Stone composition independently predicts stone size in 18,029 spontaneously passed stones
To evaluate whether the size of spontaneously passed stones (SPS) may be associated with clinical parameters.
A search for SPS was conducted in our electronic stone database, comprising data on stones analyzed over the last 33 years at our institution. Adults with upper urinary tract stones were included. Cases with stenotic urinary tract disease or past history of anastomotic urinary tract surgery were excluded. Stone size expressed as maximal stone diameter (MSD) and stone volume (SV) was compared between groups by one-way ANOVA. Logistic regression analyses were performed to identify predictors of MSD ≥ 6 mm.
Overall mean MSD and SV for 18,029 SPS was 4.1 mm and 11.5 mm3, respectively, and significantly differed between stone composition groups (p < 0.001). The lowest mean MSD and SV were found for calcium oxalate monohydrate (3.6 mm and 9.0 mm3, respectively) and the highest mean MSD and SV were found for struvite (7.9 mm and 61.0 mm3, respectively). Stone composition and increasing age were found to be independent predictors of MSD ≥ 6 mm (both p < 0.001). Sex differentiation did not contribute as a predictor of MSD ≥ 6 mm.
Stone composition and—to a lesser extent—age serve as independent predictors of size of spontaneously passed stones. Of particular importance, large spontaneously passed stones of ≥ 6 mm may be frequently found in cystine, brushite or struvite stone formers, whereas a minority of all calcium oxalate stones exceed that cutoff. Future studies shall evaluate these parameters as possible predictors of spontaneous stone passage.
KeywordsUrinary stone Stone size Stone composition Spontaneous passage Age Recommendations Adults
We wish to thank Philippe Autier, MD, MPH, PhD, Senior Faculty of the International Prevention Research Institute in Lyon for statistical assistance and review.
EXK: protocol/project development, data analysis and manuscript writing/editing; VDC: protocol/project development, data analysis and manuscript writing/editing; MA: manuscript writing/editing; SD: data analysis and manuscript writing/editing; MD: protocol/project development, data collection or management, data analysis and manuscript writing/editing; OT: protocol/project development, data analysis and manuscript writing/editing.
Compliance with ethical standards
Conflict of interest
Olivier Traxer is a consultant for Coloplast, Rocamed, Olympus, EMS and Boston Scientific. Steeve Doizi is a consultant for Coloplast. Etienne Xavier Keller is supported by a Travel Grant from the University Hospital Zurich and from the Kurt and Senta Herrmann Foundation. Vincent De Coninck is supported by the EUSP scholarship from the European Association of Urology and by a grant from the Belgische Vereniging voor Urologie (BVU).
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
- 9.Turk C, Neisius AP, Seitz C, Skolarikos A, Knoll T (2018) EAU guidelines on urolithiasis. https://uroweb.org/guideline/urolithiasis. Accessed 25 Sept 2018 (last update March 2018)
- 10.Assimos D, Krambeck A, Miller NL, Monga M, Murad MH, Nelson CP, Pace KT, Pais VM Jr, Pearle MS, Preminger GM, Razvi H, Shah O, Matlaga BR (2016) Surgical management of stones: American Urological Association/Endourological Society guideline. Part I. J Urol 196(4):1153–1160. https://doi.org/10.1016/j.juro.2016.05.090 CrossRefGoogle Scholar
- 14.Daudon M, Dessombz A, Frochot V, Letavernier E, Haymann J-P, Jungers P, Bazin D (2016) Comprehensive morpho-constitutional analysis of urinary stones improves etiological diagnosis and therapeutic strategy of nephrolithiasis. C R Chim 19(11–12):1470–1491. https://doi.org/10.1016/j.crci.2016.05.008 CrossRefGoogle Scholar
- 17.Preminger GM, Tiselius HG, Assimos DG, Alken P, Buck AC, Gallucci M, Knoll T, Lingeman JE, Nakada SY, Pearle MS, Sarica K, Turk C, Wolf JS Jr, American Urological Association E, Research I, European Association of U (2007) 2007 Guideline for the management of ureteral calculi. Eur Urol 52(6):1610–1631CrossRefGoogle Scholar
- 26.Tailly T, Larish Y, Nadeau B, Violette P, Glickman L, Olvera-Posada D, Alenezi H, Amann J, Denstedt J, Razvi H (2016) Combining mean and standard deviation of hounsfield unit measurements from preoperative CT allows more accurate prediction of urinary stone composition than mean hounsfield units alone. J Endourol 30(4):453–459. https://doi.org/10.1089/end.2015.0209 CrossRefGoogle Scholar