After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis.
PloS one. 2016 Jun 01*** epublish ***
Roswitha Siener, Noor Buchholz, Michel Daudon, Bernhard Hess, Thomas Knoll, Palle J Osther, José Reis-Santos, Kemal Sarica, Olivier Traxer, Alberto Trinchieri, EAU Section of Urolithiasis (EULIS)
University Stone Centre, Department of Urology, University of Bonn, Bonn, Germany., Endourology and Stone Services, Bart's and the London NHS Trust, London, United Kingdom., APHP, Service des Explorations Fonctionnelles, Tenon University Hospital, Pierre and Marie Curie University, Paris, France., Internal Medicine and Nephrology, Klinik im Park and University of Zürich, Zürich, Switzerland., Department of Urology, Klinikum Sindelfingen-Böblingen, University of Tübingen, Sindelfingen, Germany., Urological Research Center, Department of Urology, Lillebaelt Hospital, University of Southern Denmark, Fredericia, Denmark., Faculdade de Engenharia Clínica e Biomédica da Universidade Católica Portuguesa, Lisbon, Portugal., Department of Urology, Dr Lufti Kirdar Kartal Research and Training Hospital, Istanbul, Turkey., Department of Urology, Tenon University Hospital, Pierre and Marie Curie University, Paris, France., Department of Urology, A. Manzoni Hospital, Lecco, Italy.