Prospective, Randomized Comparison of Dual-Lumen vs Single-Lumen Flexible Ureteroscopes in Proximal Ureteral and Renal Stone Management.

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 mm3/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.

Prospective Randomized Evaluation of Idiopathic Hyperoxaluria Treatments.

Purpose: Calcium oxalate (CaOx) stone formation is influenced by urinary oxalate excretion. Stone formers with elevated urinary oxalate are commonly prescribed a low-oxalate diet or oral supplementation with vitamin B6 and magnesium to reduce urinary oxalate excretion. This study aims to compare the effects of dietary modification vs supplementation vs a combination of both on urinary oxalate. Materials and Methods: We enrolled patients with a documented history of CaOx stones and newly diagnosed idiopathic hyperoxaluria. Patients were randomized into three treatment groups: low oxalate diet (D), supplementation with 25 mg vitamin B6 and 400 mg magnesium oxide (S), or both low oxalate diet and B6/magnesium supplementation (DS). Baseline and 3-month postintervention 24-hour urine tests were obtained. The primary endpoint was change in 24-hour urinary oxalate (Ox24) at 12 weeks. Secondary endpoints included changes in other 24-hour urine parameters, compliance rates, and adverse effect rates. Results: In total, 164 patients were recruited and 62, 47, and 55 were enrolled into the D, S, and DS groups, respectively. Of these, 99 patients completed the study (56.5% of the D, 72.3% of the S, and 54.6% of the DS groups, respectively). Significant differences were noted in median percent reduction in Ox24 values (-31.1% vs -16.0% vs -23.9%, p = 0.007) in the D, S, and DS groups, respectively. Furthermore, the percentages of patients within each treatment arm who realized a decrease in Ox24 were also found to be significantly different: D = 91.4% vs. S = 67.6% vs DS = 86.7%, p = 0.027. No significant adverse events were observed in any of the study arms. Conclusion: Low oxalate diet is more effective than B6/magnesium supplementation at lowering urinary oxalate in idiopathic hyperoxaluric stone formers. Combination therapy did not produce greater reductions in urinary oxalate than either of the monotherapy arms suggesting it is of little clinical utility. Further study with long-term longitudinal follow-up is required to determine if these treatment strategies reduce recurrent stone events in this population.

Interactive Virtual Reality Renal Models as an Educational and Preoperative Planning Tool for Laparoscopic Donor Nephrectomy.

OBJECTIVE: To evaluate the efficacy of interactive virtual reality (iVR) in providing a three-dimensional (3D) experience with the donor's anatomy for surgeons and patients, we present a retrospective, case-controlled study assessing the impact of iVR renal models prior to LDN on both surgical outcomes and patients' understanding of the procedure. MATERIALS AND METHODS: Twenty patients undergoing LDN were prospectively recruited; their contrast-enhanced CT scans were transformed into iVR models. An iVR platform allowed the surgeons to rotate and deconstruct the renal anatomy; patients could also view their anatomy as the procedure was explained to them. Questionnaires assessed surgeons' understanding of renal anatomy after CT alone and after CT+iVR. Surgeons also commented on whether iVR impacted their preoperative plan. Patients assessed their anatomical understanding and anxiety level before and after iVR. Surgical outcomes for the iVR cohort were compared to a retrospectively matched, non-iVR cohort of LDN patients. RESULTS: Surgeons altered their preoperative plan in 18 of 20 LDNs after viewing iVR models. Patients reported better understanding of their anatomy (5/5) and noted decreased preoperative anxiety (5/5) after viewing iVR. When compared to the non-iVR group, the iVR group had a 25% reduction in median operative time (P < .001). In terms of surgical outcomes, patients in the iVR group had a 40% lower median relative change in postoperative creatinine (P < .001). CONCLUSION: Preoperative viewing of iVR models altered the operative approach, decreased the operative time, and improved donor patient outcomes. iVR models also reduced patients' preoperative anxiety.

Comparison of Conventional and Triple Bolus Computerized Tomographic Urography Protocols for Radiation Dose Reduction in Hematuria Evaluation: A Randomized Controlled Trial.

PURPOSE: Computerized tomographic urography is the diagnostic tool of choice for evaluating hematuria. In keeping with the ALARA (As Low As Reasonably Achievable) principle, we evaluated a triple bolus computerized tomography protocol designed to reduce radiation exposure. MATERIALS AND METHODS: Patients with macroscopic or microscopic hematuria were prospectively randomized to conventional computerized tomography (100) or triple bolus computerized tomography (100). The triple bolus computerized tomography protocol entails 2 scans: pre-contrast scan followed by 3 contrast injections at 40 seconds, 60 seconds and 20 minutes prior to the second scan to capture all 3 phases. The conventional computerized tomography protocol requires 4 scans: pre-contrast scan, and 3 post-contrast scans at the corticomedullary, nephrographic and excretory phases. Radiation exposure and the detection of urological pathology were recorded based on radiology reports. RESULTS: There were no differences in patient demographics or body mass index between the 2 groups. Triple bolus computerized tomography exposed patients to 33% less radiation (1,715 vs 1,145 mGy*cm for conventional vs triple bolus computerized tomography; p <0.001). For macroscopic hematuria, the pathology detection rates were 70% for triple bolus and 73% for conventional computerized tomography (p=0.72). For microscopic hematuria, the detection rates were 59% for triple bolus and 50% for conventional computerized tomography (p=0.68). In both groups, the rates of detection of urolithiasis, renal cysts, urological masses, bladder pathology and prostate pathology were no different between triple bolus and conventional computerized tomography. CONCLUSIONS: In both the settings of macroscopic and microscopic hematuria evaluation, triple bolus computerized tomography significantly reduces radiation exposure while providing equivalent detection of genitourinary pathology compared to conventional computerized tomography. The ability to detect upper tract filling defects was not specifically tested.

Evaluating the Quality of Online Health Information about Prostate Cancer Treatment.

INTRODUCTION: Prostate cancer is the second most common cancer in men. It is common for patients to search the Internet before and after urological consultation to better understand their diagnoses. Unfortunately, online health information is largely unregulated and may be difficult for patients to comprehend. This study aims to evaluate the readability and quality of websites describing prostate cancer treatments. METHODS: Three search engines were used to search the terms "prostate cancer" and "prostate cancer treatments" to replicate a patient seeking self-education about prostate cancer; 40 websites were identified. After excluding websites with membership fees and publicly editable content, 26 websites were analyzed; 7 were marked as advertisements. Three readability formulas (Flesch-Kincaid Grade Level, Flesch-Kincaid Reading Ease, Simple Measure of Gobbledygook) were used to generate readability scores. The DISCERN standardized questionnaire was used to evaluate website quality. RESULTS: Compared to readability scores at the American Medical Association recommended seventh grade reading level, mean readability scores for the websites analyzed were significantly higher and translated to the tenth to eleventh grade reading level. The mean DISCERN score for all websites was 47, equating to "Fair" quality. Nonadvertisement websites had significantly higher scores than websites marked as advertisements, with nonadvertisements rated "Good" quality and advertisements rated "Poor" quality. CONCLUSIONS: Most websites about prostate cancer treatment are written at a reading level too advanced for a large proportion of Americans to understand. Some optimally positioned websites are advertisements that contain poor quality information. It is the responsibility of clinicians to guide their patients toward appropriate online resources.

Ureteroscopic Doppler Ultrasonography: Mapping Renal Blood Flow from Within the Collecting System.

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.

Clinical and Metabolic Correlates of Calcium Oxalate Stone Subtypes: Implications for Etiology and Management.

Introduction: Calcium oxalate (CaOx) is the predominate component within renal calculi and can be divided into two subtypes: CaOx-monohydrate (COM) and CaOx-dihydrate (COD). COM and COD form in differing urinary environments, which suggest differential underlying metabolic abnormalities associated with each subtype. We compared clinical and metabolic findings in CaOx stone formers to delineate factors differentiating COD and COM stone formers and the implication this holds in terms of etiology and treatment. Patients and Methods: We identified CaOx stone formers that had passed their stones or had undergone endoscopic extraction between October 2014 and December 2018. Only patients who had a predominant subtype (≥80% COM or COD) and who had a 24-hour urine evaluation before medical management were included. Clinical and metabolic factors were compared in the two subgroups. Results: Out of 157 stone formers, 121 were COM and 36 were COD. COD formers were younger than COM formers with a mean age of 53 ± 16 vs 59 ± 15, respectively (p = 0.038). There were no observable differences in gender, body mass index, hypertension, diabetes mellitus, or hyperlipidemia. COM formers exhibited higher rates of hypocitraturia and hyperoxaluria, p = 0.022 and p = 0.018, respectively. Conversely, COD formers had significantly higher rates of hypercalciuria (47% vs 28%, p = 0.012). Multivariate analysis found hypercalciuria to independently predict COD (p = 0.043) and hyperoxaluria to predict COM stones (p = 0.016). Conclusion: COM formers are more likely to have hyperoxaluria, hypocitraturia, and elevated urinary oxalate levels compared to COD formers. COD formers exhibited higher incidence of hypercalciuria. These data suggest that all CaOx stones are not alike and that distinct metabolic and clinical etiological differences exist that may guide future management and prevention.

Predicting the Impacted Ureteral Stone with Computed Tomography.

OBJECTIVE: To evaluate whether preoperative computed tomography (CT) findings could predict the presence of an impacted stone. Preoperative identification of an impacted ureteral stone may influence patient preparation and operative decisions. Factors predicting ureteral stone impaction have not been clearly identified. METHODS: We identified all patients from June 2014 to July 2016 that underwent ureteroscopic treatment of an impacted ureteral stone. Patients that had ureteral prestenting or previous treatment for their stone were excluded. Noncontrast CT images were reviewed to calculate stone size, stone volume, degree of hydronephrosis (0-3), and Hounsfield units (HU) of the stone as well as the ureter distal and proximal to the stone. These were compared with a control group of patients that had nonimpacted stones. RESULTS: Patients with impacted stones had a greater stone size, volume, HU of the ureter under the stone, HU under/above ratio, and degree of hydronephrosis on univariate analysis. Multivariate analysis demonstrated that HU under the stone was a significant predictor of ureteral stone impaction (odds ratio 1.17; 95% confidence interval 1.11-1.25). Distal ureteral density above 27 HU demonstrated a sensitivity of 85%, specificity of 85%, positive predictive value of 89%, and negative predictive value of 81% for ureteral stone impaction. CONCLUSION: Impacted stones are associated with ureteral density cut-off value of 27 HU or greater. Measuring this value on preoperative noncontrast CT may help predict which patients are more likely to have impacted stones.

Ureteral stenting practices following routine ureteroscopy: an international survey.

PURPOSE: Stent omission after routine ureteroscopy (rtURS) is accepted by current guidelines and may result in decreased patient morbidity and treatment costs. In a value-based healthcare model, the added morbidity and cost of routine stent placement may be scrutinized. Furthermore, data are limited on urologist cost knowledge and it is effect on ureteral stent placement. As such, we seek to describe ureteral stenting practices and urologist cost knowledge amongst US and non-US-based urologists. METHODS: The ureteroscopic practice patterns and cost awareness of members of the Endourological Society were surveyed using an international email listserv. Respondents were grouped by practice location (US vs non-US). Logistic regression was used to evaluate the associations of surgeon practice location with stenting practices. RESULTS: 233 completed responses were received with a response rate of 13.5%. Results revealed that 55% and 71% of respondents reported ureteral stent insertion after rtURS more than 75% of the time for ureteral and renal stones, respectively. Reporting stent insertion following more than 75% of rtURS was more common among US participants for both ureteral and renal stones. Overall, reported cost knowledge was high, but lower among US participants. On multivariable analysis, US respondents were more likely to place ureteral stents after rtURS for ureteral stones more than 75% of the time when compared to those abroad (OR 3.43 p < 0.01). CONCLUSION: Ureteral stenting after rtURS is over utilized in the US compared to other countries. While this phenomenon is multifactorial in nature, cost knowledge may be under recognized as a determinant of ureteral stent placement following rtURS.

A Randomized, Double-Blind, Sham-Controlled Study Assessing Electroacupuncture for the Management of Postoperative Pain after Percutaneous Nephrolithotomy.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is the gold standard procedure for large renal calculi but postoperative (PO) pain remains a concern. Modifications of the PCNL technique and intraoperative and PO strategies have been tested to reduce pain. PO pain control reducing risk of long-term pain medication and narcotic use is of considerable importance. Acupuncture is a common medical procedure shown to alleviate PO pain. Some benefits are that it is nonpharmacologic, easy to administer, and safe. The purpose of this study was to evaluate the effects of electroacupuncture (EA) on PO pain in patients undergoing PCNL. MATERIALS AND METHODS: This was a randomized, double-blind, sham-controlled study. The study was Institutional Review Board approved and performed under standard ethical guidelines. Fifty-one patients undergoing PCNL by a single surgeon were randomized to one of the three groups: true EA (n = 17), sham EA (SEA, n = 17), and no acupuncture (control, n = 17). The EA and SEA were performed by a single licensed acupuncturist <1 hour before operation. PCNL was performed without the use of intraoperative nerve block(s) or local anesthetic. Pain scores (visual analog scale [VAS]), narcotic use (morphine equivalents), and side effects were recorded at set intervals postoperatively. RESULTS: Mean VAS scores for flank and abdomen pain were lower at all time periods in the EA compared with the SEA and control groups. Mean cumulative opioid usage was lower in the EA group immediately postoperatively compared with both SEA and control groups. Two patients in the EA group did not require any PO narcotics. No differences between groups were found for PO nausea and vomiting. No adverse effects of EA or SEA were noted. CONCLUSIONS: EA significantly reduced PO pain and narcotic usage without any adverse effects after PCNL. This promising treatment for managing PO pain warrants further investigation.

Multi-institutional Evaluation of Producing and Testing a Novel 3D-Printed Laparoscopic Trainer.

OBJECTIVE: To create, distribute, and evaluate the efficacy of a portable, cost-effective 3D-printed laparoscopic trainer for surgical skills development. METHODS: The UCI Trainer (UCiT) laparoscopic simulator was developed via computer-aided designs (CAD), which were used to 3D-print the UCiT. Once assembled, a tablet computer with a rear-facing camera was attached for video and optics. Four institutions were sent the UCiT CAD files with a 3D-printer and instructions for UCiT assembly. For a comparison of the UCiT to a standard trainer, peg transfer and intracorporeal knot tying skills were accessed. These tasks were scored, and participants were asked to rate their experience with the trainers. Lastly, a questionnaire was given to individuals who 3D-printed and assembled the UCiT. RESULTS: We recruited 25 urologists; none had any 3D-printing experience. The cost of printing each trainer was $26.50 USD. Each institution used the Apple iPad for optics. Six of eight participants assembled the UCiT in < 45 minutes, and rated assembly as somewhat easy. On objective scoring, participants performed tasks equally well on the UCiT vs the conventional trainer. On subjective scoring, the conventional trainer provided a significantly better experience vs the UCiT; however, all reported that the UCiT was useful for surgical education. CONCLUSION: The UCiT is a low cost, portable training tool that is easy to assemble and use. UCiT provided a platform whereby participants performed laparoscopic tasks equal to performing the same tasks on the more expensive, nonportable standard trainer.

Pilot Assessment of Immersive Virtual Reality Renal Models as an Educational and Preoperative Planning Tool for Percutaneous Nephrolithotomy.

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.

A New Twist on an Old Technique: Lawson Retrograde Endoscopic-Guided Nephrostomy Access for Percutaneous Nephrolithotomy in Prone Split-Leg Position.

Background: A minority of urologists performing percutaneous nephrolithotomy (PCNL) achieve their own nephrostomy access. In an effort to simplify the access part of PCNL, we herein describe our initial experience with endoscopic-guided retrograde percutaneous access in the prone split-leg position. Case Presentation(s): After informed consent, a confirmed negative urine culture, and 1 week pretreatment with tamsulosin, four carefully selected PCNL patients underwent endoscopic-guided retrograde access in a prone split-leg position using the Lawson catheter. In all the four patients, we achieved endoscopic-guided retrograde upper pole access in the prone split-leg position. A single Clavien 3B complication occurred. Total fluoroscopy time for the PCNL averaged 162 seconds (51-283). Complete stone-free rate at 1 week based on CT scan was 25%, and a stone-free rate defined as <4 mm was 100%. Conclusion: Endoscopic-guided retrograde percutaneous upper pole access can be established efficiently with a modified Lawson technique in the prone split-leg position.

Renal mass biopsy: an oncological conundrum.

PURPOSE OF REVIEW: We evaluate the reasons that the majority of urologists infrequently biopsy a T1a small renal mass (SRM). RECENT FINDINGS: The majority of urologists report that a renal mass biopsy will not change their management in patients with a SRM given concerns of safety and efficacy of the biopsy. However, when comparing the safety and efficacy of SRM biopsy with neoplasms in all other major organ systems (all of which require biopsy prior to treatment), renal mass biopsy results are favorable. In addition to being safe and effective, renal mass biopsy should be more cost-effective for the healthcare system. Finally, in properly selected patients, renal mass biopsy can be performed in the urologist's office, thereby further decreasing cost. SUMMARY: Renal mass biopsy is an essential clinical tool that needs to be incorporated into the decision-making process among patients with a T1a SRM. A biopsy-driven, tissue-specific diagnosis of SRMes should become the standard of care in urology to bring us to parity with standard practice to management of lesions identified in every other organ system.

Medical impulsive therapy (MIT): the impact of 1 week of preoperative tamsulosin on deployment of 16-French ureteral access sheaths without preoperative ureteral stent placement.

INTRODUCTION AND OBJECTIVES: Medical expulsive therapy is based on pharmacologic ureteral relaxation. We hypothesized this concept may facilitate the deployment of the large 16 French (F) ureteral access sheath (UAS) when patients are intentionally pre-treated with oral tamsulosin, i.e., medical impulsive therapy. METHODS: We retrospectively analyzed our experience with UAS deployment during endoscopic-guided percutaneous nephrolithotomy in prone position in patients pre-treated for 1 week with oral tamsulosin with a contemporary untreated cohort. Between January 2015 and September 2016, seventy-seven patients without a pre-existing ureteral stent met inclusion criteria. Demographic data, tamsulosin usage, UAS size, deployment failure, ureteral injuries, stone-free rates, and complications were recorded. Univariate and multivariate analysis was conducted to assess the impact of tamsulosin on deployment of the 16F UAS. RESULTS: There was no statistical difference between the tamsulosin (n = 40) group and non-tamsulosin (n = 37) group in regard to demographic data. The tamsulosin group had a significantly higher percentage of 16F UAS deployment, 87 vs. 43% (p < 0.001), and no significant difference in ureteral injuries (p = 0.228). Univariate and multivariate analysis revealed that tamsulosin significantly increased the odds ratio (9.3 and 19.4, respectively) for successful passage of a 16F UAS. Despite a larger stone volume, there was no significant difference in computed tomography scan complete stone-free rates (29 vs. 42%; p = 0.277) at median post-operative time of only 3 days. CONCLUSIONS: In this retrospective study, 1 week of preoperative tamsulosin was associated with an increase in the deployment of a 16F UAS in patients without preoperative ureteral stent placement.

A contemporary lower pole approach for complete staghorn calculi: outcomes and efficacy.

PURPOSE: Percutaneous nephrolithotomy (PCNL) is the preferred surgical treatment for staghorn stones. Two approaches are commonly employed to gain access into the collecting system which consists of either an upper pole (UP) approach or lower pole (LP) approach. However, opinions vary on which approach offers the best access and outcome. In this study, we aim to challenge the traditional paradigm that staghorn stones are most effectively treated through a prone UP approach. We herein report our institutional experience using a prone LP access in PCNL for patients with complete staghorn stones. METHODS: Data were prospectively collected over 3 years on 473 PCNL procedures, of which 76 patients had complete staghorn calculi (five or more calyces). Operative and peri-operative outcomes were analyzed to compare a modified LP approach with the more widely accepted UP approach. RESULTS: A total of 59/76 (77.6%) patients had LP access. There was no difference in the ability of completing the surgery utilizing a single tract as opposed to multiple tracts (74.6% of LP patients vs. 76.5% of UP patients). Stone-free rates for LP and UP access were similar (74.5 versus 70.5%, respectively; p = 0.760. Complication rates were lower for LP access vs. UP access (3.4 vs. 23.5%, p = 0.02) with two pulmonary complications in the UP group. Overall median operative time was not significantly different between LP and UP access (112.0 vs. 126.0 min, p = 0.486). CONCLUSIONS: Prone LP access demonstrated similar efficacy with decreased morbidity in patients with complete staghorn calculi compared to prone UP access.

Ureteroscopic holmium laser-assisted retrograde nephrostomy access: a novel approach to percutaneous stone removal.

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy remains a challenging procedure primarily due to difficulties obtaining access. Indeed, few urologists obtain their own access due to difficulties using a fluoroscopic or ultrasonic based antegrade puncture technique. Herein we report the first experience using holmium laser energy to obtain access in a retrograde fashion. METHODS: After a pretreatment week of tamsulosin 0.4 mg/day (one center only) and following a documented sterile urine, a total of ten patients underwent retrograde holmium laser-assisted endoscopic-guided nephrostomy access in a prone split leg position. RESULTS: In nine of ten patients, ureteroscopic guided, holmium laser access via an upper pole posterior calyx was achieved. In one patient, the laser tract could not be safely dilated and antegrade endoscopic and fluoroscopic guided access was performed. The mean operative time was 202 min; the mean fluoroscopy time was 32 s (6/9 cases). The mean pre-operative stone volume was 14,420 mm3. CT imaging on post-operative day 1 revealed 6/6 patients had residual stone fragments with total mean volume of 250 mm3 (96% reduction); there were no residual fragments in three patients who were evaluated with non-CT radiographic imaging (KUB). There was a single complication requiring angioembolization due to a subcapsular hematoma with associated secondary tearing of an inter-polar vessel remote from the nephrostomy site. CONCLUSIONS: Holmium laser-assisted endoscopic-guided retrograde access in a prone split-leg position was successfully performed at two institutions. The accuracy of nephrostomy placement and lessening of fluoroscopy time are two potential benefits of this approach.

Fluid Dynamic Analysis of Hand-Pump Infuser and UROMAT Endoscopic Automatic System for Irrigation Through a Flexible Ureteroscope.

INTRODUCTION: To evaluate the flow characteristics produced by a manual and automated-pump irrigation system connected to a flexible ureteroscope. MATERIALS AND METHODS: An in vitro analysis of a manual hand-pump infuser (HP) and the UROMAT Endoscopic Automatic System for Irrigation® (E.A.S.I.) pump was performed. Standard irrigation tubing was used to connect a three-way valve to a flexible ureteroscope, the irrigation system, and a digital manometer. Flow rate and irrigation pressure measurements were recorded over a 15-minute period using pressure settings of 150 and 200 mm Hg for both irrigation pump systems. Once the HP was inflated to the initial pressure, it was not reinflated over the course of the trial. Data were collected with the working channel unoccupied and with placement of a 200 µm (0.6F) holmium laser fiber, 1.7F nitinol stone retrieval basket, or 2.67F guidewire. RESULTS: The difference in pressure measured at the site of inflow of irrigation to the ureteroscope was significantly greater using the HP compared to the E.A.S.I. pump at pressure settings of 150 mm Hg with and without the use of ureteroscopic instrumentation (p < 0.001), and at 200 mm Hg with instrumentation in the working channel (p < 0.01). There was no significant difference in the flow rate of irrigation through the open-channel ureteroscope over the course of 5 minutes between the two pump systems. CONCLUSION: The flow rates of irrigation produced by the HP and the E.A.S.I. pump are similar at pressures of 150 and 200 mm Hg irrespective of the occupancy of a ureteroscope's working channel during the first 5-minutes of irrigation. Irrigation pressure at the entry site of the ureteroscope is subject to significant variability with use of the HP compared to the E.A.S.I. pump irrigation system.

Percutaneous Management of Stone Containing Calyceal Diverticula: Associated Factors and Outcomes.

PURPOSE: We evaluated the outcomes of percutaneous treatment and metabolic evaluation of calyceal diverticula with associated stones. MATERIALS AND METHODS: We retrospectively identified 51 patients with a calyceal diverticulum in our prospectively maintained percutaneous nephrolithotomy database. Patients with complete data were separated into 14 with stones isolated to the diverticulum and 15 with renal stones in and outside the diverticulum. A total of 571 patients with renal stones but no diverticulum were used for comparison. Statistical differences were assessed using the chi-square test and the t-test. RESULTS: Patients with stones isolated to the diverticulum were younger (44 vs 54 years, p = 0.024), had a lower body mass index (23.2 vs 27 kg/m2, p = 0.032) and were more often female (71% vs 44%, p = 0.046) compared to patients with renal stones but no diverticulum. Calyceal diverticula were anterior in 19 of 29 cases and in the upper pole in 15. Average diverticular size was 2.5 cm with a 1.5 cm stone burden. Percutaneous treatment was successful in 96% of patients with a 4% complication rate. The diverticular neck was dilated in 22 of 51 patients (43%). During 5-year followup in the 51 patients there was 1 stone recurrence, which was managed by ureteroscopy, while 46 and 5 patients showed complete absence and reduction of the diverticulum, respectively. Of the calyceal diverticular stones 82% contained calcium phosphate compared to only 33% in patients with renal stones but no diverticulum. All patients with a diverticulum had at least 1 metabolic derangement. CONCLUSIONS: Percutaneous treatment of calyceal diverticula is safe and effective regardless of size or location, including anterior diverticula. Infundibular neck dilation does not appear to be necessary. There are metabolic abnormalities in a significant proportion of patients with a calyceal diverticulum.