Aquablation versus HoLEP in patients with benign prostatic hyperplasia: a comparative prospective non-randomized study.

PURPOSE: The question of best surgical treatment for lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH) remains controversial. We compared the outcomes of aquablation and holmium laser enucleation of the prostate ("HoLEP") in a prospective cohort. METHODS: Patients with BPH underwent aquablation or HoLEP according to their preference between June 2020 and April 2022. Prostate volume ("PV"), laboratory results, postvoid residual volume, uroflowmetry, IPSS, ICIQ-SF, MSHQ-EjD, EES and IIEF were evaluated preoperatively and at three, six and 12 months postoperatively. We also analyzed perioperative characteristics and complications via the Clavien Dindo ("CD") classification. RESULTS: We included 40 patients, 16 of whom underwent aquablation and 24 HoLEP. Mean age was 67 years (SD 7.4). Baseline characteristics were balanced across groups, except the HoLEP patients' larger PV. IPSS fell from 20.3 (SD 7.1) at baseline to 6.3 (SD 4.2) at 12 months (p < 0.001) without differences between aquablation and HoLEP. HoLEP was associated with shorter operation time (59.5 (SD 18.6) vs. 87.2 (SD 14.8) minutes, p < 0.001) and led to better PV reduction over all timepoints. At three months, aquablation's results were better regarding ejaculatory (p = 0.02, MSHQ-EjD) and continence function (p < 0.001, ICIQ-SF). Beyond three months, erectile, ejaculatory, continence function and LUTS reduction did not differ significantly between aquablation and HoLEP. CD ≥ grade 3b complications were noted in six patients in aquablation group while only one in HoLEP group (p = < 0.01). CONCLUSIONS: While aquablation revealed temporary benefits regarding ejaculation and continence at three months, HoLEP was superior concerning operation time, the safety profile and volumetric results.

Assessment of Patient Risk Profiles by a Male Sexual Health Direct-to-Consumer Prescription Platform: A Cross-Sectional Study.

Background: Direct-to-consumer (DTC) online prescription platforms (OPP) for sexual health represent a potential paradigm shift in the diagnosis and treatment for sexual dysfunctions in the way men seek care. Knowledge of patients' risk profile using these platforms is limited. Aim: To assess risk profiles of patients reaching out to health care professionals through their DTC. Methods: Anonymized data originally collected between February 2021 to May 2022 by a DTC platform in the men's health care space were retrospectively analyzed. Data included the content of patient requests through a communication function, as well as the corresponding responses by the attending physician on staff. Each request was then assessed by two independent urologists and categorized by the level of the risk profile as well as the need to refer the patient to further medical evaluation. Results: Of 585 patient requests, 531 (90.8%) were classified as low risk. In the high-risk group, 32 patients were recommended to schedule an urgent appointment at a specialist. Only three patients (0.5%) were advised to seek emergency care. The overall referral rate for both risk groups was 52.3%. The requests of 279 patients (47.7%) were assessed as digitally treatable. Almost all patients who were digitally treatable were low risk. Side effects accounted for only 9.6% of all requests in the low-risk group, compared with 46.3% in the high-risk group. Conclusion: Overall, low-risk levels in the requests of patients using a DTC platform were reported, with almost half of them suitable to be solved digitally, whereas the other half required referral to an in-person specialist.

YouTube is inadequate as an information source on delayed ejaculation.

The prevalence of delayed ejaculation in sexually active men is reportedly 3%. Due to its rarity and uncertain definitions, people seek information about delayed ejaculation on the internet. YouTube is one of the largest video platforms preferred global for gathering medical information. We aimed to determine the quality of YouTube videos on delayed ejaculation. YouTube search was performed with the keywords "delayed and retarded ejaculation", and we recorded the first 400 videos according to relevance. The search results were saved in the playlist, and the first 400 videos were evaluated by two independent urologists. DISCERN and Global Quality Scale (GQS) were used to assess the reliability and quality of videos. Repeated (n = 17), off-topic (n = 279), non-English videos (n = 37), and videos with no audio (n = 16) were excluded from the study. The remaining 51 videos were evaluated. DISCERN and GQS scores were statistically significantly associated with video durations (r = 0.329, P = 0.018 and r = 0.349, P = 0.012; respectively). A statistically significant association was also observed between and DISCERN and GQS scores with video power index values (r = 0.466, P = 0.001 and r = 0.422, P = 0.002; respectively). 62.7% (n = 32) videos were low quality, 23.5% (n = 12) were intermediate quality, and 13.7% (n = 7) were high quality according to the GQS. Most of the YouTube content on delayed ejaculation was of poor quality. Physicians should be aware of this situation, and take the lead in bringing high-quality videos about delayed ejaculation to the community.

Penile Autophotography Underestimates the Degree of Penile Curvature in Peyronie's Disease.

BACKGROUND: Penile curvature is the most debilitating symptom of Peyronie's disease (PD); the evaluation of the degree of angulation is essential for planning treatment strategy. However, the most used method of penile at-home autophotography (AHP) is associated with some potential pitfalls and discrepancies compared with different assessment methods. OBJECTIVE: To compare the degree of penile curvature quantified by AHP and in-office intracavernosal alprostadil injection (ICI) prior to therapy. DESIGN, SETTING, AND PARTICIPANTS: Data from 55 PD patients of a single tertiary referral center were analyzed. All patients provided standardized AHP of the erect phallus. Clinic-based assessment included ICI with curvature measurement and completion of the International Index of Erectile Function (IIEF-15). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The Wilcoxon and/or chi-square test was used to compare the degree of curvature obtained using AHP and ICI, and to evaluate whether erectile dysfunction was a predictor of a relevant difference of >10° in curvature assessment between AHP and ICI. RESULTS AND LIMITATIONS: Our study showed a significant (p < 0.001) difference in the degree of penile curvature between AHP (48° [38°; 55°]) and ICI (50° [40°; 65°]). Patients suffering from erectile dysfunction tend to have a higher difference in the degree of penile curvature between AHP and ICI than patients with good erectile function (p < 0.001). Our study is not devoid of limitations. First, we did not use Peyronie's Disease Questionnaire, as suggested by the European Association of Urology guidelines. Second, we did not evaluate inter- and intraobserver variations in the measurements. CONCLUSIONS: AHP tends to underestimate the extent of penile curvature compared to ICI. Erectile dysfunction is an independent predictor of measurement differences of >10° between AHP and ICI. PATIENT SUMMARY: It is necessary to evaluate the degree of penile curvature in Peyronie's disease prior to therapy decision. The at-home self-photography underestimates the real degree of penile curvature compared with an erection by in-office penile drug injection. Especially men suffering from erectile dysfunction carry the risk of a high difference in the measured degree of penile curvature, with a potential impact on the further treatment.

Tyrosine Kinase Inhibitors in the Treatment of Metastasised Renal Cell Carcinoma-Future or the Past?

BACKGROUND: To review and discuss the literature on applying tyrosine kinase inhibitors (TKIs) in the treatment of metastasised renal cell carcinoma (mRCC). MATERIALS AND METHODS: Medline, PubMed, the Cochrane database, and Embase were screened for randomised controlled trials, clinical trials, and reviews on treating renal cell carcinoma, and the role of TKI. Each substance's results were summarised descriptively. RESULTS: While TKI monotherapy is not currently recommended as a first-line treatment for metastasized renal cell carcinoma, TKIs are regularly applied to treat treatment-naïve patients in combination with immunotherapy. TKIs depict the first-choice alternative therapy if immunotherapy is not tolerated or inapplicable. Currently, seven different TKIs are available to treat mRCC. CONCLUSIONS: The importance of TKIs in a monotherapeutic approach has declined in the past few years. The current trend toward combination therapy for mRCC, however, includes TKIs as one significant component of treatment regimens. We found that to remain applicable to ongoing studies, both when including new substances and when testing novel combinations of established drugs. TKIs are of major importance for the treatment of renal cancer now, as well as for the foreseeable future.

Perioperative Outcomes of Transurethral Resection, Open Prostatectomy, and Laser Therapy in the Surgical Treatment of Benign Prostatic Obstruction: A "Real-World" Data Analysis from the URO-Cert Prostate Centers.

INTRODUCTION: The aim of the study is to compare length of hospital stay, transfusion rates, and re-intervention rates during hospitalization for transurethral resection of the prostate (TUR-P), open prostatectomy (OP), and laser therapy (LT) for surgical treatment of benign prostatic obstruction (BPO). METHODS: URO-Cert is an organization, in which clinical data of prostatic diseases from 2 university, 19 public, and 3 private hospitals and 270 office-based urologists are collected in order to document treatment quality. Data on diagnostics, therapy, and course of disease are recorded web based. The analysis includes datasets from 2005 to 2017. RESULTS: Of 10,420 patients, 8,389 were treated with TUR-P, 1,334 with OP, and 697 with LT. Median length of hospital stay was 6 days (IQR: 4-7) for TUR-P, 9 days (IQR: 7-11) for OP, and 5 days (IQR: 4-6) for LT (p < 0.001). Risk for a hospital stay ≥7 days was higher for OP versus TUR-P (OR: 7.25; 95% CI = 6.27-8.36; p < 0.001) and LT (OR: 17.89; 95% CI = 14.12-22.65; p < 0.001) and higher for TUR-P versus LT (OR: 2.47; 95% CI = 2.03-3.01; p < 0.001). OP had a significantly higher risk for transfusions than TUR-P (OR: 2.44; 95% CI = 1.74-3.41; p < 0.001) and LT (OR: 3.32; 95% CI = 1.56-7.01; p < 0.001). Transfusion rates were not significantly different between TUR-P and LT (OR: 1.36; 95% CI = 0.66-2.79; p = 0.51). Risk of re-intervention was not different between all 3 approaches. CONCLUSION: OP was associated with higher transfusion rates and longer hospital stay than TUR-P and LT. Risk of transfusion was not different between TUR-P and LT, but TUR-P was inferior to LT concerning length of hospital stay. Re-intervention rates during hospitalization did not differ between the groups.

Safety and side effects of transperineal prostate biopsy without antibiotic prophylaxis.

STUDY AIMS: To investigate safety and side effects of transperineal prostate biopsy without antibiotic prophylaxis. Secondary aim was to identify whether the number of cores influenced the occurrence of complications. PATIENTS AND METHODS: A cohort of 184 patients undergoing perineal prostate biopsy without antibiotic prophylaxis from 2015 to 2017 was analyzed retrospectively. On average, 41 cores were taken via two perineal skin punctures. Demographic and clinical data were obtained from patients´ electronic medical records. Binary logistic regression was performed to identify predictors for complications with the following covariates: age, prostate specific antigen (PSA), prostate volume, Prostate Imaging Reporting and Data System score, history of prostatitis, therapeutic anticoagulation, risk factors for urinary tract infection, surgery duration, and the number of biopsy cores. Furthermore, we calculated chi-squared tests with post hoc analyses for differences in the occurrence of complications between quartiles of the above-mentioned parameters. RESULTS: The overall complication rate was 10.8% (20/185). Out of 20, 19 (95 %) complications were ≤ grade 2 according to the Clavien-Dindo classification. There were two cases of afebrile urinary tract infection, and no patient developed fever or sepsis. Acute urinary retention was reported in 10 patients (5.4 %). The total number of cores was not associated to infectious complications or acute urinary retention rates. CONCLUSIONS: Transperineal prostate biopsy without antibiotic prophylaxis is a safe procedure. Neither postoperative fever nor sepsis occurred. An increased number of cores through two skin punctures was not associated with more complications.

Laser-guided real-time automatic target identification for endoscopic stone lithotripsy: a two-arm in vivo porcine comparison study.

INTRODUCTION AND OBJECTIVE: Thermal injuries associated with Holmium laser lithotripsy of the urinary tract are an underestimated problem in stone therapy. Surgical precision relies exclusively on visual target identification when applying laser energy for stone disintegration. This study evaluates a laser system that enables target identification automatically during bladder stone lithotripsy, URS, and PCNL in a porcine animal model. METHODS: Holmium laser lithotripsy was performed on two domestic pigs by an experienced endourology surgeon in vivo. Human stone fragments (4-6 mm) were inserted in both ureters, renal pelvises, and bladders. Ho:YAG laser lithotripsy was conducted as a two-arm comparison study, evaluating the target identification system against common lithotripsy. We assessed the ureters' lesions according to PULS and the other locations descriptively. Post-mortem nephroureterectomy and cystectomy specimens were examined by a pathologist. RESULTS: The sufficient disintegration of stone samples was achieved in both setups. Endoscopic examination revealed numerous lesions in the urinary tract after the commercial Holmium laser system. The extent of lesions with the feedback system was semi-quantitatively and qualitatively lower. The energy applied was significantly less, with a mean reduction of more than 30% (URS 27.1%, PCNL 52.2%, bladder stone lithotripsy 17.1%). Pathology examination revealed only superficial lesions in both animals. There was no evidence of organ perforation in either study arm. CONCLUSIONS: Our study provides proof-of-concept for a laser system enabling automatic real-time target identification during lithotripsy on human urinary stones. Further studies in humans are necessary, and to objectively quantify this new system's advantages, investigations involving a large number of cases are mandatory.

Current Disposable Ureteroscopes: Performance and Limitations in a Standardized Kidney Model.

Objectives: Due to the increasing fragility of the instruments and rising concerns about the sterility of reprocessable scopes, several single-use devices for flexible ureteroscopy have been introduced. In this study, we compare currently available disposable digital and fiberoptic flexible ureteroscopes with a contemporary reusable fiberoptic device. Materials and Methods: LithoVue™, Pusen Uscope® (UE3011, UE3022), Flexor®Vue™, and a reusable fiber optic flexible ureteroscope (BOA vision®) were tested in kidney models. The setup included (1) visualization of all calices (correct assignment of colored pearls) and (2) the extraction of human calculi with a standard disposable extraction device (NGage®). We documented the effective visualization, stone extraction, and times to completion. In addition, the surgeons' workload and performance were determined using the National Aeronautics and Space Administration-Task Load Index. Results: In visualizing and identifying calices, the LithoVue and both generations of the Uscope performed similarly, but time to completion was significantly longer for all single-use devices in comparison with the Boa Vision. LithoVue retracted stones almost as well as the reusable scope (97% vs 95%/82%/96% stone clearance), while accessibility was impeded using Uscope UE3011, as reflected by the retrieval time per stone (73 vs 102 seconds/stone). This disadvantage has, however, been overcome with the new Uscope Generation UE3022, showing a retrieval time of only 65 seconds per stone, excelling over the reusable scope in this category. The Uscope UE3022 image quality was also rated best, but showed no significant difference. Conclusions: In comparison with disposable ureteroscopes available, LithoVue offers performance and characteristics similar to a reusable device, while the FlexorVu's performance does not yet yield satisfactory results for clinical use. The first generation of Uscope exhibits potential, but requires further technical improvements to match the performance of a reusable device. With the new-generation UE3022, Pusen has made significant improvement and offers a quality comparable with the LithoVue's.

Use of Artificial Intelligence for Medical Literature Search: Randomized Controlled Trial Using the Hackathon Format.

BACKGROUND: Mapping out the research landscape around a project is often time consuming and difficult. OBJECTIVE: This study evaluates a commercial artificial intelligence (AI) search engine (IRIS.AI) for its applicability in an automated literature search on a specific medical topic. METHODS: To evaluate the AI search engine in a standardized manner, the concept of a science hackathon was applied. Three groups of researchers were tasked with performing a literature search on a clearly defined scientific project. All participants had a high level of expertise for this specific field of research. Two groups were given access to the AI search engine IRIS.AI. All groups were given the same amount of time for their search and were instructed to document their results. Search results were summarized and ranked according to a predetermined scoring system. RESULTS: The final scoring awarded 49 and 39 points out of 60 to AI groups 1 and 2, respectively, and the control group received 46 points. A total of 20 scientific studies with high relevance were identified, and 5 highly relevant studies ("spot on") were reported by each group. CONCLUSIONS: AI technology is a promising approach to facilitate literature searches and the management of medical libraries. In this study, however, the application of AI technology lead to a more focused literature search without a significant improvement in the number of results.

A High-Fidelity Phantom for the Simulation and Quantitative Evaluation of Transurethral Resection of the Prostate.

Transurethral resection of the prostate (TURP) is a minimally invasive endoscopic procedure that requires experience and skill of the surgeon. To permit surgical training under realistic conditions we report a novel phantom of the human prostate that can be resected with TURP. The phantom mirrors the anatomy and haptic properties of the gland and permits quantitative evaluation of important surgical performance indicators. Mixtures of soft materials are engineered to mimic the physical properties of the human tissue, including the mechanical strength, the electrical and thermal conductivity, and the appearance under an endoscope. Electrocautery resection of the phantom closely resembles the procedure on human tissue. Ultrasound contrast agent was applied to the central zone, which was not detectable by the surgeon during the surgery but showed high contrast when imaged after the surgery, to serve as a label for the quantitative evaluation of the surgery. Quantitative criteria for performance assessment are established and evaluated by automated image analysis. We present the workflow of a surgical simulation on a prostate phantom followed by quantitative evaluation of the surgical performance. Surgery on the phantom is useful for medical training, and enables the development and testing of endoscopic and minimally invasive surgical instruments.

A Novel Laser Lithotripsy System with Automatic Real-Time Urinary Stone Recognition: Computer Controlled Ex Vivo Lithotripsy is Feasible and Reproducible in Endoscopic Stone Fragmentation.

PURPOSE: Urinary stone treatment has been strongly influenced by advances in technology. Nevertheless, the photonic characteristics of stones as the treatment target have been neglected. Monitoring fluorescence spectra is sufficient for automatic target differentiation and laser feedback control as previously described. We investigated the characteristics of fluorescence signals and the clinical practicability of real-time laser feedback control during lithotripsy. MATERIALS AND METHODS: Fluorescence excitation light was superimposed on a holmium laser beam into the treatment fiber. Spectra were recorded and signal amplitude changes were analyzed during increases in distance between the fiber tip and the stone to identify the optimal threshold level for stone recognition. Ho:YAG lithotripsy was performed under in vitro surgical conditions in porcine tissue while our feedback system autonomously controlled the laser impulse release during lithotripsy. The tissue was then endoscopically and macroscopically examined for laser induced lesions. RESULTS: Mean ± SD autofluorescence signal amplitudes from urinary stone samples varied between 142 ± 29 and 1,521 ± 152 ADU while tissue and endoscope coating emission was negligible. Signal amplitude decreased rapidly at distances larger than 1 to 2 mm. Clinically reliable threshold values for target recognition could be set to prevent laser pulse emission if the stone was out of range or urothelial tissue might be harmed by laser irradiation. We observed no incorrectly released laser pulse or injury to tissue during autonomously controlled holmium laser lithotripsy. CONCLUSIONS: Our laboratory study strengthens the evidence that tracking real-time autofluorescence spectra during endoscopic stone surgery via automatic feedback control of the laser impulse release may become a potentially useful clinical tool for surgeons who navigate in the upper urinary tract.

Experimental Evaluation of Human Kidney Stone Spectra for Intraoperative Stone-Tissue-Instrument Analysis Using Autofluorescence.

PURPOSE: The precision and safety of laser lithotripsy in the upper urinary tract is solely controlled by the surgeon. To our knowledge laser systems with integrated real-time analysis of target tissues are not available. An intelligent laser system with automated target differentiation and laser feedback control would provide tremendous improvement in patient safety and surgical precision. We evaluated the technical, medical and physical conditions for real-time analysis using fluorescence for future development of a new laser for lithotripsy. MATERIALS AND METHODS: We collected data on the fluorescence spectra of 82 native human calculi covering the 8 most relevant subtypes compared to the spectra of endoscope components, the organic porcine urinary tract and pure samples of urinary stone compositions. Data analysis was performed to determine differences in sample signal intensities and emission wavelengths. RESULTS: All native stones showed a significant fluorescence signal compared to porcine urinary tract tissue or endoscope components. The amplitude of the fluorescence signal varied by a factor of 75. The weakest signal of stone material was 3.6-fold larger than the strongest signal of pig kidney tissue (mean ± SD 0.038 ± 0.043 vs 0.00058 ± 0.00058 arbitrary units). No fluorescence signal was observed for endoscope components. Fluorescence amplitude and spectral curve form were found to be unrelated to stone type. CONCLUSIONS: Our study provides essential information on the spectral differentiation of tissue, urinary stones and relevant endoscope components. The measurements indicate that differentiation by fluorescence is possible for all relevant stone types.

Desperate need for better management of Fournier's gangrene.

INTRODUCTION: To compare earlier and later patient groups with Fournier's gangrene, specifically with the incidence of rising antibiotic resistance rates in mind. Primary endpoints were to compare therapy, outcomes, and resistance rates. MATERIAL AND METHODS: A multicentric, retrospective, multi-national study was performed. Two groups with different time frames of treatment were defined: Group 1 (n = 50) and Group 2 (n = 104). Demographics and outcomes were analysed using Student-t test, chi-square test, or Fisher exact test. Survival data were estimated using the Kaplan Meier method and compared by Log rank testing. RESULTS: There were no significant demographic differences. Nor was there any significant difference in therapy or outcomes in the groups except for the duration of intensive care unit treatment, which lasted a mean 6.3 days in Group 1 and 11.5 days in Group 2 (p = 0.018). Survival time did not improve over the years (p = 0.268). We fortunately did not observe an increased rate of multi-resistant organisms (p = 1.000). This study's limitations are mainly due to its retrospective study design. CONCLUSIONS: Despite increasing antibiotic resistance rates worldwide, it was not apparent in our population. But the situation for these patients is alarming, since final outcome failed to improve over the last ten years despite more intensive critical-care therapy.

Robotic waterjet wound debridement - Workflow adaption for clinical application and systematic evaluation of a novel technology.

OBJECTIVE: We evaluated the clinical potential of a novel robotic system for autonomous performance of waterjet wound debridement. SUMMARY BACKGROUND DATA: Within the last decade, waterjet wound debridement has proven to be a valid alternative to the conventional approach using sharp spoons and scalpel. METHODS: The DLR MIRO robot using the DLR MICA instrument for robotic surgery was adapted for actuation of an ERBEJET 2 flexible endoscopic waterjet probe. Waterjet debridement of various wound shapes and sizes using a porcine skin model was compared between this novel robotic system and a control group of human medical professionals with regard to wound area cleaned by the waterjet, off-target area, and procedural time. RESULTS: After the wound area was registered in the robotic system, it automatically generated a cleaning path and performed debridement based on generated surface model. While the robotic system demonstrated a significant advantage for the covered wound area (p = 0.031), the average off-target area was not significantly different from human controls. Human participants had high variability in cleaning quality across users and trials, while the robotic system provided stable results. Overall procedural time was significantly lower in trials performed by humans. CONCLUSIONS: Robotic waterjet wound debridement is a promising new technological approach compared to the current clinical standard of interventional wound therapy, providing higher efficiency and quality of wound cleaning compared to human performance. Additional trials on more complicated wound shapes and in vivo tissue are necessary to more thoroughly evaluate the clinical potential of this technology.

Robotic stone surgery - Current state and future prospects: A systematic review.

OBJECTIVE: To provide a comprehensive review of robot-assisted surgery in urolithiasis and to consider the future prospects of robotic approaches in stone surgery. MATERIALS AND METHODS: We performed a systematic PubMed© literature search using predefined Medical Subject Headings search terms to identify PubMed-listed clinical research studies on robotic stone surgery. All authors screened the results for eligibility and two independent reviewers performed the data extraction. RESULTS: The most common approach in robotic stone surgery is a robot-assisted pyelolithotomy using the da Vinci™ system (Intuitive Surgical Inc., Sunnyvale, CA, USA). Several studies show this technique to be comparable to classic laparoscopic and open surgical interventions. One study that focused on ureteric stones showed a similar result. In recent years, promising data on robotic intrarenal surgery have been reported (Roboflex Avicenna™; Elmed Medical Systems, Ankara, Turkey). Initial studies have shown its feasibility and high stone-free rates and prove that this novel endoscopic approach is safe for the patient and comfortable for the surgeon. CONCLUSIONS: The benefits of robotic devices in stone surgery in existing endourological, laparoscopic, and open treatment strategies still need elucidation. Although recent data are promising, more prospective randomised controlled studies are necessary to clarify the impact of this technique on patient safety and stone-free rates.

Validating Automated Kidney Stone Volumetry in CT and Mathematical Correlation with Estimated Stone Volume Based on Diameter.

OBJECTIVES: To validate AutoMated UroLithiasis Evaluation Tool (AMULET) software for kidney stone volumetry and compare its performance to standard clinical practice. MATERIALS AND METHODS: Maximum diameter and volume of 96 urinary stones were measured as reference standard by three independent urologists. The same stones were positioned in an anthropomorphic phantom and CT scans acquired in standard settings. Three independent radiologists blinded to the reference values took manual measurements of the maximum diameter and automatic measurements of maximum diameter and volume. An "expected volume" was calculated based on manual diameter measurements using the formula: [Formula: see text] Results: Ninety-six stones were analyzed in the study. We had initially aimed to assess 100. Nine were replaced during data acquisition due of crumbling and four had to be excluded because the automated measurement did not work. Mean reference maximum diameter was 13.3 mm (5.2-32.1 mm). Correlation coefficients among all measured outcomes were compared. The correlation between the manual and automatic diameter measurements to the reference was 0.98 and 0.91, respectively (p < 0.001). Mean reference volume was 1200 mm3 (10-9000 mm3). The correlation between the "expected volume" and automatically measured volume to the reference was 0.95 and 0.99, respectively (p < 0.001). CONCLUSIONS: Patients' kidney stone burden is usually assessed according to maximum diameter. However, as most stones are not spherical, this entails a potential bias. Automated stone volumetry is possible and significantly more accurate than diameter-based volumetric calculations. To avoid bias in clinical trials, size should be measured as volume. However, automated diameter measurements are not as accurate as manual measurements.

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.