Yao F. et al., 2022: Furosemide improves the stone clearance rate of extracorporeal shockwave lithotripsy for kidney stones but not ureteral stones: a systematic review and meta-analysis.
Yao F, Li K, Huang S, Cheng X, Jiang X.
Department of Urology, People's Hospital of Chongqing Banan District, Chongqing, China.
Department of Urology, People's Hospital of Chongqing Banan District, Chongqing 401320, China.
Introduction: We conducted a meta-analysis (MA) to investigate the effects of furosemide on the prognosis of extracorporeal shockwave lithotripsy (SWL) therapy to remove renal (RS) and ureteric stones (US).
Methods: We screened scientific databases including PubMed, Clinicalkey, Google Scholar, Medline, Embase, and Cochrane, from the date of establishment until March 2022, to search for randomized controlled trials evaluating SWL, in combination with furosemide (experimental group) or with SWL alone (control group), in treating RS or US. Our search terms included furosemide, extracorporeal SWL, and urolithiasis. For this MA, we employed the Cochrane Collaboration's RevMan version 5.3.0.
Results: Six trials, involving 1344 participants, with RS (n = 1097) and/or US (n = 247), met our predefined criteria. This included 137 proximal ureteral stones (PUSs), 35 mid-ureteral stones (MUS), and 75 distal ureteral stones (DUS). In case of RS, the experimental group exhibited significantly enhanced clearance, relative to controls (risk ratio [RR] = 1.16, 95% confidence interval [CI] = 1.07-1.25, p = 0.0002), yet there was no obvious difference in the PUS, MUS, and DUS (RR = 1.14, 95% CI = 0.97-1.33, p = 0.10; odds ratio [OR] = 1.26, 95% CI = 1.40-3.95, p = 0.69; RR = 1.21, 95% CI = 0.99-1.49, p = 0.06). There was also no marked difference between fragmentations in either group. Only reports of SWL treatment of RS provided adequate data on shocks, sessions, and complications for our analysis. Unfortunately, there was no significant alteration between the two groups.
Conclusion: According to our analysis, furosemide strongly accelerates the clearance rate of SWL-treated RS. However, it does not enhance the fragmentation rate. Given this evidence, we propose that furosemide does not significantly improve the efficacy of SWL therapy in removing US.
Ther Adv Urol. 2022 Oct 15;14:17562872221128473. doi: 10.1177/17562872221128473. eCollection 2022 Jan-Dec. PMID: 36267107. FREE ARTICLE
In view of the variable results of stone disintegration and stone clearance reported in the literature, the need of improved SWL-technique seems important. Ever since the clinical introduction of SWL, approximately four decades ago, interest has been devoted to the importance of the fluid-stone interface.
Accordingly, administration of fluids, diuretics, and establishment of artificial hydronephrosis have been applied during SWL treatment. Moreover, administration of diuretics after SWL, in the immediate follow-up period, has been considered of value for the outcome of SWL.
The authors of the current report have carried out a systematic review and meta-analysis to shed some further definite light on this issue. Only six RCTs, comprising 547 patients with renal stones given diuretics and 550 controls, were extracted from the literature published over a period of 17 years. The overall number of patients with ureteral stones treated with diuretics was 123 compared with 124 controls. Given the small number of RCTs and the limited number of patients included in the studies, it is doubtful if a definite answer was given to the scientific question, but the following points need attention:
1. Renal stones were not better disintegrated when SWL was carried out with administration of furosemide.
2. Ureteral stones were not better disintegrated when furosemide was given. This conclusion is in accordance with our own results .
3. Better clearance of renal stones was, however, recorded with SWL + furosemide. The same outcome, however, was not observed when ureteral stones were treated in a similar way.
The clinical conclusion of these findings is that furosemide might be of value when renal stones are SWL- treated, but this regimen seems unimportant and can be ignored for treatment of ureteral stones.
Discrepancies in the literature might be explained by lack of information
on how effective the diuretic effect was. High pressure infusion is usually not used and the urine volume during the procedure not measured. It is also likely that different stone properties and anatomical locations influences establishment of a stone-water interface. Contrary to what is true for numerous other systematic reviews and meta-analysis in the field of urolithiasis treatment, I think that there still is room for additional studies on how diuresis should be accomplished during SWL and how effective it can be on the outcome of renal stone SWL.
1. Tiselius HG, Aronsen T and Boghard S. Is high diuresis an important prerequisite for successful SWL-disintegration of ureteral stones. Urol Res 210; 38:143-146