Renal stone analysis: why and how?

Abstract

Upper urinary tract stone disease is widespread in the developed world. On both clinical and economic grounds it is now accepted that evidence-based medical intervention is the only approach likely to make a significant impact on the incidence, and more importantly, the recurrence rates of this disease. Targeted medical prophylaxis requires reliable information on stone type which, when combined with relevant blood and urine analyses, allows identification of treatable risk factors. Data from an external quality assurance scheme indicate that stone analysis is poorly performed in many laboratories, and it is probable that this results in ill-informed patterns of investigation, inappropriate therapy, missed diagnoses of rarer causative disorders and wasteful further investigation of 'non-renal' stone artefacts. Renal stone analysis is a specialist investigation requiring appropriate analytical and interpretative expertise if the information is to be used to enhance patient care. For those laboratories not able to offer this, for whatever reason, referral is the only defensible approach to service provision. The methods currently employed in many departments have no place in modern clinical biochemistry practice.

Flexible Ureteroscopy with Holmium Laser Lithotripsy: A New Choice for Intrarenal Stone Patients

“…The incidence of nephrolithiasis has considerably increased around the world in last 2 decades [1,2]. In 2011, the morbidity of nephrolithiasis in Europe was 1.2-1.4%, while it was 1-5% in China [3,4].…”

Urinary stone composition in Oman: with high incidence of cystinuria

“…This necessitates a thorough metabolic workup and an accurate quantitative stone analysis. The present study used infrared spectroscopy as it is specific, rapid relatively versatile, and shows superior performance for both common and rare components [5]. Infrared spectroscopy uses a spectrophotometer that exposes sample molecules to infrared light [6].…”

Radiographic and Laboratory Data (“the Megaprofile”) Can Accurately Guide Medical Management in the Absence of Stone Analysis

“…In recent years, the availability of stone composition has been reduced, and the accuracy of some reports has been questioned. [4][5][6] Whereas traditional surgical techniques involved removing intact calculi, which could then be sent for analysis, the advent of lithotriptic techniques has resulted in more fragments than whole stones. The likelihood of missing components is inherently increased, potentially leading to misleading conclusions.…”

“…[4][5][6][7] Krambeck and colleagues reported significant variation in the compositions reported by five different commercial laboratories who were sent similar specimens. 6 These inaccuracies were particularly common when stones contained more than one component, as is the case in the majority of stones.…”