Calcium Oxalate Monohydrate Stones Research Articles

Proof-of-concept for a novel nanotechnology-based treatment for urolithiasis

Proof-of-concept of photonic lithotripsy in an in vitro setting and its ability to fragment the most common stone types is demonstrated. Effectiveness of different classes of photonic nanoparticles in fragmenting human stones is assessed. De-identified human stones were collected after institutional approval. Stones of a size range between 2–4 mm were rehydrated in simulated urine for 24 h. Stones were then coated with a solution of nanoparticles prior to activation with either a 785 nm or 1320 nm near-infrared energy source. Photonic lithotripsy achieved greater than 70% success rate in fragmentating calcium oxalate monohydrate stones using carbon-based nanoparticles for both near-infrared wavelengths. For gold-based nanoparticles, there was a similar success rate with the 785 nm wavelength but a significant decrease when using the 1320 nm wavelength energy source. All stones fragmented with the energy source at a distance ≥ 20 mm from the stone’s surface. Limitations include the use of mixed-composition stones, a lack of complete stone immersion in liquid during treatment, and smaller stone size. Different classes of nanoparticles when excited with a near-infrared energy source can fragment common stone types in vitro. This technology has the potential to change the way we approach and treat patients with urolithiasis in a clinical setting.

How much energy do we need to ablate 1 cubic millimeter of stone during Thulium Fiber Laser lithotripsy? An in vitro study.

Both Holmium:yttrium-aluminium-garnet (Ho:YAG) laser and Thulium Fiber Laser (TFL) can effectively treat all urinary stone types. This in vitro study evaluated the ablation volume per pulse (AVP) and required energy needed to ablate 1mm3 (RE, J/mm3) of various stone types at different laser settings with TFL. 272-µm core-diameter laser fibers (Boston Scientific©) were connected to a 50Watts TFL generator (IPG®). An experimental setup immerged human stones of calcium oxalate monohydrate (COM), uric acid (UA), and cystine (CYS) with a single pulse lasing emission (0.5/0.8/1J), in contact mode. Stones were dried out before three-dimensional scanning to measure AVP and deduce from the pulse energy (PE) and AVP the RE. A direct comparison with known Ho:YAG's AVP and RE was then carried out. AVP for COM stones was significantly greater than those for CYS stones and similar to UA stones (p = 0.02 and p = 0.06, respectively). If AVP increased with PE against COM and UA stones, AVP decreased against CYS stones. 1J PE resulted in a threefold lower RE compared with other PE for COM stones. On the contrary, RE for CYS increased with PE, whereas PE did not had influence on RE for UA. TFL was associated with greater AVP for COM, but lower for UA and CYS stones compared to Ho:YAG laser. This in vitro study firstly describes the ablation volume per pulse and required energy to treat a cubic millimeter of three frequent human stone types, and suggest TFL could not be suited for cystine. Therefore, stone composition could be considered when choosing the laser source for lithotripsy.

The optimal Holmium laser settings for disintegration of cystine and calcium oxalate monohydrate stones: In vitro study

ABSTRACT Objective Disintegrating cystine and calcium oxalate monohydrate stones present a formidable challenge owing to their hardness and distinct composition. This study aimed to establish optimal laser settings for these hard stones lithotripsy. Patients and Methods Cystine and calcium oxalate monohydrate stones were extracted from two patients. Two experiments were conducted in vitro by utilizing a 272 μm laser fiber with variable settings to disintegrate the cystine and calcium oxalate monohydrate stones. In the first experiment, energy was adjustable while frequency was constant, whereas the second experiment involved constant energy with adjustable frequency on each type of stone and each experiment was repeated three times to ensure robustness and reliability. Results Our findings indicated that for cystine stones, use of higher total power with high energy and low frequency proved to be effective. Conversely, for calcium oxalate monohydrate stones, settings involving higher total power with low energy and high frequency demonstrated superior efficacy and safety. Conclusion Holmium (Ho: YAG) laser settings with higher total power, high energy, and low frequency effectively disintegrate cystine stones despite increased heat, which was measured by a thermometer with a thermocouple. For calcium oxalate monohydrate stones, higher total power, high frequency, and low energy settings are recommended and safe.

Effect of Blumea Balsamifera Extract on the Kinetics of Calcium Oxalate Monohydrate (COM) Dissolution

Blumea balsamifera is a commercially available herbal drug that has anti-urolithic and diuretic properties. This study quantifies the effect of B. balsamifera extract on the dissolution kinetics of Calcium Oxalate Monohydrate (COM) crystals by modeling the dissolution of Ca2+. COM dissolution follows a first-order diffusion-controlled process. The extract did not change the dissolution phenomena. At 10 ppm, the extract had no significant effect on the rate constant (P = 0.166) and surface concentration (P = 0.372). Increasing the extract to 20 ppm did not change the dissolution phenomena and model parameters. The extract significantly decreases the equilibrium Ca2+ concentration with P = 0.0010 and P = 0.0179 at 10 and 20 ppm of extract, respectively. B. balsamifera extract binds free Ca2+ in the synthetic urine. This increases the amount of Ca2+ that dissolves but does not significantly increase the rate of dissolution suggesting that urine volume is more important for COM stone dissolution.

Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model.

To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time. An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings. High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold. Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.

Distinguishing characteristics of pediatric patients with primary hyperoxaluria type 1 in PEDSnet

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive inborn error of metabolism that causes oxalate deposition, leading to recurrent calcium oxalate kidney stones, chronic kidney disease and systemic oxalosis, which produces a broad range of serious life-threatening complications. Patients with PH1 have delayed diagnosis due to the rarity of the disease and the overlap with early-onset kidney stone disease not due to primary hyperoxaluria. The objective of this study was to determine the clinical features of individuals <21 years of age with PH1 that precede its diagnosis. We hypothesized that a parsimonious set of features could be identified that differentiate patients with PH1 from patients with non-primary hyperoxaluria-associated causes of early-onset kidney stone disease. We determined the association between clinical characteristics and PH1 diagnosis in a case-control study conducted between 2009 and 2021 in PEDSnet, a clinical research network of eight US pediatric health systems. Each patient with genetically confirmed PH1 was matched by sex and PEDSnet institution to up to 4 control patients with kidney stones without PH of any type. We obtained patient characteristics and diagnostic test results occurring before to less than 6 months after study entrance from a centralized database query and from manual chart review. Differences were examined using standardized differences and multivariable regression. The study sample included 37 patients with PH1 and 147 controls. Patients with PH1 were younger at diagnosis (median age of 3 vs 13.5 years); 75% of children with PH1 were less than 8 years-old. Patients with PH1 were more likely to have combinations of nephrocalcinosis on ultrasound or CT (43% vs 3%), lower eGFR at diagnosis (median=52mL/min/1.73m2 vs 114mL/min/1.73m2), and have normal mobility. Patients with PH1 had higher proportion of calcium oxalate monohydrate kidney stones than controls (median=100% vs 10%). There were no differences in diagnosis of failure to thrive, stone size, or echocardiography results. Children with PH1 are characterized by presentation before adolescence, nephrocalcinosis, decreased eGFR at diagnosis, and calcium oxalate monohydrate stone composition. If externally validated, these characteristics could facilitate earlier diagnosis and treatment of children with PH1.

Development of a burst wave lithotripsy system for noninvasive fragmentation of ureteroliths in pet cats

BackgroundUpper urinary tract stones are increasingly prevalent in pet cats and are difficult to manage. Surgical procedures to address obstructing ureteroliths have short- and long-term complications, and medical therapies (e.g., fluid diuresis and smooth muscle relaxants) are infrequently effective. Burst wave lithotripsy is a non-invasive, ultrasound-guided, handheld focused ultrasound technology to disintegrate urinary stones, which is now undergoing human clinical trials in awake unanesthetized subjects.ResultsIn this study, we designed and performed in vitro testing of a modified burst wave lithotripsy system to noninvasively fragment stones in cats. The design accounted for differences in anatomic scale, acoustic window, skin-to-stone depth, and stone size. Prototypes were fabricated and tested in a benchtop model using 35 natural calcium oxalate monohydrate stones from cats. In an initial experiment, burst wave lithotripsy was performed using peak ultrasound pressures of 7.3 (n = 10), 8.0 (n = 5), or 8.9 MPa (n = 10) for up to 30 min. Fourteen of 25 stones fragmented to < 1 mm within the 30 min. In a second experiment, burst wave lithotripsy was performed using a second transducer and peak ultrasound pressure of 8.0 MPa (n = 10) for up to 50 min. In the second experiment, 9 of 10 stones fragmented to < 1 mm within the 50 min. Across both experiments, an average of 73–97% of stone mass could be reduced to fragments < 1 mm. A third experiment found negligible injury with in vivo exposure of kidneys and ureters in a porcine animal model.ConclusionsThese data support further evaluation of burst wave lithotripsy as a noninvasive intervention for obstructing ureteroliths in cats.

Pediatric age-related distribution of calcium oxalate monohydrate and calcium oxalate dihydrate in urinary tract stones: metabolic, gender and ethnic correlates.

Previous studies of pediatric urolithiasis have suggested possible associations between the relative proportions of calcium oxalate dihydrate (COD) and calcium oxalate monohydrate (COM) stones with age, gender, and ethnicity. This study aimed to investigate the composition and distribution of calcium oxalate stones according to these clinical factors and the metabolic correlates of the different subtypes in pediatric stone formers. We retrospectively reviewed the database of all first-time stone formers between 2014 and 2019. Infrared spectrometry was used to determine stone composition. Stones were categorized by their highest relative component and reported as a percentage of occurrences in the cohort as a whole and by patient gender, age (divided into three age groups: 1-5, 6-12, 13-18 years), and ethnicity. Clinical and metabolic correlates were analyzed. Of 2,479 consecutive stones submitted to our chemical stone lab, 220 first-time pediatric stone formers were identified. COD stones were the predominant subtype in the youngest group, and COM stones in the oldest group (OR 0.39, 95% CI:0.18-0.86, p=0.036). In the intermediate-age group (6-12 years), COM stones were more prevalent in Arab boys and COD stones in girls of either ethnicity. COD stones were associated with hypercalciuria (p< 0.0001), and COM stones with hyperoxaluria (p=0.0024). Hypercalciuria and hypocitraturia were the most prevalent abnormalities at ages 1-5 and 13-18, respectively. Analysis of calcium oxalate stone subtypes and their metabolic correlates in stone formers has significant clinical relevance, specifically in children. In the present study, COD stones and hypercalciuria were more common in younger children, and COM stones and hypocitraturia in adolescents. These findings suggest unique, complex interactions driving stone formations in children that may guide a more practical, limited, and cost-effective approach to metabolic evaluations, choice of treatment, and preventive measures, particularly in first-time calcium oxalate pediatric stone-formers.

MP05-18 FLUID TEMPERATURE EFFECT ON SUPERPULSE THULIUM FIBER LASER STONE ABLATION

You have accessJournal of UrologyCME1 Apr 2023MP05-18 FLUID TEMPERATURE EFFECT ON SUPERPULSE THULIUM FIBER LASER STONE ABLATION Kalon L. Morgan, Andrei D. Cumpanas, Nittesh Katta, Rohit Bhatt, Antonio R. H. Gorgen, Allen Rojhani, Paul Piedras, Seyed Amiryaghoub Lavasani, Zachary E. Tano, Sohrab N. Ali, Pengbo Jiang, Roshan M. Patel, Thomas Milner, Jaime Landman, and Ralph V. Clayman Kalon L. MorganKalon L. Morgan More articles by this author , Andrei D. CumpanasAndrei D. Cumpanas More articles by this author , Nittesh KattaNittesh Katta More articles by this author , Rohit BhattRohit Bhatt More articles by this author , Antonio R. H. GorgenAntonio R. H. Gorgen More articles by this author , Allen RojhaniAllen Rojhani More articles by this author , Paul PiedrasPaul Piedras More articles by this author , Seyed Amiryaghoub LavasaniSeyed Amiryaghoub Lavasani More articles by this author , Zachary E. TanoZachary E. Tano More articles by this author , Sohrab N. AliSohrab N. Ali More articles by this author , Pengbo JiangPengbo Jiang More articles by this author , Roshan M. PatelRoshan M. Patel More articles by this author , Thomas MilnerThomas Milner More articles by this author , Jaime LandmanJaime Landman More articles by this author , and Ralph V. ClaymanRalph V. Clayman More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003216.18AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The absorption coefficient measures the energy lost to the medium through which a laser beam passes. Prior mid-infrared laser studies have shown that as the temperature of the medium increases, there is less loss of energy into the medium. Accordingly, we evaluated the impact of irrigation temperature on the amount of stone ablation when using the superpulse Thulium fiber laser (sTFL). METHODS: Optical coherence tomography (OCT), a non-invasive, high-resolution imaging technique, was used to generate a detailed surface image during single pulse sTFL lithotripsy (0.5 J, 1.0 Hz, 1.25 ms) of 12 samples of each of the following stone compositions: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), and uric acid (UA). Stones were immersed in either room temperature (20°C) or body temperature (37°C) 0.9% saline. With the tip of a 200 µm laser fiber in contact with the stone, a single pulse was applied at two separate sites on each stone. OCT determined the volume of stone removed per each laser pulse. Data were evaluated using an unpaired t-test (Figure 1) (Table 1). RESULTS: Regardless of stone composition, the mean volume of stone ablated during sTFL at 37°C was significantly greater than at room temperature. The single pulse of the sTFL ablated 12.4%, 24.4% and 28.6% more stone at 37°C irrigation for COM stones (p=0.034), COD stones (p=0.014) and UA stones (p=0.007), respectively (Table 1). CONCLUSIONS: sTFL efficiency in ablating COM, COD, and UA stones is enhanced when using irrigation warmed to 37°C. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e51 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kalon L. Morgan More articles by this author Andrei D. Cumpanas More articles by this author Nittesh Katta More articles by this author Rohit Bhatt More articles by this author Antonio R. H. Gorgen More articles by this author Allen Rojhani More articles by this author Paul Piedras More articles by this author Seyed Amiryaghoub Lavasani More articles by this author Zachary E. Tano More articles by this author Sohrab N. Ali More articles by this author Pengbo Jiang More articles by this author Roshan M. Patel More articles by this author Thomas Milner More articles by this author Jaime Landman More articles by this author Ralph V. Clayman More articles by this author Expand All Advertisement PDF downloadLoading ...

PD28-04 ADVANCED BURST WAVE LITHOTRIPSY FOR HUMAN TRIALS

You have accessJournal of UrologyCME1 Apr 2023PD28-04 ADVANCED BURST WAVE LITHOTRIPSY FOR HUMAN TRIALS Arturo Holmes, Ekaterina Kuznetsova, Shivani Ramesh, Adam D. Maxwell, Ga Won Kim, John Kucewicz, Bryan W. Cunitz, Wayne Kreider, Barbrina Dunmire, Michael R. Bailey, Mathew D. Sorensen, and Jonathan D. Harper Arturo HolmesArturo Holmes More articles by this author , Ekaterina KuznetsovaEkaterina Kuznetsova More articles by this author , Shivani RameshShivani Ramesh More articles by this author , Adam D. MaxwellAdam D. Maxwell More articles by this author , Ga Won KimGa Won Kim More articles by this author , John KucewiczJohn Kucewicz More articles by this author , Bryan W. CunitzBryan W. Cunitz More articles by this author , Wayne KreiderWayne Kreider More articles by this author , Barbrina DunmireBarbrina Dunmire More articles by this author , Michael R. BaileyMichael R. Bailey More articles by this author , Mathew D. SorensenMathew D. Sorensen More articles by this author , and Jonathan D. HarperJonathan D. Harper More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003313.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The first in human trials of burst wave lithotripsy (BWL) demonstrated consistent fragmentation of upper tract stones with no or mild hematuria. However, for a randomized, controlled trial of treating 2-7 mm stones we wanted improved image resolution to not miss any fragments and ability to break stones to<1 mm at skin to stone depths of 4-10 cm on ultrasound. The system was redesigned and tested to add these improvements. METHODS: A new ultrasound platform for imaging, ultrasonic propulsion, and BWL was designed and constructed (‘Propulse2’). The imaging employed high-bandwidth phased array probes and Verasonics Vantage imaging engine. Resolution changes were compared against existing devices in a standard imaging phantom. Longer focus therapy transducers were designed. Additionally, the transducers operate at frequencies between 350-800 kHz. A high-power pulse generator was developed to achieve pressure at greater depths, produce longer duration pulses, and enable interleaving BWL with ultrasonic propulsion pulses and accelerate fragmentation. To test the therapeutic capabilities, rehydrated 2-7 mm calcium oxalate monohydrate stones were sonicated with each transducer and frequency in a calyx phantom in 2.5-minute intervals for 20 minutes. After each interval, the fragments were weighed and sieved to 1 and 2 mm, then returned to the phantom. Burst cycle durations between 5 to 160 cycles were tested with and without interleaved pulses and depths 4-10 cm all at focal peak negative pressures of 7 MPa. RESULTS: Imaging contrast (signal to noise ratio) with the old and new systems was 1.62 and 3.45 at 6 cm depth and 1.07 and 1.75 at 10 cm depth. Lateral resolution was improved by a factor of 2.1 at 6 cm and 2.5 at 10 cm. Targeting accuracy was measured to be within 1 mm for all transducers. On average for all stones and conditions, 81% and 75% of the stone mass was comminuted to<2 mm and < 1mm fragments respectively in 20 minutes (Figure 1A). Subanalysis of fragmentation to<2 mm fragments showed fewer than 20 cycles were less effective even with increased pulse repetition rate to equalize energy (Figure 1B). CONCLUSIONS: The system demonstrated over twice the imaging contrast and resolution and capability to fragment stones more finely over a 4-10 cm depth. Propulse2 has been approved for human trials (ClinicalTrials.gov number, NCT04796792). Source of Funding: Work supported by NIDDK P01 DK043881. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e819 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Arturo Holmes More articles by this author Ekaterina Kuznetsova More articles by this author Shivani Ramesh More articles by this author Adam D. Maxwell More articles by this author Ga Won Kim More articles by this author John Kucewicz More articles by this author Bryan W. Cunitz More articles by this author Wayne Kreider More articles by this author Barbrina Dunmire More articles by this author Michael R. Bailey More articles by this author Mathew D. Sorensen More articles by this author Jonathan D. Harper More articles by this author Expand All Advertisement PDF downloadLoading ...

MP16-08 DISTINGUISHING CHARACTERISTICS OF CHILDREN WITH PRIMARY HYPEROXALURIA TYPE 1 IN PEDSNET

You have accessJournal of UrologyCME1 Apr 2023MP16-08 DISTINGUISHING CHARACTERISTICS OF CHILDREN WITH PRIMARY HYPEROXALURIA TYPE 1 IN PEDSNET Gregory Tasian, Kimberley Dickinson, Julia Schuchard, Grace Park, Nicole Marchesani, Akanksha Mittal, Nathan Cheng, Christina Ching, David Chu, Ryan Walton, Karyn Yonekawa, Caroline Gluck, Kathleen Kan, William DeFoor, Kyle Rove, and Christopher Forrest Gregory TasianGregory Tasian More articles by this author , Kimberley DickinsonKimberley Dickinson More articles by this author , Julia SchuchardJulia Schuchard More articles by this author , Grace ParkGrace Park More articles by this author , Nicole MarchesaniNicole Marchesani More articles by this author , Akanksha MittalAkanksha Mittal More articles by this author , Nathan ChengNathan Cheng More articles by this author , Christina ChingChristina Ching More articles by this author , David ChuDavid Chu More articles by this author , Ryan WaltonRyan Walton More articles by this author , Karyn YonekawaKaryn Yonekawa More articles by this author , Caroline GluckCaroline Gluck More articles by this author , Kathleen KanKathleen Kan More articles by this author , William DeFoorWilliam DeFoor More articles by this author , Kyle RoveKyle Rove More articles by this author , and Christopher ForrestChristopher Forrest More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003236.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Primary hyperoxaluria type 1 (PH1) is an ultra-rare disorder of hepatic overproduction of oxalate that causes early onset kidney stones, chronic kidney disease, and systemic oxalosis. We sought to identify defining clinical characteristics of children with PH1 in order to develop approaches that facilitate its early diagnosis. METHODS: We determined the association between patient-level characteristics of PH1 in a case-control study conducted between January 2009 and August 2021 in PEDSnet, a clinical research network of eight pediatric health systems in the United States. We matched each patient with confirmed PH1 to 4 control patients with kidney stone disease not due to PH1 by sex and PEDSnet site at date of diagnosis (cohort entrance date). We obtained patient characteristics and diagnostic test results occurring before to less than 6 months after cohort entrace from a centralized query of the data pooled from the electronic health records and from manual chart review at each PEDSnet site. Differences in patient characteristics and diagnostic test results between patients were compared using paired tests as appropriate for the distribution of and type of data. RESULTS: The study sample included 37 patients with PH1 and 147 controls. Compared to patients with kidney stone disease not due to PH1, patients with PH1 were younger, were less likely to have immobility, had a higher percentage of stone comprised of calcium oxalate monohydrate, and had a lower eGFR measured within 6 months of cohort entrance (Table 1). There were no statistically significant differences in prevalent diagnosis of failure to thrive, cumulative stone size on ultrasound, nephrocalcinosis on ultrasound or CT, or echocardiography results. CONCLUSIONS: In this study, children with PH1 were characterized by presentation before adolescence, absence of immobility, high percentage of calcium oxalate monohydrate stone composition, and decreased eGFR at diagnosis. If validated in external populations, these consortium of characteristics may enable a strong clinical suspicion for PH1 diagnosis, facilitating confirmatory testing, and facilitating initation of targeted therapeutics. Source of Funding: Alnylam Pharmaceuticals © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e205 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gregory Tasian More articles by this author Kimberley Dickinson More articles by this author Julia Schuchard More articles by this author Grace Park More articles by this author Nicole Marchesani More articles by this author Akanksha Mittal More articles by this author Nathan Cheng More articles by this author Christina Ching More articles by this author David Chu More articles by this author Ryan Walton More articles by this author Karyn Yonekawa More articles by this author Caroline Gluck More articles by this author Kathleen Kan More articles by this author William DeFoor More articles by this author Kyle Rove More articles by this author Christopher Forrest More articles by this author Expand All Advertisement PDF downloadLoading ...

Calcineurin B inhibits calcium oxalate crystallization, growth and aggregation via its high calcium-affinity property

Calcineurin inhibitors (CNIs) are widely used in organ transplantation to suppress immunity and prevent allograft rejection. However, some transplant patients receiving CNIs have hypocitraturia, hyperoxaluria and kidney stone with unclear mechanism. We hypothesized that CNIs suppress activities of urinary calcineurin, which may serve as the stone inhibitor. This study aimed to investigate effects of calcineurin B (CNB) on calcium oxalate monohydrate (COM) stone formation. Sequence and structural analyses revealed that CNB contained four EF-hand (Ca2+-binding) domains, which are known to regulate Ca2+ homeostasis and likely to affect COM crystals. Various crystal assays revealed that CNB dramatically inhibited COM crystallization, crystal growth and crystal aggregation. At an equal amount, degrees of its inhibition against crystallization and crystal growth were slightly inferior to total urinary proteins (TUPs) from healthy subjects that are known to strongly inhibit COM stone formation. Surprisingly, its inhibitory effect against crystal aggregation was slightly superior to TUPs. While TUPs dramatically inhibited crystal-cell adhesion, CNB had no effect on this process. Ca2+-affinity assay revealed that CNB strongly bound Ca2+ at a comparable degree as of TUPs. These findings indicate that CNB serves as a novel inhibitor of COM crystallization, growth and aggregation via its high Ca2+-affinity property.

Распространенность видов мочевых камней среди взрослого населения РФ и некоторых стран СНГ

Background: the study on the prevalence of kidney stone types in various territories of the country and the world is of great importance, mainly in predicting the burden on the healthcare system in general and the urological community in particular. Besides, in terms of calculating the probability of the disease relapse even during effectively conducted metaphylactic therapy. Aim: to assess the prevalence of kidney stone types among the adult population in various regions of the Russian Federation, Belarus, Kazakhstan and the kidney stone composition depending on age and gender. Patients and Methods: data on the kidney stone composition are presented by INVITRO in an anonymized form for the period 2018–2021. The article presents the analysis of stone samples obtained from patients of 12 regions: Moscow (n=2623), Belarus (n=324), Kazakhstan (n=87), Republic of Crimea (n=59), and Far Eastern (FE) (n=214), Volga (n=398), North Caucasus (n=109), North-Western (n=385), Siberian (n=740), Ural (n=891), Central (n=566), Southern (n=371) Federal Regions. The analysis of the stones was conducted by infrared spectrometry or X-ray diffraction. Results: the prevalence of kidney stones from more than one component in the adult population of the Russian Federation, Kazakhstan and Belarus was assessed. 6787 kidney stones were examined in both genders. One-component stones were detected in 448 (6.6%) people, two-component stones — in 4005 (59%), multicomponent stones — in 2334 (34.4%). The most common mineral of the one-component stone is calcium oxalate monohydrate (COM). In the structure of one-component stones, stones from COM and uric acid/uric acid dihydrate were statistically significantly more common among male patients, while struvite stones were found among female patients. When assessing the distribution of one-component stones in accordance with age and gender, there was a significant increase in the number of COM stones in both male and female patients aged from 26 to 70 years. Among two-component stones, the most common combination of minerals is COM + calcium oxalate dihydrate (COD) in all age groups. Adding that, it is statistically significant among male patients vs. female patients — 67.4% vs. 32.6% (p&lt;0.001). The most common combination of minerals in multicomponent stones is the combination of COM + COD + carbonate-apatite, which was found in all age groups with the highest rates among male patients aged 31–50 years, among female patients aged 31–40 years, and in stable rates at the age of 41–60 years. Stones from COM + COD + struvite was most commonly determined at the age of 31–60 years. Conclusion: the revealed occurrence patterns of various stone types, depending on the place of residence, gender and age, should be taken into account when choosing an adequate metaphylactic treatment tactics. KEYWORDS: urolithiasis, metaphylaxis, calcium oxalate monohydrate, citraturia, phytotherapy. FOR CITATION: Saenko V.S., Vinarov A.Z., Demidko Yu.L. et al. Prevalence of kidney stone types among the adult population of the Russian Federation and CIS countries. Russian Medical Inquiry. 2023;7(4):202–211 (in Russ.). DOI: 10.32364/2587-6821-2023-7-4-202-211.

Impact of ureteral access sheath use on outcomes of flexible ureteroscopy for renal stones

Introduction and objective: Improvements in endoscopic technologies have led to an expansion of flexible ureteroscopy indications in the treatment of renal and ureteral stones. Ureteral access sheath (UAS) was introduced in the clinical practice to facilitate endoscopic access into the upper urinary tract, reduce intrarenal pressure during the procedure and allow the extraction of fragments. The objective of this study is to analyze the impact of UAS on the efficacy and safety of flexible ureteroscopy (fURS) for the treatment of renal stones. Material and methods: a prospectively collected database including 251 consecutive patients treated with fURS between January 2018 and November 2022 was analyzed. Patients were divided into two groups: group 1 – without UAS, 21 patients (8.3%) and group 2 – with UAS, 231 patients (91.7%). UAS was used at the surgeon’s discretion and 3 patients (1.2%) underwent a sheathless procedure due to failure of UAS insertion. Data on patients’ preoperative characteristics and fURS efficacy and safety were compared. Results: There were no statistically significant differences in patients’ preoperative characteristics except for stone size and surface, which were significantly larger in group 2 (9.6±4.1 vs 13.8±5.2 mm; р&lt;0.001 and 68.6±74.2 vs 128.3±109.3 mm2, p=0.002, respectively). Operating time was significantly longer in group 2 (33.6±12.9 vs 42.0±12.9 min, p=0.005). Stone-free rate after a single procedure and at 3rd postoperative month was similar between groups (95.2% vs 87%, p=0.486 and 95.2% vs 88.7%, p=0.709, respectively). The intra- and postoperative complication rates were higher for group 1 (4.8% vs 0.8%, р=0.011 and 14.3% vs 12.1%, p=0.062, respectively). Multivariate regression model identified stone surface (р&lt;0.001), number of stones (p=0.005) and calcium oxalate monohydrate stone composition (р=0.005), but not UAS use (p=0.580), as independent predictors for stone-free rate following fURS. Conclusions: The results of this study suggest that UAS use has no impact on the efficacy of fURS and is not associated with an increased rate of intra- and postoperative complications.

Benchtop Evaluation of Miniature Percutaneous Nephrolithotomy Lithotrites

Introduction: Percutaneous nephrolithotomy (PCNL) is the preferred treatment for kidney stones >2 cm. While PCNL has traditionally been performed using 24F to 30F access sheaths, there is a trend toward smaller sheaths and scopes to perform mini-PCNL (mPCNL). We performed benchtop assessment of multiple mPCNL lithotrites. Methods: One 1 cm3, hard Begostone phantom was placed in a cylinder with four 5.5 mm cylindrical openings to simulate the size of a 16.5F mPCNL sheath. Lithotripsy was performed with the 1.5 and 1.9 mm Trilogy, 1.83 mm ShockPulse, or a 200 μm Holmium:YAG (Ho:YAG) laser. Suction was used for the mechanical lithotrites. The Trilogy probes were set at 50% impact, 6 Hz, 80% ultrasound and 10% suction. The ShockPulse was used at high-power setting with low suction. The 1.9 mm Trilogy probe was used with a 15F mini-nephroscope. The 1.83 mm ShockPulse, 1.5 mm Trilogy and laser fiber were used with a 12F mini-nephroscope. The 120 W holmium laser was set at 0.5 J/70 Hz Moses-Distance. Ten independent runs were performed with modality. Time to complete stone clearance was recorded and mass stone clearance rates were calculated. Results: The Trilogy 1.9 mm showed superior stone clearance rate (11.69 ± 3.68 mg/s) vs the ShockPulse (SP) 1.83 mm (6.29 ± 1.37 mg/s, p = 0.003), the laser fiber (4.73 ± 0.61 mg/s, p < 0.0005), and the Trilogy 1.5 mm (6.84 ± 1.21 mg/s). The 200 μm laser fiber was inferior to all mechanical lithotrites. There was no difference between the 1.5 mm Trilogy and the 1.83 mm ShockPulse (p = 0.772). This translates to 3.9, 4.8, and 8.1 minutes less treatment time vs the 1.5 mm Trilogy, SP, and laser, respectively, for a spherical 1.5 cm diameter calcium oxalate monohydrate stone. Conclusion: Among these four commonly used mPCNL lithotripters, the Trilogy 1.9 mm demonstrated superior stone clearance rates in this benchtop model vs the Ho:YAG laser, 1.83 mm SP, and Trilogy 1.5 mm. Future clinical testing is warranted to evaluate the optimal lithotrite for mPCNL.

Incidence and risk factors for urolithiasis recurrence after endourological management of kidney stones: A retrospective single-centre study.

Almost half of the patients have hadrecurrent nephrolithiasis despite undergoing effective treatment. Our objective is to determine the recurrence rate of lithiasis after endourological management of nephrolithiasis and identify the risk factors for these recurrences. Data were gathered retrospectively from all patients who were treated for nephrolithiasis by endourological management from May 2014 to January 2017 in our university hospital. The patients were devised into two groups: with and without recurrence. Many variables were also compared between these two groups. During this period 265 patients were treated for upper urinary tract stone. A total of 190 patients were included in the study. The median age and median BMI of the patients were 57.5 years and 25.2kg/m2, respectively. A biochemical analysis of the stones was performed in 117 (61.5%) patients. The most common types of stones were calcium oxalate monohydrate stones (n=44, 23.2%), mixed stones (n=39, 20.5%) including mixed calcium oxalate (n=10; 8.5%), calcium oxalate dihydrate stones (n=13, 6.8%) and uric acid stones (n=11, 5.8%). At the end of a median follow-up of 32 months (range, 13-61 monthes), 49 patients (25.8%) had a recurrent stone. In univariate analysis, the risk factors for recurrence were BMI greater than 25kg/m2 (HR: 2; P<0.05), diabetes (HR: 3.73; P<0.008) and smoking (HR: 3.1; P<0.039). However age (HR: 0.96: P<0.003) and high blood pressure (HR: 0.37; P<0.027) were protective factors. In multivariate analysis, diabetes, smoking, hypertension, and age are still risk factors for recurrence. Stone recurrence is common after the management of urinary stones. In this study25.8% of patients had recurred stone disease after endourological management with a median follow-up of 32 months. Our study findings showed that diabetes and smoking are risk factors for recurrence, while age and blood hypertension are protective factors that decreased the risk of recurrence.

Comparison of Four Dual-Energy CT Scanner Technologies for Determining Renal Stone Composition: A Phantom Approach.

Background Studies have investigated the value of various dual-energy CT (DECT) technologies for determining renal stone composition. However, sparse multivendor comparison data exist. Purpose To compare the performance of four DECT technologies in determining renal stone composition at standard- and low-dose acquisitions. Materials and Methods This was an in vitro phantom study. Seventy-one urinary stones (size: 2.7-14.1 mm) of known chemical composition (51 calcium, four struvite, four cystine, and 12 urate) were placed in a custom-made cylindrical phantom. Consecutive scans with manufacturer-recommended protocols and dose-optimized institutional protocols (up to 80% reduction in volumetric CT dose index) were obtained with rapid kilovolt peak switching DECT (rsDECT) (n = 2), dual-source DECT (n = 2), twin-beam DECT (tbDECT) (n = 1), and dual-layer detector-based CT (dlDECT) (n = 1) scanners. The image data sets were analyzed using effective atomic number and dual-energy ratio indexes of maximally available and comparable spectra. The performance of each combination of scanner technology, method, and acquisition was assessed. Logistic regression models were used to calculate the area under the receiver operating characteristic curve (AUC). Results After image analysis, all scanners except tbDECT had an AUC greater than 0.95 in at least one acquisition in distinguishing urate from other stones. All DECT techniques were able to help differentiate calcium oxalate monohydrate stones with moderate accuracy (AUC: 0.70-0.83), and brushite was differentiated from urate with AUC greater than 0.99. There was no correlation between performance and acquisition with dose-optimized and/or vendor-recommended settings. Conclusion All four dual-energy CT (DECT) technologies enabled accurate determination of stone composition at standard- and low-dose acquisitions; however, performance varied based on the scanner parameters, DECT technique, and stone type. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Ringl and Apfaltrer in this issue.

MP32-05 BENCHTOP EVALUATION OF MINIATURE PERCUTANEOUS NEPHROLITHITOMY LITHOTRITES

You have accessJournal of UrologyCME1 May 2022MP32-05 BENCHTOP EVALUATION OF MINIATURE PERCUTANEOUS NEPHROLITHITOMY LITHOTRITES Patrick Whelan, Christopher Kim, Christian Tabib, Russell Terry, Glenn Preminger, and Michael Lipkin Patrick WhelanPatrick Whelan More articles by this author , Christopher KimChristopher Kim More articles by this author , Christian TabibChristian Tabib More articles by this author , Russell TerryRussell Terry More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002581.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Percutaneous nephrolithotomy (PCNL) is the preferred surgical treatment for kidney stones >2cm. While PCNL has traditionally been performed using access sheaths from 24-30Fr in size, there is presently a trend toward using increasingly smaller sheaths (<20Fr) and scopes to perform what has been termed “mini-PCNL.” Smaller mechanical lithotripsy instruments have therefore been developed for this purpose, but are limited in comparative effectiveness. We performed benchtop assessment of multiple mini-PCNL lithotrites. METHODS: One 1cm3, hard Begostone phantom, mimicking a calcium oxalate monohydrate stone, was placed in a cylinder with four 5.5mm cylindrical openings to simulate size of a 16.5Fr mini-PCNL sheath to drain via Venturi effect. Lithotripsy was then performed with either the 1.9mm Trilogy (EMS), 1.83mm ShockPulse (SP, Olympus) and 200mm Holmium:YAG laser. Suction was used for the mechanical lithotrites. The Trilogy probes were used at 50% impact, 6Hz, 80% ultrasound and 10% suction. The ShockPulse was used at high-power setting. The 1.9mm probe was used with a 15Fr mini nephroscope (Olympus). The ShockPulse, 1.5mm Trilogy and laser fiber were used with a 12Fr mini nephroscope (Karl-Storz). The laser was set at 0.5J/70Hz Moses-Distance (MD) (Lumenis). 10 independent runs were performed with each probe. Time to complete stone clearance was recorded and mass stone clearance rates were calculated. RESULTS: The Trilogy 1.9mm probe showed superior stone clearance rate (11.69±3.68 mg/s) vs the SP 1.83mm probe (6.29±1.37 mg/s, p=0.003) and the laser fiber (4.73 ± 0.61 mg/s, p <0.0005), respectively (Figure 1). The SP was also superior to the laser (p=0.016). This translates to 4.6 and 7.9 minutes less treatment time vs the SP and laser, respectively, for a spherical 1.5cm diameter calcium oxalate monohydrate stone. CONCLUSIONS: Among these three commonly used mini-PCNL probes, the Trilogy 1.9 demonstrated clearly superior stone clearance rates in this benchtop model. This could be due to improved lithotrite properties and use of suction evacuation, especially compared to the laser. Future clinical testing is warranted to evaluate optimal lithotrite for miniPCNL. Source of Funding: Boston Scientific provided funding for this study through an educational grant © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e533 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Patrick Whelan More articles by this author Christopher Kim More articles by this author Christian Tabib More articles by this author Russell Terry More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement PDF DownloadLoading ...

MP26-10 CLINICAL AND METABOLIC FACTORS AFFECTING RELATIVE PROPORTION OF CALCIUM OXALATE MONOHYDRATE AND DIHYDRATE IN PURE CALCIUM OXALATE STONES

You have accessJournal of UrologyCME1 May 2022MP26-10 CLINICAL AND METABOLIC FACTORS AFFECTING RELATIVE PROPORTION OF CALCIUM OXALATE MONOHYDRATE AND DIHYDRATE IN PURE CALCIUM OXALATE STONES Mohammad Hout, Vedant Acharya, Madhumita Parmar, Ruben Blachman Braun, Jonathan Katz, Robert Marcovich, and Hemendra Shah Mohammad HoutMohammad Hout More articles by this author , Vedant AcharyaVedant Acharya More articles by this author , Madhumita ParmarMadhumita Parmar More articles by this author , Ruben Blachman BraunRuben Blachman Braun More articles by this author , Jonathan KatzJonathan Katz More articles by this author , Robert MarcovichRobert Marcovich More articles by this author , and Hemendra ShahHemendra Shah More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002569.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Calcium oxalate stone are the commonest variety of urinary calculi. Patients contain varying amount of its sub-types- calcium oxalate monohydrate and dihydrate. Few studies from past demonstrate varying metabolic defects in patients with both sub-types. The aim of present study was to study influence of various clinical and metabolic factors on relative proportion of calcium oxalate monohydrate and dihydrate in pure calcium oxalate stones. METHODS: We retrospectively examined stone analysis report of all patients who underwent endourological procedure for stone removal at our center from Jan 2017 to December 2019. Stones made of pure calcium oxalate with varying proportion of its subtypes were identified. Patient with combination of calcium oxalate with other components were excluded from study. Chart review was performed of all this patient to identify those who had 24-hour urinary stone risk profile done within 3 month of stone analysis and prior to start of medical management of stone. Statistical analysis was performed using SPSS 24. Correlational analysis between stone composition and clinical and metabolic variables was performed with the Spearman test. RESULTS: Of 120 calcium oxalate stones, 66 contained > 60% monohydrate and 8 contained > 60% dihydrate. The mean age in patients with dihydrate stone was 39.6 + 17 and monohydrate was 55.3 + 14.6. (P=0.002). Correlation analysis suggested that age, BMI and urinary Ph. Calcium oxalate saturation, brushite saturation and uric acid saturation were found to have significant co-relation with percentage of calcium oxalate dihydrate or calcium oxalate monohydrate stone composition (Figures 1 and 2). CONCLUSIONS: Calcium oxalate dihydrate stones former are younger and have lower BMI than those with monohydrate stones. Similarly as urinary Ph become more alkaline, the relative proportion of dihydrate increases. Source of Funding: none © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e442 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mohammad Hout More articles by this author Vedant Acharya More articles by this author Madhumita Parmar More articles by this author Ruben Blachman Braun More articles by this author Jonathan Katz More articles by this author Robert Marcovich More articles by this author Hemendra Shah More articles by this author Expand All Advertisement PDF DownloadLoading ...

PD19-04 NOBODY LIKES BURNT POPCORN: THE MOST EFFICIENT POPCORNING SETTINGS IN A NOVEL 3D-KIDNEY MODEL THAT LIMITS THERMAL INJURY

You have accessJournal of UrologyCME1 May 2022PD19-04 NOBODY LIKES BURNT POPCORN: THE MOST EFFICIENT POPCORNING SETTINGS IN A NOVEL 3D-KIDNEY MODEL THAT LIMITS THERMAL INJURY Christian Tabib, Zachary Dionise, Sabrina Tran, Francois Soto-Palou, Pei Zhong, Glenn Preminger, and Michael Lipkin Christian TabibChristian Tabib More articles by this author , Zachary DioniseZachary Dionise More articles by this author , Sabrina TranSabrina Tran More articles by this author , Francois Soto-PalouFrancois Soto-Palou More articles by this author , Pei ZhongPei Zhong More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002557.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: When stone popcorning, the use of higher energy with little to no irrigation is preferred. However, this combination of high power with low flow can lead to increased risk of thermal damage with longer laser firing times. Using predetermined lasering and irrigation ‘cool down’ durations within a novel, anatomically accurate 3D kidney model, our aim was to identify the laser settings that produce the most efficient popcorning without reaching thermal dose (t43) that causes tissue damage. METHODS: Hard Begostone phantoms, mimicking calcium oxalate monohydrate stones, were crushed and sieved to 2-4mm fragments. Fragments were then separated by size measuring 2-2.8mm, 2.8-3.35mm, and 3.35-4mm and mixed by mass at a ratio of 2:2:1, respectively. Approximately 0.5g of fragments were placed in the upper pole of our anatomical 3D-printed kidney model. Each triplicate trial consisted of iterative laser/irrigation cooling cycles for two minutes using a MosesTM 120H 2.0 laser (Table). Laser firing and cooling times were determined by measuring t43 with each laser setting, allowing for maximal laser to cooling ratio that would not exceed tissue injury threshold (t43 70 min). After treatment, stones were dried and sieved into <1mm, 1-2mm, 2-2.8mm, 2.8-3.35, and 3.35-4mm fragments, which were then weighed. Ablation efficiency was calculated as post-treatment mass <1mm, with comparisons by ANOVA and Tukey post-hoc tests. RESULTS: Overall, the most efficient setting was 0.5J/90Hz with no irrigation; while the most efficient setting using low irrigation were 0.4J/110Hz and 0.5/J/80Hz SP (Figure). Even with shorter laser times, popcorning was more efficient with no irrigation, especially at high powers (all p<0.05). CONCLUSIONS: When accounting for thermal dose, 0.5J/90Hz without irrigation provides the most efficient popcorning, despite shorter laser times. When thermal injury is of special concern and the surgeon prefers low flow, 0.4J/110Hz appears most efficient. Last, if extended frequency is unavailable, 0.6J/80Hz without irrigation should be used. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e350 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christian Tabib More articles by this author Zachary Dionise More articles by this author Sabrina Tran More articles by this author Francois Soto-Palou More articles by this author Pei Zhong More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement PDF DownloadLoading ...