the encrusted stent. RESULTS: Overall 58 patients, 39 males and 19 females with a median age of 51 years old were included in the study. Indwelling time was < 6 months, 6-12 months and > 12 months in 22%, 57% and 21% of the cases, respectively. All US were successfully removed. Semi-rigid ureteroscopy (URS) and flexible ureteroscopy (fURS) were used in 90% of the cases. In 10% of the cases, a second-stage percutaneous nephrolithotomy (PCNL) or endoscopic combined intrarenal surgery (ECIRS) was performed. All US were successfully released. Stone-free rate was 84% at 1-month. Overall complication rate was 10.5% (mostly postoperative fevers, 5.4%). CONCLUSION: Removal of the encrusted US is a challenging procedure. Appropriate decision-making and knowledge of specific tricks may result in safe and successful management of significant EUS.

The feasibility of robot-assisted radical cystectomy: an experimental study.

PURPOSE: To investigate the feasibility of the avatera system for performing robot-assisted radical cystectomy (RARC) followed by intracorporeal reconstruction of ileal neobladder. METHODS: Six anesthetized female pigs were used to perform RARC and formation of the intracorporeal orthotopic ileal neobladder. Three surgeons with different level of expertise in the use of robotic systems performed RARC after a short instructional lecture and a 2-h hands-on training. The urinary diversion phase was performed only by the experienced surgeon. The successful completion of the procedure, operative time for demolitive and reconstructive phases, intraoperative blood loss and malfunction of the robotic system were evaluated. RESULTS: An improvement of the operative time was observed for each surgeon. The experienced surgeon, the fellow and the resident improved their time by 11, 15, and 22 min, respectively, between the first and the second RARC performed. The most significant time difference was demonstrated by the resident, who had no previous experience in using robotic systems. The time difference between the first and the last orthotopic ileal neobladder creation for the experienced surgeon was 51 min. CONCLUSION: The feasibility of avatera system for performing complex surgical procedure such as RARC with intracorporeal neobladder formation was demonstrated by this experimental study. No major bleeding or severe malfunctions were observed during the procedures. Significant improvement in operative time was demonstrated with the increasing experience from 1st to 6th case.

Market potentials of robotic systems in medical science: analysis of the Avatera robotic system.

PURPOSE: To evaluate the potential opportunities and possible competitiveness of Avatera robotic system (ARS) (Avateramedical, Germany), and perform predictive cost-analysis for its implementation and dissemination. MATERIAL AND METHODS: Our study employed a projective quantitative research design. SWOT (strengths, weaknesses, opportunities, threats) analysis was used to map ARS internal competencies towards external contexts, and potential opportunities and risks in the robotic market. The ARS purchase and procedural costs were evaluated in two different scenarios. RESULTS: In the first scenario, setting the purchase cost of the Avatera at around $1.3-1.5 million, a total $400 procedural cost reduction compared to the RAS performed with the da Vinci Xi can be calculated. In the second scenario, with a purchase cos of the ARS of $700.000-800.000 and considering a 5-year period with an annual ARS volume of 500 procedures, only an additional $300 will be attributed to the robot itself. Our projections revealed that for an effective competition the purchase cost of ARS should range between $700.000 and $800.000 during the initial phase of market entry. The marketing strategy of the ARS should be oriented towards countries without any robotic system in operational use, followed by countries where the competition intensity in the marketplace is low. CONCLUSION: The introduction of new robotic systems will greatly affect and reshape the market of robotic surgery. The ARS has all the technical capacity ensuring the performance of high-quality surgical procedures. A fast spread and implementation of the ARS could be expected should the purchase and maintenance costs be kept low.

Long-term outcomes of paclitaxel-coated balloons for non-malignant ureteral strictures.

PURPOSE: To evaluate the clinical efficacy and safety of drug-coated balloon (DCB) ureteroplasty for the management of non-malignant ureteral strictures. MATERIAL AND METHODS: A prospective "off-label" monocentric single-arm pilot study investigating the safety and efficacy of drug-coated balloon (DCB) (Lutonix®; BD, USA) was performed. Twenty-five patients with benign ureteral strictures related to uretero-enteric anastomosis (n = 13); lithiasis (n = 5), post-surgical complications (iatrogenic n = 5), transplanted kidney (n = 1) and post-radiotherapy (n = 1) were included. Following lesion crossing, predilatation was performed using 4-7 mm high-pressure balloon catheter (5-6Fr) with a balloon pressure of 6-7 atm based on the manufacturer's recommendation. In the absence of rupture of the ureteral wall, the DCB was dilated for 4 min. across the lesion. The process was repeated if deemed necessary to a maximum of three stricture dilatations. We analysed both clinical and radiological primary patency (no signs of ipsilateral hydronephrosis or improvement of the existing residual dilatation at the follow-up examinations) and secondarily safety endpoints. RESULTS: Mean lesion length was 40 ± 28.5 mm. Mean time follow up was 36 months ± 10.46 months. Strictures were located at upper ureteric (12%), lower ureteric (32%), ureterovesical anastomosis (4%) and uretero-enteric anastomosis (52%) levels. The overall radiological success at 1-year follow-up was 88% (22/25 patients). In 56% patients (14/25 patients with primary patency) the nephrostomy catheter was removed 21 days following a single DCB procedure. In 32% (8/25 patients) an additional dilatation sessions were required for maintaining the ureteral patency. The overall failure rate at 1-year follow-up was 12% (3/25 patients). Only one case of febrile urinary tract infection in a female patient (acute pyelonephritis) was encountered after the first dilatation. CONCLUSIONS: Paclitaxel-coated balloon ureteroplasty proved to be safe and effective for the treatment of non-malignant ureteral strictures. Larger studies are warranted to validate these promising initial results.

The effect of prolonged laser activation on irrigation fluid temperature: an in vitro experimental study.

PURPOSE: To investigate the effect of prolonged laser activation on irrigation fluid temperature by varying the power settings flow rate (10-30 ml/min). MATERIALS AND METHODS: An experimental study using a 20 ml syringe, 12/14 ureteral access sheath, a dual-lumen catheter and a thermocouple was performed. The laser was fired with 12 W (0.3 J × 40 Hz), 40 W (1 J × 40 Hz), 60 W (1.5 J × 40 Hz) using Quanta Ho 150 W (Quanta System, Samarate, Italy). All trials were performed with fluid outflow rate of 10, 20 and 30 ml/min with the fixed fluid volume at 10 ml. RESULTS: Continuous laser activation for 10 min with the outflow rate of 10 ml/min using only 12 W resulted to continuous temperature rise to as high as 83 °C. Similar rise of temperatures were observed for 40 W and 60 W with 10 ml/min outflow rate with intermittent laser activation. With 20 and 30 ml/min outflow rates the maximum temperatures for all power settings were below the threshold (< 43 °C). However, the time to reach the same total emitted energy was 60% and 40% shorter 60 W and 40 W, respectively. CONCLUSION: Our study found that continuous laser activation with as less as 12 W using 10 ml/min outflow rate increased the irrigation fluid temperature above the threshold only after 1 min. In the current experimental setup, with the fluid outflow rate of 20 and 30 ml/min safe laser activation with 60 W and 40 W (temperature < 43 °C) can be achieved reaching the same total emitted energy as with 12 W in significantly shorter time period.

Worldwide practice patterns of percutaneous nephrolithotomy.

PURPOSE: To evaluate the current practice of percutaneous nephrolithotomy (PCNL), conducting a worldwide survey among urologists with a special interest in endo-urology. METHODS: A 22-question survey was specifically developed by the European Association of Urology (EAU) young academic urologists (YAU) and uro-technology (ESUT) groups and globally distributed via SurveyMonkey to almost 2000 members of Endourology Society. The questionnaire included questions dedicated to the demographics and general practice of the participating urologists. RESULTS: In total, 441 responses (male/female ratio - 418/23) were received. A comparatively higher percentage of specialists (56.2%) practiced in academic institutions and had specific endo-urological fellowship training (56.7%). The classical prone PCNL remained the most practiced approach among the surveyed specialists, 47.7% stated to always do prone PCNLs, while 51.8% of respondents used multiple positioning options as required. The PCNL tract was mostly performed by urologists (84.3%) and fluoroscopic guidance was still predominantly used by 74.5% of respondents. The most practiced tract dilation method was balloon dilator used by 42% of respondents. Most of the surveyed urologists had ultrasonic, pneumatic or laser lithotripsy devices in their armamentarium. The use of some form of post-procedural drainage was reported in 85.1% of respondents, whereas tubeless PCNL remained a fairly uncommon practice. CONCLUSION: The majority of urologists still use prone positioning, get their own access under fluoroscopy guidance and use a balloon for tract dilation. However, we also identified that when necessary, urologists will deviate from routine practice and change strategy, adopting other approaches for PCNL.

Comparison of renal parenchymal trauma after standard, mini and ultra-mini percutaneous tract dilation in porcine models.

OBJECTIVE: To evaluate whether reducing tract dilation diameter in PCNL (percutaneous nephrolithotomy) procedures results in minimizing of renal trauma of the percutaneous tract. METHODS: A percutaneous renal access tract was established bilaterally to 11 pigs. Two pigs were euthanized immediately after the experiment, while nine pigs were sacrificed 1 month later. The percutaneous accesses were dilated up to 30Fr, 22Fr or 12Fr. The animals underwent a contrast-enhanced computer tomography immediately after the procedure and 30 days later. DMSA-scintigraphy with SPECT-CT was also performed. The kidneys of all animals were harvested for histological evaluation. The volume of scar tissue and the percentage of renal volume replaced by scar tissue were calculated. RESULTS: Immediate post-procedural CT-scans revealed a significant difference in defect diameter among the three modalities. However, the scar volume calculated on CT-images and histopathology showed a significant difference only when 30Fr dilation was compared to 12Fr dilation. The percentage of scar volume was negligible in all cases, but there was still a statistical difference between 30 and 12Fr dilation. Dilation up to 22Fr revealed no statistical differences compared to the other two modalities. DMSA-scintigraphy showed no scar tissue in any case. CONCLUSION: Dilation up to 30Fr may cause a significantly larger scar tissue on renal parenchyma compared to 12Fr dilation as it was shown on CT-images and microscopic evaluation, but based on the DMSA/SPECT-CT this difference seems to be insignificant to the renal function. The scar tissue caused by 22Fr dilation seemed to have no significant difference from the other modalities.

The use of 14/16Fr ureter access sheath for safe and effective management of large upper ureteral calculi.

OBJECTIVE: To evaluate the effectiveness of ureteroscopic lithotripsy for the management of large proximal ureteral stones > 10 mm using 14/16 Fr ureteral access sheath (UAS). MATERIALS AND METHODS: Patients' data from prospective database undergoing ureteroscopic laser lithotripsy with a use of 14/16Fr UAS were collected. All patients were pre-stented prior to the procedure. The fragmentation was performed with a semi-rigid ureteroscope using holmium laser energy with a power setting of 35 W (frequency-35 Hz; energy-1 J). Follow-up was scheduled at 4 weeks and 3 months postoperatively. RESULTS: In total 78 patients, 43 males and 35 females, were included in the study. The mean age of the patients was 59.5 ± 13.3 with a mean maximal stone diameter of 13.4 ± 2.1. The mean operative time was 35.7 ± 9.7 and the mean hospital stay was 2 ± 0.7 days. The primary SFR at 4 weeks was 73 patients (93.6%), while all 78 patients (100%) were stone free at 3-month follow-up, 2 of the patients receiving additional treatment. In total, 8 (10.2%) patients experienced Grade II complications. Intraoperative ureteral lesions were observed in 41 (52.6%) cases. Out of them 31 patients (39.7%) developed Grade 1, 8 patients (10.3%) Grade 2 and only 3 patients (2.6%) Grade 3 lesions. CONCLUSION: The use of 14/16Fr ureteral access sheath on pre-stented patients was associated with successful outcomes. A high stone-free rate of 93.6% was achieved at 4-week follow-up. The procedure was not associated with increased rate of postoperative complications and intraoperative ureteral injury.

What is the impact of pulse modulation technology, laser settings and intraoperative irrigation conditions on the irrigation fluid temperature during flexible ureteroscopy? An in vivo experiment using artificial stones.

PURPOSE: To investigate the effect of different combinations of laser power settings and irrigation conditions using the pulse modulation technology of Quanta™ on irrigation fluid temperature (IFT) during FURS (flexible ureteroscopy) on an in-vivo porcine model with artificial stones. MATERIALS AND METHODS: A female pig was used. Following the insertion of artificial stones (Begostone™, BEGO USA, Lincoln, RI), a K-type thermocouple was fixed to the created percutaneous access tract. Real-time recordings of IFT during FURS were performed without UAS (ureteral access sheath), with 10/12 UAS, 12/14 UAS and 14/16 UAS. Stone fragmentation was achieved using Quanta Litho Cyber Ho 150 W™ (Samarate, Italy). The IFT was recorded for 30 s, during laser activation, with power settings of 20, 40, 60, 75 and 100 W under both manual pump and gravity irrigation. RESULTS: The IFT rise above 54 °C was recorded above a power of 40 W when gravity irrigation was used. The use of UAS prolonged the time for IFT to reach high values, although high power settings increase IFT within seconds from the laser activation. Under pump irrigation, only the 100 W power setting without the use of UAS resulted in dangerous IFT after approximately 10 s. CONCLUSION: The high-power Ho:YAG laser can cause a damaging thermal effect to the kidney exceeding the threshold of 54 °C, under gravity irrigation. Lower power settings (up to 40 W) can be used with safety. According to our experiment, when using high power settings, the use of UAS and manual pump irrigation, is the safest combination regarding renal thermal damage.

Nonpapillary prone endoscopic combined intrarenal surgery: effectiveness, safety and tips, and tricks.

PURPOSE: To evaluate the effectiveness and safety of nonpapillary prone endoscopic combined intrarenal surgery (ECIRS) and provide practical tips and tricks for the successful accomplishment of the procedure respecting the anatomical particularities. MATERIAL AND METHODS: This study is an analysis of a prospectively collected database including all cases of ECIRS performed between January 2019 and December 2021 in a high-volume tertiary center. All patients underwent the procedure in prone-split leg position. A nonpapillary renal puncture was performed. The used access sheaths were 22Fr or 30Fr. Lithotripsy was performed anterogradely with a dual-energy lithotripter with incorporated suction and retrogradely with holmium Yttrium-Aluminum-Garnet laser. RESULTS: A total of 33 patients were included. The initial stone-free rate (SFR) was 84.8% and the final SFR was 90.9%. The median stone size was 35 mm and 60% of patients had staghorn calculi. The prevalence of renal abnormalities was 21.3%, including 3 cases of horseshoe kidney, 2 cases of malrotation and 2 cases with complete duplicated systems. The median operative time was 47 min. The median hospital stay was 3 days and median hemoglobin loss was 1.2 gr/dL. Overall, the complication rate was 9.1%, all being Grade II complications (n = 2 fever and n = 1 transient bleeding). CONCLUSIONS: Nonpapillary prone ECIRS is an effective and safe procedure. Standardization of the procedure is critical to achieve good outcomes. Patients who benefit the most are probably the ones where additional punctures can be avoided using this technique, namely patients with renal abnormalities, incrusted ureteral stents and staghorn stones.

The use of ureteral access sheath during mini-percutaneous nephrolithotomy with high-power holmium YAG laser.

PURPOSE: To present our preliminary results and describe a technical modification of mini-PCNL (12Fr) with the insertion of a ureteral access sheath (UAS) to facilitate the procedure. METHODS: A prospective study for the time period of January 2020 to January 2021 was conducted including patients with renal stones sized ≤ 25 mm in whom prone mini-PCNL (tract size 12Fr) together with the retrograde insertion of UAS was performed. All patients had been prestented at least 1 week prior to the planned surgery. A single-step tract dilation to 12Fr diameter was performed through a nonpapillary medial puncture. The lithotripsy was achieved using high-power holmium yttrium aluminum garnet laser (Ho:YAG) with the 60 W power setting (40 Hz and 1.5 J). The follow-up investigations were planned at 1-month after the surgery. RESULTS: In total, 32 patients with the median age and stone size of 56.5 (IQR = 53-62) years and 20.8 (IQR = 19.3-22.7) mm were included. The median operative and cumulative fluoroscopy time were 34.0 (IQR = 29.9-37.5) and 1.9 (1.8-2.1) min, respectively. The stone-free rate (SFR) at 1-month follow-up was 93.8% (30/32). Only one patient developed a fever and required prolonged antibiotic administration. None of the patients experienced clinically significant bleeding. CONCLUSION: Our preliminary results showed that the use of UASs during mini-PCNL procedures is feasible and provides directed evacuation of the stone fragments reaching 93.8% SFR at a 1-month follow-up. Future well-designed studies are necessary to prove our findings.

Comparison between standard, mini and ultra-mini percutaneous nephrolithotomy for single renal stones: a prospective study.

PURPOSE: Based on the current trend of miniaturization of instruments used in percutaneous nephrolithotomy (PCNL), it is necessary to compare different PCNL modalities regarding their access sheath size used. Thus, the safety and efficacy among standard, mini and ultra-mini PCNL (s-PCNL, m-PCNL, um-PCNL) were compared. METHODS: We performed a prospective, non-randomized trial between January 2018 and July 2020. Patients with stones classified as Guy's stone score grade I were included. The set-up for s-PCNL and m-PCNL included a 30 Fr and 22 Fr percutaneous tract, respectively. In both set-ups, an ultrasonic/ballistic lithotripter was utilized. In the case of um-PCNL, a 12 Fr percutaneous tract was established. A high-power laser was used for lithotripsy. Hemoglobin drop, complication rate, length of hospital stay (LOS), stone-free rate (SFR) and operation time were evaluated. RESULTS: A total of 84 patients, 28 patients per method, were evaluated. Hemoglobin drop was higher in the s-PCNL group when compared to m-PCNL (p = 0.008) and um-PCNL groups (p < 0.001), while um-PCNL group had the slightest hemoglobin drop. LOS was similar between s-PCNL group and m-PCNL group, but um-PCNL group required shorter hospital stay than the other two modalities (p < 0.001). The complication and transfusion rates as well as SFR did not differ between groups. Operation time in the um-PCNL set-up was longer compared to s-PCNL (p < 0.001) and m-PCNL (p = 0.011), whereas s-PCNL and m-PCNL did not differ significantly. CONCLUSION: m-PCNL showed less hemoglobin drop, but similar operation time and SFR when compared to s-PCNL. um-PCNL showed even less hemoglobin drop, but the operation time was longer compared to the two other modalities.

Electromagnetic-guided puncture: a tool or a tale?

PURPOSE OF REVIEW: The puncture technique and site of the puncture can impact the clinical outcome and the development of postoperative adverse events following percutaneous nephrolithotomy (PCNL). The aim of the current review was to discuss the available puncture guidance approaches and outline the potential role of the recently introduced electromagnetic-guided method. RECENT FINDINGS: The puncture and PCNL tract establishment is usually performed using fluoroscopic or ultrasound guidance or a combination of two approaches. Electromagnetic-guided puncture is one of the most recent advancements of technology. The puncture navigation to the renal collecting system is available after placing a special wire with an electromagnetic tracking sensor into the desired calyx through the flexible ureterorenoscope. The available experimental and clinical studies have shown a high first puncture rate, decreased median time for obtaining a puncture, and shorter learning curves for beginners. SUMMARY: Fluoroscopic and ultrasound guidance are the main approaches used by urologists. However, these modalities require a steep learning curve, approximately 60 cases for reaching competency. The initial data on electromagnetic navigation have shown the feasibility and potential promising outcomes of this novel approach. New studies are required to investigate its potential implementation opportunities in the daily practice of urologists.

Stone ablation rates using innovative pulse modulation technology: Vapor tunnel, virtual basket, and bubble blast. An in vitro experimental study.

INTRODUCTION AND OBJECTIVES: Virtual BasketTM , Bubble BlastTM , and Vapor TunnelTM are three laser pulse modulation technologies that modify the holmium: yttrium-aluminum-garnet (Ho:YAG) laser pulse transmission through the creation of bubbles emerging from the fiber tip with different effects on the target stone. The primary outcome of the current study was to test the stone ablation rates for the different pulse modulation modes, Virtual Basket, Bubble Blast, and Vapor Tunnel, using different power, energy, and frequency settings. MATERIALS AND METHODS: Quanta Cyber: Ho 150 WTM , a 365 µm PrecisionTM fiber, and hard and soft phantom BegoStonesTM were used in an in vitro experimental configuration in a saline bath. In the Virtual Basket mode, the combinations of power, energy and frequency were tested; 10 W = 0.5 J × 20 Hz, 10 W = 0.5 J × 20 Hz, 60 W = 1 J × 60 Hz and 60 W = 2 J × 30 Hz. In the Bubble Blast mode, the combinations, 12 W = 1.2J × 10 Hz, 60 W = 1.2J × 50 Hz and 60 W = 2 J × 30 Hz, were tested. Similarly, the combination of 10 W = 0.5 J × 20 Hz was tested with Vapor Tunnel mode. High-speed camera captures of the bubble formation and regular photographs of the fragmentation pattern were also taken for each mode. RESULTS: High power lithotripsy was faster and related to higher ablation rates. The Virtual Basket, Bubble Blast, and Vapor Tunnel modalities showed different ablation rates for the same energy and frequency settings. For hard stones, there was an improvement in the ablation rate using 60 W = 2 J × 30 Hz compared with 60 W = 1 J × 60 Hz and 60 W = 1.2 J × 50 Hz. The highest ablation rates were recorded using the Virtual Basket mode with the high-power settings of 2 J of energy and 30 Hz of frequency. CONCLUSIONS: The Virtual BasketTM pulse-modulation technology was related to the highest ablation rates for both hard and soft stones, compared to the Bubble BlastTM and the Vapor TunnelTM technologies in high-power and low-power lithotripsy respectively. For the same high power settings, higher energy seems to provide higher ablation rates.

Correction to: Metastasectomy for visceral and skeletal oligorecurrent prostate cancer.

The authors have requested the removal of the Excel file in Electronic Supplementary Material to protect patient's privacy.

Metastasectomy for visceral and skeletal oligorecurrent prostate cancer.

OBJECTIVES: Metastasis direct therapy (MDT) is a common practice in different fields of oncology. However, there is a lack of data on surgical MDT in visceral/skeletal oligometastatic prostate cancer (PCa). We aimed to assess the role of surgical excision of visceral and skeletal PCa recurrence. METHODS: Seventeen PCa patients experienced metachronous visceral or skeletal oligometastatic recurrence following maximal local treatment. Oligometastatic recurrence was defined as 1-3 lesions, detected with the best imaging technique available at the time of diagnosis. All patients underwent metastasectomy and were followed for a median of 43 months. Postoperative complications were graded using the Clavien-Dindo classification of surgical complications. Kaplan-Meier plots were used to assess overall survival. RESULTS: Fourteen patients (82%) had visceral lesions, two had bone lesions (12%), and one had an abdominal wall metastasis (6%). Four patients (24%) were under active ADT at the time of metastasectomy. PSA decreased after metastasectomy in 16 (94%) patients. Ten (77%) of the 13 ADT-naïve patients had a PSA decrease of ≥ 50%. Following metastasectomy, 16 (94.1%) patients developed metastatic recurrence of which 11 (64.7%) were again oligometastatic, amenable for repeated MDT. The median time to metastatic recurrence was 14 months (range 6.4-40). We observed 8% Clavien-Dindo grade 3-4 complications in 21 procedures. CONCLUSIONS: In this report, we analyzed the outcomes of surgical excision of visceral and skeletal PCa recurrence following primary treatment. We found that removing metastasis to the bone and viscera can be associated with long-term disease-free periods at a low rate of serious complications. These exploratory results should be confirmed in prospective studies.

Percutaneous antegrade management of large proximal ureteral stones using non-papillary puncture.

Objective: To evaluate the feasibility and the safety of medial non-papillary percutaneous nephrolithotomy (npPCNL) for the management of large proximal ureteral stones. Methods: We evaluated prospectively collected data of 37 patients with large proximal ureteral stones more than 1.5 cm in diameter treated by prone npPCNL. Depending on stone size, in-toto stone removal or lithotripsy using the Lithoclast® Trilogy (EMS Medical, Nyon, Switzerland) was performed. Perioperative parameters including operative time (from start of puncture to the skin suturing), stone extraction time (from the first insertion of the nephroscope to the extraction of all stone fragments), and the stone-free rate were evaluated. Results: Twenty-one males and 16 females underwent npPCNL for the management of large upper ureteral calculi. The median age and stone size of treated patients were 58 (interquartile range [IQR]: 51-69) years and 19.3 (IQR: 18.0-22.0) mm, respectively. The median operative time and stone extraction time were 25 (IQR: 21-29) min and 8 (IQR: 7-10) min, respectively. One case (2.7%) of postoperative bleeding and two cases (5.4%) of prolonged fever were managed conservatively. The stone-free rate at a 1-month follow-up was 94.6%. Conclusion: The npPCNL provides a straight route to the ureteropelvic junction and proximal ureter. Approaching from a dilated portion of the ureter under low irrigation pressure with larger diameter instruments results in effective and safe stone extraction within a few minutes.