Asymptomatic Bacteriuria and Urological Surgery: Risk Factor or Not? Results From the National and Multicenter TOCUS Database.

PURPOSE: Current guidelines recommend screening and treatment of asymptomatic bacteriuria prior to all urological surgeries breaching the mucosa. But little evidence supports this recommendation. At the least, risk stratification for postoperative UTI to support this strategy is lacking. The aim of this study was to define the associated factors for postoperative febrile infectious complications (UTI or surgical site infection) in urological surgery. MATERIALS AND METHODS: We conducted a retrospective, multicentric study including all consecutive patients undergoing any urological surgery with preoperative urine culture. The primary outcome was the occurrence of a UTI or surgical site infection occurring within 30 days after surgery. RESULTS: From 2016 to 2023, in 10 centers, 2389 patients were included with 838 (35%) positive urine cultures (mono-/bi-/polymicrobial). Postoperative infections occurred in 106 cases (4.4%), of which 44 had negative urine cultures (41%), 42 had positive mono-/bimicrobial urine cultures (40%), and 20 had polymicrobial urine cultures (19%). In multivariable analysis, UTI during the previous 12 months of surgery (odds ratio [OR] 3.43; 95% CI 2.07-5.66; P < .001), monomicrobial/bimicrobial preoperative urine culture (OR 3.68; 95% CI 1.57-8.42; P = .02), polymicrobial preoperative urine culture (OR 2.85; 95% CI 1.52-5.14; P < .001), and operative time (OR 1.09; 95% CI 1.04-1.15; P < .001) were independent associated factors for postoperative febrile infections. CONCLUSIONS: Positive urine culture, including preoperative polymicrobial urine culture, prior to urological surgery was associated with postoperative infection. Additionally, patients experiencing infectious complications also had a higher incidence of other complications. The effectiveness of systematic preventive antibiotic therapy for a positive urine culture has not been conclusively established.

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

INTRODUCTION: 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. METHODS: 272-µm core-diameter laser fibers (Boston Scientific©) were connected to a 50 Watts 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 (0.5/0.8/1 J), 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. RESULTS: 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. 1 J 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. CONCLUSION: 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.

Is "Kidney Stone Calculator" efficient in predicting ureteroscopic lithotripsy duration? A holmium:YAG and thulium fiber lasers comparative analysis.

PURPOSE: This study aimed to evaluate the ability of Kidney Stone Calculator (KSC), a flexible ureteroscopy surgical planning software, to predict the lithotripsy duration with both holmium:YAG (Ho:YAG) and thulium fiber laser (TFL). METHODS: A multicenter prospective study was conducted from January 2020 to April 2023. Patients with kidney or ureteral stones confirmed at non-contrast computed tomography and treated by flexible ureteroscopy with laser lithotripsy were enrolled. "Kidney Stone Calculator" provided stone volume and subsequent lithotripsy duration estimation using three-dimensional segmentation of the stone on computed tomography and the graphical user interface for laser settings. The primary endpoint was the quantitative and qualitative comparison between estimated and effective lithotripsy durations. Secondary endpoints included subgroup analysis (Ho:YAG-TFL) of differences between estimated and effective lithotripsy durations and intraoperative outcomes. Multivariate analysis assessed the association between pre- and intraoperative variables and these differences according to laser source. RESULTS: 89 patients were included in this study, 43 and 46 in Ho:YAG and TFL groups, respectively. No significant difference was found between estimated and effective lithotripsy durations (27.37 vs 28.36 min, p = 0.43) with a significant correlation (r = + 0.89, p < 0.001). Among groups, this difference did not differ (p = 0.68 and 0.07, respectively), with a higher correlation between estimated and effective lithotripsy durations for TFL compared to Ho:YAG (r = + 0.95, p < 0.001 vs r = + 0.81, p < 0.001, respectively). At multivariate analysis, the difference was correlated with preoperative (volume > 2000 mm3 (Ho:YAG), 500-750 mm3 SV and calyceal diverticulum (TFL)), operative (fragmentation setting (p > 0.001), and basket utilization (p = 0.05) (Ho:YAG)) variables. CONCLUSION: KSC is a reliable tool for predicting the lithotripsy duration estimation during flexible ureteroscopy for both Ho:YAG and TFL. However, some variables not including laser source may lead to underestimating this estimation.

Ureteroscopic management in cystinuric patients: long-term results from a tertiary care referral center.

OBJECTIVE: To evaluate long-term surgical and functional outcomes of cystinuric patients exclusively treated with Ureteroscopy (URS). METHODS: Data from patients treated for cystine stones at a single academic center were retrospectively analyzed. The management protocol consisted of (i) treating symptomatic or > 7 mm stones, (ii) multi-staged URS for voluminous stones, (iii) referring patients to a dedicated nephrological clinic. The eGFR was calculated according to the MDRD formula. CKD category was assessed according to the NKF classification. Relevant CKD was defined as CKD category ≥ 3a. Descriptive statistics were used to analyze the cohort data. RESULTS: Data from 46 cystinuric patients treated with 332 URS were available. Median age at diagnosis and at first URS in our center were 18 and 32 years, respectively. Median follow-up was 101 months. Median number of URS and recurrences per patient were 6 and 2, respectively. The median interval between the first and the last available creatinine level was 64 months. Median first and last eGFR were 72 and 74 mL/min, respectively. Overall, 83% of patients had stable or improved renal function within the study period. Ureteral stricture occurred in 3 (6.5%) patients. CONCLUSIONS: Cystinuria requires intensive endoscopic management. Most patients treated with URS have stable or improved renal function within a long-term follow-up. CKD is a not neglectable event that potentially occurs at an early stage of life. Current findings should be considered for the surgical management of cystinuric patients.

Initial clinical experience with the pulsed solid-state thulium YAG laser from Dornier during RIRS: first 25 cases.

INTRODUCTION: Holmium:yttrium-aluminium-garnet (Ho:YAG) and thulium fiber (TFL) lasers are currently the two laser sources recommended for endocorporeal laser lithotripsy (ELL). Recently, the pulsed-thulium:YAG (Tm:YAG) laser was also proposed for ELL, as an answer to both Ho:YAG and TFL limitations. We aimed to evaluate the efficiency, safety, and laser settings of Tm:YAG laser in ELL during retrograde intrarenal surgery (RIRS). METHODS: A prospective study of the first 25 patients with ureteral and renal stones who underwent RIRS using the Thulio (pulsed-Tm:YAG, Dornier©, Germany) was performed in a single center. 272 µm laser fibers were used. Stone size, stone density, laser-on time (LOT) and laser settings were recorded. We also assessed the ablation speed (mm3/s), Joules/mm3 and laser power (W) values for each procedure. Postoperative results, such as stone-free rate (SFR) and zero fragments rate (ZFR) were also recorded. RESULTS: A total of 25 patients were analyzed (Table 1). The median (IQR) age was 55 (44-72) years old. Median (IQR) stone volume was 2849 (916-9153)mm3. Median (IQR) stone density was 1000 (600-1174)HU. Median (IQR) pulse energy, pulse rate and total power were 0.6 (0.6-0,8)J, 15(15-20)Hz and 12(9-16)W, respectively. All procedures used "Captive Fragmenting" pulse modulation (Table 2). The median (IQR) J/mm3 was 14,8 (6-21). The median (IQR) ablation rate was 0,75 (0,46-2)mm3/s. One postoperative complications occurred (streinstrasse). SFR and ZFR were 95% and 55%, respectively. CONCLUSION: The pulsed-Tm:YAG laser is a safe and effective laser source for lithotripsy during RIRS, using low pulse energy and low pulse frequency.

Thulium:YAG laser: a good compromise between holmium:YAG and thulium fiber laser for endoscopic lithotripsy? A narrative review.

PURPOSE: To provide a technological description of the new pulsed solid-state Thulium:YAG laser (Tm:YAG). In addition, current available literature on Tm:YAG lithotripsy is also reviewed. MATERIALS AND METHODS: Medline, Scopus, Embase, and Web of Science databases were used to search for Tm:YAG operating mode articles. RESULTS: Tm:YAG technology works with a laser cavity with thulium-doped YAG crystal, pumped by laser diodes. Laser beam operates at 2013 nm, with an adjustable peak power (≥ 1000 W) and the minimal fiber laser diameter is of 200 µm. It has an intermediate water absorption coefficient and peak power-pulse duration. Various pulse modulations are proposed, aiming to minimize stone retropulsion. Multiple comparative in vitro studies suggest that Tm:YAG's ability to fragment stones is similar to the one of the Ho:YAG laser; on the contrary, its ability to dust all stone types is similar to the one of the TFL, with a low retropulsion. A single in vivo study assessed Tm:YAG lithotripsy feasibility. CONCLUSIONS: The new pulsed solid-state thulium:YAG laser could represent a safe and effective compromise between Ho:YAG laser and TFL for endoscopic lithotripsy, either in retrograde intra-renal surgeries or in percutaneous nephrolithotomy.

Ureteral stents: What your eyes can't see! An in vitro study.

OBJECTIVES: To characterize and compare in vitro the surfaces of ureteral stents (STENTS) before utilization. METHODS: Our in vitro experiment included six unused STENTS models: three double-pigtail with side orifices (ImaJin and Stenostent [Coloplast©,France], TriaSoft [BostonScientific©,USA]), two double-pigtail without side orifice (Vortek-TumorStent [Coloplast©,France], Urosoft-TumorStent [Bard-Angiomed©,Germany]) and one single-pigtail (J-Fil [Rocamed©,Monaco]). STENTS were made of polyurethane except for ImaJin (silicone). For all STENTS, four parts of the stent were specifically analyzed under high-resolution scanning electron microscopy (HR-SEM,FEI-XL40 [Philips©,France]): surface core, lateral orifice, ureteral loop, and black marking surface. Each experiment was repeated with three different samples from three different stents. STENTS analysis included multiple imperfection searches, defined as irregularities>10µm. RESULTS: All STENTS presented imperfections with no discernible differences. Imperfections were mainly located on the stent loop and on the lateral orifice. For STENTS without side orifice (J-Fil, Urosoft) imperfections were also reported, on the beveled cut as well as the distal loop orifice. Marking surfaces examinations found defects in the Urosoft and imperfections in the ImaJin and Stenostent. The Triasoft presented a better smoothness on marking surfaces compared to other STENTS. Additional matter was reported on the loop distal orifice for J-Fil and ImaJin but all STENTS presented irregular cross-sectional aeras. CONCLUSION: All ureteral stents are not perfectly smooth even before utilization. Imperfections were noticed regardless to stent composition or shape, and could play a role in the incrustation phenomenon, is association with inner irregularities, infection, and urine composition. Both manufacturing and material could have an impact on the stent external surface's smoothness.

Optimizing Outcomes in Flexible Ureteroscopy: A Narrative Review of Suction Techniques.

OBJECTIVE: The aim of this review is to summarize the existing suction systems in flexible ureteroscopy (fURS) and to evaluate their effectiveness and safety. METHODS: A narrative review was performed using the Pubmed and Web of Science Core Collection (WoSCC) databases. Additionally, we conducted a search on the Twitter platform. Studies including suctions systems in fURS were included. Editorials, letters and studies reporting intervention with semirigid ureteroscopy, PCNL and mPCNL were excluded. RESULTS: A total of 12 studies were included in this review. These studies comprised one in vitro study, one ex vivo study, one experimental study and eight cohort studies. The Pubmed and WoSCC searches identified three suction techniques (Irrigation/Suctioning system with control of pressure, suction ureteral access sheath (sUAS) and direct in scope suction (DISS)), and the Twitter search identified four of them. The overall results showed that suction is an effective and safe technique that improves stone-free rates, reduces operative time and limits complication rates after fURS. CONCLUSIONS: The use of suctioning during common endourological procedures has been shown to improve safety and efficacy in several indications. However, randomized controlled trials are needed to confirm this.

Clinical Reproducibility of the Stone Volume Measurement: A "Kidney Stone Calculator" Study.

BACKGROUND: An accurate estimation of the stone burden is the key factor for predicting retrograde intra-renal surgical outcomes. Volumetric calculations better stratify stone burden than linear measurements. We developed a free software to assess the stone volume and estimate the lithotrity duration according to 3D-segmented stone volumes, namely the Kidney Stone Calculator (KSC). The present study aimed to validate the KSC's reproducibility in clinical cases evaluating its inter-observer and intra-observer correlations. METHODS: Fifty patients that harbored renal stones were retrospectively selected from a prospective cohort. For each patient, three urologists with different experience levels in stone management made five measurements of the stone volume on non-contrast-enhanced computed tomography (NCCT) images using the KSC. RESULTS: the overall inter-observer correlation (Kendall's concordance coefficient) was 0.99 (p < 0.0001). All three paired analyses of the inter-observer reproducibility were superior to 0.8. The intra-observer variation coefficients varied from 4% to 6%, and Kendall's intra-observer concordance coefficient was found to be superior to 0.98 (p < 0.0001) for each participant. Subgroup analyses showed that the segmentation of complex stones seems to be less reproductible. CONCLUSIONS: The Kidney Stone Calculator is a reliable tool for the stone burden estimation. Its extension for calculating the lithotrity duration is of major interest and could help the practitioner in surgical planning.

Endoscopic Conservative Treatment of Upper Urinary Tract Urothelial Carcinoma with a Thulium Laser: A Systematic Review.

INTRODUCTION: Thulium lasers (TLs), namely the Thulium fiber laser (TFL) and the Thulium:YAG (Tm:YAG), are being increasingly adopted for the conservative treatment of upper urinary tract urothelial carcinoma (UTUC). However, to date, the real clinical impact of TLs on UTUC management remains not well-characterized. We performed a review of the literature to summarize the current evidence on TLs for UTUC treatment. MATERIALS AND METHODS: We performed a systematic review in January 2023 using the Embase and Medline online databases, according to the PRISMA recommendations and using the PICO criteria. Outcomes of interest were: (i) to assess the safety and feasibility of TLs in the treatment of UTUC, and (ii) to evaluate the oncological outcomes in terms of tumor recurrence and conservative treatment failure. Moreover, we described TL characteristics and its interaction with soft tissue. RESULTS: a total of 458 articles were screened, and six full texts including 273 patients were identified. All the included studies were retrospective series. Mean patient age ranged from 66 to 73 years. The indication of a conservative treatment was elective and imperative in 21.7-85% and 15-76% of cases, respectively. Laser power settings varied from 5 to 50 W. No intraoperative complications were reported, and all the procedures were successfully performed. The tumor recurrence rate was 17.7-44%, and the indication to radical nephroureterectomy was 3.7-44% during a follow-up of 6-50 months. Most of the postoperative complications were mild and transient, and ureteral strictures were reported in two studies. Major limitations were the retrospective nature of the studies, the small sample sizes, and the short follow-up. CONCLUSIONS: TL is an effective and safe technology for endoscopic UTUC treatment. However, current available literature lacks prospective and multicentric studies with large population sizes and long-term follow-up.