Illumination matters part IV: blackout and whiteout in flexible ureteroscopy - first report on a phenomenon observed by PEARLS.

PURPOSE: To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model. MATERIAL AND METHODS: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively). RESULTS: Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances. CONCLUSION: Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist's choice of instruments and settings.

Patient's preferences: an unmet need by current urolithiasis guidelines: a systematic review.

INTRODUCTION: Shared decision making (SDM) in surgical specialties was demonstrated to diminish decisional regret, decisional anxiety and decisional conflict. Urolithiasis guidelines do not explicit patient preference to choose treatment. The aim of this review article was to perform a systematic evaluation of published evidence regarding SDM in urinary stone treatment. METHODS: A systematic review in accordance PRISMA checklist was conducted using the MEDLINE (PubMed) database. Inclusion criteria were studies that evaluated stone treatment preferences. Reviews, editorials, case reports and video abstracts were excluded. ROBUST checklist was used to assess quality of the studies. RESULTS: 188 articles were obtained. After applying the predefined selection criteria, seven articles were included for final analysis. Six out of seven studies were questionnaires that propose clinical scenarios and treatment alternatives. The last study was a patient preference trial. A general trend among included studies showed a patient preference towards the least invasive option (SWL over URS). The main reasons to choose one treatment over the other were stone-free rates, risk of complications and invasiveness. DISCUSSION: This review provides an overview of the patients' preferences towards stone treatment in small- and medium-sized stones. There was a clear preference towards the least invasive management strategy. The main reason was less invasiveness. This is opposed to the global trends of performing more ureteroscopies and less SWL. Physicians played a pivotal role in counselling patients. SDM should be encouraged and improved. The main limitation of this study is the characteristics of the included studies.

Pulsed thulium:YAG laser-ready to dust all urinary stone composition types? Results from a PEARLS analysis.

PURPOSE: To evaluate whether stone dust can be obtained from all prevailing stone composition types using the novel pulsed thulium:YAG (p-Tm:YAG), including analysis of stone particle size after lithotripsy. METHODS: Human urinary stones of 7 different compositions were subjected to in vitro lithotripsy using a p-Tm:YAG laser with 270 µm silica core fibers (Thulio®, Dornier MedTech GmbH®, Wessling, Germany). A cumulative energy of 1000 J was applied to each stone using one of three laser settings: 0.1 J × 100 Hz, 0.4 J × 25 Hz and 2.0 J × 5 Hz (average power 10 W). After lithotripsy, larger remnant fragments were separated from stone dust using a previously described method depending on the floating ability of dust particles. Fragments and dust samples were then passed through laboratory sieves to evaluate stone particle count according to a semiquantitative analysis relying on a previous definition of stone dust (i.e., stone particles ≤ 250 µm). RESULTS: The p-Tm:YAG laser was able to produce stone dust from lithotripsy up to measured smallest mesh size of 63 µm in all seven stone composition types. Notably, all dust samples from all seven stone types and with all three laser settings had high counts of particles in the size range agreeing with the definition stone dust, i.e., ≤ 250 µm. CONCLUSION: This is the first study in the literature proving the p-Tm:YAG laser capable of dusting all prevailing human urinary stone compositions, with production of dust particles ≤ 250 µm. These findings are pivotal for the broader future implementation of the p-Tm:YAG in clinical routine.

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion.

OBJECTIVE: To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years. METHODS: We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics. RESULTS: During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43). CONCLUSIONS: We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

Retrograde intra renal surgery and safety: pressure and temperature. A systematic review.

PURPOSE OF REVIEW: Retrograde intra renal surgery (RIRS) with laser lithotripsy represents the gold-standard to treat renal stones up to 20 mm. Controlling intraoperative parameters such as intrarenal pressure (IRP) and temperature (IRT) is mandatory to avoid complications. This article reviews advances in IRP and IRT over the last 2 years. RECENT FINDINGS: We conducted a PubMed/Embase search and reviewed publications that include temperature and pressure during RIRS. Thirty-four articles have been published which met the inclusion criteria. Regarding IRP, a consensus has emerged to control IRP during RIRS, in order to avoid (barotraumatic and septic) complications. Several monitoring devices are under evaluation but none of them are clinically approved for RIRS. Ureteral access sheath, low irrigation pressure and occupied working channel help to maintain a low IRP. Robotic systems and suction devices would improve IRP intraoperative management and monitoring. IRT determinants are the irrigation flow and laser settings. Low power settings(<20 W) with minimal irrigation flow (5-10 ml/min) are sufficient to maintain low IRT and allows continuous laser activation. SUMMARY: Recent evidence suggests that IRP and IRT are closely related. IRP depends on inflow and outflow rates. Continuous monitoring would help to avoid surgical and infectious complications. IRT depends on the laser settings and the irrigation flow.

[Stage at diagnosis of prostate cancer in an institutional hospital. Review and comparison of national and international data]. / Etapa al diagnóstico de cáncer de próstata en un hospital institucional. Revisión y comparación de datos nacionales e internacionales.

INTRODUCTION: Prostate cancer (PCa) is a disease with a high prevalence and incidence worldwide. Screening has pursued the early diagnosis of this disease to provide early treatment. We sought to characterize patients from a local hospital with respect to diagnosis and staging and to compare these results with previously reported data. METHODS: We conducted a retrospective analysis of patients diagnosed with PCa at an institutional hospital. Clinical variables were collected at the time of diagnosis, staging methods, TNM stage, and histological grade. RESULTS: 129 patients were included in the analysis. The median PSA (ng/mL) at diagnosis was 7.29. The histological grade was classified as ISUP 1 in 37.5%. An MRI was performed in 42.19% of the patients, being classified mostly as PIRADS 4 (21.09%). PET-CT PSMA staging was used mainly in the high-risk group, preferring contrast-enhanced CT and bone scintigraphy in the other groups. 6.25% were classified as N1 and 9.37% as M1. CONCLUSION: The stage at diagnosis in our series is somewhat higher than that reported by developed countries but considerably lower than that published by other Latin American countries and even from other hospitals in our country. It is of great national relevance to have clear protocols for screening and access to PSA to reduce the cases diagnosed in advanced stages.

How do we assess the efficacy of Ho:YAG low-power laser lithotripsy for the treatment of upper tract urinary stones? Introducing the Joules/mm3 and laser activity concepts.

OBJECTIVES: To estimate the total energy needed to ablate 1mm3 of stone volume (Joules/mm3) during flexible ureteroscopic lithotripsy using a low-power Ho:YAG laser device, as a proxy of lithotripsy efficacy. PATIENTS AND METHODS: We selected 30 patients submitted to flexible ureteroscopy for renal stones whose volume was bigger than 500 mm3. A 35 W Ho:YAG laser (Dornier Medilas H Solvo 35, Germany) was used for every procedure with a 272 µm laser fiber. We recorded laser parameters, the total energy delivered by the laser fiber, the time from the first laser pulse until the last one (lithotripsy time), and the active laser time as provided by the machine. We then estimated J/mm3 values and determinants, along with ablation speed (mm3/s), and laser activity (ratio between laser active time and lithotripsy time). RESULTS: Median (IQR) stone volume and stone density were respectively 1599 (630-3502) mm3 and 1040 (753-1275) Hounsfield units (HU). In terms of laser parameters, median (IQR) energy and frequency were 0.6 (0.4-0.8) J and 15 (15-18) Hz. Median (IQR) total delivered energy and lithotripsy time were 37,050 (13,375-57,680) J and 68 (36-88) min, respectively. Median (IQR) J/mm3 and ablation speed were, respectively, 19 (14-24) J/mm3 and 0.7 (0.4-0.9) mm3/s. The laser was active during 84% (70-95%) of the total lithotripsy time. HU density > 1000 was associated with reduced efficacy. CONCLUSIONS: It is possible to perform laser lithotripsy using a low-power laser device with a virtually continuous laser activity. The estimation of the pre-operative parameters as well as the J/mm3 values are fundamental for a proper pre-operatory planning.

Operator-assisted vs self-achieved basketing during ureteroscopy: results from an in vitro preference study.

OBJECTIVES: A recently introduced device (LithoVue Empower™ or LE, Boston Scientifics, USA) allows the surgeon to directly control the stone-retrieving basket without the need of an assistant during flexible ureteroscopy. We aimed to evaluate the stone-retrieval performance of this device. METHODS: We used a bench-training model for flexible ureteroscopy, the Key-box (K-Box®, Porgès-Coloplast, France), to compare the LE configured with a 1.9F stone-retrieval tipless basket (ZeroTip™, Boston Scientific, USA) and a traditional assistant-maneuvered 1.9F stone-retrieval tipless basket. Seven experienced endo-urologists and seven residents-in-training retrieved a fake stone from three different renal cavities of the K-Box with increasing access complexity first with the traditional basket and then with the LE device. We recorded retrieval time and all the operators filled in the NASA Task Load Index (TLI) for the self-evaluation of their performance. We then compared the use of LE in terms of retrieval time, failure rates, and NASA-TLI scores. RESULTS: Stone retrieval times and failure rates were similar according to the retrieval technique, although residents had non-statistically significant shorter times with the LE. NASA-TLI scores revealed lower frustration (p = 0.03) when LE was used by experienced urologists as compared to the traditional basketing. When stratifying the analyses according to surgical experience, fully trained urologists performed faster stone retrieval and showed lower effort scores than residents-in-training (p < 0.05). CONCLUSIONS: The individually controlled retrieval system is an effective device assisting stone retrieval and does not necessitate specific training among experienced endo-urologists. Young residents might benefit from LE during their learning curve.

A Practical Guide for Intra-Renal Temperature and Pressure Management during Rirs: What Is the Evidence Telling Us.

INTRODUCTION: One of the main limitations of Ho:YAG lithotripsy is represented by its advancement speed. The need for faster lithotripsy has led to the introduction of high-power laser equipment. This general trend in increasing Ho:YAG lithotripsy power has certain points that deserve to be considered and analyzed. The objective is to carry out a narrative review on intrarenal temperature and pressure during ureteroscopy. METHODS: A literature search using PUBMED database from inception to December 2021 was performed. The analysis involved a narrative synthesis. RESULTS: Using more power in the laser correlates with an increase in temperature that can be harmful to the kidney. This potential risk can be overcome by increasing either the irrigation inflow or outflow. Increasing irrigant flow can lead to high intrarenal temperature (IRP). The factors that allow the reduction of intrarenal pressure are a low irrigation flow, the use of a ureteral access sheath of adequate diameter according to the equipment used, and the occupation of the working channel by the laser or basket. CONCLUSION: To maintain a safe temperature profile, it has been proposed to use chilled irrigation fluid, intermittent laser activation or to increase irrigation flow. This last recommendation can lead to increased IRP, which can be overcome by using a UAS. Another option is to use low power laser configurations in order to avoid temperature increases and not require high irrigation flows.

High- and Low-Power Laser Lithotripsy Achieves Similar Results: A Systematic Review and Meta-Analysis of Available Clinical Series.

Purpose: There is no clear evidence that high-power (HP) laser generators perform better than low-power (LP) ones in terms of lithotripsy outcomes. We aimed to perform a systematic review of literature to compare the efficacy outcomes of both HP and LP during ureteroscopic lithotripsy. Materials and Methods: A computerized bibliographic search of the Medline, Embase, and Cochrane databases was performed for all studies reporting perioperative outcomes of HP and LP lithotripsy. Using the methodology recommended by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, we identified 22 nonrandomized noncomparative retrospective studies published between 2015 and 2019 that were eligible for inclusion in this systematic review. Because of the lack of comparative studies, we decided to perform two separate meta-analytic syntheses for LP and HP studies, then we compared them using a Wald-type test. Results: Overall, the selected studies included 6403 patients. Study design, exposure assessment, selection criteria, and outcome of interest were heterogeneous. LP studies were more common (n = 17, 77%), whereas HP studies were more common in the latest inclusion period. Faster lithotripsy (32.9 minutes vs 63.9 minutes, p < 0.01) was observed in HP studies. However, stone volume resulted twofold higher (2604 mm3vs 1217 mm3, p = 0.048) in LP studies. Pooled stone-free rate was similar in both LP and HP studies, 81% and 82%, respectively, p > 0.05. No difference in complication rate was observed between the two groups, p = 0.12. Conclusions: HP laser lithotripsy appears to require shorter operative time, with similar stone-free and complication rates as compared with LP traditional lithotripsy. However, when taking into account stone burden, this advantage seems to be lost, or at least not to be comparable with what observed in laboratory studies. Because of the lack of high-level comparative evidence, further clinical studies are needed to elucidate the benefits of using HP laser generators during ureteroscopic stone treatment.

Etapa al diagnóstico de cáncer de próstata en un hospital institucional. Revisión y comparación de datos nacionales e internacionales

Introducción: El cáncer prostático (CaP) es una patología de alta prevalencia e incidencia mundial. El tamizaje ha perseguido el diagnóstico precoz de esta enfermedad para otorgar tratamientos oportunos. Nosotros buscamos caracterizar los pacientes de un hospital local respecto al diagnóstico y etapificación, y comparar estos resultados con datos previamente reportados. Material y Método: Análisis retrospectivo de pacientes diagnosticados con CaP en un hospital institucional. Se recolectaron variables clínicas al momento del diagnóstico, los métodos de etapificación, el estadío según TNM y grado histológico. Resultados: Se incluyeron 129 pacientes en el análisis. La mediana de APE (ng/mL) al diagnóstico fue de 7,29. El grado histológico fue clasificado como ISUP 1 en 37,5%. Se realizó una resonancia magnética multiparamétrica de próstata (RMmp) en el 42,19% de los pacientes, siendo clasificados como PIRADS 4 en mayor proporción (21,09%). La etapificación con PET-CT PSMA se utilizó principalmente en el grupo de alto riesgo y ante dudas frente a etapificación con medios convencionales. Se prefirió la Tomografía computada (TC) contrastada y la cintigrafía ósea en los otros grupos. 6,25% fue catalogado N1 y 9,37% M1. Conclusión: La etapa al diagnóstico de nuestra serie es algo mayor a lo reportado por países desarrollados, pero considerablemente menor a lo publicado por otros países de Latinoamérica e inclusive de otros hospitales de nuestro país. Pareciera ser de gran relevancia nacional contar con protocolos claros de tamizaje y acceso a APE con el fin de disminuir los casos diagnosticados en etapas avanzadas.

Introduction: Prostate cancer (PCa) is a disease with a high prevalence and incidence worldwide. Screening has pursued the early diagnosis of this disease to provide early treatment. We sought to characterize patients from a local hospital with respect to diagnosis and staging and to compare these results with previously reported data. Methods: We conducted a retrospective analysis of patients diagnosed with PCa at an institutional hospital. Clinical variables were collected at the time of diagnosis, staging methods, TNM stage, and histological grade. Results: 129 patients were included in the analysis. The median PSA (ng/mL) at diagnosis was 7.29. The histological grade was classified as ISUP 1 in 37.5%. An MRI was performed in 42.19% of the patients, being classified mostly as PIRADS 4 (21.09%). PET-CT PSMA staging was used mainly in the high-risk group, preferring contrast-enhanced CT and bone scintigraphy in the other groups. 6.25% were classified as N1 and 9.37% as M1. Conclusion: The stage at diagnosis in our series is somewhat higher than that reported by developed countries but considerably lower than that published by other Latin American countries and even from other hospitals in our country. It is of great national relevance to have clear protocols for screening and access to PSA to reduce the cases diagnosed in advanced stages.

Screeninig en cáncer de próstata, ¿En qué estamos ahora? Revisión de la literatura / Proatate cancert screeninig, where are we now ? a review of the literature

El cáncer de próstata es el segundo cáncer más prevalente en hombres en el mundo. Corresponde a la segunda causa de muerte por cáncer en hombres en Chile y EE.UU. convirtiéndose de esta manera en un problema de salud pública relevante. Hemos visto una serie de modificaciones a las recomendaciones de tamizaje del cáncer de próstata. Esta revisión tiene por objetivo resumir los principales acontecimientos en cuanto a recomendaciones sobre screening. La USPSTF ha realizado recomendaciones y variaciones a estas, siendo la última publicada en abril 2017. En Chile el screening no está incluido dentro de un programa ministerial y las últimas recomendaciones son del 2010. El uso y abuso del APE conlleva un stress emocional y eventuales complicaciones al paciente. Parece razonable, entonces, plantear un algoritmo basado no sólo en un parámetro predeterminado para definir si un paciente debe realizarse una biopsia o no, sino que incorporar al paciente en una toma de decisión informada.(AU)

Prostate cancer is the second cancer diagnosed in men in the world. It corresponds to the second cause of cancer death in men in Chile and the United States, thus becoming a relevant public health problem. We've seen a number of changes in prostate cancer screening recommendations. This review aims to summarize the main events regarding recommendations on screening. The USPSTF has made recommendations and variations to these subject, the last one being published in April 2017. In Chile, screening is not included in a ministerial program and the latest recommendations date from 2010. The use and abuse of the PSA brings emotional stress, as well as risks to the patient. It seems reasonable to propose an algorithm based not only on a parameter to define whether a patient requires a biopsy or not, but to incorporate the patient into an informed decision-making.(AU)