Clinical Kidney Journal, 2018, vol. 11, no. 3, 362–363 doi: 10.1093/ckj/sfy025 Advance Access Publication Date: 11 April 2018 Editorial Comment EDITORIAL C OMMENT Shock-wave lithotripsy or ureterorenoscopy for renal stones? 1 2 1 Pietro Manuel Ferraro , Francesco Pinto and Giovanni Gambaro Nefrologia, Fondazione Policlinico Universitario A. Gemelli–Universita ` Cattolica del Sacro Cuore, Roma, Italy and Urologia, Fondazione Policlinico Universitario A. Gemelli – Universita ` Cattolica del Sacro Cuore, Roma, Italy Correspondence and offprint requests to: Pietro Manuel Ferraro; E-mail: firstname.lastname@example.org; Twitter handle: @FerraroManuel ABSTRACT Kidney stones are a common condition with high direct and indirect costs; to date, the optimal urological approach for some particular presentations including non-lower pole kidney stones between 10 and 20 mm of diameter is not clear. A limited number of randomized controlled trials and observational longitudinal studies suggests that ureterorenoscopy (URS) could be superior to shock-wave lithotripsy (SWL) in achieving stone-free rates in this setting; however, such reports are generally weakened by a number of limitations including small sample size and scarce control for confounding. In this issue, Fankhauser et al.  report the results of a large observational retrospective study on the comparative efﬁcacy and safety of URS and SWL for the treatment of previously untreated kidney stones. Keywords: endourology, lithotripsy, nephrolithiasis, observational studies, outcomes Kidney stone disease is a common condition, with an increasing the authors selected 1282 with previously untreated lower and prevalence and high direct and indirect costs [2–4]; both envir- non-lower pole stones and a stone diameter between 5 and onmental and genetic factors are thought to play a role in its de- 20 mm. The study sample was then divided based on the treat- velopment [5–7]. A number of urological procedures are ment type in 999 patients treated with SWL and 283 treated nowadays available to treat patients who present with this con- with URS, and both efficacy and safety outcomes evaluated. For dition. Both the American Urological Association (AUA) and the the first, rates of stone-free and freedom from reintervention European Association of Urology (EAU) guidelines recommend during follow-up were used, whereas for the latter the authors the use of either shock-wave lithotripsy (SWL) or ureteroreno- used the Clavien–Dindo grading system of perioperative compli- scopy (URS) to treat lower pole and non-lower pole kidney cations until discharge. Compared with patients treated with stones 10 mm and non-lower pole stones between 10 and SWL, those treated with URS had higher stone-free rates (84% 20 mm; for lower pole stones between 10 and 20 mm, the AUA versus 71%) and freedom from reintervention (79% versus 55%). guideline does not recommend SWL as first-line treatment, and The results remained significant after adjustment for a number the EAU does not recommend SWL in the presence of unfavour- of potential confounders and were confirmed in a subsample of able factors including shock-wave-resistant stones (e.g. brushite 735 patients matched, based on a propensity score whose calcu- or cystine stones) and anatomic abnormalities [8, 9]. lation included age, gender, body mass index, stone size and In this issue of Clinical Kidney Journal, Fankhauser et al.  number of stones. A subgroup analysis based on stone location analysed the efficacy and safety of SWL and URS as first-line confirmed that URS was associated with better outcomes for treatments for previously untreated kidney stones20 mm. Of non-lower pole stones, although stone-free rates were similar all the patients treated in their centre between 2003 and 2014, for the two techniques for lower pole stones, but with a Received: 28.2.2018. Editorial decision: 1.3.2018 V C The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact email@example.com Downloaded from https://academic.oup.com/ckj/article-abstract/11/3/362/4967701 by Ed 'DeepDyve' Gillespie user on 20 June 2018 SWL or URS for renal stones? | 363 significantly different freedom from reintervention rate. These stones20 mm and in finding the balance between obtaining results have not been explained by the authors but might be a optimal rates of stone clearance and minimizing subsequent consequence of forced indications to URS (stone volume, lower complications. calix anatomy), even if the minimal fragments residual after URS led to higher freedom from reintervention. Overall, 3.7% of CONFLICT OF INTEREST STATEMENT SWL patients and 7.4% of URS patients experienced periopera- tive complications. None declared. The results presented in this article have not In this study, the only independent predictors of stone-free been published previously in whole or part. rate and freedom from reintervention were treatment modality and the stone size measured bidimensionally. An important REFERENCES topic is to determine the optimal method for assessing stone vol- 1. Fankhauser CD, Hermanns T, Lieger L et al. Extracorporeal ume, and thus stone burden, a helpful tool in predicting treat- shock wave lithotripsy versus ﬂexible ureterorenoscopy in ment outcome for renal stones. EAU and AUA guidelines consider the bidimensional size [8, 9]. The precise measurement the treatment of 15 untreated renal calculi. Clin Kidney J 2018; 2018: 1–6 of stone volume by 3D reconstruction can be accomplished using modern computer tomography (CT) scanning software , how- 2. Scales CD, Smith AC, Hanley JM et al. Prevalence of kidney stones in the United States. Eur Urol 2012; 62: 160–165 ever this technique is not available in all hospitals or with rou- tine acute colic scanning protocols. The evaluation of Hounsfield 3. Croppi E, Ferraro PM, Taddei L et al. Prevalence of renal stones in an Italian urban population: a general practice- unit is another important tool in predicting treatment efficacy. Therefore, maximum diameters as measured by either X-ray or based study. Urol Res 2012; 40: 517–522 4. Saigal CS, Joyce G, Timilsina AR. Direct and indirect costs of CT are used in the calculation of stone volume based on a sca- lene ellipsoid formula, as recommended by the EAU . nephrolithiasis in an employed population: opportunity for disease management? Kidney Int 2005; 68: 1808–1814 The strength of the study by Fankhauser et al. lies in the large number of patients analysed (almost double the number 5. Ferraro PM, Taylor EN, Gambaro G et al. Dietary and lifestyle risk factors associated with incident kidney stones in men of patients included in a recent systematic review and meta- analysis on the same topic ), in the ample span of time and women. J Urol 2017; 198: 858–863 6. Ferraro PM, D’Addessi A, Gambaro G. When to suspect a gen- included in the analysis and in the consistency of its results after propensity score matching. However, a number of limita- etic disorder in a patient with renal stones, and why. Nephrol Dial Transplant 2013; 28: 811–820 tions must also be considered. As acknowledged by the authors, the observational and monocentric nature of the study means 7. Goldfarb DS, Fischer ME, Keich Y et al. A twin study of genetic and dietary inﬂuences on nephrolithiasis: a report from the the results could be prone to various potential biases and re- sidual confounding. In particular, although the authors employ Vietnam Era Twin (VET) Registry. Kidney Int 2005; 67: 1053–1061 multivariate regression techniques and propensity score matching to control for potential confounders, the role of un- 8. Assimos D, Krambeck A, Miller NL et al. Surgical man- agement of stones: American Urological Association/ measured and unknown confounders could not be entirely ruled out. The variables included in the models do not necessar- Endourological Society Guideline, PART II. J Urol 2016; 196: 1161–1169 ily capture the indications to treat the patient with one given procedure, and such indications as well as their efficacy could 9. Tu ¨ rk C, Petrı ´k A, Sarica K et al. EAU guidelines on interven- tional treatment for urolithiasis. Eur Urol 2016; 69: 475–482 have changed over the relatively wide span of time included in the analysis. Pre-treatment and post-treatment total stone bur- 10. Finch W, Johnston R, Shaida N et al. Measuring stone volume-three-dimensional software reconstruction or an el- den was not investigated systematically, e.g. employing a standardized imaging protocol, but rather obtained from a mix- lipsoid algebra formula? BJU Int 2014; 113: 610–614 11. Donaldson JF, Lardas M, Scrimgeour D et al. Systematic re- ture of ultrasonography, X-ray and CT scans. If the relative use of those imaging techniques varied across treatment groups, view and meta-analysis of the clinical effectiveness of shock wave lithotripsy, retrograde intrarenal surgery, and percu- this could have influenced the results. Similarly, the timing of imaging evaluation during follow-up was not defined, and the taneous nephrolithotomy for lower-pole renal stones. Eur groups could have potentially differed in follow-up length; Urol 2015; 67: 612–616 in that case, the use of time-to-event analysis techniques 12. Gambaro G, Croppi E, Bushinsky D et al. The risk of chronic kidney disease associated with urolithiasis and its uro- rather than logistic regression could have been preferred. Furthermore, the study only collects information on procedure- logical treatments: a review. J Urol 2017; 198: 268–273 related complications until discharge; a sizable number of 13. Denburg MR, Jemielita TO, Tasian GE et al. Assessing the risk reports have brought attention to the long-term effects of SWL of incident hypertension and chronic kidney disease after procedures including high blood pressure, chronic kidney dis- exposure to shock wave lithotripsy and ureteroscopy. Kidney ease and diabetes [12–14], and a longer follow-up coupled with a Int 2016; 89: 185–192 larger sample size would be needed to capture them. Finally, 14. Fankhauser CD, Kranzbu ¨ hler B, Poyet C et al. Long-term ad- the lack of a clear advantage of URS over SWL for lower pole verse effects of extracorporeal shock-wave lithotripsy for stones, a finding that is not supported by the results of meta- nephrolithiasis and ureterolithiasis: a systematic review. analyses of randomized controlled trials [11, 15], deserves fur- Urology 2015; 85: 991–1006 ther elucidation. 15. Mi Y, Ren K, Pan H et al. Flexible ureterorenoscopy (F-URS) Notwithstanding such limitations, the study by Fankhauser with holmium laser versus extracorporeal shock wave litho- et al. provides interesting findings that could prove helpful in tripsy (ESWL) for treatment of renal stone <2 cm: a meta- guiding the choice for stone removal in patients with analysis. Urolithiasis 2016; 44: 353–365 Downloaded from https://academic.oup.com/ckj/article-abstract/11/3/362/4967701 by Ed 'DeepDyve' Gillespie user on 20 June 2018
Clinical Kidney Journal – Oxford University Press
Published: Apr 11, 2018
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