Minimal invasive treatment of urethral strictures: An experimental study of the effect of paclitaxel coated balloons in the wall of strictured rabbit's urethra

PURPOSE

The aim of this study is the evaluation of the distribution of paclitaxel (PTX) released by a coated balloon in the layers of rabbit's urethra.

METHODS

18 rabbits were included. A laser device was used for the stricture formation. After two weeks, dilation of the strictured urethra was performed by using Advance 35LP PTA balloons and Advance 18 PTX PTA balloons. The experimental models were divided into 3 groups. The group Α included two rabbits without any intervention except for the stenosis procedure. Group B compromised six rabbits that underwent dilation with Advance 35LP PTA balloons. Group C consisted of 10 rabbits to which dilation with both Advance 35LP PTA balloons and Advance 18 PTX PTA balloons was applied. Histological evaluation and Immunohistochemistry were performed on all specimens.

RESULTS

Inflammation, fibrosis and ruptures were detected in the specimens of the study. In specimens of Group C the decrease of inflammation and fibrosis rate was greater. Anti-PTX antibody was detected in the epithelium, lamina propria and smooth muscle layer of all specimens of urethras that have been harvested immediately and 1 day after the dilation with Advance 18 PTX PTA balloon and it was not observed in any layer of the urethral wall of the rest of the examined specimens of Group C.

CONCLUSIONS

PTX's enrichment was detected in the smooth muscle layer of all specimens that have been harvested immediately and 24h after the dilation with Advance 18 PTX PTA balloons. PTX may play an inhibitive role in the recurrence of the stenosis.

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.

Use of artificial stones in training and laboratory studies, have we found the right material? Outcomes of a systematic review from the European School of Urology

Objective

In this review, we investigated the current literature to find out which artificial stones (AS) are available in endourology, and in which experimental and training schemes they are used.

Materials and Methods

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Twenty-one out of 346 studies met our inclusion criteria and are presented in the current review. The inclusion criteria were the existence of AS and their use for laboratory and training studies.

Results

There is a wide variety of materials used for the creation of AS. BegoStone powder (BEGO USA, Lincoln, Rhode Island) and plaster of Paris™ were used in most of the studies. In addition, Ultracal-30 (U. S. Gypsum, Chicago, IL) was also used. Other materials that were used as phantoms were AS created from plaster (Limbs and Things, UK), standardized artificial polygonal stone material (Chaton 1028, PP13, Jet 280; Swarovski), model stones consisting of spheres of activated aluminum (BASF SE, Ludwigshafen am Rhein, Deutschland), Orthoprint (Zhermack, Badia Polesine, Italy), and a combination of plaster of Paris, Portland cement, and Velmix (calcium sulfate powder). Many experimental settings have been conducted with the use of AS. Our research demonstrated nine studies regarding testing and comparison of holmium: yttrium-aluminum-garnet laser devices, techniques, and settings. Six studies were about extracorporeal shock wave lithotripsy testing and settings. Three experiments looked into treatment with percutaneous nephrolithotomy. Additionally, one study each investigated imaging perioperatively for endourological interventions, stone bacterial burden, and obstructive uropathy.

Conclusion

AS have been used in a plethora of laboratory experimental studies. Independent of their similarity to real urinary tract stones, they present a tremendous potential for testing and training for endourological interventions.

Self-removal of catheter after robot-assisted radical prostatectomy: a feasibility study

Self-removal of urinary catheter as an option after robot-assisted radical prostatectomy (RARP) has never been explored in literature. We report the feasibility and outcome of the first study of this novel concept in our hospital. We conducted a prospective audit of self-TWOC (trial without catheter) in men who underwent consecutive RARP in our centre between April 2022 and September 2022. Men who had self-TWOC filled a questionnaire about the outcomes of self-TWOC. Carbon footprint and carbon offset for each hospital TWOC avoided were calculated. Of the 129 who underwent self-TWOC, 112 filled the questionnaire and were hence included in the final analysis. Self-TWOC was successful in all the 112 (100%) men in the study. 99.1% of men were satisfied with self-TWOC at home. We managed to avoid 79.6 ± 36.72 km of travel and 77 min of travel time for every self-TWOC. This also saved 85£/patient on clinic expenses and fuel cost savings of 9.87-15.99£ per patient depending on car engine size/type. The carbon footprint calculated was 20 kg CO2 assuming average engine sized diesel/petrol cars and 10 kg CO2 for an average UK petrol hybrid car. The calculated carbon offset per patient for diesel/petrol cars: 0.32£, petrol hybrid: 0.16£. Self-TWOC for 80-160 patients will save the carbon emissions equivalent to that of a passenger on a London-New York Trans-Atlantic flight. Self-TWOC is safe, affordable and is sustainable to the environment. Widespread acceptance of this practice change will be a small, but steady step towards greener health systems across the world.

Assessment of routine same-day discharge surgery for robot-assisted radical prostatectomy

INTRODUCTION

It is important for robotic surgery to be cost-effective, especially by reducing the length of stay (LOS). Therefore, we developed a protocol for day-case robot-assisted radical prostatectomy (RARP). This study aimed to validate this as a safe practice of care and to assess the potential benefits to the hospital and patient.

METHODS

In this single-centre study, all patients booked for RARP between April 2022 and October 2022 were screened for suitability for day case. All tumour types were included. Exclusion criteria were a history of complex abdominal surgeries, salvage prostatectomy, body mass index (BMI) > 35 and patient living alone or > 150 km away from the hospital. All day-case RARPs were performed as a morning case with a protocol for review throughout the day with evening discharge if mobilising independently and eating/drinking well. The primary outcome of the study was success rate of discharge home on day of surgery (DOS) with secondary outcomes of readmissions and complications. A patient questionnaire was completed at home including both visual analogue scale (VAS) for pain and satisfaction rating.

RESULTS

Forty-five patients underwent day-case RARP over a 6-month period with minimum of 30 days of follow-up. 41/45 (91%) had successful DOS discharge home. The four admissions overnight were due to dizziness, low oxygen saturation, intraoperative complications and a diagnosis of COVID-19. There were no readmissions and no 30-day complications. The most common issues at home were catheter discomfort and constipation with low mean VAS pain score and low nausea reported. The overall patient satisfaction rating was very high at 4.8/5, and 97% said they would recommend to a family member. The cost saving for the hospital was 400 pounds per patient.

CONCLUSION

Day-case procedure is a viable, safe and efficient pathway for appropriately selected and counselled patients undergoing RARP.

Outcomes of thulium prostatectomy with "Oyster technique" versus transurethral prostatectomy (TURP): a randomized control trial

PURPOSE

To compare the perioperative and postoperative outcomes between Oyster prostate vaporesection using Tm-YAG laser and the conventional transurethral prostatectomy using monopolar energy.

METHODS

Patients with LUTS with an accumulative size of at least 60 ml were randomly assigned to one of two parallel groups to undergo Tm-YAG laser vaporesection (Group 1) or conventional monopolar transurethral prostatectomy (Group 2). The primary endpoints were the reduction in IPSS and the increase in Qmax postoperatively. Secondary endpoints included the Hemoglobin drop, the complication rate, the changes in urodynamic parameters, the duration of hospitalization and catheterization and the changes in IIEF during the 24-month follow-up.

RESULTS

In total 32 and 30 patients were enrolled in Groups 1 and 2, respectively. Patient age (p = 0.422) and prostate volume were similar among the groups (p = 0.51). The outcomes in terms of IPSS decrease and Qmax amelioration were comparable (p = 0.449 and p = 0.237, respectively). Operative and hospitalization times were lower in Group 1 (p = 0.002 and p = 0.004, respectively). Hemoglobin drop, changes in urodynamic parameters and improvement in IIEF and QoL scores did not differ among the two Groups. The average time with the catheter was 2.06 ± 0.35 and 2.5 ± 0.82 (p = 0.003) days for Group 1 and Group 2, respectively. The overall complication rate was 6.2% for Group 1 and 13.3% for Group 2.

CONCLUSIONS

The Oyster technique leads to similar postoperative outcomes compared to the standard monopolar transurethral prostatectomy. The shorter catheterization, hospitalization and operation time should be considered advantages of the Oyster technique.

The effect of percutaneous tract dilation technique on renal parenchymal trauma: An experimental in vivo study on a porcine model

Purpose

The purpose of this study was to evaluate renal parenchymal trauma of two-step dilation compared to the conventional Amplatz gradual dilation during percutaneous nephrolithotomy on a porcine model.

Materials and Methods

A nonpapillary percutaneous access tract was established under fluoroscopic guidance in both kidneys of four female pigs. On the right kidney of each pig, gradual dilation was performed using an Amplatz dilator set with a gradual dilation to 30 Fr, whereas on the left, a two-step dilation was utilized using only 16 Fr and 30 Fr dilators. Two of the animals were euthanized immediately after the procedure and the remaining two 1 month later. The pigs that were kept alive underwent a contrast-enhanced computed tomography immediately, 15, and 30 days postoperatively. A dimercaptosuccinic acid (DMSA) scintigraphy and single-photon emission computed tomography-computed tomography (CT) were also performed after the last CT and afterward, the pigs were sacrificed. All kidneys were harvested for pathohistological examination.

Results

The follow-up radiologic imaging showed similar parenchymal damage caused by the compared dilation techniques and an expected reduction in scar size in the later scans. No scar was identified by DMSA in any kidney. Gross and microscopic examinations conducted both on the kidneys that were harvested immediately after the procedure and the ones from the animals that were left to heal, revealed no significant differences in tissue damage, grade of fibrosis, or inflammation depending on the dilation method.

Conclusions

Our study showed no inferior outcomes caused by two-step dilation compared to gradual dilation regarding renal parenchymal damage following a nonpapillary puncture. In fact, postoperative imaging findings suggested a trend toward better healing and less scar tissue when the two-step method was used.

Holmium: Yttrium-aluminum-garnet laser lithotripsy: Is there a difference in ablation rates between short and long pulse duration?

Introduction

The high-power holmium: yttrium-aluminum-garnet lasers provide a wide variety of settings for stone disintegration. The aim of this in vitro study is to evaluate the effect of short and long pulse duration on ablation rates on urinary stones.

Materials and Methods

Two types of artificial stones were created by BegoStone™ with different compositions (15:3 and 15:6, stone/water ratio). Stones with a 15:3 and 15:6 powder-to-water ratio were defined as hard and soft stones, respectively. Lithotripsy was performed with different laser settings using a custom-made in vitro model consisting of a 60 cm long and 19 mm diameter tube. The ablation rate is defined as the final total mass subtracted from the initial total mass and divided to the time of treatment. Stone ablation rates were measured according to different laser settings with total power of 10W (0,5J-20 Hz, 1J-10 Hz, 2J-5 Hz) and 60W (1J-60 Hz, 1,5J-40 Hz, 2J-30 Hz).

Results

Higher pulse rates and higher total power settings were related to higher ablation rates. Short pulse duration was more effective on soft stones, whereas long pulse duration was more effective on hard stones. For the same power settings, the highest energy-lowest frequency combination resulted in higher ablation rate in comparison to the lowest energy-higher frequency combination. Finally, short and long pulse average ablation rates do not differ so much.

Conclusion

Regardless of the stone type and pulse duration, utilization of higher power settings with higher energies increased the ablation rates. Higher ablation rates were demonstrated for hard stones using long pulse duration, and for soft stones with short pulse duration.

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.

Clearance of Metal Particles After Percutaneous Nephrolithotomy with Trilogy Lithotripter

Purpose: To evaluate the clearance of metal particles produced and released in the pelvicaliceal system (PCS) during percutaneous nephrolithotomy (PCNL) with the use of the Swiss Lithoclast^® Trilogy dual-energy (EMS Urology, Nyon, Switzerland) lithotripter. Methods: An experimental in vivo study and a clinical investigation of case series were conducted. An in vivo porcine model with two pigs for lithotripsy (after inserting artificial stones into the collecting system) and two pigs for submucosal injection of metal particles (provided by the manufacturer of Trilogy) was conducted. Porcine kidney histology analysis for metal leftovers was conducted immediately or 2 weeks after the surgery. A prospective observational study design included 10 consecutive patients treated with conventional 30F PCNL or with 22F mini-PCNL technique. Only the patients with the confirmed metal particles in the PCS during the initial PCNL and the need for additional retrograde intrarenal surgery over a period of 2-4 weeks were selected. The presence of metal particles was evaluated during the second endoscopic surgery. Results: The generated metal particles during PCNL and the submucosally injected particles were not found macroscopically 2 weeks postoperatively in porcine models. No pathologic changes such as foreign body granuloma or inflammation were found. Similarly, no metal particles were observed during the second look endoscopy (n = 10). Conclusion: Metal particles observed endoscopically using the Trilogy lithotripter are cleared with no pathologic evidence of tissue damage from the metal particles 2 weeks after the procedure. Thus, the intraoperative release of any particle by the Trilogy lithotripter should not raise any safety concerns.

Factors affecting the irrigation fluid temperature during laser lithotripsy: in vitro experimental study

OBJECTIVE

To investigate the effect of the diameter of laser fiber, pelvis volume, presence and type of the stone on irrigation fluid temperature rise.

MATERIAL AND METHODS

A 20ml syringe, 12/14 ureteral access sheath(UAS), a dual-lumen catheter and a thermocouple were used.  The 12/14Fr UAS(Cook Ireland Ltd., Limerick, Ireland) and the Thermocouple(SE001, Pico Technologies, Cambridgeshire, UK) were inserted in the syringe. The syringe was closed allowing outflow from the UAS with rate at 10ml/min. The Quanta Ho 150W(Quanta System, Samarate, Italy) laser was used and fired with 10W(2Jx5Hz), 20W(2 × 10 Hz), 40W(2 × 20 Hz), 60W(2 × 30 Hz). These power settings were tested in different conditions: fibers(200µm, 365µm and 550µm), volumes(5ml, 10ml and 20ml) and artificial stones(soft, hard). The laser was activated for 30 seconds and reactivation was performed when the temperature reached below 26 ⁰C.

RESULTS

For all trials 60W of energy resulted in higher temperature rise. No differences were observed when different fibers were used. The highest temperatures (up to 80 ⁰C) for 60W were reported in 5ml syringe and the lowest (<45 ⁰C) with 20ml.  The maximal temperature of >59°C was recorded for the power of 60W(1Jx60Hz). The temperature exceeded 43 ⁰C when power settings >40W were applied.

CONCLUSION

Increasing the overall power, increases the irrigation fluid temperature significantly. The smaller the volume of the pelvis, the greater the temperature elevation. The fiber size did not affect the temperature increase pattern. The presence of artificial stones was associated with the absorption of energy emitted by the laser.

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.

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.

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 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.

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.

Could the high-power laser increase the efficacy of stone lithotripsy during retrograde intrarenal surgery?

OBJECTIVE

To compare a high-power setting holmium yttrium aluminum garnet (Ho:YAG) laser lithotripsy to the established low-power setting approach during Retrograde Intrarenal Surgery (RIRS).

MATERIAL AND METHODS

Our study analyzed the data of consecutive patients managed with RIRS. The patients were divided into 2 groups according to the employed laser settings of power, energy and frequency; dusting (20W=0.5Jx40Hz) (Group1) and stone "self-popping" (60W=1.5-2Jx30-40Hz) (Group 2). Perioperative outcomes including operative time (OT) and stone disintegration time (SDT) were compared between groups. Stone-free rate (SFR) was evaluated 1 month after the surgery.

RESULTS

Overall, 174 patients with 179 renal units were included. The dusting mode was utilized in 98 patients (100 renal units), whereas 76 patients (79 renal units) underwent the stone "self-popping" technique. The SFR was 82.1% for both groups. The OT and SDT were 60.1 ± 18.6min and 32.6 ± 9.4min respectively for Group 1, and 44.9 ± 15.5min and 16.5 ± 4.7min respectively for Group 2. According to the final analysis, laser lithotripsy using stone the "self-popping" technique was significantly faster compared to the dusting technique with a coefficient value of 14.12min (CI = 8.8 - 19.44) and 15.84min (CI = 13.44 - 18.2) for OT and SDT, respectively.

CONCLUSION

The stone "self-popping" technique with the power at 60W, frequency at 30-40Hz and energy at 1.5-2.0J is a safe and effective modality for the active treatment of renal stones. In comparison to the dusting mode, it resulted in significantly faster procedures (14.12min) possessing similar SFR.

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.

1627 We Are Donors: Redeveloping Educational Material for Schools in Response To COVID-19

Aim

We Are Donors is a UK registered charity aiming to increase the number of organ and blood donors across the UK through student led education at schools and universities. Over the last two years we have spoken to over 4000 students and have shown that the program improves awareness of organ donation, facilitates discussion within families and increases the number of planned organ donor registry sign ups. In response to COVID-19 our educational sessions moved online, and we studied what impact this had on engagement with the students and how our material could be redeveloped to improve outcomes.

Method

We compared the feedback from 1514 children aged 11-18 years who received face to face presentations in August 2018 - May 2019 with that from a group of 141 children aged 14 -18 years from 5 schools who received live online sessions using the same powerpoint presentation between March 2020 - June 2020.

Results

The change to online delivery reduced recommendation of the talk to a friend from 88% to 69%. Moving to online sessions also resulted in reduced post session feedback. To tackle these issues, we re-developed our presentation in collaboration with Slido to feature interactive elements, a quiz (including a leaderboard) and a real-time question and answer session. We also incorporated an immediate feedback survey.

Conclusions

Our study highlights new challenges that educators are facing when moving to online platforms. While moving online allows more students to be reached, maintaining high levels of student engagement is challenging.

The best treatment approach for lower calyceal stones ≤ 20 mm in maximal diameter: mini percutaneous nephrolithotripsy, retrograde intrarenal surgery or shock wave lithotripsy. A systematic review and meta-analysis of the literature conducted by the European Section of Uro-Technology and Young Academic Urologists

INTRODUCTION

The highest in quality data in the literature which compared mini percutaneous nephrolithotripsy (mPCNL), retrograde intrarenal surgery (RIRS) and shock wave lithotripsy (SWL) for the management of lower pole stone (LPS) with a maximal diameter ≤20mm were investigated by means of systematic review (SR) and meta-analysis.

EVIDENCE ACQUISITION

A SR of the literature was conducted on PubMed®, Cochrane, SCOPUS® and EMBASE® in January 2020. The study complied with the PRISMA statement and recommendations of the EAU Guidelines office. Only randomized controlled trials (RCTs) comparing retrograde intrarenal surgery (RIRS), shock wave lithotripsy (SWL) and mini-percutaneous nephrolithotripsy (mPCNL) were selected for the meta-analysis. The endpoints were the efficacy of each modality, measured by stone-free rate (SFR), operative time and retreatment rate and the safety of each method, based on hospitalization time and complications. Subgroup analyses for stones with a maximal diameter <10mm and 10-20 mm were performed.

EVIDENCE SYNTHESIS

Twenty-one RCTs were included in the meta-analysis. mPCNL had the highest SFR and the lowest retreatment rate among the three modalities, while SWL had the lowest SFR and the highest retreatment rate. The operative and hospitalization time were shorter in the case of SWL, whereas they were similar in the case of mPCNL and RIRS. The highest complication rate was observed in mPCNL group, which accounted for 8.3-22.4%, while RIRS and SWL had similar complication rates, which ranged between 1.3-31.4% and 0-48.5%, respectively. Further classification of the complications according to Clavien-Dindo system revealed that SWL had lower grade II complication rates compared to mPCNL and RIRS. Regarding stones <10mm, SWL and RIRS had similar SFR, complication rate, operation and hospitalization time. SWL had higher retreatment rate.

CONCLUSIONS

For LPSs ≤20mm, mPCNL provides the highest SFR and the lowest retreatment rate. This modality has a higher complication rate and longer hospital stay in comparison to the other modalities. SWL provides the lowest SFR with the highest retreatment rate. RIRS has similar complication rate to SWL and could be preferred over SWL. For stones up to 10mm, SWL may provide a valid alternative. Despite a higher retreatment rate, its SFR is similar to RIRS.

Drug-delivering devices in the urinary tract: A systematic review

Objective

: To systematically review the use of drug-eluting stents (DES) and drug-coated balloons (DCB) in urology.

Materials and Methods

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Scopus, Web of science and Cochrane Library online databases were searched in February 2019. Experimental and clinical studies, which included the placement of a DES or dilatation with DCB for investigating their potential use in the urinary tract for the management of ureteric or urethral pathologies, were included. The primary endpoint was to evaluate the current use of DES and DCB in urology.

Results

A total of 29 articles were included in the systematic review. A total of 10 studies tested DES or DCB containing anti-proliferative agents (paclitaxel, zotarolimus, sirolimus, halofugione). Antibiotic agent-containing DES were tested in nine studies (triclosan, quinolones, teicoplanin, nitrofurantoin, silver sulfadiazine). A total of eight studies investigated the release of anti-inflammatory agents by DES (ketorolac, indomethacin, EW-7197). Another group studied heparin-eluting stents.

Conclusion

Despite the inconclusive outcomes of the three randomised controlled trials, drug-coated/eluting devices constitute a promising field in urology for the prevention of complications associated with conventional stents including pain and encrustation. Pre-clinical in vitro and in vivo studies have shown their ability to mitigate inflammation, inhibit re-stenosis and improve pain as indicated by declined use of anti-inflammatory drugs.

Abbreviations: DES: drug-eluting stents; DCB: drug-coated balloons; DCS: drug-coated stents; HF: halofungione; MCP-1: monocyte chemoattractant protein 1; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTCA: percutaneous transluminal coronary angioplasty; RANTES: regulated on activation, normal T-cell expressed and secreted; RCT: randomised controlled trial; USSQ, Ureteric Stent Symptoms Questionaire.

Non-papillary percutaneous nephrolithotomy for treatment of staghorn stones

BACKGROUND

The aim of this study was to evaluate the non-papillary puncture for Percutaneous Nephrolithotomy (PCNL) for the treatment of staghorn stones in terms of safety and efficacy.

METHODS

Data of 53 patients undergoing PCNL for staghorn stones were retrospectively collected from January 2015 to December 2019. A non-papillary puncture was performed with a two- step track dilation technique up to 30Fr. A 26 Fr semirigid nephroscope and an ultrasonic lithotripter with integrated suction (Swiss Lithoclast master, EMS S.A, Nyon, Switzerland) were used for the treatment. Demographics and perioperative data were retrospectively gathered from an institutional board approved database.

RESULTS

The average stone size was 60.1±16.1 mm. Mean operative time was 54.57±14.83 minutes, while mean time using fluoroscopy was 2.67±1.02 minutes. Mean number of accesses was 1.2 (a total of 64 accesses). Flexible nephroscope was never used. Primary stone-free rate after PCNL was 81.1% (43 patients). Mean hemoglobin drop was 1.6±1.86 gr/dL. Overall patient stay was 3.94±0.82 days, while overall complication rate was 20.7% (11 patients), with only one patient requiring blood transfusion due to pseudoaneurysm.

CONCLUSIONS

The use of non-papillary access for PCNL in the treatment of staghorn stones resulted in promising results in terms of stone-free rate, operating time, complication rate, hemoglobin drop and reduced the number of percutaneous tracts. These parameters of the current investigation were directly comparable to current literature. The safety and efficacy of a non-papillary approach for the treatment of staghorn stones could be advocated.

Non-papillary percutaneous nephrolithotomy for treatment of staghorn stones

BACKGROUND

The aim of this study was to evaluate the non-papillary puncture for Percutaneous Nephrolithotomy (PCNL) for the treatment of staghorn stones in terms of safety and efficacy.

METHODS

Data of 53 patients undergoing PCNL for staghorn stones were retrospectively collected from January 2015 to December 2019. A non-papillary puncture was performed with a two- step track dilation technique up to 30Fr. A 26 Fr semirigid nephroscope and an ultrasonic lithotripter with integrated suction (Swiss Lithoclast master, EMS S.A, Nyon, Switzerland) were used for the treatment. Demographics and perioperative data were retrospectively gathered from an institutional board approved database.

RESULTS

The average stone size was 60.1±16.1 mm. Mean operative time was 54.57±14.83 minutes, while mean time using fluoroscopy was 2.67±1.02 minutes. Mean number of accesses was 1.2 (a total of 64 accesses). Flexible nephroscope was never used. Primary stone-free rate after PCNL was 81.1% (43 patients). Mean hemoglobin drop was 1.6±1.86 gr/dL. Overall patient stay was 3.94±0.82 days, while overall complication rate was 20.7% (11 patients), with only one patient requiring blood transfusion due to pseudoaneurysm.

CONCLUSIONS

The use of non-papillary access for PCNL in the treatment of staghorn stones resulted in promising results in terms of stone-free rate, operating time, complication rate, hemoglobin drop and reduced the number of percutaneous tracts. These parameters of the current investigation were directly comparable to current literature. The safety and efficacy of a non-papillary approach for the treatment of staghorn stones could be advocated.

Effects of irrigation parameters and access sheath size on the intra-renal temperature during flexible ureteroscopy with a high-power laser

OBJECTIVES

To investigate the effect of different laser power settings on intra-renal temperature (IRT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model.

METHODS

Following ethics approval, 2 female pigs weighing ~ 28 kg were used. Under general anesthesia, a percutaneous access was obtained to fix a K-type thermocouple inside the pelvi-calyceal system for real-time recording of IRT during FURS without UAS, UAS-10/12, UAS-12/14, and UAS-14/16F. A high-power holmium laser was used and the IRT was recorded during laser activation for up to 60 s at a laser power of 20 W, 40 W, and 60 W under gravity irrigation and manual pump irrigation.

RESULTS

Under gravity irrigation, FURS without UAS was associated with hazardous IRT at a laser power as low as 20 W for as short as 20 s of laser activation. The IRT was rendered borderline when UAS was used. This UAS buffering effect disappeared with the use of higher laser-power settings (40 W and 60 W) with the maximal IRT exceeding 60 °C. Moreover, laser activation at 60 W was associated with very rapid increase in IRT within few seconds. Under pump irrigation, laser activation at the highest power setting (60 W) for 60 s was associated with a safe IRT, even without the use of UAS. The maximal IRT was below 45 °C.

CONCLUSION

The use of high-power Ho:YAG laser carries potentially harmful thermal effect when used under gravity irrigation, even when large-diameter UAS is used. High-power settings (> 40 W) require high irrigation flow. The use of UAS is advisable to reduce the IRT and balance any intra-renal pressure increase.

Experimental Studies of Nonabsorbable Polymeric Surgical Clips for Use in Urologic Laparoscopy

Objective: This study aimed to compare the stability of the Click'aV^® (Grena^®), Click'aV plus (Grena), and Hem-o-lok^® (Weck^®, Teleflex^®) polymer clips and the evaluation of the clips stability on a complete porcine artery. Materials and Methods: A dynamometer with a custom support and clamp unit was used. The crank gradually increased the tension force being applied on the clip via the suture. Different directions for the application of the force were tested. The highest force before the start of slipping the suture was noted. The procedure was repeated three times for each ligating clip. Results: For transverse stability, the "XL-size" Grena Click'aV Plus required preventing slippage at a greater force compared to the Hem-o-lok (p = 0.0071). No significant differences found statistically between the Grena Click'aV and Hem-o-lok clips (p = 0.1). For longitudinal stability, the Hem-o-lok required a significantly higher force to be opened compared to the Click'aV (p = 0.0036), but no statistically significant difference was found compared to the Click'aV Plus (p = 0.1). Concerning porcine artery stability, the artery slipped through the Click'aV clip in both measurements at a force of 10.2 and 9.4 N. In contrast, the arteries were cut in all measurements using the Click'aV Plus and the Hem-o-lok clips at forces of 11.8 and 12.8 N and 12.9 and 14.2 N, respectively. None of the clips leaked with up to 300 mm Hg of intra-arterial pressure applied to porcine renal arteries. Conclusions: The Grena Click'aV Plus clip has similar performance to the Hem-o-lok clip, and this clip can be equally useful for ligating vessels in laparoscopic urologic surgeries. We believe, from our findings in this study as well as those from other reports, that vascular clips applied properly by experienced surgeons provide a safe, reliable, and considerable cost-saving option for vascular control in urologic laparoscopic surgery.

Combination Therapy with Alpha-blocker and Phosphodiesterase-5 Inhibitor for Improving Lower Urinary Tract Symptoms and Erectile Dysfunction in Comparison with Monotherapy: A Systematic Review and Meta-analysis

CONTEXT

The effects of combination therapy consisted of an α-blocker and a phosphodiesterase-5 inhibitor (PDE5I) for the treatment of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED).

OBJECTIVE

To systematically investigate the efficacy and safety of combination therapy in comparison with monotherapy.

EVIDENCE ACQUISITION

The study complied with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement and the recommendations of the European Association of Urology Guidelines office. The study was registered in the PROSPERO database with ID CRD42018086619. Only comparative prospective studies, randomized or quasirandomized, with at least one control group with monotherapy were selected for the meta-analysis. The primary endpoint was the quality of life related to LUTS and ED, measured with the International Prostate System Score (IPSS), maximum flow rate (Qmax), postvoid residual (PVR), and International Index of Erectile Function (IIEF). Secondary endpoints included the adverse events rate. In the subgroup analysis of the influence of adding a PDE5I to the treatment of LUTS, the use of different PDE5Is was considered.

EVIDENCE SYNTHESIS

After the screening of 6687 publications, 25 randomized controlled trials were considered eligible to be included in the meta-analysis. In the combination group, IPSS was lower and Qmax was higher than in the α-blocker group, with mean differences (MDs) of 1.41 (95% confidence interval [CI]: 0.42, 2.41; I² = 71%, p =  0.005) and -1.01 ml/s (95% CI: -1.58, -0.43; I² = 58%, p =  0.0006), respectively. The mean change of the IPSS was bigger in the combination group, with an MD of -1.72 (95% CI: -2.55, -0.89; I² = 37%, p <  0.0001). The mean change of Qmax was insignificant, with an MD of -0.61 (95% CI: -1.57, 0.34; I² = 63%, p =  0.21), as well as PVR and the mean change of PVR, with MDs of 0.65 (95% CI: -5.37, 6.66; I² = 76%, p =  0.83) and -20.79 (95% CI: -48.94, 7.37; I² = 75%, p =  0.15), respectively. The IIEF and the mean change of the IIEF had no difference between the combination group and the PDE5I-monotherapy group, with MDs of 1.82 (95% CI: -0.91, 4.54; I² = 40%, p =  0.19) and 0.25 (95% CI: -1.11, 1.62; I² = 47%, p =  0.72), respectively. Regarding the adverse events, the meta-analysis was in favor of monotherapy. None of the studies reported any serious or severe adverse event.

CONCLUSIONS

Treatment with combination therapy is more effective for the improvement of the IPSS. Less significant improvement was shown in Qmax. The beneficial effect of combination therapy regarding ED remains equivocal. The combination therapy seemed to be safe and well tolerated.

PATIENT SUMMARY

In this study, we review the effects of the combination therapy consisting of an α-blocker and a phosphodiesterase-5 inhibitor for the treatment of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED). We found strong evidence to suggest the combination therapy for the improvement of LUTS. Benefits regarding the treatment of ED are less clear.

The use of S-curved coaxial dilator for urethral dilatation: Experience of a tertiary department

Objective:

Urethral strictures can be treated by urethral dilation, optical internal urethrotomy, or open surgical reconstruction (urethroplasty). Urethral dilation is done with filiforms and followers, balloons, or coaxial dilators inserted over a guidewire. The S-curved coaxial dilator (SCCD) was designed to facilitate the passage of the dilator through the stricture and the urethra because it imitates the curved anatomy of the male urethra. This study presents our experience with SCCD.

Materials and Methods:

We used this kind of dilation in 310 patients. The technique included the insertion of a hydrophilic floppy-tipped guidewire through the urethra directly into the bladder under fluoroscopic control. The SCCDs were then inserted over the guidewire. Dilators of gradually increased size from 8F to 20F were used. The follow-up of the patients includes uroflowmetry and measurement of postvoid residual at 4 weeks, 6 months, or in the case of a recurrence of symptoms.

Results:

The age of the patients were 69.08 ± 15.77 years. The causes of urethral stricture were iatrogenic (n = 114), traumatic (n = 35), infectious (n = 22), and of unknown origin (n = 139). The stricture length was 1.62 ± 0.85 cm. The mean number of dilations needed per case was 2 (range: 1–15), and the time between the dilations was 212.19 ± 253.9 days. We had seven failures.

Conclusion:

We propose the S-curved coaxial dilators for urethral dilation as a safe and effective technique because of their similarity to the shape of the male urethra and because of their hydrophilic coating.