Totally tubeless, tubeless, and tubed percutaneous nephrolithotomy for treating kidney stones.

BACKGROUND: Percutaneous nephrolithotomy (PNL) is the standard of care for removing large kidney stones (> 2 cm). Once the procedure is complete, different exiting strategies exist to manage the percutaneous tract opening, including placement of an external nephrostomy tube, placement of an internal ureteral stent, or no external or internal tube. The decision to place or not place a tube is handled differently among clinicians and may affect patient outcomes. OBJECTIVES: To assess the effects of tubeless PNL (with ureteral stenting), totally tubeless PNL (without ureteral stenting or nephrostomy), and standard PNL (nephrostomy only) for the treatment of kidney stones in adults. SEARCH METHODS: We performed a systematic literature search in multiple biomedical databases (CENTRAL, MEDLINE, Embase, Web of Science), as well as in two clinical trial registries. We also handsearched reference lists of relevant publications and conference proceedings. We applied no language restrictions. The latest search update was conducted in September 2022. SELECTION CRITERIA: We included randomized controlled and quasi-randomized controlled trials of adult patients who received tubeless, totally tubeless, or standard PNL for treating kidney stones. We defined tubeless PNL as no nephrostomy tube, but ureteral stenting, while totally tubeless PNL meant no nephrostomy tube or ureteral stenting. Both interventions were compared to standard PNL with placement of a nephrostomy tube (only). We considered access tubes of any sizes. We only considered unilateral PNL with single-tract access. There were no exclusions on stone composition, size, or location. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the literature, extracted data, assessed risk of bias, and rated the certainty of evidence using GRADE. Primary outcomes were severe adverse events and postoperative pain, and secondary outcomes were operating time, length of hospital stay, and stone-free rate. We used the random-effects model for meta-analysis. MAIN RESULTS: We included 10 studies in the review. Participant age varied among studies, ranging from 20 to 60 years. Detailed information on stone characteristics was rarely presented. Tubeless PNL versus standard PNL We are very uncertain whether there is a difference in severe adverse events (SAEs) between tubeless PNL and standard PNL (risk ratio (RR) 1.53, 95% confidence interval (CI) 0.14 to 16.46; I2 = 42%; 2 studies, 46 participants; very low-certainty evidence). Tubeless PNL may have little to no effect on pain on postoperative day one (mean difference (MD) 0.56 lower, 95% CI 1.34 lower to 0.21 higher; I2 = 84%; 4 studies, 186 participants; low-certainty evidence), and probably results in little to no difference in operating room time (MD 0.40 longer (in minutes), 95% CI 4.82 shorter to 5.62 longer; I2 = 0%; 3 studies, 81 participants; moderate-certainty evidence). Tubeless PNL may reduce length of hospital stay (MD 0.90 shorter, 95% CI 1.45 shorter to 0.35 shorter; I2 = 84%; 6 studies, 238 participants; low-certainty evidence). We are very uncertain of the effect of tubeless PNL on blood transfusions (RR 0.64, 95% CI 0.16 to 2.52; I2 = 0%; 4 studies, 161 participants; very low-certainty evidence), sepsis or fever (RR 0.50, 95% CI 0.05 to 4.75; I2 = not applicable; 2 studies, 82 participants; very low-certainty evidence), or readmissions (RR 1.00, 95% CI 0.07 to 14.21; I2 = not applicable, 1 study, 24 participants; very low-certainty evidence). Totally tubeless versus standard PNL Totally tubeless PNL may result in lower SAE rates (RR 0.49, 95% CI 0.19 to 1.25; I2 = 0%; 2 studies, 174 participants; low-certainty evidence) and pain on postoperative day one (MD 3.60 lower, 95% CI 4.24 lower to 2.96 lower; I2 = Not applicable; 1 study, 50 participants; low-certainty evidence). Totally tubeless PNL may result in little to no difference in operating room time (MD 6.23 shorter (in minutes), 95% CI 14.29 shorter to 1.84 longer; I2 = 72%; 2 studies, 174 participants; moderate-certainty evidence) and sepsis or fever (RR 0.33, 95% CI 0.01 to 7.97; I2 = not applicable; 1 study, 90 participants; low-certainty evidence). Totally tubeless PNL likely shortens the length of hospital stay (MD 1.55 shorter, 95% CI 1.82 shorter to 1.29 shorter; I2 = 0%; 4 studies, 274 participants; moderate-certainty evidence). We are very uncertain of the effect of totally tubeless PNL on blood transfusions (RR 0.62, 95% CI 0.26 to 1.48; I2 = 0%; 4 studies, 274 participants; very low-certainty evidence) or readmissions (RR not estimable, 95% CI not estimable; I2 = not applicable; 1 study, 50 participants; very low-certainty evidence). We found no studies comparing tubeless mini versus standard mini-PNL or totally tubeless mini versus standard mini-PNL. AUTHORS' CONCLUSIONS: When comparing tubeless to standard PNL with regard to the predefined primary outcomes of this review, there may be little difference in early postoperative pain, while we are very uncertain of the effect on SAEs. People treated with tubeless PNL may benefit from a reduced length of stay compared to standard PNL. When comparing totally tubeless to standard PNL, early postoperative pain and severe adverse events may be reduced with totally tubeless PNL. The certainty of evidence by outcome was mostly very low (range: moderate to very low) for the comparison of tubeless to standard PNL and low (range: moderate to very low) for the comparison of totally tubeless to standard PNL. The most common reasons for downgrading the certainty of the evidence were study limitations, inconsistency, and imprecision. We did not find randomized trial evidence for other comparisons. Overall, further and higher-quality studies are needed to inform clinical practice.

In vivo Temperature Assessment during Holmium Laser Enucleation of the Prostate.

INTRODUCTION: Holmium laser enucleation of the prostate (HoLEP) has become popular worldwide for the surgical treatment of benign prostate hyperplasia. Holmium laser is considered an ideal transurethral thermomechanical device for enucleating the prostate. Although there is evidence on Ho:YAG laser-related heat generation, the studies mainly investigated ex vivo temperature generation during holmium laser lithotripsy. In this in vivo study, we aimed to assess for the first time the real-time heat generated during HoLEP. METHODS: Fifteen HoLEP procedures were included. The study was conducted over a time period of 16 months. To investigate the temperature generation, a preoperatively inserted rectal temperature probe and a temperature sensor within a suprapubic bladder catheter were used to record the temperature change during enucleation and coagulation. RESULTS: The mean values of the temperature change during the laser enucleation and coagulation were -0.35 ± 0.203 K (IQR: 0.23) and +0.14 ± 0.259 K (IQR: 0.3), respectively, in rectal measurements. Temperature differences during laser use and coagulation were <+1 K and <+5 K, respectively, in bladder measurements. We measured no temperature >37.1°C during the procedures and no temperature values considered harmful to the human body. CONCLUSION: Sufficient irrigation flow rates and irrigation monitoring during HoLEP are obligatory. To prevent a high and uncontrolled temperature rise, the surgeon or operating room staff should pay attention to the irrigation's continuity.

Thermal effects of thulium: YAG laser treatment of the prostate-an in vitro study.

PURPOSE: To objectively determine whether there is potential thermal tissue damage during Tm:YAG laser-based LUTS treatment. METHODS: Our experimental model was comprised of a prostatic resection trainer placed in a 37 °C water bath. In a hollowed-out central area simulating the urethral lumen, we placed a RigiFib 800 fibre, irrigation inflow regulated with a digital pump, and a type K thermocouple. A second thermocouple was inserted 0.5/1 cm adjacently and protected with an aluminum barrier to prevent it from urethral fluid. We investigated continuous and intermittent 120 W and 80 W laser application with various irrigation rates in eight measurement sessions lasting up to 14 min. Thermal measurements were recorded continuously and in real-time using MatLab. All experiments were repeated five times to balance out variations. RESULTS: Continuous laser application at 120 W and 125 ml/min caused a urethral ∆T of ~ 15 K and a parenchymal temperature increase of up to 7 K. With 50 ml/min irrigation, a urethral and parenchymal ∆T of 30 K and 15 K were reached, respectively. Subsequently and in absence of laser application, prostatic parenchyma needed over 16 min to reach baseline body temperature. At 80 W lower temperature increases were reached compared to similar irrigation but higher power. CONCLUSIONS: We showed that potentially harming temperatures can be reached, especially during high laser power and low irrigation. The heat generation can also be conveyed to the prostate parenchyma and deeper structures, potentially affecting the neurovascular bundles. Further clinical studies with intracorporal temperature measurement are necessary to further investigate this potentially harming surgical adverse effect.

Temperature assessment study of ex vivo holmium laser enucleation of the prostate model.

PURPOSE: There isscarce evidence to date on how temperature develops during holmium laser enucleation of the prostate (HoLEP). We aimed to determine the potential heat generation during HoLEP under ex vivo conditions. METHODS: We developed two experimental setups. Firstly, we simulated HoLEP ex vivo using narrow-neck laboratory bottles mimicking enucleation cavities and a prostate resection trainer. Seven temperature probes were placed at different locations in the experimental setup, and the heat generation was measured separately during laser application. Secondly, we simulated high-frequency current-based coagulation of the vessels using a roller probe. RESULTS: We observed that the larger the enucleated cavity, the higher the temperature rises, regardless of the irrigation flow rate. The highest temperature difference with an irrigation flow was approximately + 4.5 K for a cavity measuring 100ccm and a 300 ml/min irrigation flow rate. The higher flow rate generates faster removal of the generated heat, thus cooling down the artificial cavity. Furthermore, the temperature differences at different irrigation flow rates (except at 0 ml/min) were consistently below 5 K. Within the resection trainer, the temperature increase with and without irrigation flow was approximately 0.5 K and 3.0 K, respectively. The mean depth of necrosis (1084 ± 176 µm) achieved by the roller probe was significantly greater when using 144 W energy. CONCLUSION: Carefully adjusted irrigation and monitoring during HoLEP are crucial when evacuating the thermal energy generated during the procedure. We believe this study of ours provides evidence with the potential to facilitate clinical studies on patient safety.

A novel endoimaging system for endoscopic 3D reconstruction in bladder cancer patients.

INTRODUCTION: The methods employed to document cystoscopic findings in bladder cancer patients lack accuracy and are subject to observer variability. We propose a novel endoimaging system and an online documentation platform to provide post-procedural 3D bladder reconstructions for improved diagnosis, management and follow-up. MATERIAL AND METHODS: The RaVeNNA4pi consortium is comprised of five industrial partners, two university hospitals and two technical institutes. These are grouped into hardware, software and clinical partners according to their professional expertise. The envisaged endoimaging system consists of an innovative cystoscope that generates 3D bladder reconstructions allowing users to remotely access a cloud-based centralized database to visualize individualized 3D bladder models from previous cystoscopies archived in DICOM format. RESULTS: Preliminary investigations successfully tracked the endoscope's rotational and translational movements. The structure-from-motion pipeline was tested in a bladder phantom and satisfactorily demonstrated 3D reconstructions of the processing sequence. AI-based semantic image segmentation achieved a 0.67 dice-score-coefficient over all classes. An online-platform allows physicians and patients to digitally visualize endoscopic findings by navigating a 3D bladder model. CONCLUSIONS: Our work demonstrates the current developments of a novel endoimaging system equipped with the potential to generate 3D bladder reconstructions from cystoscopy videos and AI-assisted automated detection of bladder tumors.

Radiation exposure during retrograde intrarenal surgery (RIRS): a prospective multicenter evaluation.

PURPOSE: Retrograde intrarenal surgery (RIRS) may require extensive X-ray usage. We evaluated the impact of preoperative surgeon briefing regarding the inclusion and evaluation of fluoroscopy time (FT) and dose area product (DAP) in a multicenter study on the applied X-ray usage. METHODS: A prospective multicenter study of 6 tertiary centers was performed. Each center recruited up to 25 prospective patients with renal stones of any size for RIRS. Prior to study´s onset, all surgeons were briefed about hazards of radiation and on strategies to avoid high doses in RIRS. Prospective procedures were compared to past procedures, as baseline data. FT was defined as the primary outcome. Secondary parameters were stone-free rate (SFR), complications according to the Clavien, SATAVA and postureteroscopic lesion scale. Results were analyzed using T test, chi-squared test, univariate analysis and confirmed in a multivariate regression model. RESULTS: 303 patients were included (145 retro- and 158 prospective). Mean FT and DAP were reduced from 130.8 s/565.8 to 77.4 s/357.8 (p < 0.05). SFR was improved from 85.5% to 93% (p < 0.05). Complications did not vary significantly. Neither stone position (p = 0.569), prestenting (p = 0.419), nor surgeons' experience (> 100 RIRS) had a significant impact on FT. Significant univariate parameters were confirmed in a multivariate model, revealing X-ray training to be radiation protective (OR - 44, p = 0.001). CONCLUSIONS: Increased surgeon awareness of X-ray exposure risks has a significant impact on FT and DAP. This "awareness effect" is a simple method to reduce radiation exposure for the patient and OR staff without the procedures´ outcome and safety being affected.

Application of artificial neural networks for automated analysis of cystoscopic images: a review of the current status and future prospects.

BACKGROUND: Optimal detection and surveillance of bladder cancer (BCa) rely primarily on the cystoscopic visualization of bladder lesions. AI-assisted cystoscopy may improve image recognition and accelerate data acquisition. OBJECTIVE: To provide a comprehensive review of machine learning (ML), deep learning (DL) and convolutional neural network (CNN) applications in cystoscopic image recognition. EVIDENCE ACQUISITION: A detailed search of original articles was performed using the PubMed-MEDLINE database to identify recent English literature relevant to ML, DL and CNN applications in cystoscopic image recognition. EVIDENCE SYNTHESIS: In total, two articles and one conference abstract were identified addressing the application of AI methods in cystoscopic image recognition. These investigations showed accuracies exceeding 90% for tumor detection; however, future work is necessary to incorporate these methods into AI-aided cystoscopy and compared to other tumor visualization tools. Furthermore, we present results from the RaVeNNA-4pi consortium initiative which has extracted 4200 frames from 62 videos, analyzed them with the U-Net network and achieved an average dice score of 0.67. Improvements in its precision can be achieved by augmenting the video/frame database. CONCLUSION: AI-aided cystoscopy has the potential to outperform urologists at recognizing and classifying bladder lesions. To ensure their real-life implementation, however, these algorithms require external validation to generalize their results across other data sets.

Current and future applications of machine and deep learning in urology: a review of the literature on urolithiasis, renal cell carcinoma, and bladder and prostate cancer.

PURPOSE: The purpose of the study was to provide a comprehensive review of recent machine learning (ML) and deep learning (DL) applications in urological practice. Numerous studies have reported their use in the medical care of various urological disorders; however, no critical analysis has been made to date. METHODS: A detailed search of original articles was performed using the PubMed MEDLINE database to identify recent English literature relevant to ML and DL applications in the fields of urolithiasis, renal cell carcinoma (RCC), bladder cancer (BCa), and prostate cancer (PCa). RESULTS: In total, 43 articles were included addressing these four subfields. The most common ML and DL application in urolithiasis is in the prediction of endourologic surgical outcomes. The main area of research involving ML and DL in RCC concerns the differentiation between benign and malignant small renal masses, Fuhrman nuclear grade prediction, and gene expression-based molecular signatures. BCa studies employ radiomics and texture feature analysis for the distinction between low- and high-grade tumors, address accurate image-based cytology, and use algorithms to predict treatment response, tumor recurrence, and patient survival. PCa studies aim at developing algorithms for Gleason score prediction, MRI computer-aided diagnosis, and surgical outcomes and biochemical recurrence prediction. Studies consistently found the superiority of these methods over traditional statistical methods. CONCLUSIONS: The continuous incorporation of clinical data, further ML and DL algorithm retraining, and generalizability of models will augment the prediction accuracy and enhance individualized medicine.

Thermal effects of Ho:YAG laser lithotripsy during retrograde intrarenal surgery and percutaneous nephrolithotomy in an ex vivo porcine kidney model.

PURPOSE: To evaluate the thermal effect of high-power holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy in flexible/semirigid ureteroscopy (fURS/sURS) and percutaneous nephrolithotomy (PNL) in a standardized ex vivo porcine kidney model with real-time temperature assessment. METHODS: The experimental setup consisted of three models designed to evaluate the thermal effects of Ho:YAG laser lithotripsy in fURS, sURS and PNL, respectively. In all setups, a postmortem porcine kidney was placed in a 37 °C water bath. Three thermocouples were inserted into the renal parenchyma while a flexible thermocouple was placed 3-4 mm proximal to the laser fiber to measure temperature variations in the collecting system. The thermal impact was evaluated in relation to laser power between 5 and 100 W and various irrigation rates (37 °C, 0-100 ml/min). RESULTS: In all three experimental setups, sufficient irrigation was required to prevent potentially damaging temperatures into the renal pelvis and parenchyma. Even 5 W in fURS can lead to a potentially harming temperature rise if insufficient irrigation is applied. Particularly, high-power settings ≥ 30 W carry an elevated risk for critical temperature rises. The results allow the definition of a specific irrigation threshold for any power setting to prevent critical temperatures in the present study design. CONCLUSIONS: Ho:YAG laser lithotripsy bears the risk of thermal damages to the urinary tract even at low-power settings if inadequate irrigation is applied. Sufficient irrigation is mandatory to perform safe Ho:YAG laser lithotripsy. Based on the results, we developed a formula calculating the approximate ΔT for irrigation rates ≥ 30 ml/min: ΔT = 15 K × (power [W]/irrigation [ml/min]).

Efficacy and safety of aquablation of the prostate for patients with symptomatic benign prostatic enlargement: a systematic review.

PURPOSE: The aim of this systematic review is to summarize the contemporary literature on aquablation and evaluate its safety and efficacy for the treatment of symptomatic BPE. EVIDENCE ACQUISITION: A systematic search of English language literature was performed using the PubMed-MEDLINE and Web of Science libraries up to 24 July 2019 by combining PICO (patient population, intervention, comparison, and outcome) terms. We retrieved 16 studies, including 446 patients treated with aquablation eligible for data extraction and analysis. Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were followed. EVIDENCE SYNTHESIS: We identified a randomized controlled trial (RCT) comparing aquablation to transurethral resection of the prostate (TURP) with 6-month, 1-year, and 2-year outcomes, three single-center and single-arm studies, three multicenter and single-arm studies, and five subgroup analyses. Aquablation significantly improved International Prostate Symptom Score (IPSS), IPSS-quality of life (IPSS-QoL), maximum urinary flow rate (Qmax) and post void residual (PVR) from baseline to last follow-up in all prospective studies. At 2-year follow-up, aquablation showed non-inferior symptom relief compared to TURP, with a lower risk of anejaculation favoring aquablation and no significant differences regarding Clavien-Dindo events. Although a significant hemoglobin drop was reported in all aquablation single-arm studies and when compared to TURP, it did not translate into increased transfusion rates. CONCLUSIONS: Data from the WATER trial demonstrates that aquablation is comparable to TURP in effectively improving symptom scores and functional parameters related to BPE and bladder outlet obstruction. The evidence provided supports the safety of aquablation assessed by procedure-related adverse events.

Current Standards in the Endoscopic Management of Bladder Cancer: A Survey Evaluation among Urologists in German-Speaking Countries.

INTRODUCTION: To assess the current diagnostic, treatment, and documentation strategies for bladder cancer (BC) in German-speaking countries. MATERIALS AND METHODS: A 14-item web-based survey was distributed among members of the German, Austrian, and Swiss Associations of Urology, addressing physicians who perform cystoscopies and transurethral resection of bladder tumors (TURB). RESULTS: The survey was responded to by 308 of 5,564 urologists with a mean age of 49.5 years (response rate: 5.5%). The majority of participants (57.3%) practice in an outpatient setting. White light cystoscopy only is used by 60.2%, with additional photodynamic diagnosis and narrow band imaging by 36.8 and 12.5%, respectively. Endoscopic findings are documented in written form by 93.5%, followed by image capture (33.7%) and a central data archive (20.8%). Inpatient hospital urologists document cystoscopic findings by freehand drawing (21.4 vs. 11.4%, p = 0.017), and with a fixed bladder scheme (31.3 vs. 7.4%, <0.05) significantly more frequently. Cystoscopic findings are mainly conveyed to other health professionals in written form (77.4%), and significantly more often by inpatient urologists (p < 0.05). CONCLUSIONS: Significant differences exist in the approach to documenting and communicating cystoscopic BC findings. Accurate graphic documentation of lesions, visualization of the mucosa's totality, and meticulous consultation of previous surgical reports require improvements to reduce recurrence and progression rates.

Residual stone fragments: clinical implications and technological innovations.

PURPOSE OF REVIEW: To summarize the recent literature on the topic of residual stone fragments in particular novel developments in this field. RECENT FINDINGS: The urological position towards residual fragments has shifted in recent years from observation, to active retrieval with innovative methods, to algorithm-based predictions of surgical outcomes. Novel technologies have been described to extract residual fragments through magnetism, a polyethylene endoscopic pouch and a biocompatible stone adhesive. In an effort to have a tighter grip over the outcome of residual fragments, artificial neural networks (ANNs) have been developed to accurately predict surgical outcomes in terms of stone clearance and secondary procedures. SUMMARY: Growing evidence continues to show the term clinically insignificant residual fragments (CIRF) for residual fragments of 4 mm or less to be a misnomer. In fact, only a third of CIRF is spontaneously cleared from the kidney after surgery and may become a cause for reintervention being both costly and significantly affecting patients' well being. Several novel methods which have been developed to extract residual fragments require further in-vivo investigations to confirm their safety and efficacy. ANNs algorithms are increasingly being used to predict surgical outcomes in stone therapy and assist in preoperative patient counselling and decision-making.

Stone-Free Rate after Treating Kidney Stones Exceeding 10 mm via Flexible Ureteroscopy: Can Endoscopic Assessment Replace Low-Dose Computed Tomography Control?

INTRODUCTION: It is unclear whether endoscopic assessment of the stone-free rate after flexible ureteroscopy (fURS) is as effective as assessment with low-dose computed tomography (CT) scan. METHODS: Prospective documentation of patients with kidney stones > 10 mm diameter from 2 different centers (Freiburg, Regensburg), who underwent fURS and were declared to be endoscopically completely stone-free. Low-dose CT control performed 4-8 weeks postoperatively. RESULTS/CONCLUSION: Thirty-eight patients were treated between October 2015 and August 2016 (12 F, 26 M). Average age was 55.9 years (range 19-82, SD 17.24), and body mass index was 29.7 kg/m2 (range 23.5-42.5, SD 4.37). There were 2.0 (range 1-7, SD 1.55) stones with a mean diameter of 15 mm (range 10-40, SD 6.78) per kidney. Mean surgery time was 74 min (range 38-124, SD 24.28), and lithotripsy was necessary in 33 cases. CT was performed 5.4 weeks afterwards (range 4-8, SD 1.43). One patient had a 2 mm residual which was extracted by URS. Strictly speaking, endoluminal stone removal control failed in only that patient, yielding a negative predictive value of 97%. A routine postoperative CT scan would thus appear unnecessary in the case of negative endoscopic control for residual fragments and should be avoided to reduce radiation exposure. Further investigations with larger patient populations are necessary.

Thermal effects of Ho: YAG laser lithotripsy: real-time evaluation in an in vitro model.

PURPOSE: To evaluate the thermal effect of Ho:YAG laser lithotripsy in a standardized in vitro model via real-time temperature measurement. METHODS: Our model comprised a 20 ml test tube simulating the renal pelvis that was immersed in a 37 °C water bath. Two different laser fibers [FlexiFib (15-45 W), RigiFib 1000 (45-100 W), LISA laser products OHG, Katlenburg-Lindau, Germany] were placed in the test tube. An Ho:YAG 100 W laser was used in all experiments (LISA). Each experiment involved 120 s of continuous laser application, and was repeated five times. Different laser settings (high vs. low frequency, high vs. low energy, and long vs. short pulse duration), irrigation rates (0 up to 100 ml/min, realized by several pumps), and human calcium oxalate stone samples were analyzed. Temperature data were acquired by a real-time data logger with thermocouples (PICO Technology, Cambridgeshire, UK). Real-time measurements were assessed using MatLab®. RESULTS: Laser application with no irrigation results in a rapid increase in temperature up to ∆28 K, rising to 68 °C at 100 W. Low irrigation rates yield significantly higher temperature outcomes. Higher irrigation rates result immediately in a lower temperature rise. High irrigation rates of 100 ml/min result in a temperature rise of 5 K at the highest laser power setting (100 W). CONCLUSIONS: Ho:YAG laser lithotripsy might be safe provided that there is sufficient irrigation. However, high power and low irrigation resulted in potentially tissue-damaging temperatures. Laser devices should, therefore, always be applied in conjunction with continuous, closely monitored irrigation whenever performing Ho:YAG laser lithotripsy.

The stone surgeon in the mirror: how are German-speaking urologists treating large renal stones today?

OBJECTIVE: To elucidate the current treatment strategies of LRS in German-speaking Europe. Little is known about the treatment of large renal stones (LRS > 3 cm) in daily urological practice. LRS therapy can be, however, challenging and hazardous. MATERIALS AND METHODS: A 39 item web-based survey was performed among urologists listed by the German, Austrian and Swiss Associations of Urology, addressing professionals treating LRS "on their own" and working in a German-speaking country. Uniparametric descriptions indicated as absolute numbers and percentages without p values, simple linear associations and bubble plots without arithmetic means or bar charts with standard deviation between targeted parameters and percentages were used. RESULTS: 266 of the 6586 responding urologists claimed to treat urinary stones on a regular basis. The majority of them were male (90.2%) and over 50 years old (42.9%). Most stones are treated in non-university hospitals (69.5%). 81.9% of all the institutions treat more than 150 cases/y. Open surgery is still performed in 45.5% of the centres, laparoscopy in 32%. Percutaneous nephrolithotomy (PNL) is the primary treatment option. Antimicrobial strategies vary considerably. Serious complications seem to be rare. However, quite a few responders reported treatment-related deaths. The main limitation is the absolute number of urologists performing LRS treatment, which is unknown. CONCLUSIONS: The German-speaking urologist treating LRS is a male and over 50. Although he performs PNL primarily, he is not averse to open surgery and SWL. He applies guidelines and employs modern equipment. Only antimicrobial strategies are out of line with the international standards.

Combined prostatic urethral lift and remodeling of the prostate and bladder neck: a modified transurethral approach in the treatment of symptomatic lower urinary tract obstruction.

PURPOSE: The aim of the study was to evaluate the feasibility and safety of combining prostatic urethral lift (PUL) and a limited resection of the prostatic middle lobe or bladder neck incision in the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). METHODS: Twenty-eight patients were treated at two tertiary centers and followed prospectively. Patient evaluations included patient characteristics, relief of LUTS symptoms, erectile and ejaculatory function, continence, operative time and adverse events. Patients were followed for a mean of 10.9 months. RESULTS: Patient characteristics were as follows: age 66 years (46-85), prostate volume 39.6 cc (22-66), preoperative IPSS/AUASI 20 (6-35)/QoL 3.9 (1-6)/peak flow 10.5 mL/s (4.0-19)/post-void residual volume (PVR) 123 mL (0-500). Mean operating time was 31 min (9-55). Postoperative complications were minor except for the surgical retreatment of one patient for blood clot retention (Clavien 3b). One patient required catheterization due to urinary retention. Reduction of symptoms (IPSS - 59.6%), increase in QoL (+ 49.0%), increase in flow (+ 111.5%), and reduction of PVR (- 66.8%) were significant. Antegrade ejaculation was always maintained. CONCLUSION: Our data suggest that a combination of PUL and transurethral surgical techniques is feasible, safe, and effective. This approach may be offered to patients with moderate size prostates including those with unfavorable anatomic conditions for PUL. This procedure is still 'minimally invasive' and preserves sexual function. In addition, it may add to a higher functional efficacy compared to PUL alone. STUDY REGISTER NUMBER: DRKS00008970.

Viability and biocompatibility of an adhesive system for intrarenal embedding and endoscopic removal of small residual fragments in minimally-invasive stone treatment in an in vivo pig model.

PURPOSE: To evaluate the viability and biocompatibility of a novel, patented bioadhesive system for intrarenal embedding and retrieval of residual fragments after endoscopic lithotripsy. Complete stone clearance via active removal of residual fragments (RF) after intracorporeal laser lithotripsy may be time-consuming and fail in many cases. Therefore, the novel adhesive has been developed and evaluated for the first time in an in vivo pig model in the present work. METHODS: Four female domestic pigs underwent flexible ureteroscopy (RIRS) or percutaneous nephrolithotomy (PNL) under general anesthesia (8 kidneys, 4 × RIRS, 4 × PNL) evaluating the bioadhesive system. INTERVENTIONS: RIRS without adhesive system (sham procedure, kidney I); 3 × RIRS using the bioadhesive system (kidneys II-IV); and 4 × PNL using the bioadhesive system (V-VIII). We endoscopically inserted standardized human stone probes followed by comminution using Ho:YAG lithotripsy. The bioadhesive (kidney II-VIII) was then applied and the adhesive-stone fragment complex extracted. After nephrectomy, all kidneys were evaluated by two independent, blinded pathologists. Endpoints were the procedure's safety and adhesive system's biocompatibility. RESULTS: We observed no substantial toxic effects. We were able to embed and remove 80-90% of fragments. However, because of the pig's hampering pyelocaliceal anatomy, a quantified, proportional assessment of the embedded fragments was compromised. CONCLUSIONS: For the first time, we demonstrated the proven feasibility and safety of this novel bioadhesive system for embedding and endoscopically removing small RF in conjunction with a lack of organ toxicity in vivo.

Is Endoscopic Vasectomy Just a Dream: An ex vivo Study on Feasibility and Reliability of Endoluminal Occlusion of Porcine Vas Deferens.

INTRODUCTION AND AIM: Surgical vasectomy remains the gold standard for fertility control in men. Endoluminal occlusion of the seminal ducts, thus avoiding an external incision, may become an appealing alternative to this approach. As our group has shown, nontraumatic endoscopic inspection of the seminal ducts is feasible in the human cadaver. We investigated the feasibility and reliability of occlusion using several commercially available medical sealing agents in the porcine vas deferens (VD). METHODS AND MAIN OUTCOME MEASURES: Tests were conducted using 25 porcine spermatic ducts (10 cm length) ex vivo. The explanted specimens were fixed and cannulated using the Seldinger technique. We administered 5 different agents (n-butyle-2-cyanoacrylate, n-butyle-2-cyanoacrylate in combination with a platinum vascular coil, Tissucol Duo S®, Gelita Spon® and AFP Plug®) endoluminally. Tightness was evaluated after 5, 15, 60, 360, 720, and 1,440 min for each of the five grades, respectively, using a solution of methylene blue and saline injected under controlled pressure of 300 mm Hg followed by histological examination. RESULTS: All agents were administered into the porcine seminal ducts (4 out of 5 via a ureteric catheter). Gelita Spon® and Tissucol Duo S® did not occlude the lumen sufficiently, whereas n-butyle-2-cyanoacrylate, n-butyle-2-cyanoacrylate in combination with coil, Tissucol Duo and AFP Plug® performed satisfactorily. In particular, cyanoacrylate combined with a coil was able to close the seminal duct tightly and for a long time. Histological findings confirmed this sealant's gapless adhesion. AFP Plug® application revealed similarly good results. However, its form needs to be optimized to ensure its suitability for endoscopic use. CONCLUSION: Various developments regarding minimally invasive fertility control methods have been underway for decades. Further miniaturization of endoscopy and novel materials may pave the way for endoscopic fertility control in males in the future. We demonstrated the potential of commercially available medical sealing agents to reliably occlude the porcine VD.

Novel Biocompatible Adhesive for Intrarenal Embedding and Endoscopic Removal of Small Residual Fragments after Minimally Invasive Stone Treatment in an Ex Vivo Porcine Kidney Model: Initial Evaluation of a Prototype.

PURPOSE: Residual fragments related to endoscopic intracorporeal lithotripsy are a challenging problem. The impact of residual fragments remains a subject of discussion and growing evidence highlights that they have a central role in recurrent stone formation. Therefore, we developed a novel bioadhesive system for intrarenal embedding and retrieval of residual fragments after endoscopic lithotripsy in an ex vivo porcine kidney model. MATERIALS AND METHODS: In a standardized setting 30 human stone fragments 1 mm or less were inserted in the lower pole of an ex vivo porcine kidney model. We assessed the extraction efficacy of flexible ureteroscopy using the bioadhesive system in 15 preparations and a conventional retrieval basket in 15. Outcomes were compared regarding the endoscopic and macroscopic stone-free rate, and overall time of retrieval. RESULTS: Embedding and retrieving the residual fragment-bioadhesive complex were feasible in all trial runs. We observed no adverse effects such as adhesions between the adhesive and the renal collecting system or the instruments used. The stone-free rate was 100% and 60% in the bioadhesive and conventional retrieval groups, respectively (p = 0.017). Mean retrieval time was significantly shorter at 10 minutes 33 seconds vs 36 minutes 56 seconds in the bioadhesive group vs the conventional group (p = 0.001). CONCLUSIONS: This novel method involving adhesive based complete removal of residual fragments from the collecting system has proved to be feasible. Our evaluation in a porcine kidney model revealed that this technology performed well. Further tests, including inpatient studies, are required to thoroughly evaluate the benefit and potential drawbacks of bioadhesive based extraction of residual fragments after intracorporeal lithotripsy.

Level of evidence, sponsorship, conflict of interest policy and commercial impact of PubMed-listed clinical urolithiasis-related trials in 2014.

OBJECTIVES: To evaluate published trials on urolithiasis regarding level of evidence, type of sponsorship and declared conflicts of interest (COIs), and to elucidate a potential commercial impact. MATERIALS AND METHODS: We performed a systematic PubMed(®) literature search using a predefined Boolean search term to identify PubMed-listed clinical research studies on urolithiasis in 2014 (fourth quarter). All authors screened the results for eligibility criteria and two independent reviewers evaluated and performed data extraction of predefined endpoints, including level of evidence, declaration of COI and sponsorship/funding (as indicated in the published print version), and commercial impact. RESULTS: A total of 110 clinical trials in urolithiasis listed in PubMed met the inclusion criteria. Levels of evidence 1, 2, 3 and 4 were found in 15%, 14%, 21% and 51% of trials, respectively. A COI was indicated in a total of 90% of publications, 93% of which declared no existing conflict of interest. Sponsorship was indicated in 36% of publications, 55% of which stated public funding, 33% institutional funding, 10% industrial funding and 2% both public and industrial funding. A total of 11% of the published trials were rated as having a high commercial impact. CONCLUSION: The present study provides evidence of increasing levels of evidence for published clinical trials on urolithiasis in 2014 (as compared with earlier data). Ninety percent of publications indicated conflicts of interest, whereas sponsoring of studies was declared only by one-third. A considerable number of trials involved issues of high commercial impact. Recently established legal programmes and voluntary acts on self-reporting of financial relationships will enhance transparency in the future; however, increased public funding will be needed to further promote the quality of trials on urolithiasis.