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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.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.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).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.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement.

To present the evidence of latest developments of lasers for the surgical treatment of benign prostatic hyperplasia (BPH). We focused on recent advancements in Ho:YAG laser such as Moses technology, the Thulium Fiber Laser (TFL), the blue diode laser, and hybrid laser.Laser enucleation of prostate techniques using either Ho:YAG laser with the Moses technology and Moses 2.0, or TFL seem efficient and safe compared with the standard enucleation using Ho:YAG laser. Only in vitro studies evaluated the blue diode laser and hybrid laser (combination of a continuous wave TFL and blue diode laser). Blue diode laser showed intermediate incision depth and minimal coagulation depth compared with Ho:YAG laser and Super Pulse TFL. Hybrid laser showed deep incision depth and small coagulation area compared with Ho:YAG laser and continuous wave TFL.Surgical treatment of BPH using Moses technology, Moses 2.0, and TFL shows encouraging results comparable to the standard enucleation using Ho:YAG laser. Only in vitro data are currently available for blue diode laser and hybrid laser. Future well-designed studies comparing these technologies and evaluating them on specific risk groups of patients as well as the long-term durability of outcomes are needed.

OBJETIVES: To assess the effect of various factors on laser fiber tip degradation with the Thulium Fiber Laser (Tm-fiber): fiber stripping, adjustable laser settings (energy, frequency, peak power)...

OBJECTIVE: To assess the fiber-tissue interaction through ablation, coagulation, and carbonization characteristics of the Ho:YAG laser and Super Pulsed Thulium Fiber Laser (TFL) in a non-perfused p...

Objectives: The Thulium Fiber Laser (TFL) is studied as an alternative to the holmium:yttrium-aluminium-garnet (Ho:YAG) laser for lithotripsy, with the advantage of an induced bubble stream (IBS). ...

To assess whether the introduction of single use flexibles ureteroscopes (su-fURS) at our high-volume centre had an advantageous impact on the turn-over and breakage rates of reusable fURS (re-fURS). We analysed re-fURS number of usages and breakages at our centre between February 2015 and December 2018. We recorded the number of usages for analysed scope between the first usage until a breakage requiring reconditioning. Usage count was restarted following each reconditioning episode. Since su-fURS (Lithovue, Boston Scientific, USA) were introduced at our center in September 2016, we had the chance to compare different re-fURS life cycles according to both su-fURS availability and usage intensity (i.e., number of su-fURS used during each re-fURS life cycle). We then explored the relationship between su-fURS usage intensity and reusable scope survival (i.e., number of utilizations before any breakage requiring reconditioning) using locally weighted scatterplot smoothing (LOWESS) approach. Five different re-fURSs were employed at our centre, for a total of 1820 usages and 40 breakages requiring reconditioning. The overall mean (SD) number of usages before breaking was 40 (22). After su-fURS introduction, mean (SD) re-fURS number of usages increased from 35 (22) to 49 (20), (+ 40%, p = 0.02). The relationship between su-fURS usage intensity and reusable scopes survival showed a linear survival increase after 10 or more su-fURS scopes were used per life cycle. The life cycle of re-fURS increased by 40% after the introduction of su-fURS. Ten or more used su-fURS per life cycle were associated with increased re-fURS survival.

Nowadays, urolithiasis has become a highly prevalent disease. Recent studies indicate that retrograde intrarenal surgery (RIRS) is becoming more popular among surgical treatments due to the preference of patients and providers. This minimally invasive procedure results in high stone-free rates and relatively low morbidity; however, complications resulting from infection can still occur, including acute urinary tract infection, systemic inflammatory response syndrome, and sepsis.To identify the independent risk factors for sepsis following RIRS, as well as general risk factors that may contribute to this life-threatening complication in the pre- and intraoperative periods.A literature review was conducted in April 2020 using the Medline, Scopus, and Cochrane databases. We searched the references of included papers.We screened 2306 manuscripts and selected 13 for inclusion. The sepsis rate ranged from 0.5% to 11.1%, and the septic shock rate ranged from 0.3% to 4.6%. All selected studies mentioned risks for sepsis and/or infective complications (including sepsis), but only four of them addressed independent risks for urosepsis. These independent risk factors were stone size, high irrigation pressure, prolonged stent dwelling time (30 d), sepsis as an indication for stent insertion, female gender, positive intraoperative bladder urine culture, longer surgical time, and diabetes mellitus.RIRS is associated with a low sepsis rate, according to the latest evidence. However, given that this is a serious life-threatening complication, knowing its potential risk factors is extremely important.In this report, we looked at the outcome of sepsis after planned retrograde intrarenal surgery for stone disease in patients with and without comorbidities. This information may be useful for colleagues in their daily practice.

Endocorporeal laser lithotripsy (ELL) is currently the gold standard for the treatment of renal stones during retrograde intra-renal surgery (RIRS). The newly-authorised thulium fibre laser (Tm-Fibre) in now evaluated as a holmium:yttrium-aluminium-garnet (Ho:YAG) laser alternative, which is the most well-known laser source for ELL. This update aimed to present the fundamentals of pulsed lasers for EEL [technology, period, pulse characteristic (rate, duration, energy, shape), peak power, average power], and the available lithotripsy modes for both Tm-Fibre and Ho:YAG lasers.

Resume Objectif L’objectif du Comite des Troubles Mictionnels de l’Homme (CTMH) de l’Association Francaise d’Urologie (AFU) etait de mettre a jour les recommandations francaises parues en 2012 et celles de l’EAU parues en 2019 concernant la prise en charge chirurgicale et interventionnelle de l’obstruction sous-vesicale (OSV) liee a une hyperplasie benigne de prostate (HBP). Methodes Une revue systematique de la litterature (PubMed®), concernant l’OSV liee a l'HBP, a ete conduite entre 2018 et 2020 afin de completer celle prise en compte par les recommandations precedentes. Ce travail a comporte une strategie bibliographique predefinie puis une analyse critique de la litterature avec attribution de niveaux de preuve et redaction de conclusions et de recommandations permettant de repondre aux questions cliniques posees. Resultats/recommandations Proposer une incision cervicoprostatique (ICP) pour traiter chirurgicalement les patients ayant des symptomes du bas appareil urinaire (SBAU) moderes a severes avec un volume prostatique 80 cm3. Les implants intra-prostatiques sont une alternative pour traiter les SBAU chez les patients souhaitant conserver leur fonction ejaculatoire et ayant un volume prostatique Conclusion Les evolutions notables des techniques de prise en charge chirurgicales de l’OSV liee a l’HBP s’orientent vers une diminution de la morbidite des gestes et une amelioration de la qualite de vie au-dela du simple traitement des SBAU.

Resume Introduction De nombreuses techniques dites mini-invasives ont emerge ces dernieres annees dans le traitement chirurgical de l’obstruction due a l’hyperplasie benigne de la prostate (HBP). L’objectif de cet article etait de faire le point sur leurs evolutions et leurs resultats respectifs. Materiel et methode Une revue coherente de la litterature entre 2013 et 2020 a ete realisee par un panel d’experts nationaux de la chirurgie de l’HBP. Les donnees ont ensuite ete discutees par l’ensemble des co-auteurs afin d’obtenir un consensus vis-a-vis des articles selectionnes et de leur analyse. Un etat des lieux a enfin ete redige pour proposer une vue d’ensemble de ces avancees technologiques et de leur disponibilite en France. Resultats Le traitement de l’obstruction sous-vesicale liee a l’HBP s’est beaucoup diversifie ces 5 dernieres annees. L’inventaire comporte 5 nouvelles technologies permettant aujourd’hui une desobstruction transuretrale non ablative (UROLIFT®, ITIND®), transuretrale ablative (REZUM®), transuretrale ablative avec assistance robotique (AQUABEAM®) ou endovasculaire par embolisation des arteres prostatiques. Seul l’UROLIFT® est consideree comme une technologie etablie dans les dernieres recommandations de l’EAU. Les quatre autres sont en cours d’evaluation et des recommandations europeennes n’ont ete emises uniquement pour deux d’entre eux, l’AQUABEAM® et l’embolisation des arteres prostatiques. Conclusion Ces nouvelles techniques mini-invasives ont pour but d’augmenter les options therapeutiques pour la prise en charge de l’HBP afin de proposer une prise en charge plus adaptee aux souhaits du patient. Certaines se positionnent en alternative au traitement chirurgical, d’autres a la place du traitement medical ou entre le traitement medical et chirurgical. Ces technologies ne sont pas toutes au meme niveau de developpement, d’evaluation et de niveau de preuve mais ont en commun une diffusion restreinte en France, compte tenu notamment de leur cout. Leur utilisation au sein d’etudes validees permettra de positionner leur utilisation ulterieure de facon plus precise.

Resume But Etude medico-economique comparative des couts entre resection transuretrale monopolaire de la prostate (RTUP) en hospitalisation complete avec 3 nuits et photovaporisation prostatique (PVP) au laser Greenlight en ambulatoire. Materiel et methodes Une analyse retrospective par minimisation des couts sur la periode 2017-2019 a ete realisee dans un centre hospitalier prive francais pour les sejours associes aux actes de RTUP et de PVP en rapport avec une hypertrophie benigne de la prostate. L’estimation de la balance couts-benefices peri-operatoire liee aux deux techniques a ete realisee du point de vue de l’etablissement par la methode du micro-costing. Resultats 871 resections d’adenome de prostate ont ete realisees sur la periode de l’etude, dont 743 photovaporisations prostatiques (soit 85 %). La duree de sejour moyenne des patients operes d’une RTUP etait de 3,7 jours versus 0,9 jours pour la PVP dont 64,7 % etaient realisees en ambulatoire. La balance couts/recettes est en faveur de la PVP en ambulatoire par rapport a la RTUP en hospitalisation conventionnelle de 3 nuits, avec une difference de plus de 500€ par patient pour des sejours de niveau de severite 1. Conclusion Dans le centre hospitalier prive de notre etude, la PVP en ambulatoire apparaissait financierement plus interessante qu’une RTUP avec trois nuits d’hospitalisation complete pour un patient de niveau de severite 1. Le gain financier pour l’etablissement se trouve principalement dans la reduction de la duree moyenne de sejour et la prise en charge ambulatoire. Niveau de preuve 3.

To explore the risk of encrustation and biofilm formation for silicone ureteral stents compared to percuflex polymer stents, through a randomized multicenter study. Design, setting and participants: A Multicenter, prospective, randomized, single blind, comparative study of hydrocoated silicone stent (Coloplast Imajin® hydro) versus Percuflex™ Plus stent (Boston Scientific), in 141 patients treated by flexible URS for a kidney stone. The study had ethical committee approval in the respective hospitals. Outcome measurements and statistical analysis: Endpoints related to encrustation were biofilm formation and mineral encrustation after a period of 3-week indwelling time. They were evaluated at removal through a scoring scale of ureteral stents encrustation, infrared spectroscopy and optical microscopy of inner and outer surfaces of tips, angles and along the stent’s body. Comparison was performed using ANOVA. 119 stents were available after removal for analysis, 56 in the silicone and 63 in the Percuflex TM Plus group. Mean dwelling duration was 21.8 days for silicone, 22.1 days for PercuflexTM Plus. There was significantly more biofilm on Percuflex™ Plus compared to silicone (1.24 ± 0.08 vs 0.93 ± 0.09, p = 0.0021), and more mineral encrustation (1.22 ± 0.10 vs 0.78 ± 0.11, p = 0.0048), respectively. This multicenter randomized study shows that silicone-hydrocoated stents are less prone to encrustation than PercuflexTM Plus after a 3-week dwelling period and confirms the low encrustation potential of silicone.

Objective: To compare whether the outcomes of ultrasound-guided access percutaneous nephrolithotomy (USGA-PCNL) are similar to standard fluoroscopy-guided access percutaneous nephrolithotomy (FGA-P...

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. We used a bench-training model for flexible ureteroscopy, the Key-box (K-Box®, Porges-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. 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

Purpose:We compared the hydrocoated silicone stent (Coloplast Imajin® hydro) to Percuflex™ Plus stent (Boston Scientific) in terms of patient comfort and quality of life after flexible ureteroscopy...

To compare intrapelvic pressure (IPP) levels achieved during f-URS, mini-PCNL, standard PCNL, and endoscopic combined intrarenal surgery in a kidney model. A silicone model simulating the complete urinary tract was used for all the experiments. We compared: a 9.5Fr f-URS, a 12Fr mini-nephroscope and a 26Fr nephroscope. The irrigation pressure was set at 40 and 193 cmH2O. We compared: f-URS-S ± ureteral access sheath (UAS, 10/12Fr, 11/13Fr, 12/14Fr) ± 273 μm laser fiber, Mini-PCNL with different sizes of operating sheath (15/16Fr, 16.5/17.5Fr, 21/22Fr) ± 365 μm laser fiber, Standard PCNL with an operating sheath of 30Fr ± Lithotripter LithoClast Master 11.4Fr. f-URS: IPP values ranged between 1.4 and 46.2 cmH2O. Factors reducing IPP were an irrigation pressure at 40 cmH2O, an occupied working channel, and the use of a UAS except with the 10/12Fr at 193 cmH2O. Mini-PCNL: IPP values ranged between 2.4 and 39.7 cmH2O. Factors reducing IPP were irrigation pressure at 40 cmH2O, a large operating sheath (> 15/16Fr). The occupation of the working channel did not affect the IPP at 40 cmH2O, while it decreased at 193 cmH2O. Standard PCNL: IPP values ranged between 1.4 and 7.3 cmH2O. Occupancy of the working channel did not affect IPP at 40 cmH2O, while it increased at 193 cmH2O. We recorded for the first time IPP values according to different endourological techniques and configurations. IPP never exceed 50 cmH2O irrespectively of the assessed technique/setup. The factors reducing IPP were a low irrigation pressure (40 cmH2O), the use of a UAS or a working sheath appropriate to the diameter of the endoscope, as well as the occupation of the working channel in the case of f-URS.

Objectives To evaluate the risk of contracting severe COVID‐19, defined as COVID‐19 specific intensive care unit (ICU) admission or death, for patients undergoing urological surgery during the epidemic. To define consequences of receiving surgery for COVID‐19 patients. Patients and Methods This is a multicenter observational cohort study. Every patient receiving a urological procedure in Paris academic urological centers during the 4 initial weeks of surgical restrictions were included. Their status was updated minimum 3 weeks after the procedure. The main outcomes were the COVID‐19 specific ICU admission and death. Statistics were mostly descriptive. The Post‐operative COVID‐19 confirmed group was compared with non‐COVID patients using Chi‐square tests for categorical and Wilcoxon test tests for continuous variables. Results During the 4‐week period, 552 patients received surgery within 8 centers. At follow‐up, 57 (10%) patients were lost. Among the 11 preoperative COVID‐19 cases, one remained in ICU, no new admission, and no death. For the non‐COVID patients, 57 (12%) developed COVID‐related symptoms; only one case (0.2%) required COVID‐19 specific ICU and 3 (0.6%) patients died of COVID‐19 after surgery. Conclusions Performing urological surgery during the COVID‐19 epidemic peak has a limited impact on ICU admissions but presents a real (0.6%) risk of specific mortality. Surgical activities should be maintained according to this risk.

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. 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). 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. 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.

Objective To investigate the effects of laser temporal pulse shaping of the super-pulse thulium fibre laser (SPTFL) and to compare these in controlled in vitro conditions with various holmium: yttrium aluminium garnet (Ho:YAG) pulse delivery modes. Materials and methods The SPTFL (Urolase SP, IRE-Polus, Fryazino, Russia), with an emission wavelength of 1.94 μm, and a Ho:YAG laser (P120H; Lumenis, Yokneam, Israel) with Moses technology were compared. Pulse shape, stone retropulsion and ablation efficiency were evaluated using BegoStones and compared for each laser mode: short (SP), long (LP), and Moses pulse (MP) for Ho:YAG, regular pulse (RP) and dual pulse (DP) for SPTFL. Results The Ho:YAG SP mode exhibited an asymmetrical pulse shape, with a steep leading slope and a much more gradual trailing slope, without any flat section. Pulses generated by the SPTFL were significantly longer and therefore had lower peak power than those generated by the Ho:YAG laser at equivalent energy settings. Retropulsion for the holmium:YAG LP and MP modes was similar and lower than that for the SP mode, but higher than for the SPTFL (all P ≤ 0.02), with an average stone displacement approximately four times and two times lower for SPTFL as compared to the Ho:YAG laser. Comparison of ablation volumes indicated that the SPTFL induced significantly higher (twofold) ablation than the Ho:YAG laser. Conclusions The magnitude and initial velocity of stone retropulsion decreased with longer pulse duration and lower pulse peak power, without sacrificing ablation efficiency. These observations are manifest when comparing the Ho:YAG laser with the SPTFL. The novel SPTFL provides greater versatility and control of pulse variables than the Ho:YAG laser. Further clinical investigation of practical benefits achievable with pulse-shaping SPTFL modes is warranted.

To evaluate the feasibility of measuring the intrapelvic pressure (IPP) during f-URS with a wire including a pressure sensor and to assess IPP profiles during the procedure. Patients undergoing f-URS for stone disease were recruited. A wire with pressure sensor was placed in the renal cavities to measure IPP. For these cases, either no ureteral access sheath (UAS) or 10/12 or 12/14-Fr UASs were used according to surgeon discretion. Irrigation was ensured by a combination of a continuous pressure generator set at 80 cmH2O and a hand-assisted irrigation system providing on-demand forced irrigation to provide proper visibility. Pressures were monitored in real time and recorded for analysis. Four patients undergoing five f-URS were included. IPP monitoring was successful in all patients. Mean baseline IPP was 6 cmH2O. During f-URS with only the endoscope in the renal cavities and irrigation pressure set at 80 cmH2O without any forced irrigation, the mean IPP was 63 cmH2O. Mean IPP during laser lithotripsy with the use of on-demand forced irrigation was 115.3 cmH2O. The maximum pressure peaks recorded during this therapeutic period using forced irrigation ranged from 289.3 to 436.9 cmH2O. High IPP levels may be achieved during f-URS with on-demand irrigation systems. The impact of these high pressures on the risk of complications and long-term consequences still need to be evaluated adequately. But, in this preliminary pilot study, IPP could be reliably and conveniently monitored and recorded using a wire with a digital pressure sensor.

To evaluate whether stone dust can be obtained from all prevailing stone composition types using the thulium fiber laser (TFL) for lithotripsy. Where applicable, stone dust was further characterized by morpho-constitutional analysis. Human urinary stones were submitted to in vitro lithotripsy using a FiberLase U2 TFL generator with 150 µm silica core fibers (IPG Photonics®, IPG Medical™, Marlborough, MA, USA). Laser settings were 0.05 J, 320 Hz and 200 μs. A total of 2400 J were delivered to each stone composition type. All evaluated stones had a > 90% degree of purity (calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, carbapatite, struvite, brushite and cystine). Spontaneously floating stone particles were considered as stone dust and collected for analysis by scanning electron microscopy and Fourier transform infrared spectroscopy. Stone dust could be retrieved from all evaluated urinary stones after TFL lithotripsy. Most stone dust samples revealed changes in crystalline organization, except for calcium oxalate monohydrate and carbapatite, which conserved their initial characteristics. Mean maximal width of stone dust particles did not exceed 254 µm. The TFL is capable to produce stone dust from all prevailing stone types. Morpho-constitutional changes found in stone dust suggest a photothermal interaction of laser energy with the stone matrix during TFL lithotripsy.

To propose a size-related definition of stone dust produced by lithotripsy of urinary stones. Stone dust was defined as particles small enough to adhere to the following criteria: (1) spontaneous floating under 40 cm H2O irrigation pressure; (2) mean sedimentation time of > 2 s through 10 cm saline solution; (3) fully suitable for aspiration through a 3.6 F working channel. Irrigation, sedimentation, and aspiration tests were set up to evaluate each criterion. Primary outcome was particle size limit agreeing with all three criteria. Stone particles with a given size limit (≤ 2 mm, ≤ 1 mm, ≤ 500 µm, ≤ 250 µm, ≤ 125 µm and ≤ 63 µm) were obtained from laser lithotripsy, including samples from prevailing stone types: calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, carbapatite, struvite, brushite, and cystine. All particles ≤ 250 µm from all stone types were in agreement with all three criteria defining stone dust, except for struvite where size limit for a positive irrigation and sedimentation test was ≤ 125 µm. A size limit of ≤ 250 µm seems to generally adhere to our definition of stone dust, which is based on floating and sedimentation proprieties of stone particles, as well as on the ability to be fully aspirated through the working channel of a flexible ureteroscope.

Holmium:YAG(Ho:YAG) is currently the standard for lithotripsy. Superpulsed Thulium Fiber Laser(TFL) has been evaluated as an alternative for lithotripsy, using laser fibers with core-diameters(CDF) down to 50 µm and additional available settings suitable for “dusting” technique. This in-vitro study compared ablation rates, fissures and fragments’ size with 150µmCDF or 272µmCDF with different laser settings using TFL and Ho:YAG. 150CDF and 272CDF were compared using three settings for TFL “fine dusting”(FD:0.15 J/100 Hz); “dusting”(D:0.5 J/30 Hz); “fragmentation”(Fr:1 J/15 Hz) and Ho:YAG(D and Fr). An experimental setup consisting of immerged 10 mm cubes of artificial hard(H) or soft(S) stone phantoms was used with a 20 s’ lasing time and a spiral trajectory, in contact mode. Fragments (acquired through sieves) and stones were observed under optical microscopy before three-dimensional scanning to measure fragments and fissures(DOF) mean diameters and ablation volumes. Ablation volumes in with 150CDF-TFL and 272CDF-TFL were higher than those for 272CDF-Ho:YAG in both “dusting” (twofold and threefold) and “fragmentation”(1,5-fold and twofold). “Fine dusting” ablation rates with 150CDF-TFL and 272CDF-TFL were respectively at least 1,5-fold and twofold higher than those for 272CDF-Ho:YAG in “dusting”. 150CDF produced significantly smaller DOF than 272CDF in all settings against S and H except in fragmentation. 150CDF produced lower fragments’ diameter than 272CDF in all settings except dusting. These preliminary studies demonstrate that at equal settings and CDF, TFL ablation rates are at least two-fold higher than those with Ho:YAG. 150CDF produces smaller fissures and fragments (that meets the definition of “dusting” lithotripsy) than 272CDF and higher ablation volumes than Ho:YAG.

Resume But Identifier les causes d’hospitalisation prolongee chez les patients traites par ureteroscopie souple (URS-S). L’objectif secondaire a ete d’identifier des facteurs predictifs de complication. Materiel Une etude de cohorte retrospective monocentrique a ete menee entre janvier 2011 et decembre 2015. Ont ete inclus tous les patients consecutifs traites par URS-S dans le cadre d’une intervention programmee, quelle que soit l’indication, durant la periode etudiee ET restes hospitalises au moins une journee en plus de la duree d’hospitalisation postoperatoire traditionnelle de notre centre (> j1). Une analyse multivariee a ete realisee pour rechercher les facteurs predictifs d’hospitalisation prolongee. Resultats Au total, 272 patients ont ete inclus dans notre analyse. La duree mediane d’hospitalisation postoperatoire etait de deux jours [2–18]. 47 % des patients sortis a plus de j1 n’avaient aucune complication. Parmi eux, 56 % etaient restes pour surveillance simple decidee par le chirurgien sans qu’aucun traitement specifique n’ait ete introduit et 52 % pour poursuite d’une antibiotherapie par voie intraveineuse initiee en preoperatoire. Parmi les 144 patients restants et ayant eu une complication, 85,4 % (123/144) avaient une complication mineure (Clavien 1 ou 2). En analyse multivariee, les facteurs predictifs d’avoir une hospitalisation prolongee (sortie > j1) etaient un antecedent neurologique (paraplegie, spina bifida, sclerose en plaque) avec un odds ratio de 4,39 [1,7 ; 11,4] Conclusion Les causes d’hospitalisation prolongee etaient principalement les comorbidites. Un nombre non negligeable de patients etaient restes hospitalises sans complication. L’identification des facteurs predictifs de complications et d’hospitalisation prolongee peut permettre une meilleure selection des patients eligibles a la chirurgie ambulatoire et selectionner ceux pour qui l’hospitalisation traditionnelle reste recommandee. Niveau de preuve 3.

With an increase in the number of ureteroscopy (URS) procedures, URS is now performed more widely and is becoming a standard procedure for all urologists. There is also a rise in the complexity of these procedures and URS is now offered for treatment of stones as well as for diagnosis and treatment of urothelial tumours. We wanted to provide a 'pictorial review' of the 'tips and tricks' of URS, as the finer and technical details are often easier to understand and remember with images rather than through textual explanations.

Objective To assess the intermediate- and long-term effect of high-grade ureteral injuries from ureteral access sheaths. Methods Patients undergoing ureteroscopy for upper tract calculi were prospectively enrolled at 2 sites from 2010 to 2015. A 12/14 French sheath was used and the ureter was inspected with a flexible ureteroscope during withdrawal of the sheath and recorded. The videos were then evaluated by 2 blinded endourologists, and any injuries were graded per the Traxer ureteral injury scale. Only high-grade injuries were included. The primary endpoint was defined as ongoing hydronephrosis without an obstructing stone on follow-up imaging indicating a ureteral stricture. Logistic regression analysis was used to assess the relationship between hydronephrosis, ureteral injury, and other patient variables. Results Fifty-six patients were identified with high-grade ureteral injuries. Sixteen patients (28.6%) were female. Median age was 56.4 years (range 14-85). Median follow-up was 35.8 months (range 0-88). Three patients (5.5%) had hydronephrosis on follow-up imaging, only 1 of whom developed a de novo ureteral stricture. On univariate analysis, hydronephrosis was associated with a shorter stent duration (P = .11) and older age (P = .17). Conclusion Endoscopically identified high-grade ureteral lesions following ureteral access sheath placement do not lead to clinically significant sequelae on intermediate term follow-up, with a stricture rate comparable to those without visible injuries of 1.8%.

To present attributes of currently available flexible ureteroscopes to define the best flexible ureteroscope for upper tract urothelial carcinoma (UTUC) treatment. Scopus and Medline databases were searched for articles relating to performance of flexible ureteroscopes. A consensus for final inclusion of articles judged to be relevant for UTUC treatment was reached between the authors. Instrument characteristics were extracted from manufacturers’ product brochures. Smaller cross-sectional size of instruments is associated with increased probability for successful primary access to the upper urinary tract. The smallest flexible ureteroscopes are fiberoptic scopes. Smaller ureteroscopes also allow comparatively increased irrigation flow at constant intrarenal pressure. Digital flexible ureteroscopes achieve superior image quality compared to their fiberoptic counterparts, at the price of lower end-deflection ability. Image enhancement technologies such as narrow-band imaging (NBI), photodynamic diagnosis (PDD) and Image 1-S (formerly SPIES) are based on subjective image interpretation by the operator. NBI and PDD significantly increase tumor detection rate. The highest subjective image quality score of the Image 1-S technology is reached by the “Clara + Chroma” mode. Single-use ureteroscopes offer potential advantages over reusable scopes, including sterility, absence of contamination, immediate availability and exemption of previous instrument wear. Miniaturization, digital image caption and image enhancement technologies seem to be the major determinants defining the best flexible ureteroscope for UTUC treatment. The impact of further factors, such as distal tip design, torque, working channel position, risk of contamination, as well as upcoming technological innovations should be evaluated in randomized controlled trials.

Resume La cystinurie est une maladie monogenique induisant une perte de fonction d’un transporteur d’acides amines dibasiques implique dans la reabsorption de cystine au niveau des tubules renaux proximaux. L’excretion urinaire de cystine chez ces patients est augmentee d’un rapport 10 a 60 par rapport au sujet sain, responsable d’une sursaturation avec precipitation de cristaux de cystine dans les reins et de calculs dans les cavites excretrices. La physiopathologie de la cystinurie est particuliere : la concentration plasmatique de cystine est souvent normale alors que l’absorption intestinale est diminuee. Ce paradoxe est explique par une absorption intestinale preservee de cysteine et de methionine qui sont deux acides amines soufres metabolises notamment en cystine. Le principe du traitement consiste a empecher la formation de cristaux de cystine dans les reins afin de prevenir la survenue d’une maladie lithiasique, mais aussi d’une authentique nephropathie cristalline responsable d’une insuffisance renale chez plus de la moitie des patients. Le traitement medical des patients cystinuriques repose (1) sur une diminution de l’excretion urinaire quotidienne de cystine qui est le reflet de l’absorption intestinale et donc des apports en methionine ; (2) sur une augmentation du seuil de solubilite urinaire de la cystine afin de prevenir une precipitation cristalline intratubulaire et intracavitaire par une dilution et une alcalinisation des urines avec des valeurs cibles de 3 L et un pH urinaire aux alentour de 7,5. Le traitement par sulfhydryle dont le but est de dissocier les ponts disulfures des molecules de cystine avec un effet modeste sur la dissolution des calculs de cystine constitues ne devrait en toute logique etre utilise en dernier recours une fois les mesures dietetiques et la cible de pH urinaire obtenue.

Objectifs L’etude in vitro de la lithotritie laser (LL) utilise des calculs humains (CH) ou synthetiques (CS). Devant l’augmentation de la pulverisation laser (Dusting), peu d’echantillons humains sont disponibles. Les CS sont donc privilegies, confectionnes par melange d’eau et de plâtre, avec la problematique de leur rehydratation lors des LL. L’objectif etait de comparer les volumes d’ablation (VA) entre CS homogenes (CSHo) ou heterogenes(CSHe), et par rapport au poids ablate (PA). Methodes Les CSHo et CSHe durs (COM) ou tendre (UA) etaient confectionnes par melange de BegostonePlus (Bego®) et brassage lent ou rapide avec exsufflation, respectivement. Des fibres laser (Boston Scientific®) connectees au TFL (IPG Photonics®) 50 W (272 μm ou 150 μm) ou au MH1 Ho :YAG 30 W (Rocamed®) (272 μm) ont ete utilisees selon trois parametres laser (« fine dusting » [FD : 0,15 J/100 Hz], « dusting » [D : 0,5 J/30 Hz] et « fragmentation » [Fr : 1 J/15 Hz]). Une emission laser de vingt secondes etait realisee respectant une spirale de rayon 4 mm en contact avec les CS cubiques de 10 mm, prealablement peses et immerges. Apres sechage, les calculs etaient peses et scannes (Quantum FX, Perkin Elmer). Les volumes d’ablation etaient mesures par segmentation (3DSlicer [NIH]) ( Fig. 1 ). La correlation PA-VA (cPA-VA) etait evaluee pour chaque groupe. Resultats Avec les CSHe, les VA en Dusting etaient quatre et trois fois superieurs avec le TFL par rapport au Ho :YAG contre COM (p Tableau 1 ). Avec les CSHo cette difference n’etait plus significative contre UA en Dusting (p = 0,08) et Fragmentation (p = 0,09). L’utilisation des CSHo etait associee a des differences non significatives entre TFL-150 μm et TFL-272 μm, et entre TFL-150 μm et Ho :YAG-272 μm. La cPA-VA etait superieure en cas de CSHo par rapport au CSHe (0,853 versus 0,428, p Tableau 2 ). Si la cPA-VA etait acceptable en cas de COM (CSHo ou CSHe), il n’est pas possible d’utiliser l’approximation du VA par le PA en cas d’UA. Conclusion L’efficacite in vitro d’une LL est plus precise en utilisant les VA plutot que les PA. L’approximation du VA par le PA est acceptable et moins couteuse en cas de CSHo et dur (COM) bien que les calculs urinaires ressemblent plus aux CSHe (COM ou UA).

Context Morphoconstitutional analysis of urinary stones is perhaps the most important examination in the evaluation of a patient with urolithiasis. Objective A comprehensive stone classification system was developed in the early 1990s by Michel Daudon, which included the main types of stones and their possible physiopathogenic origin. Evidence acquisition A narrative review of the articles published about this classification was conducted, without time limit. Evidence synthesis Two analytical steps are needed for the classification process: the microscopic examination, which gives the stone morphology, and the physical analysis, which provides the stone constitution. Upon completion of a full analysis, knowledge of the principal crystal species of the stone is acquired. In addition, this analysis highlights the possible causes of the lithogenic process, taking in account less frequent, but severe, pathologies. Conclusions The aim of this report is to summarize the principal etiological causes for urinary stone formation thanks to the morphoconstitutional analysis and to present its contribution in the field of urinary stones. Patient summary We looked at all types of stones and found that their origin varies according to the underlying pathology of the patient.

There is currently insufficient in vivo evidence that high-power Ho:YAG lasers improve retrograde intrarenal surgery or the ablation efficacy. While prospective trials are awaited, a low-cost, silent, low-power Ho:YAG laser that requires only a standard electrical outlet is more than sufficient for retrograde intrarenal surgery.

Despite the worldwide spread of Ho:YAG lasers in urology departments, the physical principles behind their functioning may still seem obscure to many urologists. Moreover, a new laser source, the thulium fiber laser (TFL), was recently approved for stone lithotripsy. Here we describe the concepts of peak power and pulse modulation for laser lithotripsy, analyzing both Ho:YAG lasers and TFLs. Different pulse modalities are available for Ho:YAG lasers—long and short pulses and Moses technology—each with a different pulse shape and peak power. Lower peak power and a more rectangular pulse shape provide higher ablation efficiency and lower stone retropulsion. These characteristics are perfectly embodied by TFL, which shows the most effective ablation efficiency in laboratory studies. A long pulse is the most effective modality for Ho:YAG lasers. Moses technology, despite its promising rationale, is not superior to long-pulse mode. Clinical studies are needed in order to confirm these laboratory data. Patient summary: Laser lithotripsy is one of the main options for the treatment of urinary stones. The peak power and pulse modulation influence the choice of the optimal laser mode for the treatment of urinary stones. Thulium fiber lasers have shown the most favorable dusting profile in terms of both peak power and pulse modality in laboratory studies, but clinical evidence is still lacking. Peak power and pulse modulation influence choice of the optimal laser mode for the treatment of urinary stones. Thulium fiber lasers show the best profile in terms of both peak power and pulse modulation, although clinical studies are still awaited.

Resume Trois risques d’exposition oculaire lors des chirurgies endoscopiques urologiques existent : les projections de liquides biologiques et d’irrigation, le rayonnement laser et les rayons X. Afin de prevenir ces risques et leurs consequences, le port de lunettes de protection est recommande. Cette revue a pour objectif de detailler chacun de ces risques et donner les elements necessaires pour une protection adaptee.

To define which long-term stent would work best in malignant ureteral obstruction (MUO) and benign ureteral obstruction (BUO), focusing on their mechanisms of action, price and insertion approach. A systematic review was developed using the MEDLINE and Scopus databases and in accordance with the PRISMA checklist. There were no language restrictions for the search. Studies describing the use of metallic ureteric stents for MUO and for BUO in humans were included. We analyzed five types of metallic stents (35 papers) and also the experience with the tumor and extra-anatomical stents. The Resonance, Memokath and Allium ureteral stents were found to be useful in BUO and MUO. The Uventa stent performed well in chronic ureteral obstruction. The Detour bypass stent was a recommended option in those patients who had complete obstruction of the ureter and were unfit for reconstructive surgery. There was no difference with regard to the insertion technique and both antegrade and retrograde approaches were equally successful. Although tumor stents showed a good performance, there were very few published studies on it. Metallic stents are a suitable option for MUO and BUO. When compared to standard double J stents, although they are relatively high priced, they show a financial benefit in the long-term. The Detour bypass stent seems to be an effective alternative for complete ureteral obstruction or patients unfit for surgery. Further prospective randomized studies should be done on the effectiveness of tumor stents versus metallic stents.

To explore the mechanisms behind the potential protective effect of coffee and tea consumption, regarding urinary stone formation, previously demonstrated in large epidemiological studies. A systematic review was performed using the Medline, Cochrane library (CENTRAL) and Scopus databases, in concordance with the PRISMA statement. English, French and Spanish language studies, regarding the consumption of caffeinated and decaffeinated coffee and tea, and the relationship to urinary stone formation were reviewed. Meta-analyses, systematic reviews, case reports and letters, unpublished studies, posters and comments abstracts were excluded. As per the inclusion criteria, 13 studies were included in the final review. The major findings show that caffeine increases urinary excretion of calcium, sodium and magnesium, in addition to a diuretic action with consumption > 300–360 mg (approximately four cups of coffee). Together with other components of coffee, this beverage might have potential protective effects against the formation of urinary stones. Tea exerts many protective effects against stone formation, through the accompanying water intake, the action of caffeine and the effects of components with antioxidant properties. Caffeine has a hypercalciuric effect, balanced partially by a diuretic effect which appears after consumption of large quantities of caffeine. The current available literature supports in general, a potentially protective role for tea against stone formation, mainly for green tea. Additional standardization in this field of research, through specification of tea and coffee types studied, and their respective compositions, is needed for further clarification of the relation between coffee, tea and urinary stones.

To explore the relationship between the consumption of coffee and tea with urolithiasis. We evaluated large epidemiological and small clinical studies to draw conclusions regarding their lithogenic risk. A systematic review was performed using the Medline and Scopus databases, in concordance with the PRISMA statement. English, French, and Spanish language studies regarding the consumption of caffeinated and decaffeinated coffee and tea, and the relationship to urinary stone disease were reviewed. Case reports and letters, unpublished studies, posters, and comments were excluded. As per the inclusion criteria, 13 studies were included in the final review. Most studies, including four large prospective studies and one meta-analysis, reported a reduced risk of stone formation for coffee and tea. Caffeine has a diuretic effect and increases the urinary excretion of calcium, but if these losses are compensated for, moderate caffeine intakes may have little or no deleterious effects. Green and Herbal teas infused for short time had low oxalate content compared to black tea. There is no evidence that moderate consumption of coffee raises the risk for stone formation in healthy individuals, provided the recommended daily fluid intake is maintained. The currently available literature supports in general a protective role for tea against the stone formation, mainly for green tea. However, heterogeneity of published data and lack of standardization needs to be addressed before final and clear conclusions can be given to patients and to the public in general.

INTRODUCTION AND OBJECTIVE:Holmium: YAG (Ho:YAG) laser is currently the standard for lithotripsy. Recently, Superpulsed Thulium Fiber Laser (TFL) has been evaluated as an alternative for lithotrips...

Introduction Kidney Stone Calculator (KSC) est un outil que nous avons developpe pour mesurer le volume lithiasique total (VLT) et estimer la duree operatoire de lithotritie laser endocorporelle (LLE) au cours de l’ureterorenoscopie souple (URS-S), a partir du scanner abdominopelvien preoperatoire non injecte (TDM AP IV-). L’objectif de cette etude etait de realiser une evaluation preclinique et clinique de cet outil. Methodes Une base de donnees scanographiques (17) etait prealablement constituee : 9 calculs humains, 6 calculs synthetiques cubiques, 2 situations cliniques (calcul unique et coralliforme). Apres formation, les VLT etaient mesures en aveugle par trois operateurs (interne, urologue senior, ingenieur). Une analyse des coefficients de correlation inter-operateurs et de Kendall etait realisee. Fut conduite ensuite une etude clinique multicentrique prospective en double aveugle incluant des patients avec calculs renaux traites par URS-S avec LLE et TDM AP IV- preoperatoire dans 3 centres, entre janvier et mars 2020. Etaient collectees les caracteristiques demographiques, lithiasiques (diametre maximum, VLT, densite) et operatoires (materiel, duree et parametres de LLE avec laser Holmium :YAG, energie totale delivree, complications). Les durees de LLE effective (EfLLE) et estimee (EsLLE) par KSC ont ete comparees, ainsi que 5 facteurs influencant potentiellement cette estimation : calcul caliciel inferieur non relocalisable ou non relocalise, diametre de la gaine d’acces, mode de LLE et experience de l’operateur. Resultats Aucune difference significative n’etait retrouvee entre les operateurs (Op1-Op2 : p = 0,35, Op1-Op3 : p = 0,69, Op2-Op3 : p = 0,29). Une forte concordance inter-operateur etait retrouvee (Kendall : 0,98 et correlation Pearson : 0,99). Concernant l’evaluation clinique, 26 patients furent inclus dans trois centres, avec un âge median de 55,5 ans. Le sex-ratio etait de 2 hommes pour 1 femme, avec un IMC median de 28,7 kg/m2. Les patients presentaient un calcul unique, caliciel inferieur et une densite > 1000 UH dans 66 %, 42 % et 85 %, respectivement ( Tableau 1 ). Une difference mediane de 14 % (5,4–24,8) entre EsLLE et EfLLE etait constatee (p = 0,36), majoree en cas de calcul caliciel inferieur non relocalisable (p = 0,008), en mode Fragmentation ( Tableau 2 , Tableau 3 ). Le diametre de la gaine d’acces ureterale et l’experience de l’operateur n’influencaient pas significativement cette difference (p = 0,46 et p = 0,07, respectivement). L’energie par mm3 et le debit d’ablation medians etaient de 17,6 J/mm3 et 23,8 mm3/min, respectivement. Conclusion Kidney Stone Calculator est un outil de planification operatoire reproductible et fiable. Il permet d’estimer le VLT et la duree de LLE a partir du TDM AP IV- preoperatoire avec fenetrage osseux manuel sans prerequis. Les calculs caliciels inferieurs non relocalisables, le mode Fragmentation et l’experience moindre de l’operateur peuvent conduire a sous-estimer la duree de LLE. Une etude clinique sur un plus grand nombre de patients est necessaire pour valider ces resultats.

Introduction: Holmium:yttrium–aluminium–garnet (Ho:YAG) is currently the gold standard for lithotripsy for the treatment of all known urinary stone types. Stone composition and volume are major determinants of the lithotripsy. This in vitro study evaluated the required energy to ablate 1 mm3 of various stone types with different laser settings using Ho:YAG. Methods: 272 µm core-diameter laser fibers (Boston Scientific©) were connected to a 30 Watt MH1 Ho:YAG generator (Rocamed®). An experimental setup consisting of immerged human stones of calcium oxalate monohydrate (COM), uric acid (UA) or cystine (Cys) was used with a single pulse lasing emission (0.6/0.8/1 J), in contact mode. Stones were dried out before three-dimensional scanning to measure ablation volume per pulse (AVP) and required energy to treat 1 mm3 (RE). Results: All settings considered, ablation volumes per pulse (AVP) for COM were significantly lower than those for UA and Cys (p = 0.002 and p = 0.03, respectively), whereas AVP for Cys was significantly lower than those for UA (p = 0.03). The mean REs at 0.6 J pulse energy (PE) for COM, Cys and UA were 34, 8.5 and 3.2 J, respectively The mean REs at 1 J PE for COM, Cys and UA were 14.7, 6.4 and 2 J, respectively. At 0.6 J PE, RE for COM was more than tenfold and fivefold higher than those for UA and Cys, respectively. Conclusion: This in vitro study shows for the first time a volumetric evaluation of Ho:YAG efficiency by the ablation volume per pulse on human stone samples, according to various pulse energies. The REs for COM, UA and Cys should be considered in clinical practice. In vivo imaging was performed at Life Imag-ing Facility of Paris Descartes University (Plateforme Imageries du Vivant), supported by France Life Imaging (grant ANR-11-INBS-0006) and Infrastructures Biologies-Santé.

Objectifs La vitesse optimale de deplacement (VOD) de la fibre laser pour realiser la pulverisation lithiasique est une variable inconnue a ce jour, autant pour le laser thulium fibre (TFL) que pour le laser Holmium :YAG (Ho :YAG). L’objectif etait de determiner in vitro la VOD de la fibre laser lors d’une lithotritie endocorporelle en fonction des parametres laser avec le TFL et l’Ho :YAG, au moyen des volumes d’ablation (VA). Methodes Des fibres laser (Boston Scientific) de diametre 272 μm connectees au TFL (IPG Photonics) 50 W ou au MH1 Ho :YAG 30 W (Rocamed) ont ete comparees selon trois modes de lithotritie TFL (« fine dusting » [FD : 0,05–0,15 J/100–600 Hz], « dusting » [D : 0,5 J/30–60 Hz] et « fragmentation » [Fr : 1 J/15–30 Hz]) et deux modes Ho :YAG (« dusting » [D : 0,5 J/20 Hz] et « fragmentation » [Fr : 1 J/15 Hz]). Une emission laser de deux secondes etait realisee en contact avec des calculs synthetiques (Begostone) durs, en position statique ou avec un deplacement de 5, 10 ou 20 mm. Apres sechage, les calculs etaient scannes (Quantum FX, Perkin Elmer). Les VA etaient mesures par segmentation (3DSlicer [NIH]) ( Fig. 1 ). Resultats Quels que soient les parametres ou source laser, les VA dynamiques (VAD) etaient superieures aux VA statiques (VAS) (Tableau 1). En Dusting, les VAS et VAD etaient trois et quatre fois superieurs avec le TFL par rapport au Ho :YAG (p Tableau 1 ). Pour le TFL, les VODTFL etaient de 5 mm/s en Fine Dusting, Dusting et Fragmentation, sauf a 0,15 J-100 Hz (10 mm/s). Les profils de VOD entre TFL et Ho :YAG differaient, avec une VODTFL a 0,15 J-100 Hz identique a la VODHo :YAG a 0,5 J-20 Hz. A 50 mJ, la VODTFL etait proportionnelle a la frequence, toutefois non retrouvee a 0,15, 0,5 et 1 J ( Tableau 2 ). Conclusion Cette etude retrouve une VODTFL inferieure par rapport a la VODHo :YAG en Dusting, traduisant une potentielle utilisation plus aisee du TFL pour realiser une pulverisation optimale. La VOD semble d’avantage varier selon le couple energie-frequence, que selon la frequence seule. Que cela soit en position statique ou dynamique, les VATFL est 3 a 4 fois superieurs aux VAHo :YAG.