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Background: Urologists frequently activate foot pedals in a low-light operating room (OR). Pedal activation in low-light conditions poses the potential for incorrect pedal activation, potentially leading to increased radiation exposure, patient burns, or OR fires. This study compares speed, accuracy, dark adaptation, and surgeon preference for pedal activation in 4 lighting conditions. Materials and Methods: During a simulated percutaneous nephrolithotomy (PCNL), pedals for C-arm, laser, and ultrasonic lithotripter (USL) were randomized to 3 different positions. Urology attendings, residents, and medical students activated pedals in a randomized order in 4 settings: a dark OR with no illumination, an OR with overhead illumination, a dark OR with glowstick illumination, and a dark OR with blacklight illumination. Endpoints included pedal activation time; number of attempted, incomplete, and incorrect activations; dark adaptation; and subjective pedal preference. ANOVA was used for analysis with p < 0.05 considered significant. Results: In our study with 20 participants, the mean pedal activation times were significantly faster when using glowstick illumination (6.77 seconds) and blacklight illumination (5.34 seconds) compared with the no illumination arm (8.47 seconds, p < 0.001). Additionally, individual pedal activations for the C-arm, laser, and USL were significantly faster with glowstick and blacklight illumination compared with a dark OR ( p < 0.001 for all). The blacklight illumination arm demonstrated decreased attempted (0.30 vs. 3.45, p < 0.001), incomplete (1.25 vs. 7.75, p < 0.001), and incorrect activations (0.35 vs. 1.25, p < 0.001) compared with the dark setting, while demonstrating no difference compared with having room lights on. Dark adaptation was significantly improved with blacklight illumination compared with having the room lights on (134.5 vs. 140.5 luminance, p < 0.001). All participants (100%) preferred illuminated pedals compared with the dark OR, with 90% favoring the blacklight illumination. Conclusions: During a simulated PCNL, blacklight illumination significantly improved accuracy and efficiency of pedal activation compared with the conventional dark OR, while maintaining the surgeon's dark adaptation.

Introduction: The thulium fiber laser (TFL) generates a focused beam, which can be transmitted to laser fibers with small core diameters and may facilitate in situ lower-pole lithotripsy. This study compares lithotripsy performance of the 150 and 200 µm TFL in a lower pole benchtop kidney model. Materials and Methods: Using a 3D model printed from an actual kidney, in situ laser lithotripsy was performed on 1 cm lower-pole BegoStones (calcium oxalate monohydrate consistency) using four different settings (all 20W) and two fiber sizes (150 and 200 µm). Procedure time, laser time, total pulse energy, and fiber stripping were compared between the two fibers using an ANOVA or independent t-test . Results: The 150 µm fiber at 0.2 J × 100 Hz had the shortest lasing and procedure time (17.3 and 18.5 minutes) and lowest total pulse energy (20.75 kJ) compared with other study arms ( p < 0.001). Overall procedure time, lasing time, and total pulse energy were significantly different between the 8 settings ( p < 0.001 for all). At higher frequency (100 and 200 Hz), lasing time was significantly faster compared with 20 and 50 Hz (19.9 vs 27.3 minutes; p < 0.001). Furthermore, the average total procedure time was shorter with 150 µm compared with 200 µm regardless of settings (23.2 vs 29.8 minutes; p < 0.001). Conclusion: The 150 µm fiber results in shorter procedure and lasing time at lower total energy levels during lower-pole in situ lithotripsy. Overall, the fastest setting was 0.2 J and 100 Hz with the 150 µm fiber. Smaller laser fibers can potentially allow more efficient in situ laser lithotripsy with better irrigation and visibility at higher deflection angles.

Introduction: Flat-panel detector C-arms (FCs) are reported to reduce radiation exposure and improve image quality compared with conventional image intensifier C-arms (CCs). The purpose of this study was to compare radiation exposure and image quality between three commonly used FCs. Materials and Methods: A cadaver model was placed in the prone position to simulate percutaneous nephrolithotomy. We compared the following three FCs: OEC Elite CFD from GE HealthCare, Zenition 70 from Philips, and Ziehm Vision RFD from Ziehm Imaging. To measure the radiation dose, optically stimulated luminescence dosimeters (OSLDs) were utilized during five 300-second trials, conducted under three settings: automatic exposure control (AEC), AEC with low dose (LD), and LD with the lowest pulse rate (LDLP). Ten blinded urologists evaluated the image quality. Data were statistically analyzed using the analysis of variance (ANOVA) and Tukey's B post hoc tests. Results: In the AEC setting, the Philips C-arm demonstrated lower ventral OSLD exposure (42,446 mrad) compared with both the GE (51,076 mrad) and Ziehm (83,178 mrad; p  < 0.001) C-arms. Similarly, in the LD setting, the Philips C-arm resulted in less ventral OSLD exposure (25,926 mrad) than both the Ziehm (30,956 mrad) and GE (38,209 mrad; p  < 0.001) C-arms. Meanwhile, in the LDLP setting, the Ziehm C-arm showed less ventral OSLD exposure (4019 mrad) than both the GE (7418 mrad) and Philips (8229 mrad; p  < 0.001) C-arms. All three manufacturers received adequate image quality ratings at the AEC and LD settings. However, at LDLP, the Ziehm C-arm received inadequate ratings in 8% of images, whereas both the GE and Philips C-arms received 100% adequate ratings ( p  = 0.016). Conclusions: Radiation produced by flat-panel C-arms varies dramatically, with the highest exposure (Ziehm) being almost double the lowest (Philips) in AEC. Improved picture quality at the lowest settings may come at the cost of increased radiation dose. Surgeons should carefully select the machine and settings to minimize radiation exposure while still preserving the image quality.

Introduction: With the rise in the detection of incidental small renal masses (SRM), the management paradigm for these patients has become an issue of increasing concern. We aim to identify areas of consensus, controversy, and opportunities for improvement among recently published guidelines and assess the strength of evidence for the management of SRMs. Methods: We reviewed practice guidelines for SRMs promulgated by the American Urological Association, European Association of Urology, National Comprehensive Cancer Network, American Society of Clinical Oncology, European Society for Medical Oncology, and the Chinese Society of Clinical Oncology. Levels of evidence and strength of recommendations for evaluation, management and follow-up were analyzed with regard to consensus, conflict, and neglect. Results: There is consensus among guidelines for the initial evaluation and treatment of SRMs; however, discrepancies exist with regard to indications for active surveillance, thermal ablation, and timing/method of follow-up after treatment. Routine renal mass biopsy is not recommended by any guideline. Overwhelmingly, guideline statements are based on low to moderate levels of evidence; only 23% of the reviewed guidelines were based on high-level evidence, 38% based on moderate-level, and 39% on low-level evidence or expert opinion. Conclusions: Despite all six guidelines sharing a consensus on most management topics regarding SRMs, the ongoing lack of high-level evidence precludes gold standard recommendations in the areas of diagnosis, treatment, and follow-up. More high-quality studies are needed to develop a stronger, data-supported universal guideline for the management of SRMs.

Introduction and Objectives: We sought to compare the effectiveness and efficiency of the superpulse thulium fiber laser (sTFL to the holmium: yttrium-aluminum-garnet [Ho:YAG] laser for ureteroscopic "dusting" of implanted renal stones in an in vivo porcine model. Methods: Twenty-four porcine kidneys (12 juvenile female Yorkshire pigs) were randomized to Ho:YAG or sTFL treatment groups. Canine calcium oxalate stones were scanned with computed tomography to calculate stone volume and stone density; the stones were randomized and implanted into each renal pelvis via an open pyelotomy. In all trials, a 14F, 35 cm ureteral access sheath was placed. With a 9.9F dual lumen flexible ureteroscope, laser lithotripsy was performed using dusting settings: Ho:YAG 200 μm laser fiber at 16 W (0.4 J, 40 Hz) or sTFL 200 μm laser fiber at 16 W (0.2 J, 80 Hz). Lithotripsy continued until no fragments over 1 mm were observed. No stone basketing was performed. Throughout the procedures, intrarenal and renal pelvis temperatures were measured using two percutaneously positioned K-type thermocouples, one in the upper pole calyx and one in the renal pelvis. After the lithotripsy, the ureteropelvic junction was occluded, the kidneys were bivalved, and all residual fragments were collected, dried, weighed, and then measured with an optical laser particle sizer. Results: Implanted stones were similar in volume and density in both groups. Intraoperative collecting system temperatures were similar for both groups (all <44°C). Compared to Ho:YAG, sTFL ablated stones faster (9 vs 27 minutes, p  < 0.001) with less energy expenditure (8 vs 26 kJ, p  < 0.001), and a greater stone clearance rate (73% vs 45%, p  = 0.001). After sTFL lithotripsy, 77% of the remaining fragments were ≤1 mm vs 17% of fragments ≤1 mm after Ho:YAG treatment ( p  < 0.001). Conclusions: In an in vivo porcine kidney, using dusting settings, sTFL lithotripsy resulted in shorter ablation times, higher stone clearance rates, and markedly smaller stone fragments than Ho:YAG lithotripsy.

Introduction: We sought to compare the safety, efficacy, efficiency, and surgeon experience during upper urinary tract stone management with single-lumen (SLFU) vs dual-lumen flexible ureteroscopes (DLFU). Materials and Methods: Seventy-nine patients with proximal ureteral or renal stone burden <2 cm were randomized to a SLFU or DLFU. We recorded times for ureteroscopy (URS), laser lithotripsy, stone basketing, as well as intraoperative and postoperative complications. The rate of stone clearance and stone free status were calculated using CT imaging. Surgeons completed a survey after each procedure rating various metrics regarding ureteroscope performance. Results: Thirty-five patients from the single-lumen group and 44 patients from the dual-lumen group had comparable median URS time (37 vs 35 minutes, p  = 0.984) and basketing time (12 vs 19 minutes; p  = 0.584). Median lithotripsy time was decreased in the dual-lumen group (single: 6 vs dual: 2 minutes, p  = 0.017). The stone clearance rate was superior in the dual-lumen group (single: 3.7 vs dual: 7.1 mm 3 /min, p  = 0.025). The absolute stone-free rate (SFR) was superior for the dual-lumen group (single: 26% vs dual: 48%, p  = 0.045). No differences in intraoperative (single: 0% vs dual: 2%; p  = 0.375) and postoperative complications (single: 7% vs dual: 11%, p  = 0.474) were observed. Surgeons' ratings of the dual-lumen ureteroscope was superior for visibility, comfort, ease of use, and overall performance. Conclusions: The use of the dual-lumen ureteroscope in patients with renal and proximal ureteral stones <2 cm provided shorter lithotripsy time, higher stone clearance rates, improved SFR, and superior surgeon ratings when compared with SLFUs.

Purpose: We evaluated our experience of a multidisciplinary approach to renal mass biopsy (RMB) for small renal masses (SRMs) employing in-office ultrasound (US)-guided biopsy by urology (24%), CT, or US biopsy by interventional radiology (IR) (79%), and endoscopic ultrasound (EUS)-guided biopsy by gastroenterology (GI) (4%). Materials and Methods: A single-institution retrospective review of patients who underwent RMB for SRM from May 2013 to August 2019 was conducted. Data regarding patient demographics, tumor characteristics, biopsy technique, histopathology, and management were collected. Diagnostic rates, concordance with final pathology, complications, and outcomes were analyzed. Results: Of the 192 biopsies reviewed, 63% biopsies were malignant, 20% were benign, and 17% were nondiagnostic. Based on biopsy results, 71 patients (37%) elected active surveillance. Thirty-eight (20%) patients underwent cryoablation, 56 (29%) underwent partial nephrectomy, 14 (7%) underwent radical nephrectomy, and the remaining patients were treated elsewhere. The rate of surgery for benign pathology after pretreatment RMB was 3%. The concordance rate between biopsy and final pathology was 99% for malignancy, 96% for specific pathology subtype, and 85% for renal cell carcinoma grade. Median time from diagnosis to definitive treatment was 97 days (urology: 76, IR: 110 and GI: 54, p  = 0.002). Three (1.6%) Clavien I complications were reported. Conclusion: Our multidisciplinary approach to RMB for clinical stage T1a demonstrated favorable safety and diagnostic rates, which effectively directed management strategies and minimized surgery for benign disease. Urologist-performed office biopsies significantly shortened the time from diagnosis to definitive treatment. Our experience with GI EUS biopsy has demonstrated feasibility and safety for tumors that were otherwise not accessible percutaneously.

Introduction: We sought to examine the intrarenal fluid and tissue temperature alterations during dusting and fragmentation with the thulium fiber laser (TFL) in an in vivo porcine kidney. Materials and Methods: In two female Yorkshire pigs, temperature was continuously measured within the upper, interpolar, and lower calices along with the renal pelvis using multipoint thermal sensor probes; another temperature probe was situated at the tip of the ureteroscope. Four experimental protocols were performed for each animal: dual lumen ureteroscope with both warmed (37°C) irrigation and room temperature (20°C-22°C) irrigation and single lumen ureteroscope with warmed and room temperature irrigation. Of note, in each pig, one kidney underwent ureteroscopy (URS) with a 14F ureteral access sheath (UAS) in place, whereas the other kidney had no UAS placed. A 200-μm TFL fiber was fired at three laser settings: (1) dusting at 0.5 J, 80 Hz (40 W) with continuous activation until 5 minutes expired or a temperature of 44°C was reached, (2) low-power fragmentation 1 J, 10 Hz, (10 W), and (3) high-power fragmentation at 1.5 J, 20 Hz (30 W). In all cases, the pulse width was 1 ms. For fragmentation, the laser was activated for 10 seconds with a 2-second intermission for a 1-minute period (five cycles). Results: In the absence of a UAS, in all but one circumstance, temperatures reached or exceeded 44°C at all laser settings with the use of either warm or room temperature irrigation fluid, regardless of the type of ureteroscope used. Of concern, temperatures recorded at the tip of the URS were 4°C to 22°C less than the temperatures recorded in the renal calices. In contrast, with a 14F UAS in place, six distinct groups had temperatures that did not exceed 44°C, specifically at low- and high-power fragmentation settings with room temperature irrigation for both sets of ureteroscopes and at dusting and low-power fragmentation settings with warm temperature irrigation solely for the single lumen ureteroscope. Temperatures recorded at the tip of the ureteroscope with the deployment of a UAS yielded temperature differences ranging from 17°C less to 19°C more than the renal calices. Conclusions: TFL is a novel laser technology for lithotripsy. In the absence of a UAS, high-power TFL fragmentation settings in particular may create temperatures within the collecting system that could result in urothelial tissue injury. Of note, peak temperatures recorded at the tip of the ureteroscope may misrepresent the actual intrarenal temperature during TFL laser lithotripsy.

Introduction: The disproportionate costs of state-of-the-art endoscopic equipment prohibit urologists from performing endoscopy in underserved countries. Given the global prevalence of smartphones, we engineered a $45 alternative endoscope utilizing three-dimensional printed attachments, an 8 × lens, and a 1000-lumen light-emitting diode cordless flashlight (Endockscope System [ES]). Materials and Methods: At the 34th World Congress of Endourology in Cape Town, South Africa (WCE 2016; 4-year group), and at the 39th Congress of the Société Internationale d'Urologie (SIU) in Athens, Greece (SIU 2019; 8-month group), a total of 40 ES kits were distributed free of charge to an international group of urologists. Participants were given instructions and a hands-on demonstration of the device. Urologists given an ES were subsequently asked to complete a survey between June and September 2020 that included questions regarding user satisfaction, comfort, and comparability of the ES to standard endoscopic systems. Results: Urologists from 23 countries received ES kits. Overall, 10 of 22 urologists (10/22; 45%) from the 4-year group and 18 of 18 urologists (18/18; 100%) from the 8-month group completed the survey. The ES device was used by 80% (8/10) and 83% (15/18) of urologists from the 4-year and the 8-month groups, respectively. Of note, the greatest impact of ES usage was among urologists from the most impoverished countries. Of those who used the ES, 44% (4/9) of urologists from the 4-year cohort and 47% (8/17) from the 8-month cohort reported they were able to perform more endoscopic procedures directly because of the ES. Moreover, 57% (4/7) of the 4-year participants and 67% (10/15) of the 8-month participants found the ES equal or superior in quality to their standard endoscopic equipment. Conclusion: The ES provided an effective and inexpensive system that enabled urologists in resource-challenged countries to effectively perform and expand their use of urologic endoscopy.

Percutaneous nephrolithotomy (PCNL) is the treatment of choice for kidney stones >2 cm in size. Obtaining a nephrostomy tract to access the kidney is a key step in this procedure that ultimately determines the patient's outcome. We describe each step of the endoscopic guided approach to PCNL as performed at the University of California, Irvine. Each step of the endoscopic guided PCNL is described and depicted in the video. Surgical steps depicted in the video are from various recorded PCNL procedures from our institution. This guide outlines the indications, preoperative preparation, patient positioning, surgical steps, and postoperative care for patients undergoing PCNL using the endoscopic guided approach. Direct observation of nephrostomy puncture, tract dilation using the balloon, and passing of the Amplatz sheath allow for proper access to the kidney and lower risk of injury. By following this systematic module of endoscopic guided PCNL, a nephrostomy tract can be created and accessed under direct observation, facilitating the routine steps of PCNL.

Introduction: A detailed understanding of renal tumor anatomy is required to perform partial nephrectomy. We evaluated the utility of a CT-based interactive virtual reality (iVR) display to assist surgeons' understanding of the precise location of the renal tumor. Methods: CT scans and iVR models of 11 patients with a mean R.E.N.A.L. nephrometry score of 6.9 were evaluated. Seven faculty urologists and six urology residents reviewed CT scans and positioned each tumor onto a digital three-dimensional model of the same kidney, although without the tumor present. A week later, participants repeated the session using both iVR models and CT scans. For both time points, the overlap between the surgeon-inserted tumor and the actual tumor location was calculated. Participants answered a 1 to 10 Likert scale survey to gauge their understanding of renal and tumor anatomy based on CT alone vs CT+iVR. Results: Median tumor overlap for the entire cohort was 28% after CT review and 42% after CT+iVR ( p  = 0.05); among faculty urologists, for CT+iVR vs CT alone, percentage overlap improved (47% vs 33%, p  = 0.033) and the incidence of 0% overlap decreased (19%-4%, p  = 0.024), respectively. Among residents, there was no significant difference for either percentage overlap or 0% overlap for CT vs CT+iVR. The percentage overlap for the two tumors with high R.E.N.A.L. nephrometry scores (i.e., 10) increased from 51% to 67% after using CT+iVR ( p  = 0.039). The combination of CT+iVR was an independent predictor of improved overlap vs CT alone (odds ratio 2.22, 95% confidence interval 1.04-4.78, p  = 0.039). Faculty surgeons' survey responses showed an improved understanding of the tumor location and shape with the addition of iVR ( p  < 0.05). Conclusions: The addition of patient-specific iVR models to standard CT imaging improved the ability of faculty urologists to accurately configure the location of a renal tumor, and improved their understanding of tumor anatomy.

Purpose: To assess the efficacy of dual-energy CT (DECT) in predicting the composition of urinary stones with a single index (dual energy ratio [DER]) and five indices. Methods: Patients undergoing DECT before active urolithiasis treatment were prospectively enrolled in the study. Predictions of stone composition were made based on discriminant analysis with a single index (DER) and five indices (stone density at 80 and 135 kV, Zeff [the effective atomic number of the absorbent material] of the stone, DER, dual-energy index [DEI] and dual-energy difference [DED]). After extraction, stone composition was evaluated by means of physicochemical analyses (X-ray phase analysis, electron microscopy, wet chemistry techniques, and infrared spectroscopy). Results : A total of 91 patients were included. For calcium oxalate monohydrate (COM) stones, the sensitivity, specificity, and overall accuracy of DECT with one index (DER) were 83.3%, 89.8%, and 86.8%, respectively; for calcium oxalate dihydrate (COD) and calcium phosphate stones-88.2%, 92.9%, and 91.2%, respectively; for uric acid stones-0%, 98.8% and 97.8%, respectively; for struvite stones-60%, 95.3%, and 93.4%, respectively. Discriminant analysis with five indices yielded the following sensitivity, specificity, and overall accuracy: 95.2%, 89.8%, and 92.3% for COM stones, 85.3%, 96.4%, and 92.3% for COD stones, and 100% in all three categories for both uric acid and struvite stones. Conclusions: DECT is a promising tool for stone composition assessment. It allowed for evaluation of chemical composition of all stone types with specificity and accuracy ranging from 85% to 100%. Five DECT indices have shown much better diagnostic accuracy compared to a single DECT index.

Introduction: Herein we provide the first report regarding in vivo porcine renal forniceal, papillary, and infundibular blood flow at the urothelial level using a novel ureteroscopic Doppler transducer. Materials and Methods: Nephroureteroscopy was performed on 11 female Yorkshire pigs to map the forniceal, papillary, and infundibular blood flow. A Doppler transducer was mounted to a 3F 120 cm catheter; the probe was passed through the working channel of a flexible ureteroscope. Blood flow was categorized from 0 (no flow) to 3 (highest flow) based on auditory intensity. At each site, a holmium laser probe was activated until it penetrated ∼1 cm into each of the examined areas; bleeding times were recorded. Results: The frequency of the Doppler transducer signal was proportional to the blood velocity within the vessel with expected increased bleeding times confirmed after puncture with a holmium laser. Analysis demonstrated that the 6 o'clock position of the fornix had significantly greater blood flow than any other forniceal location ( p  < 0.001). The center of each papilla had the least blood flow ( p  < 0.001). Blood flow was significantly higher at the infundibular level compared with the caliceal fornices at all locations (anterior, posterior, upper pole, midkidney, and lower pole) ( p  < 0.001). Conclusions: In a porcine model, a miniaturized Doppler ultrasound probe used during ureteroscopy demonstrated that the renal papilla had the least amount of blood flow whereas the infundibula had the highest blood flow. These data may serve to inform site selection during percutaneous nephrostomy placement.

Introduction: Endoscopic enucleation of the prostate (EEP) is a safe method of treating benign prostatic hyperplasia, regardless of prostate volume and type of applied energy. To date, however, there has been no study that examines complication rates with respect to the type of applied energy. This study aims to address this problem by providing a retrospective analysis of >1400 patients who have undergone prostate enucleation. Materials and Methods: We performed a retrospective analysis of all patients undergoing EEP between 2013 and 2018 at a single tertiary institution. This analysis included patients who had undergone one of three forms of EEP: holmium laser enucleation of the prostate (HoLEP), thulium fiber laser enucleation of the prostate (ThuFLEP), or monopolar enucleation of the prostate (MEP). We compared intraoperative and early postoperative complications, as well as complications at 3 and 6 months follow-up. Results: A total of 1413 patients were included in this study; 36% patients underwent HoLEP, 57.5% had ThuFLEP, and 6.5% MEP. The most frequent complication in the early postoperative period was a mild fever (2.76% of the cases). The morcellation was delayed to a separate stage because of intensive hemorrhaging in 1.4% of the cases. Bladder tamponade was found in 1.1% of the cases. We found no correlation between complication rate and either prostate volume or energy source. Stress urinary incontinence was found in 3.9% of patients at 3 months and in only 1.4% of patients at 6 months after the operation. Urethral stricture at 6 months after the surgery was found in 1.4% of patients, whereas bladder neck sclerosis was found in only 0.9% of these cases. No significant difference was observed between these complication frequencies and any preoperative factors or energy source. Conclusions: All EEP types are safe with equal rates of complications intraoperatively, postoperatively, and at 6 months follow-up.

Objective: To assess optical performance and diagnostic capability of the Endockscope system (ES) vs the standard endoscopic system (SES) using four rigid/semi-rigid endoscopes. The ES combines a smartphone, lens system, and a rechargeable light-emitting diode (LED) light source to provide a low-cost alternative ($45) to the standard camera and high-powered light source ($45,000) used in endoscopic procedures. Materials and Methods: Video clips (<20 seconds) of standard rigid nephroscopy, semi-rigid ureteroscopy, rigid cystoscopy, and laparoscopy in two adult male cadavers were recorded using the ES combined with either the Apple iPhone X or Samsung Galaxy S9+ and also with the high-definition SES (Karl Storz). Sixteen urologists blinded to the camera modality assessed the image resolution, brightness, color, sharpness, and overall quality using a Likert-type scale; acceptability for diagnostic purposes was judged on a binary scale (yes/no). Results: For rigid cystoscopy, there was no statistical difference between both ES systems and the SES. For semi-rigid ureteroscopy the two ES systems performed equal to or better than the SES. For rigid nephroscopy, the ES plus Galaxy was comparable to the SES, except in brightness ( p  < 0.05), whereas the ES plus iPhone was inferior in various parameters. For laparoscopy, the ES plus Galaxy was inferior to the SES in brightness and overall quality ( p  < 0.05); the ES plus iPhone was inferior for all laparoscopic image parameters compared with the SES. For diagnostic purposes, the ES plus Galaxy was equivalent to the SES for all endoscopes; the ES plus iPhone was equivalent to the SES for cystoscopy, ureteroscopy, and nephroscopy. Conclusion: The ES plus the Apple iPhone X or Samsung Galaxy S9+ offers comparable imaging and provides diagnostic information equivalent to the standard system for rigid endoscopy of the kidney, ureter, and bladder; the Galaxy S9+ provides comparable imaging and diagnostic capabilities for evaluation of the abdomen.

Background: Percutaneous nephrolithotomy (PCNL) requires the urologist to have detailed knowledge of the stone and its relationship with the renal anatomy. Immersive virtual reality (iVR) provides patient-specific three-dimensional models that might be beneficial in this regard. Our objective is to present the initial experience with iVR in surgeon planning and patient preoperative education for PCNL., Materials and Methods: From 2017 to 2018 four surgeons, each of whom had varying expertise in PCNL, used iVR models to acquaint themselves with the renal anatomy before PCNL among 25 patients. iVR renderings were also viewed by patients using the same head-mounted Oculus rift display. Surgeons rated their understanding of the anatomy with CT alone and then after CT+iVR; patients also recorded their experience with iVR. To assess the impact on outcomes, the 25 iVR study patients were compared with 25 retrospective matched-paired non-iVR patients. Student's t-test was used to analyze collected data., Results: iVR improved surgeons' understanding of the optimal calix of entry and the stone's location, size, and orientation (p < 0.01). iVR altered the surgical approach in 10 (40%) cases. Patients strongly agreed that iVR improved their understanding of their stone disease and reduced their preoperative anxiety. In the retrospective matched-paired analysis, the iVR group had a statistically significant decrease in fluoroscopy time and blood loss as well as a trend toward fewer nephrostomy tracts and a higher stone-free rate., Conclusions: iVR improved urologists' understanding of the renal anatomy and altered the operative approach in 40% of cases. In addition, iVR improved patient comprehension of their surgery. Clinically, iVR had benefits with regard to decreased fluoroscopy time and less blood loss along with a trend toward fewer access tracts and higher stone-free rates.

Introduction: The objective of this study was to assess the efficacy and safety of novel thulium fiber laser enucleation of the prostate (ThuFLEP) vs conventional open simple retropubic prostatectomy (OP) for large volume benign prostatic hyperplasia (BPH)., Methods: We performed a retrospective review of patients who underwent surgical treatment for large volume BPH (>80 cc) from 2015 to 2017. Preoperative patient examination included the assessment of functional parameters: International Prostate Symptom Score (IPSS), quality of life (QoL), maximum urine flow rate (Q max ), and postvoid residual urine volume. The hemoglobin level was measured before and after the operation., Results: A total of 130 patients were included in the study. Of these, 40 patients underwent OP, and 90 patients underwent ThuFLEP. Groups were similar in terms of preoperative functional parameters (IPSS, QoL, and Q max ). The mean operative time was comparable for both procedures (p = 0.285) as well as the mass of adenomatous tissue resected (p = 0.412). Resection speed was comparable (OP-0.9 vs ThuFLEP-1.0 g/min, p = 0.52). Patients in OP had significantly longer catheterization time and length of hospital stay (9.0 days vs 3.3 days, p < 0.001). At 6 months, stress urinary incontinence rate were 1.1% after ThuFLEP and 2.5% after OP., Conclusions: Despite the equally high efficacy of both modalities for infravesical obstruction due to BPH, ThuFLEP is a minimally invasive modality that is associated with a shorter hospital stay, a significantly greater return to normal activities, and a considerable reduction in rehabilitation time. Our results demonstrated that the ThuFLEP is a highly efficacious, minimally invasive modality for the management of BPH in large volume glands (>80 cc).

Introduction: We surveyed United States of America-based urologists to characterize practice patterns and indications to perform a renal mass biopsy for small renal masses., Materials and Methods: Members of the American Urological Association who practice in the United States were invited to participate in a 11-question web-based survey that was distributed via SurveyMonkey ® from December 2016 to January 2017., Results: There were 1131 respondents. The respondents equally represented all regions of the United States; the majority were in private practice. Overall, 32% of American urologists would "never" perform a biopsy of a renal mass ≤4 cm. Those who saw fewer than five small renal masses per year were more likely to "never" perform a renal biopsy on either a renal mass ≤4 cm or a renal mass 2-3 cm compared with those who saw more than five small renal masses per year (p < 0.001). Urologists who practiced at an academic hospital were more likely to perform a renal biopsy on both a renal mass ≤4 cm and a renal mass 2-3 cm compared with private practice and government-based urologists (p < 0.001 and p = 0.008 respectively). The primary reason for not performing a biopsy, cited by 68% of responding urologists, was that the results of a biopsy "would not change their management of the renal mass." Respondents independently performed only 2% of biopsies; however, almost half stated that they would be interested in learning office-based ultrasound-guided biopsy of a small renal mass., Conclusions: Among members of the American Urological Association, biopsy of a small renal mass remains an underutilized diagnostic procedure, especially in light of 6000 unnecessary surgeries annually; nonuniversity-based urologists and those who see <5 renal mass cases each year infrequently perform a biopsy. Currently, interventional radiologists perform almost all small renal mass biopsies.

Introduction: The Endockscope combines a smartphone, a battery powered flashlight and a fiberoptic cystoscope allowing for mobile videocystoscopy. We compared conventional videocystoscopy with the Endockscope paired with next generation smartphones in an ex-vivo porcine bladder to evaluate its image quality., Materials and Methods: The Endockscope consists of a three-dimensional (3D) printed attachment that connects a smartphone to a flexible fiberoptic cystoscope plus a 1000 lumen light-emitting diode (LED) cordless light source. Video recordings of porcine cystoscopy with a fiberoptic flexible cystoscope (Storz) were captured for each mobile device (iPhone 6, iPhone 6S, iPhone 7, Samsung S8, and Google Pixel) and for the high-definition (HD) H3-Z versatile camera setup with both the LED light source and the xenon light (XL) source. Eleven faculty urologists, blinded to the modality used, evaluated each video for image quality/resolution, brightness, color quality, sharpness, overall quality, and acceptability for diagnostic use., Results: When comparing the Endockscope coupled to a Galaxy S8, iPhone 7, and iPhone 6S with the LED portable light source to the HD camera with XL, there were no statistically significant differences (p < 0.01) in any metric. Eighty-two percent and 55% of evaluators considered the iPhone 7 + LED light source and iPhone 6S + LED light, respectively, appropriate for diagnostic purposes as compared with 100% who considered both the HD camera with XL and Galaxy S8 + LED appropriate. The iPhone 6 and Google Pixel coupled with the LED source were both inferior to the HD camera with XL in all metrics., Conclusions: The Endockscope system with a LED light source ($45) when coupled with either an Apple iPhone 7 or Samsung Galaxy S8 is comparable to conventional videocystoscopy with a standard camera and XL light source (total cost: $45,000).

Introduction: The most commonly performed procedure among urologists is cystoscopy. However, urologists in developing countries have limited access and funds to purchase the equipment necessary to perform this procedure. The novel Endockscope (ES) mobile endoscopic system aids in reducing this gap in both cost and accessibility., Materials and Methods: ES kits were distributed at the 2016 World Congress of Endourology in Cape Town, South Africa. All participants were given instructions on how to use the device and each participant attended a live demonstration during the conference. Eight months later, all participants were contacted via email, regular mail, or phone to complete a questionnaire designed to assess the impact of the ES device., Results: A total of 24 ES kits were distributed. After numerous emails, questionnaires sent by regular return mail, and phone calls, 12 (50%) participants completed the survey as instructed. Seventy percent of participants reported that they performed more endoscopic procedures due to the ES system. Overall, 90% of participants stated that they would purchase the ES system for personal use ($40.53). All participants reported that they would recommend the ES to others., Conclusion: The ES system provided an effective inexpensive system to enable urologists in resource-challenged countries to offer cystoscopy to more of their patients.

Introduction: Endoscopic enucleation of the prostate (EEP) has been recognized as a viable treatment modality for men with benign prostatic hyperplasia (BPH). The aim of our study was to compare the efficacy and functional outcomes of three different techniques of EEP, including monopolar enucleation (MEP), holmium laser enucleation of the prostate (HoLEP), and thulium laser enucleation of the prostate (ThuLEP)., Methods: The study consisted of a retrospective comparison of pre- and postoperative parameters in men undergoing three types of EEP: MEP, HoLEP, and ThuLEP. Functional parameters were evaluated before and 6 months after surgery, which included the International Prostate Symptom Score, maximum flow rate, postvoid residual volume, prostate volume, and sodium levels of all patients., Results: A total of 551 men with the mean age of 67.1 years were included in the study. Of these, MEP was performed on 95 patients, HoLEP was performed on 254 patients, and ThuLEP on 202 patients. The mean mass of morcellated tissue obtained during the three techniques did not differ significantly (p > 0.05). Mean procedure times of ThuLEP and HoLEP were shorter than MEP demonstrating 72, 76, and 86 minutes, respectively (p < 0.01). The mean catheterization time following laser EEPs was shorter than MEP as shown by 1.3, 1.3, and 3.8 days, respectively (p < 0.01). Hospital stay times of HoLEP and ThuLEP were shorter than MEP demonstrated by 3.3, 3.4, and 6.9 days, respectively (p < 0.01). Patients after MEP had significant decrease in postoperative hemoglobin and sodium levels. All the groups showed statistically significant improvement in the aforementioned parameters following treatment., Conclusions: Both techniques of laser enucleation proved to be efficacious in the management of BPH. MEP of the prostate seems to be a highly promising addition to the list of enucleation techniques and was determined to be an effective and acceptable procedure, despite a higher complication rate.

Introduction: We evaluated and compared five currently available energy-based vessel sealing devices to assess typical surgical metrics., Methods: We tested Caiman 5 (C5), Harmonic Scalpel Ace Plus (HA), Harmonic Ace +7 (HA7), LigaSure (LS), and Enseal G2 (ES) on small (2-5 mm), medium (5.1-7 mm), and large (7.1-9 mm) vessels obtained from 15 Yorkshire pigs. Vessels were randomly sealed and transected. We recorded sealing and transection time, charring and carbonization, thermal spread, and bursting pressure (BP). Specimens were sent for histopathologic evaluation of seal quality and thermal spread., Results: A total of 246 vessels were evaluated: 125 were arteries and 121 were veins. There was no difference in BPs for small size arteries. For medium arteries, C5 provided the highest BP (proximal and distal jaw), followed by HA7, ES, LS, and HA [1740, 1600, 1165, 1165, 981, and 571 mm Hg, respectively, HA250 mm Hg.

Purpose: Ionizing radiation is implicated in nearly 2% of malignancies in the United States; radiation shields prevent unnecessary radiation exposure during medical imaging. Contemporary radiation shield utilization for adult patients in the United States is poorly defined. Therefore, we evaluated the prevalence of protective shielding utilization in adult patients undergoing CT scans in United States' hospitals., Materials and Methods: An online survey was sent to established radiology departments randomly selected from the 2015 American Hospital Association Guide. Radiology departments conducting adult CT imaging were eligible; among 370 eligible departments, 215 departments accepted the study participation request. Questions focused on shielding practices during CT imaging of the eyes, thyroid, breasts, and gonads. Prevalence data were stratified per hospital location, size, and type. Main outcomes included overall protective shielding utilization, respondents' belief and knowledge regarding radiation safety, and organ-specific shielding prevalence., Results: Sixty-seven of 215 (31%) hospitals completed the survey; 66 (99%) reported familiarity with the ALARA (as low as reasonably achievable) principle and 56 (84%) affirmed their belief that shielding is beneficial. Only 60% of hospitals employed shielding during CT imaging; among these institutions, shielding varied based on CT study: abdominopelvic CT (13, 33%), head CT (33, 83%), or chest CT (30, 75%)., Conclusions: Among surveyed hospitals, 40% do not utilize CT shielding despite the majority acknowledging the ALARA principle and agreeing that shielding is a beneficial practice. Failure to address the low prevalence of protective shielding may lead to poor community health due to increased risk of radiation-related cancers.

Objective: To compare conventional videocystoscopy (CVC) with a novel and affordable (approximately $45) mobile cystoscopy system, the Endockscope (ES). We evaluated the ES system using both fluid (Endockscope-Fluid [ES-F]) and air (Endockscope-Air [ES-A]) to fill the bladder in an effort to expand the global range of flexible cystoscopy., Methods: The ES system comprised a portable 1000 lumen LED self-contained cordless light source and a three-dimensional printed adaptor that connects a mobile phone to a flexible fiber-optic cystoscope. Patients undergoing in-office cystoscopic evaluation for either stent removal or bladder cancer surveillance received three examinations: conventional, ES-F, and ES-A cystoscopy. Videos of each examination were recorded and analyzed by expert endoscopists for image quality/resolution, brightness, color quality, sharpness, overall quality, and whether or not they were acceptable for diagnostic purposes., Results: Six of the 10 patients for whom the conventional videos were 100% acceptable for diagnostic purposes were included in our analysis. The conventional videos scored higher on every metric relative to both the ES-F and ES-A videos (p < 0.05). There was no difference between ES-F and ES-A videos on any metric. Fifty-two percent and 44% of the ES-F and ES-A videos, respectively, were considered acceptable for diagnostic purposes (p = 0.384)., Conclusions: The ES mobile cystoscopy system may be a reasonable option in settings where electricity, sterile fluid irrigant, or access to CVC equipment is unavailable.

Background: We hypothesized that surgical skills assessment could aid in the selection process of medical student applicants to a surgical program. Recently, crowdsourcing has been shown to provide an accurate assessment of surgical skills at all levels of training. We compared expert and crowd assessment of surgical tasks performed by resident applicants during their interview day at the urology program at the University of California, Irvine., Materials and Methods: Twenty-five resident interviewees performed four tasks: open square knot tying, laparoscopic peg transfer, robotic suturing, and skill task 8 on the LAP Mentor™ (Simbionix Ltd., Lod, Israel). Faculty experts and crowd workers (Crowd-Sourced Assessment of Technical Skills [C-SATS], Seattle, WA) assessed recorded performances using the Objective Structured Assessment of Technical Skills (OSATS), Global Evaluative Assessment of Robotic Skills (GEARS), and the Global Operative Assessment of Laparoscopic Skills (GOALS) validated assessment tools., Results: Overall, 3938 crowd assessments were obtained for the four tasks in less than 3.5 hours, whereas the average time to receive 150 expert assessments was 22 days. Inter-rater agreement between expert and crowd assessment scores was 0.62 for open knot tying, 0.92 for laparoscopic peg transfer, and 0.86 for robotic suturing. Agreement between applicant rank on skill task 8 on the LAP Mentor assessment and crowd assessment was 0.32. The crowd match rank based solely on skills performance did not compare well with the final faculty match rank list (0.46); however, none of the bottom five crowd-rated applicants appeared in the top five expert-rated applicants and none of the top five crowd-rated applicants appeared in the bottom five expert-rated applicants., Conclusions: Crowd-source assessment of resident applicant surgical skills has good inter-rater agreement with expert physician raters but not with a computer-based objective motion metrics software assessment. Overall applicant rank was affected to some degree by the crowd performance rating.

Introduction: Cryoablation (CA) is a minimally invasive modality for the management of small renal cortical neoplasms (RCN). Effective ablation is dependent on achieving target temperatures during CA that result in tumor cell death. We investigated long-term oncologic outcomes following CA using multipoint thermal sensors (MTS), which allow precise temperature determination at four points along the needle., Methods: We performed a retrospective review of 20 patients with <4 cm RCN who underwent de novo CA from 2005 to 2009. In 11 procedures, MTS needles were deployed with the goal of obtaining -20°C at the tumor margin, while 9 were done without MTS. Patient demographics, tumor characteristics, and CA procedure data were retrieved and analyzed. Follow-up CT or MRI was used to assess recurrence status., Results: With a mean follow-up of 45 months, none of the 11 patients experienced a recurrence in the MTS group, compared with 4 of 9 (44.4%) patients in the non-MTS group (p = 0.026). Of the biopsy-confirmed renal cancers, none of the 6 in the MTS group, compared with 3 of 6 (50%) in the non-MTS group, recurred (p = 0.182). Age, tumor size, surgical approach, tumor histopathology, grade, follow-up time, and skin-to-tumor distance were similar between the MTS and non-MTS groups. The MTS group was also associated with increased total length of freeze (p = 0.041), procedure time (p = 0.020), cryoprobe utilization (p = 0.049), and a greater ratio of cryoprobes used per cm diameter of tumor (p = 0.003)., Conclusions: In this small renal mass pilot study, the use of MTS needles to monitor temperature and guide cryoneedle deployment was associated with improved oncologic outcomes.

Purpose: To determine the incidence and predictors of major complications in patients undergoing percutaneous cryoablation (PCA) for small renal masses., Methods: We performed a retrospective analysis of patients undergoing PCA from 2005 to 2012. We analyzed demographic, radiographic, and complication data. We defined complications as any deviation from the expected postoperative course. We determined predictors of complications., Results: A total of 190 patients were included in the study. The mean age was 69 years, and 132 (69%) were males. The mean tumor diameter was 2.2 cm (0.8-4.0 cm). The mean number of probes utilized per procedure was 2.3. We observed 16 (8.4%) complications including 14 Clavien grade I, which includes 6 (2%) large renal/retroperitoneal hematomas, 4 (2%) pneumothoraxes, 2 (1%) urinary tract infections, and 2 (1%) atrial fibrillations. There were two (1%) Clavien grade II complications (intestinal perforations). In univariable analysis, larger tumors and more probes were associated with higher risk of complications (all ps < 0.05). In multivariable analysis, larger tumor dimension (odds ratio [OR] = 2.85; 95% confidence interval [CI] = 1.34, 6.05; p = 0.006) was independently associated with major complications. After multivariable adjustments for patient's characteristics such as age, gender, American Society of Anesthesiologists, year of surgery, and histopathology, larger tumor dimension (OR = 2.85; 95%CI = 1.34, 6.05; p = 0.006) and more cryoablation probes (OR = 1.94; 95%CI = 1.36, 2.75; p < 0.001) were independently associated with higher risk of major complications., Conclusions: In a cohort of patients undergoing PCA for T1a small renal mass, larger tumor dimension and more cryoablation probes were independently associated with higher risk of complication. Although PCA is relatively safe and the major complications are infrequent, careful patient selection is crucial.

Background: The management of locally recurrent renal-cell carcinoma (RCC) following cryoablation remains a clinical dilemma. There is limited data regarding the management of locally recurrent disease in the setting of patients who have failed initial percutaneous cryoablation (PCA). We evaluate and report our experience with salvage PCA for local recurrence following renal cryoablation failure., Patients and Methods: We reviewed our experience with patients who underwent salvage PCA for local biopsy proven RCC recurrence following primary cryoablation procedures. Complications and oncologic outcomes were evaluated. Recurrence-free survival after primary and repeat cryoablation was plotted using the Kaplan-Meier curves., Results: A total 250 patients underwent primary cryoablation for RCC and 20 (8%) patients were identified who underwent repeat PCA for 21 locally recurrent tumors. The mean tumor size was 2.4 cm. Biopsy revealed clear cell in 14 patients, three papillary and four chromophobe RCC. All repeat cryoablation procedures were completed successfully, with no treatment failures on postprocedure imaging. There were no complications or deaths. With the median follow-up of 30 months (range 7-63), 3 (15%) patients experienced local recurrence. One patient had an enhancing lesion at 13 months following repeat PCA and underwent a third PCA. Two patients had recurrence at 6 and 35 months respectively and underwent successful laparoscopic partial nephrectomy. Local recurrence-free, metastasis-free and cancer-specific survival rates were 85%, 100%, and 100% respectively. Limitations include retrospective design and small number of patients., Conclusions: Repeat PCA after primary cryoablation failure is feasible, has a low complication rate, and acceptable short-term oncologic outcomes. Further studies with durable follow-up are required.

Background and Purpose: Several scoring systems have recently emerged to predict stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). We aimed to compare the most commonly used scoring systems (Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram), assess their predictive accuracy for SFR and other postoperative variables, and develop a risk group stratification based on these scoring systems., Materials and Methods: We performed a retrospective review of patients who have had a PCNL at four academic institutions between 2006 and 2013. Primary outcome was SFR within 3 weeks of the surgery and secondary outcomes were operative time (OT), complications, and length of stay (LOS). We performed chi-squared, t-test, logistic, linear, and Poisson regressions, as well as receiver operating characteristics curve with area under the curve (AUC) calculation., Results: We identified 586 patients eligible for analysis. Of these, 67.4% were stone free. Guy's, S.T.O.N.E., and CROES score were predictive of SFR on multivariable logistic regression (odds ratio [OR]: 1.398, 95% confidence interval [CI]: 1.056, 1.852, p = 0.019; OR: 1.417, 85% CI: 1.231, 1.631, p < 0.001; OR: 0.993, 95% CI: 0.988, 0.998, p = 0.004) and have similar predictive accuracy with AUCs of 0.629, 0.671, and 0.646, respectively. On multivariable linear regression, only S.T.O.N.E. was an independent predictor of longer OT (β = 14.556, 95% CI: 12.453, 16.660, p < 0.001). None of the scores were independent predictors of postoperative complications or a longer LOS. Poisson regression allowed for risk group stratification and showed the S.T.O.N.E. score and CROES nomogram to have the most distinct risk groups., Conclusions: The three evaluated scoring systems have similar predictive accuracy of SFR. S.T.O.N.E. has additional value in predicting OT. Risk group stratification can be used for patient counseling. Further research is needed to identify whether or not any is superior to the others with regard to clinical usefulness and predictive accuracy.

Purpose: To compare the costs associated with ultrasound (US)-guided hospital-based (UGHB), CT-guided hospital-based (CTG), and US-guided office-based (UGOB) percutaneous renal biopsy (PRB) for small renal masses (SRMs)., Methods: We retrospectively analyzed patient demographics, tumor characteristics, R.E.N.A.L. nephrometry scores, and cost data of patients undergoing PRB for SRM at our institution from May 2012 to September 2015. Cost data, including facility costs, professional fees, and pathology, were obtained from the departments of urology, radiology, and pathology., Results: A total of 78 patients were included in our analysis: 19, 31, and 28 UGHB, CTG, and UGOB, respectively. There was no difference in age, gender distribution, or tumor size among the three groups (p-values 0.131, 0.241, and 0.603, respectively). UGOB tumors had lower R.E.N.A.L. nephrometry scores (p=0.008). There were no differences in nondiagnostic rates between the UGHB, CTG, and UGOB groups [4 (21%), 5 (16%), and 6 (21%)] (p=0.852). There were no differences in final tumor treatment strategies utilized among the UGHB, CTG, and UGOB groups (p=0.447). There were 0, 2 (6%), and 0 complications in the UGHB, CTG, and UGOB biopsy groups. Total facility costs were $3449, $3280, and $1056 for UGHB, CTG, and UGOB PRB, respectively (p<0.0001). There was no difference between the urologist's and radiologist's professional fees (p=0.066). Total costs, including facility costs, pathology fees, and professional fees, were $4598, $4470, and $2129 for UGHB, CTG, and UGOB renal biopsy, respectively (p<0.0001)., Conclusion: For select patients with less anatomically complex, exophytic, and posteriorly located tumors, UGOB PRB provides equivalent diagnostic and complication rates while being significantly more cost-effective than either UGHB or CTG renal biopsy.

Introduction: Several holmium:YAG laser fibers for urologic applications are currently commercially available. We compared contemporary holmium laser fibers with different core sizes for performance characteristics, including energy transmission, fiber failure, fiber flexibility, and core diameter., Methods: Single-use fibers from Cook, Boston Scientific, and Storz were tested in small (200 and 272/273 μm), medium (365 μm), and large (550 and 940/1000 μm) core sizes. Fibers were tested in straight and deflected configurations. All fibers were evaluated for flexibility, true fiber diameter, energy transmission, and fiber failure. For energy transmission, fibers were tested at a pulse energy of 1 J and a frequency of 10 Hz for 30 seconds. All tests were performed on a 30 W holmium laser., Results: For the small core fibers, Storz, Cook OptiLite, and Smart Sync had the smallest core diameter (p < 0.005). In the large core group, Cook OptiLite and Boston Scientific AccuMax showed the smallest diameter. Among the small core fibers, Storz and Cook Smart Sync showed a significant higher deflection, whereas in the 550 μm group, Boston Scientific AccuMax and Cook Smart Sync were the most flexible fibers. In the large and medium core groups, Boston Scientific AccuMax showed superior energy transmission (p = 0.007 and p = 0.001, respectively), whereas in the small core group, there was no significant difference between the fibers, except for 272/3 μm (Storz was inferior compared with the competitors [p < 0.0005]). For fiber failure, Storz, Cook OptiLite, and BS AccuTrac completed all testing without failing (200 μm, bending radius <0.5 cm). In the 365 μm group, Cook OptiLite showed superior results, whereas in the large core group, Boston Scientific AccuMax was superior., Conclusions: Performance characteristics differ significantly between different laser fiber diameters and manufacturers, and fiber choice should depend on specific surgical requirements. There is a trend for less fiber fracture at long pulse, high energy, and low frequency, but this finding will require further investigation.

Purpose: To report chronological trends and geographical distributions related to the prevalence of hyperoxaluria in stone-forming patients., Materials and Methods: We systematically reviewed the existing literature between 1982 and 2013 seeking studies that assessed for hyperoxaluria (>45 mg/day [499.5 μmol/24 hour]) in recurrent stone formers. Studies that performed 24-hour urine analysis for urine oxalate in patients with recurrent urinary stones were included. Studies were divided chronologically and by geographical region, and prevalence rates of hyperoxaluria were compared between groups., Results: Our literature search provided 22 peer-reviewed articles involving 3636 patients in total. Ten studies were performed between 1982 and 2000, and 12 studies were performed between 2001 and 2013. The prevalence of hyperoxaluria in stone-forming patient cohorts was 24.8% and 45.1% (p = 0.019) in studies performed between 1982 and 2000 and 2001 and 2013, respectively. Hyperoxaluria rates were significantly higher in non-American cohorts compared with American cohorts (40.7% vs 23.0%; p = 0.018). Reported hyperoxaluria rates were higher in Asian countries compared with Western countries (56.8% and 23.8%; p < 0.001)., Conclusions: The prevalence of hyperoxaluria in stone-forming patients has increased over the past two decades and may be a contributing factor to the rising global prevalence of urolithiasis. A geographical disparity in hyperoxaluria may exist between Asian and Western countries. Future studies are needed to explain these trends and their consequences.

Objectives: To establish patterns of anatomic changes relevant to the kidney and colon during positional change between the supine and prone positions as noted on CT scans performed during percutaneous cryoablation for renal cortical neoplasms (RCN)., Methods: Nineteen patients undergoing percutaneous cryoablation for RCN with abdominal CT scan in both the supine and prone positions were included in the study. We documented the anterior/posterior, medial/lateral, and cranial/caudal anatomic changes of the kidney, kidney rotation, and the proportion of the kidney whose access was limited by the liver, spleen, and lung. We also calculated the length of the percutaneous access tract and the distance between the colon and kidney in hilar position as well as the anterior/posterior location of the colon relative to the kidney., Results: In the prone position, the kidney lies significantly more anteriorly on both sides: 4.7 cm vs 4.3 cm (L) and 4.4 cm vs 4.1 cm (R) (p = 0.02 and p = 0.03, respectively). On prone CT images, both kidneys are more cranial when compared with the supine position: 80.4 mm vs 60.8 mm (L) and 87.2 mm vs 57.4 mm (R) (p = 0.002 and p < 0.001, respectively). The skin to tumor distance is significantly shorter in the prone position (p < 0.0001 [L], p = 0.005 [R]). The colon lies closer to the hilum of the kidney and is more posteriorly located in the prone position: 1.21 cm vs 1.04 cm (L) and 0.80 cm vs 0.70 cm (R) (p = 0.005 and p = 0.005, respectively). In the prone position, the lung covers a significantly larger proportion of the right kidney (27.3 mm vs 6.05 mm, p = 0.0001)., Conclusions: We documented clinically significant anatomic alterations between supine and prone CT imaging. The changes associated with the prone position modify percutaneous access, particularly for right upper pole tumors. Prone imaging before surgery may be helpful in selected cases.

Purpose: We compared the flow characteristics of novel three-dimensional (3D) printed ureteral stents with four conventional double-pigtail stents in an ex vivo porcine model., Materials and Methods: In six ex vivo porcine urinary systems with kidneys and ureters intact, we deployed a 5F occlusion catheter in an interpolar calix. We tested each system with antegrade irrigation with a 0.9% saline bag placed 35 cm above the renal pelvis. We evaluated four standard stents (6F Universa® Soft, 7F Percuflex,™ 7/10F Applied Endopyelotomy, 8.5F Filiform Double Pigtail) and compared them with a 9F 3D printed prototype stent. For each stent, we measured the total, extraluminal, and intraluminal flow rates., Results: The mean total flow rates for 3D printed stents were significantly higher than the 6F, 7F, and 7/10F stents (P<0.05). No significant difference was seen in the total flow rate for the 3D printed stent and the 8.5F stent. The mean extraluminal flow rates for the 3D stents were similar to those of 7F stents, but significantly lower than 6F stents (P<0.001) and 8.5F stents (P<0.05) and higher than 7/10F stents (P<0.001). The mean intraluminal flow rates for the 3D printed stents were significantly higher than the 6F, 7F, 7/10F, and 8.5F stents (P<0.05)., Conclusions: In this pilot study, 3D printed stents manifested a mean total flow rate comparable to the flow rates of contemporary stents. Continued advances in technology and material may permit functionally feasible 3D printed ureteral stents.

Purpose: To evaluate the ignition and burn risk associated with contemporary fiberoptic and distal sensor endoscopic technologies., Materials and Methods: We used new and used SCB Xenon 300 light sources to illuminate a 4.8 mm fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, rigid cystoscope, semirigid ureteroscope, flexible cystoscope, flexible fiberoptic ureteroscope, distal sensor cystoscope, and a distal sensor ureteroscope (Karl Storz, Inc., Tuttlingen, Germany). We measured peak temperatures at the distal end of each device. We then evaluated each device on a flat and folded surgical drape to establish ignition risk. Finally, we evaluated the effects of all devices on human cadaver skin covered by surgical drape., Results: Peak temperatures recorded for each device ranged from 26.9°C (flexible fiberoptic ureteroscope) to 194.5°C (fiberoptic cable). Drape ignition was noted when the fiberoptic cable was placed against a fold of drape. Contact with the fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, and distal sensor cystoscope resulted in cadaver skin damage. Cadaver skin damage occurred despite little or no visible change to the surgical drape. Rigid and flexible fiberoptic cystoscopes and flexible fiberoptic ureteroscopes had no effect on surgical drapes or cadaver skin., Conclusions: Fiberoptic light cables and some endoscopic devices have the potential to cause thermal injury and drape ignition. Thermal injury may occur without visible damage to drapes. Surgeons should remain vigilant regarding the risks associated with these devices and take necessary safety precautions to prevent patient injury.

Purpose: Small renal masses (SRM) can be managed via a variety of nephron-sparing procedures (NSPs), but the association between choice of NSP and renal parenchymal volume (RPV) preservation is not well understood. We sought to examine RPV preservation after partial nephrectomy (PN) performed via open, robotic, or laparoscopic approaches and thermal ablation (TA) performed via cryoablation (CA) or radiofrequency ablation (RFA)., Patients and Methods: The study was a retrospective review of three institutional databases of patients with a SRM <4 cm treated via one of the five NSPs (open PN, laparoscopic PN, robotic PN, percutaneous CA, or percutaneous RFA). The 30 most recent consecutive cases treated via each NSP were selected to obtain a total of 150 cases for analysis. Patient characteristics were obtained via manual chart review, and tumor characteristics were assessed via the R.E.N.A.L. nephrometry score. Using three-dimensional rendering software, preoperative and postoperative RPV was calculated for the tumor-bearing kidney, excluding the tumor itself (for preoperative images) or the postsurgical/ablative defect (for postoperative images). The percent change in RPV was compared between the procedure types., Results: One hundred fifty cases were included in the final analysis, with 30 cases from each NSP category. While preoperative tumors were larger in the PN group, there was no difference in the mean nephrometry score between groups. The TA group was found to have a lower mean RPV loss (-8.1% vs -16.5%, p<0.005). There was no difference in the RPV loss between modalities of TA (CA vs RFA) or between approaches to PN (open, laparoscopic, robotic). Matched-pair analysis based on the tumor size and multivariate analysis indicated TA vs PN was independently associated with less RPV loss., Conclusions: TA is associated with less RPV loss than PN in the management of SRM, but there is no difference between modalities of TA (CA vs RFA) or between approaches to PN.

Introduction: Recent advances in three-dimensional (3D) printing technology have made it possible to print surgical devices. We report our initial experience with the printing and deployment of endoscopic and laparoscopic equipment., Materials and Methods: We created computer-aided designs for ureteral stents and laparoscopic trocars using SolidWorks. We developed three generations of stents, which were printed with an Objet500 Connex printer, and a fourth generation was printed with an EOSINT P395 printer. The trocars were printed with an Objet30 Pro printer. We deployed the printed stents and trocars in a female cadaver and in vivo porcine model. We compared the printed trocars to two standard trocars for defect area and length using a digital caliper. Paired T-tests and ANOVA were used to test for statistical difference., Results: The first two generations of stents (7F and 9F) were functional failures as their diminutive inner lumen failed to allow the passage of a 0.035 guidewire. The third generation 12F stent allowed passage of a 0.035 guidewire. The 12F diameter limited its deployment, but it was introduced in a cadaver through a ureteral access sheath. The fourth-generation 9F stents were printed and deployed in a porcine model using the standard Seldinger technique. The printed trocars were functional for the maintenance of the pneumoperitoneum and instrument passage. The printed trocars had larger superficial defect areas (p<0.001) and lengths (p=0.001) compared to Karl Storz and Ethicon trocars (29.41, 18.06, and 17.22 mm(2), respectively, and 14.29, 11.39, and 12.15 mm, respectively)., Conclusions: In this pilot study, 3D printing of ureteral stents and trocars is feasible, and these devices can be deployed in the porcine and cadaver models. Three-dimensional printing is rapidly advancing and may be clinically viable in the future.

Objective: To determine the preoperative and perioperative predictive factors of morbidity/mortality in patients undergoing percutaneous nephrolithotomy (PCNL), using the Clavien's classification., Materials and Methods: We performed a retrospective chart review of patients who underwent PCNL between January 2005 and January 2012. Preoperative and postoperative factors, such as age, obesity, surgical risk, Charlson comorbidity index, stone complexity, access calix, type of dilator used, and surgery time, were evaluated as predictors of complications., Results: A total of 354 patients were included in the study. Of these, 56% were women, with the average age of 47±12.5 years. Stone-free rate for noncomplex calculi was 85% and for complex calculi it was 68%. A total of 103 complications were recorded (29.3%). According to the modified Clavien classification system, 32 (9%) were grade 1, 39 (11%) were grade 2, 16 (4.5%) were grade 3A, 8 (2.3%) were grade 3B, 3 (0.8%) were grade 4A, 1 (0.3%) was grade 4B, and 4 (1.1%) were grade 5. In multivariate analysis female gender (odds ratio [OR] 3.1, confidence interval [CI] 1.1-8.0), Charlson score of ≥3 (OR 23.2, CI 3.5-151.1), complex stone (OR 4, CI 1.6-9.6), and duration of surgery of ≥120 minutes (OR 2.9, CI 1.2-6.9) were associated with major complications., Conclusions: PCNL is a safe procedure with acceptable efficacy for the resolution of renal calculi. The safety of the procedure should improve, especially to reduce the presence of severe complications (Clavien ≥3). We identified factors that are associated with severe complications: female gender, high Charlson, complex calculi, and surgical length ≥120 minutes.

Introduction: The aim of this in vitro study was to evaluate and compare a novel intracorporeal lithotripter, LithAssist (LA; Cook Medical, Bloomington, IN), with the Swiss LithoClast Ultra (SLU; Boston Scientific, Boston, MA) for the fragmentation and removal of artificial stones made of gypsum-based cement., Materials and Methods: Ten soft and 20 hard ultracal-30 (U-30) stones were fragmented using two lithotripters. We recorded the stone weight (grams) prior to placing them into a 60-mL syringe for fragmentation. We inserted a 30F percutaneous access sheath into the syringe and positioned the stone within its lumen. Next, we inserted the lithotripter into a right-angled nephroscope. We recorded the times required for first and complete stone disintegration, disintegration to 2 mm, and complete stone removal for each device. In addition, we recorded the stone mass following each minute of stone fragmentation., Results: In total, we subjected 5 soft and 10 hard stones to SLU and LA, respectively. All soft stones were completely disintegrated and removed with both the SLU and LA device. For soft stones, disintegration to 2 mm (2.83±0.41 vs. 4.15±0.70 minutes, p=0.049), complete disintegration (3.18±0.20 vs. 6.40±1.95 minutes, p=0.038), and complete removal (3.30±0.22 vs. 8.82±1.05 minutes, p=0.001) were faster for the SLU compared with the LA. For hard stones, fragmentation was not accomplished with the SLU, whereas with the LA, mean time for first disintegration, disintegration to 2 mm, complete disintegration, and complete removal was 3.60±1.36, 7.25±3.33, 7.54±2.94, and 8.64±2.78 minutes, respectively., Conclusions: In this in vitro study, the SLU was more efficient for softer artificial stones, and the LA was more efficient for harder artificial stones.

Purpose: The aim of this study was to evaluate and compare a novel trocars-site closure device, the WECK EFx™ Endo Fascial Closure System (EFx) with the Carter-Thomason CloseSure System® (CT) for the closure of laparoscopic trocar site defects created by a 12-mm dilating trocar., Methods: We created standardized laparoscopic trocars-site abdominal wall defects in cadaver models using a standard 12-mm laparoscopic dilating trocar. Trocar defects were closed in a randomized fashion using one of the two closure systems. We recorded time and number of attempts needed for complete defect closure. In addition, we recorded the ability to maintain pneumoperitoneum, endoscopic visualization, safety, security, and facility based on the surgeon's subjective evaluations. We compared outcomes for the EFx and CT closure systems., Results: We created 72 standardized laparoscopic trocars-site abdominal wall defects. The mean time needed for complete defect closure was 98.53 seconds (±28.9) for the EFx compared with 133.61 seconds (±54.61) for the CT (P<0.001). The mean number of attempts needed to achieve complete defect closure were 1.19 (1-3) for the EFx and 1.19 (1-2) for the CT (P=0.50). Mean scores for safety were 2.92 for EFx vs 2.19 for CT (P<0.001). Mean scores for facility were 2.97 vs 1.83 for EFx and CT, respectively (P<0.001). Mean scores for maintenance of pneumoperitoneum were 1.97 for EFx vs 2.33 for CT (P=0.022). No significant difference was observed between the EFx and the CT systems for endoscopic visualization (2.28 vs 2.50, P=0.080)., Conclusions: In this in vitro cadaver trial, the EFx was superior in terms of time needed to complete defect closure, safety, and facility. CT was superior in terms of maintenance of pneumoperitoneum. Both systems were equal in the number of attempts needed to complete the defect closure and endoscopic visualization.

Objectives: To present our experience demonstrating the feasibility of off-clamp laparoscopic partial nephrectomy (LPN) for hilar tumors and evaluate intermediate oncologic and renal functional outcomes., Patients and Methods: A retrospective review of LPN cases in nine patients was performed. Hilar lesions were defined as renal cortical tumors in direct physical contact with the renal artery, vein, or both as identified on preoperative imaging and confirmed intraoperatively. Although the renal hilum vasculature was isolated for possible clamping if needed, tumor extirpation was performed off-clamp, eliminating warm ischemia time (WIT). The clinicopathologic parameters, perioperative course, complications, and long-term oncologic and renal functional outcomes were analyzed., Results: Nine patients underwent off-clamp LPN for complex hilar tumors. The mean age was 60.5 years, mean American Society of Anesthesiologists physical classification (ASA) score was 2, and mean BMI was 27.7 kg/m(2). The mean tumor size and volume were 3.2 cm and 35.8 cm(3), respectively. A greater proportion of the tumors (55.6%) were endophytic and mostly of clear cell histology (78%). The mean operative time was 131 minutes, estimated blood loss 250 cc, need for transfusion 0%, and complication rates 22%. No positive margins were present intraoperatively or on final pathology. After a median follow-up of 42.8 months, there was no evidence of clinical or radiographic recurrence in any patient. There was no change in the mean estimated glomerular filtration rate preoperatively and at a median follow-up of 32 months (97.2 mL/minute vs 81.3 mL/minute; p=0.052)., Conclusion: Complex renal hilar tumors can be successfully managed with laparoscopic nephron-sparing surgery with elimination of WIT with preservation of perioperative, renal functional, and oncologic outcomes.

Introduction: Recent technological advancements have led to the introduction of new three-dimensional (3D) cameras in laparoscopic surgery. The 3D view has been touted as useful during robotic surgery, however, there has been limited investigation into the utility of 3D in laparoscopy., Materials and Methods: We performed a prospective, randomized crossover trial comparing a 0° 3D camera with a conventional 0° two-dimensional (2D) camera using a high definition monitor (Karl Storz, Tuttlingen, Germany). All participants completed six standardized basic skills tasks. Quality testing scores were measured by the number of drops, grasping attempts, and precision of needle entry and exiting. Additionally, resolution, color distribution, depth of field and distortion were measured using optical test targets., Results: In this pilot study, we evaluated 10 medical students, 7 residents, and 7 expert surgeons. There was a significant difference in the performance in all the six skill tasks, for the three levels of surgical expertise and training levels in 2D vs 3D except for the cut the line quality score and the peg transfer quality score. Adjusting for the training level, 3D camera image results were superior for the number of rings left (p=0.041), ring transfer quality score (p=0.046), thread the rings (no. of rings) (p=0.0004), and thread the rings quality score (p=0.0002). The 3D camera image was also superior for knot tying (quality score) (p=0.004), peg transfer (time in seconds) (p=0.047), peg transfer pegs left (p=0.012), and for peg transfer quality score (p=0.001). The 3D camera system showed significantly less distortion (p=0.0008), a higher depth of field (p=0.0004) compared with the 2D camera system., Conclusion: 3D laparoscopic camera equipment results in a significant improvement in depth perception, spatial location, and precision of surgical performance compared with the conventional 2D camera equipment. With this improved quality of vision, even expert laparoscopic surgeons may benefit from 3D imaging.

Purpose: To assess the reliability of the S.T.O.N.E. (stone size [S], tract length [T], obstruction [O], number of involved calices [N], and essence or stone density [E]) nephrolithometry scoring system by testing its reproducibility between different observers., Patients and Methods: Preoperative images of 58 patients who underwent percutaneous nephrolithotomy (PCNL) were reviewed. Medical students, urology residents, one fellow, and a urology attending independently reviewed all images and scored the renal stones. Interobserver reliabilities of the total score for all categories and each component were evaluated by the intraclass correlation (ICC) and a κ coefficient., Results: The interobserver reliability for the total score demonstrated high correlations for all components and total score (ICC=S, T, O, N, E and total 0.80, 0.97, 0.89, 0.84, 0.91, and 0.87, respectively). κ rates for individual components between two medical students were 0.36, 1, 0.31, 0.45, 0.33, and 0.30 for the S, T, O, N, E components and total score, respectively. κ values between the two urology residents were 0.71, 1, 0.92, 0.79, 0.93, and 0.67 for S, T, O, N, E components and total score, respectively. κ values between the urology fellow and an attending physician were 0.95, 1, 0.88, 0.94, 0.89, and 0.87 for S, T, O, N, E components and total score, respectively. P value for all the scoring components was <0.05, indicating that the estimated κ was not a result of chance., Conclusions: The S.T.O.N.E. nephrolithometry has excellent interobserver reliability. Quantifying the S and N metrics was the most challenging and least reliable. Standardized protocols to measure these components should be considered to improve accuracy and reproducibility of the scoring system.

Background and Purpose: Urologists are becoming increasingly aware of the importance of pretreatment percutaneous renal biopsy of small renal cortical neoplasms. A barrier to the routine performance of ultrasonography-guided percutaneous renal biopsy has been the technical challenges associated with the procedure. We evaluated a new modified needle, which incorporates an echogenic needle tip designed to improve the needle tip's visibility under ultrasonographic visualization. We evaluated and compared the ultrasonographic imaging quality of the echogenic needle (EN) and a standard needle (SN)., Methods: Forty-eight participants were recruited to perform ultrasonography-guided needle targeting and drainage of a simulated cyst within a phantom model. The simulated cysts were embedded in an opaque gel mold. Each participant was blinded to the type of needle being deployed and was asked to identify and aspirate the simulated cyst with each needle under ultrasonography guidance. Each needle was tested at three ultrasound-aiming angles, (0, 15, and 30 degrees). The quality of needle visibility under ultrasonographic imaging was assessed via a questionnaire, including needle preference and a visibility score (1-10) at each aiming angle. Participants were stratified by level of ultrasound experience., Results: For each angle tested, the EN received higher visibility ratings. The mean visibility scores for the EN vs the SN were 6.44 vs 5.52 at 0 degrees (P=0.001), 7.77 vs 6.96 at 15 degrees (P=0.0004) and 8.33 vs 7.54 at 30 degrees (P=0.0001). Participants reported significantly greater comfort using the EN needle compared with the SN (P=0.001). These results held true regardless of the sequence of needle tested first. Also, there was a significant difference in visibility scores by angle (P=0.0001). Larger angles (30>15>0) resulted in higher scores., Conclusions: In this in vitro trial, the application of the EN improved needle visibility for users of all levels of experience. Clinical correlation is pending.

Background and Purpose: Recent advances in distal sensor technologies have made distal sensor ureteroscopes both commercially and technically feasible. We evaluated performance characteristics and optics of a new generation distal sensor Flex-X(C) (X(C)) and a standard flexible fiberoptic ureteroscope Flex-X(2) (X(2)), both from Karl Storz, Tuttlingen, Germany., Materials and Methods: The ureteroscopes were compared for active deflection, irrigation flow, and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, and color representation) were measured using United States Air Force test targets. We digitally recorded a renal porcine ureteroscopy and laser ablation of a stone with the X(2) and with the X(C). Edited footage of the recorded procedure was shown to different expert surgeons (n=8) on a high-definition monitor for evaluation by questionnaire for image quality and performance., Results: The X(C) had a higher resolution than the X(2) at 20 and 10 mm 3.17 lines/mm vs 1.41 lines/mm, 10.1 vs 3.56, respectively (P=0.003, P=0.002). Color representation was better in the X(C). There was no difference in contrast quality between the two ureteroscopes. For each individual ureteroscope, the upward deflection was greater than the downward deflection both with and without accessories. When compared with the X(2), the X(C) manifested superior deflection and flow (P<0.0005, P<0.05) with and without accessory present in the working channel. Observers deemed the distal sensor ureteroscope superior in visualization in clear and bloody fields, as well as for illumination (P=0.0005, P=0.002, P=0.0125)., Conclusions: In this in vitro and porcine evaluation, the distal sensor ureteroscope provided significantly improved resolution, color representation, and visualization in the upper urinary tract compared with a standard fiberoptic ureteroscope. The overall deflection was also better in the X(C), and deflection as well as flow rate was less impaired by the various accessories.

Background and Purpose: Surgical management of a renal neoplasm in a solitary kidney is a balance between oncologic control and preservation of renal function. We analyzed patients with a renal mass in a solitary kidney undergoing nephron-sparing procedures to determine perioperative, oncologic, and renal functional outcomes., Patients and Methods: A multicenter study was performed from 12 institutions. All patients with a functional or anatomic solitary kidney who underwent nephron-sparing surgery for one or more renal masses were included. Tumor size, complications, and recurrence rates were recorded. Renal function was assessed with serum creatinine level and estimated glomerular filtration rate., Results: Ninety-eight patients underwent 105 ablations, and 100 patients underwent partial nephrectomy (PN). Preoperative estimated glomerular filtration rate (eGFR) was similar between the groups. Tumors managed with PN were significantly larger than those managed with ablation (P<0.001). Ablations were associated with a lower overall complication rate (9.5% vs 24%, P=0.01) and higher local recurrence rate (6.7% vs 3%, P=0.04). Eighty-four patients had a preoperative eGFR ≥60 mL/min/1.73 m(2). Among these patients, 19 (23%) fell below this threshold after 3 months and 15 (18%) at 12 months. Postoperatively, there was no significant difference in eGFR between the groups., Conclusions: Extirpation and ablation are both reasonable options for treatment. Ablation is more minimally invasive, albeit with higher recurrence rates compared with PN. Postoperative renal function is similar in both groups and is not affected by surgical approach.

Purpose: To analyze preoperative predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy., Patients and Methods: We retrospectively reviewed data from 397 consecutive semirigid ureteroscopic lithotripsies performed in 389 patients with ureteral stones at our institution during the calendar year 2010. Preoperative patient-related variables (age, sex, body mass index, history of urinary tract infection, previous stent placement, and time from initial presentation to intervention) and stone-related variables (laterality, numbers, location, width, and degree of hydronephrosis) were collected. Univariate analysis and multivariate logistic regression were performed to examine the statistical association between these variables and the use of intraoperative balloon ureteral dilation., Results: Intraoperative balloon dilation was performed in 109 (27.5%) procedures. Univariate analysis identified increasing stone width (P<0.001) and lack of previous stent placement (P<0.001) as preoperative predictors of intraoperative balloon dilation. Stone width (P<0.001, odds ratio [OR] 1.274, 95% confidence interval [CI] 1.147-1.415) and lack of previous stent placement (P<0.001, OR 0.025, CI 0.006-0.105) remained independently associated with intraoperative balloon dilation in multivariate logistic regression., Conclusions: To our knowledge, our study is the first to statistically analyze the potential predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy. Larger stone width was significantly associated with intraoperative balloon dilation, whereas the presence of an indwelling ureteral stent, for at least 1 week, nearly eliminated the need for balloon dilation in subsequent ureteroscopic lithotripsy.

Background and Purpose: With the increasing detection of small renal cortical neoplasms (RCNs), the preoperative prediction of histopathology has become increasingly important. Because perirenal fat (PF) is known to be metabolically active, we evaluated PF as a predictor of renal tumor histopathology., Patients and Methods: We retrospectively evaluated patients who underwent laparoscopic nephron-sparing procedures for cT(1a) RCN at two institutions. PF was measured using the digital measuring tool function on standard imaging software, at the level of the renal hilum as the perpendicular distance between the posterior surface of the kidney and the external margin of the psoas muscle. The Mann-Whitney test and logistic regression were used to examine PF, selected demographic, clinical, and operative parameters, and their association with tumor histopathology., Results: Data from 250 patients were included in this study. There were 157 (63%) men and 93 (37%) women with a median body mass index (BMI) of 28 kg/m(2). Median tumor size was 2.4 cm, and the median PF distance was 12 mm. Significant correlations were noted between PF and sex and BMI. No significant correlations were found between PF and the operative parameters. Results of a multivariate logistic regression analysis revealed that PF (P<0.01), age (P<0.04), and tumor location (P<0.04) were significant predictors of clear-cell renal-cell carcinoma (RCC) histopathology., Conclusions: In this study, PF, location of tumor, and age were significant predictors of clear-cell RCC histopathology. The correlation of PF and histopathology may be useful in preoperative decision-making and surgical planning in the management of small RCN.

Purpose: To evaluate the feasibility of a novel transvesical port (TVEP) for natural orifice translumenal endoscopic surgery (NOTES) in the porcine model., Materials and Methods: The TVEP consisted of an internal guide core and external sheath design using computer-aided design software. Transvesical peritoneoscopy, renal biopsy, as well as combined transvesical/transgastric nephrectomy were performed through the TVEP in a porcine model. Operative parameters and port performance were measured., Results: Twelve procedures were successfully performed by four surgeons. No complications occurred with introduction of the TVEP. The mean time for placement was 5.6 minutes. Steady pressure controlled CO(2) pneumoperitoneum up to 15 mm Hg with a flow of 2 L/min was achievable. The average scoring by physician of the TVEP was 4.75 for ease of placement, 5 for ability to maintain pneumoperitoneum, 4.25 for convenience of inserting instruments, and 4.5 for overall satisfaction. The average score regarding instruments exchangeability, however, was relatively low: 3.25., Conclusions: Real surgery using a novel TVEP is feasible in performing transvesical NOTES.