Seguridad, consejos y límites para el uso del láser en la cirugía retrógrada intrarrenal / Laser safety, warnings, and limits in retrograde intrarenal surgery

Objetivo Analizar la información actual sobre la seguridad del láser en la cirugía retrógrada intrarrenal (CRIR), centrándonos en las dos principales tecnologías láser que utilizamos en urología, el láser de holmio:itrio-aluminio-granate (Ho:YAG) y el láser de fibra de tulio (TFL). Métodos Revisión narrativa de los artículos más relevantes publicados en las bases de datos Medline y Scopus sobre este tema. Resultados Los láseres TFL y Ho:YAG con ajustes similares (0,2 J/40 Hz) tienen un aumento de temperatura promedio por volumen similar y la tasa de calentamiento promedio aumenta proporcionalmente a la potencia del láser, especialmente cuando se utilizan frecuencias altas. Datos preclínicos recientes que comparan ambas tecnologías láser con diferentes ajustes del láser coinciden en que cuando la energía suministrada aumenta a expensas de frecuencias más altas, el daño térmico también aumenta. Las frecuencias más altas, a pesar del aumento de temperatura en el medio de irrigación, pueden causar lesiones térmicas accidentales por láser. Conclusiones El uso de ajustes de baja frecuencia y una irrigación adecuada es fundamental para evitar lesiones térmicas en la litotricia endoscópica con láser (LEL). Además, se recomienda el uso de gafas de seguridad láser en la LEL con Ho:YAG y TFL. (AU)

Objective To analyze the current information about laser safety in retrograde intrarenal surgery (RIRS), focusing on the two main laser technologies that we use in urology, the holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and the thulium fiber laser (TFL). Methods Narrative overview of the most relevant articles published in Medline and Scopus databases about this subject. Results TFL and Ho:YAG laser at similar settings (0.2 J/40 Hz) have similar volume-averaged temperature increase and the average heating rate increase proportionally to laser power, especially when high frequencies are used. Recent preclinical data, comparing both laser technologies at different laser settings, agreed that when the delivered energy increases in expenses of higher frequencies, the thermal damage increases too. Higher frequencies, despite of the rise of temperature in the irrigation medium, can cause accidental thermal lasering lesions. Conclusions The use of low frequency settings and a proper irrigation is critical to avoid thermal injury in endoscopic laser lithotripsy (ELL). In addition, the use of laser safety eyeglasses is recommended in Ho:YAG and TFL ELL. (AU)

¿Cómo calcular el volumen litiásico y cuál es su aplicación quirúrgica? / How to estimate stone volume and its use in stone surgery: A comprehensive review?

Objetivo Las guías actuales para el tratamiento intervencionista sugieren el diámetro acumulativo de la litiasis (DAL) como factor decisivo en la elección del tratamiento quirúrgico óptimo (ureteroscopia [URS], litotricia extracorpórea por ondas de choque [LEOCh] y nefrolitotomía percutánea [NLPC]). El volumen litiásico (VL) se ha introducido recientemente para obtener una estimación más precisa de la carga litiásica. El objetivo de esta revisión es resumir los métodos disponibles para calcular el VL y su aplicación quirúrgica. Material y métodos En diciembre de 2022 se realizó una revisión sistemática de la literatura mediante búsquedas en las bases de datos Embase, Cochrane y Pubmed. Los artículos se consideraron elegibles si describían la medición del VL o la tasa libre de litiasis (TLL) tras diferentes modalidades de tratamiento (LEOCh, URS, NLPC) o la expulsión espontánea, basándose en la medición del VL. Dos revisores evaluaron de forma independiente la elegibilidad y la calidad de los artículos y realizaron la extracción de datos. Resultados En total se incluyeron 28 estudios. Todos los estudios utilizaron diferentes técnicas para calcular el VL. La medición automática del volumen pareció ser más precisa que la estimación del volumen. Los estudios in vitro mostraron que la medición automática del volumen se ajustaba más al volumen real de la litiasis, con una menor variabilidad interobservador. A diferencia de la NLPC y la LEOCh, en la URS se observó que el VL era un mejor predictor de mejor la TLL que el diámetro litiásico mayor o el diámetro acumulativo en litiasis >20mm. Conclusiones Calcular el VL —de forma manual o automática— es factible, y probablemente se ajuste más a la carga litiásica real. Aunque en el caso de las litiasis grandes tratadas mediante cirugía intrarrenal retrógrada el VL parece predecir mejor la TLL, la superioridad del VL en todas las cargas litiásicas y para todos los tipos de tratamiento está aún por demostrar. ... (AU)

Objective Current interventional guidelines refer to the cumulative stone diameter to choose the appropriate surgical modality (ureteroscopy (URS), extracorporeal shockwave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL)). The stone volume (SV) has been introduced recently, to better estimate the stone burden. This review aimed to summarize the available methods to evaluate the SV and its use in urolithiasis treatment. Material and methods A comprehensive review of the literature was performed in December 2022 by searching Embase, Cochrane and Pubmed databases. Articles were considered eligible if they described SV measurement or the stone free rate after different treatment modalities (SWL, URS, PCNL) or spontaneous passage, based on SV measurement. Two reviewers independently assessed the eligibility and the quality of the articles and performed the data extraction. Results In total, 28 studies were included. All studies used different measurement techniques for stone volume. The automated volume measurement appeared to be more precise than the calculated volume. In vitro studies showed that the automated volume measurement was closer to actual stone volume, with a lower inter-observer variability. Regarding URS, stone volume was found to be more predictive of stone free rates as compared to maximum stone diameter or cumulative diameter for stones >20mm. This was not the case for PCNL and SWL. Conclusions Stone volume estimation is feasible, manually or automatically and is likely a better representation of the actual stone burden. While for larger stones treated by retrograde intrarenal surgery, stone volume appears to be a better predictor of SFR, the superiority of stone volume throughout all stone burdens and for all stone treatments, remains to be proven. Automated volume acquisition is more precise and reproducible than calculated volume. (AU)

How to estimate stone volume and its use in stone surgery: a comprehensive review.

OBJECTIVE: Current interventional guidelines refer to the cumulative stone diameter to choose the appropriate surgical modality (ureteroscopy [URS], extracorporeal shockwave lithotripsy [ESWL] and percutaneous nephrolithotomy [PCNL]). The stone volume (SV) has been introduced recently, to better estimate the stone burden. This review aimed to summarize the available methods to evaluate the SV and its use in urolithiasis treatment. MATERIAL AND METHODS: A comprehensive review of the literature was performed in December 2022 by searching Embase, Cochrane and Pubmed databases. Articles were considered eligible if they described SV measurement or the stone free rate after different treatment modalities (SWL, URS, PCNL) or spontaneous passage, based on SV measurement. Two reviewers independently assessed the eligibility and the quality of the articles and performed the data extraction. RESULTS: In total, 28 studies were included. All studies used different measurement techniques for stone volume. The automated volume measurement appeared to be more precise than the calculated volume. In vitro studies showed that the automated volume measurement was closer to actual stone volume, with a lower inter-observer variability. Regarding URS, stone volume was found to be more predictive of stone free rates as compared to maximum stone diameter or cumulative diameter for stones >20 mm. This was not the case for PCNL and SWL. CONCLUSIONS: Stone volume estimation is feasible, manually or automatically and is likely a better representation of the actual stone burden. While for larger stones treated by retrograde intrarenal surgery, stone volume appears to be a better predictor of SFR, the superiority of stone volume throughout all stone burdens and for all stone treatments, remains to be proven. Automated volume acquisition is more precise and reproducible than calculated volume.

Laser safety, warnings, and limits in retrograde intrarenal surgery.

OBJECTIVE: To analyze the current information about laser safety in retrograde intrarenal surgery (RIRS), focusing on the two main laser technologies that we use in urology, the holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and the thulium fiber laser (TFL). METHODS: Narrative overview of the most relevant articles published in MEDLINE and Scopus databases about this subject. RESULTS: TFL and Ho:YAG laser at similar settings (0.2 J/40 Hz) have similar volume-averaged temperature increase and the average heating rate increase proportionally to laser power, especially when high frequencies are used. Recent preclinical data, comparing both laser technologies at different laser settings, agreed that when the delivered energy increases in expenses of higher frequencies, the thermal damage increases too. Higher frequencies, despite of the rise of temperature in the irrigation medium, can cause accidental thermal lasering lesions. CONCLUSION: The use of low frequency settings and a proper irrigation is critical to avoid thermal injury in endoscopic laser lithotripsy. In addition, the use of laser safety eyeglasses is recommended in Ho:YAG and TFL ELL.

2022 Recommendations of the AFU Lithiasis Committee: Laser - utilization and settings.

Endocorporeal lithotripsy has progressed thanks to the development of lasers. Two laser sources are currently available: Holmium:YAG (Ho:YAG) and more recently Thulium Fiber Laser (TFL). The settings generally used are dusting, fragmentation, and "pop-corning". These are the first recommendations on laser use for stone management and their settings. Settings must be modulated and can be changed during the treatment according to the expected and obtained effects, the location and stone type that is treated. METHODOLOGY: These recommendations have been developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether or not the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU Guidelines on urolithiasis. 2022]) and their adaptability to the French context.

2022 Recommendations of the AFU Lithiasis Committee: Ureteroscopy and ureterorenoscopy.

Technical advances, including miniaturization, have improved the deflection and optical performance of the ureteroscopes, and the availability of dedicated disposable devices have led to their increasing use for kidney and ureteral stone management. Ureterorenoscopy brings diagnostic evidence through the endoscopic description of stones and renal papillary abnormalities. Currently, intracorporeal lithotripsy during ureterorenoscopy is based on laser sources. Routine ureteral stenting is not necessary before ureterorenoscopy, especially because preoperative stenting for>30 days is considered as an independent risk factor of infection. Ureteral access sheaths allow the easy and repeated access to the upper urinary tract and thus facilitate ureterorenoscopy. Their use improves vision, decreases intrarenal pressure, and possibly reduces the operative time, but they may cause ureteral injury. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether or not the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Volumetric and functional outcomes at 1-year between percutaneous-ablation and partial-nephrectomy for T1b renal tumors.

INTRODUCTION: Indication for percutaneous-ablation (PA) is gradually expanding to renal tumors T1b (4-7cm). Few data exist on the alteration of renal functional volume (RFV) post-PA. Yet, it is a surrogate marker of post partial-nephrectomy (PN) glomerular filtration rate (GFR) impairment. The objective was to compare RFV and GFR at 1-year post-PN or PA, in this T1b population. METHODS: Patients with unifocal renal tumor≥4cm treated between 2014 and 2019 were included. Tumor, homolateral (RFVh), contralateral RFV, and total volumes were assessed by manual segmentation (3D Slicer) before and at 1 year of treatment, as was GFR. The loss of RFV, contralateral hypertrophy, and preservation of GFR were compared between both groups (PN vs. PA). RESULTS: 144 patients were included (87PN, 57PA). Preoperatively, PA group was older (74 vs. 59 years; P<0.0001), had more impaired GFR (73 vs. 85mL/min; P=0.0026) and smaller tumor volume(31.1 vs. 55.9cm3; P=0.0007) compared to PN group. At 1 year, the PN group had significantly more homolateral RFV loss (-19 vs. -14%; P=0.002), and contralateral compensatory hypertrophy (+4% vs. +1,8%; P=0.02, respectively). Total-RFV loss was similar between both (-21.7 vs. -19cm3; P=0.07). GFR preservation was better in the PN group (95.9 vs. 90.7%; P=0.03). In multivariate analysis, age and tumor size were associated with loss of RFVh. CONCLUSION: For renal tumors T1b, PN is associated with superior compensatory hypertrophy compared with PA, compensating for the higher RFVh loss, resulting in similar ΔRFV-total between both groups. The superior post-PN GFR preservation suggests that the preserved quantitative RFV factor is insufficient. Therefore, the underlying quality of the parenchyma would play a major role in postoperative GFR.

Ablation rates with Holmium:YAG and Thulium Fiber Laser: Influence of the stone phantom homogeneity. An in vitro study.

OBJECTIVES: The lithotripsy efficiency (LE) in vitro study requires artificial or human stone samples (AS, HS). With the development of dusting lithotripsy, less ex vivo HS are available. We aimed to compare Thulium Fiber Laser (TFL) and Holmium:YAG (Ho:YAG)'s LE and define the most accurate LE parameter. METHODS: Hard and soft homogenous- and heterogenous-AS (Ho-AS, He-AS) were made to reproduce calcium-oxalate monohydrate and uric acid stones, respectively by a rapid or slow brewing of BegostonePlus (Bego) and distilled water. One hundred and fifty and 272µm-laser fibers, connected to 50W-TFL and 30W-HoYAG generators, compared three settings for TFL (FD: 0.15J/100Hz; D: 0.5J/30Hz; Fr: 1J/15Hz) and two for Ho:YAG (D-Fr). An experimental setup consisted in immerged 10mm cubic stone phantoms with a 20 seconds' lasing spiral, in contact mode, repeated four times. Stones were dried, weighted and µ-scanned (ablation weight and volume [AW and AV]). RESULTS: With He-AS, dusting AV were four- and three-fold higher with TFL compared to Ho:YAG against hard and soft (P<0.05). In fragmentation, AV were two-fold higher with TFL compared to Ho:YAG against hard (P<0.05) and soft (P<0.05). Experiments with Ho-AS were associated with non-significant differences when comparing TFL-150µm and TFL-272µm. The ablation weight-volume correlation coefficients was higher with Ho-AS than with He-AS (P<0.0001), and with hard than soft AS. If the LE can be estimated by the AW with hard AS, this approximation is not consistent for soft AS. CONCLUSION: TFL presented higher ablation rates than Ho:YAG, significant with He-AS. If the AW is acceptable and less expensive for hard Ho-AS, AV are more accurate for He-AS, which are suggested to imitate closely HS.

End-to-side versus end-to-end uretero-ureteral anastomosis in preemptive kidney transplantation from living donors: A monocentric experience.

PURPOSE: End-to-end (ETE) pyeloureterostomy is an alternative to ureteroneocystostomy for urinary anastomosis during kidney transplantation (KT). In preemptive KT from living donors (PKT-LD), end-to-side (ETS) uretero-ureteral anastomosis could have the benefits of pyeloureterostomy without ligation of the native kidney ureter. This study aimed to compare ETS to ETE uretero-ureteral anastomosis in PKT-LD. METHODS: A monocentric retrospective 8-year study included all consecutive cases of PKT-LD, excluding ureteroneocystomy anastomosis and homolateral nephrectomy. Two groups were compared: ETS and ETE. Perioperative data on graft function and urological complications were collected. RESULTS: One hundred and six patients were included: 48 patients in the ETS group and 58 patients in the ETE group. Median follow-up was 37.5 months [17.3; 57.5]. The estimated glomerular filtration rate at postoperative day ten and 3 months was similar in both groups. The overall complication rate was 16%, with no significant difference between the 2 groups. There was one ureteral stenosis in each group. None of the patients in the ETS group presented urinary fistula, whereas it occurred in one (1.7%) in the ETE group. Back pain due to native kidney obstruction occurred in 5 patients in the ETE group (8.6%), but not in the ETS group. CONCLUSION: In preemptive kidney transplantation from living donors, urinary anastomosis can safely be performed as an end-to-side uretero-ureteral anastomosis, with low urological complications. It could prevent symptoms and complications due to native kidney obstruction. LEVEL OF EVIDENCE: IV.

Posterior transperitoneal robot-assisted partial nephrectomy in the treatment of renal tumors: Feasibility of a hybrid approach.

PURPOSE: Robot-assisted partial nephrectomy (RAPN) for posterior renal tumors may be performed through anterior (transperitoneal) or posterior (retroperitoneal) approach depending on surgeon's expertise. We propose herein a surgical artifice using daVinci Xi system to combine advantages of both approaches. MATERIALS AND METHODS: From November 2019 to November 2020, patients with posterior renal mass, candidate for RAPN were prospectively included after informed consent. After positioning patient in lateral position, daVinci Xi system was docked on tumor side, to initiate transperitoneal procedure. Posterolateral dissection of perinephric space along fascia retrorenalis was conducted until psoas major muscle was exposed. Three additional robotic ports were then inserted in lumbar space, and RAPN was resumed after rotating daVinci Xi boom. Demographics, tumor characteristics, perioperative outcomes, estimated glomerular filtration rate (eGFR) and follow-up data were analyzed. RESULTS: Ten consecutive patients underwent RAPN with the modified technique. All cases were performed robotically, without modification of port placement. Median (range) tumor diameter was 37 (21-48mm) with median RENAL score of 8 (4-10) Median operative time and warm ischemia time were respectively 128min (70-180min) and 19min (14-22). One patient had a Clavien-Dindo grade II complication. At median follow-up of 13 months (6-18), all patients had eGFR comparable to baseline. CONCLUSIONS: We report the feasibility and safety of a new hybrid posterior transperitoneal approach for RAPN using daVinci Xi system. Limitations include the absence of RENAL score>10 and pT2 tumors. Greater experience is needed to assess learning curve for surgeons untrained to robotic lomboscopy.

Pulsed lasers and endocorporeal laser lithotripsy.

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.

Smoking cessation at the workplace. Results of a randomised controlled intervention study. Worksite physicians from the AIREL group.

OBJECTIVES: To compare the effects of a worksite intervention by the occupational physician offering simple advice of smoking cessation with a more active strategy of advice including a "quit date" and extra support. POPULATION: Employees of an electrical and gas company seen at the annual visit by their occupational physicians. CRITERIA END POINTS: Smoking point prevalence defined as the percentage of smokers who were non-smokers at one year. Secondary criteria were the percentage of smokers who stopped smoking for more than six months and the difference in prevalence of smoking in both groups. METHODS: Randomised controlled trial. The unit of randomisation was the work site physician and a random sample of the employees of whom he or she was in charge. The length of the follow up was one year. Each of 30 work site physicians included in the study 100 to 150 employees. RESULTS: Among 504 subjects classified as smokers at baseline receiving simple advice (group A) and 591 the more active programme (group B), 68 (13.5%) in group A and 109 (18. 4%) were non-smokers one year later (p=0.03; p=0.01 taking the occupational physician as the statistical unit and using a non-parametric test). Twenty three subjects (4.6%) in group A and 36 (6.1%) in group B (p=0.26) declared abstinence of six months or more. Among non-smokers at baseline, 3.4% in both groups were smokers after one year follow up. The prevalence of smokers did not differ significantly at baseline (32.9% and 32.4%, p=0.75). After the intervention the prevalence of smoking was 30.8% in group A and 28. 7% in group B (p=0.19). An increase of the mean symptoms score for depression in those who quit was observed during this period. CONCLUSIONS: A simple cessation intervention strategy during a mandatory annual examination, targeting a population of smokers independently of their motivation to stop smoking or their health status, showed a 36% relative increase of the proportion of smokers who quit smoking as compared with what can be achieved through simple advice.