Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Urolithiasis is a major clinical and economic burden for health care systems. International epidemiological data suggest that the incidence and prevalence of stone disease is increasing. This study demonstrates that the number of diagnoses and procedures relating to kidney stone disease has increased significantly in the last 10 years in the UK. Management of stone disease comprises a significant and increasing proportion of urological practice in the UK, which has implications for work force planning, training, service delivery and research in this field. OBJECTIVE To summarize the changes in prevalence and treatment of upper urinary tract stone disease in the UK over the last 10 years. METHODS Data from the Hospital Episode Statistics (HES) website (http://www.hesonline.nhs.uk) were extracted, summarized and presented. RESULTS The number of upper urinary tract stone hospital episodes increased by 63% to 83 050 in the 10‐year period. The use of shock wave lithotripsy (SWL) for treating all upper tract stones increased from 14 491 cases in 2000–2001 to 22 402 cases in 2010 (a 55% increase) with a 69% increase in lithotripsy for renal stones. There was a 127% increase in the number of ureteroscopic stone treatments from 6 283 to 14 242 cases over the 10‐year period with a 49% increase from 2007/2008 to 2009/2010. There was a decline in open surgery for upper tract stones from 278 cases in 2000/2001 to 47 cases in 2009/2010 (an 83% reduction). Treatment for stone disease has increased substantially in comparison with other urological activity. In 2009/2010, SWL was performed almost as frequently as transurethral resection of the prostate or transurethral resection of bladder tumour, ureteroscopy for stones was performed more frequently than nephrectomy, radical prostatectomy and cystectomy combined, and percutaneous nephrolithotomy was performed more frequently than cystectomy. CONCLUSIONS The present study highlights the increase in prevalence and treatment of stone disease in the UK over the last 10 years. If this trend continues it has important implications for workforce planning, training, service delivery and research in the field of urolithiasis.

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OBJECTIVE To describe the effect of a specific c‐kit receptor inhibitor (imatinib mesylate) on human detrusor strips in vitro and guinea‐pig cystometry in vivo, and to show histological data suggesting differences in the distribution of interstitial cells of Cajal (ICC)‐like cells in ‘normal’ and overactive human detrusor, as these cells have been identified as possible mediators of spontaneous activity and excitability in bladder smooth muscle. MATERIALS AND METHODS Specimens of human detrusor were stained immunohistochemically with a c‐kit antibody. Human detrusor strips were mounted in a superfused organ‐bath apparatus, and smooth muscle contraction was evoked with carbachol and electrical field stimulation in the presence and absence of imatinib mesylate. Also, guinea‐pig urodynamic studies were conducted before and after i.v. administration of imatinib mesylate, and changes in bladder variables and spontaneous activity were recorded. RESULTS Imatinib mesylate (10−6M) inhibited evoked smooth muscle contraction and spontaneous activity in overactive human detrusor, with less effect on normal human tissue. Imatinib mesylate (10−5M) improved bladder capacity, compliance, voided volumes, urinary frequency, and reduced contraction thresholds and spontaneous activity during guinea‐pig cystometry. c‐kit labelling showed significantly more ICC‐like cells in overactive human detrusor than in normal specimens. CONCLUSION c‐kit receptor blockers have inhibitory effects on guinea‐pig and overactive human detrusor, possibly via c‐kit receptors on bladder ICC‐like cells. This and the possibility that there are more ICC‐like cells in overactive bladder suggest that the c‐kit receptor may provide a novel target for treating detrusor overactivity.

Objective  To explore the relationship between uroflow variables and lower urinary tract symptoms (LUTS); to define performance statistics (sensitivity, specificity, positive and negative predictive values) for maximum urinary flow rate (Qmax ) with respect to bladder outlet obstruction (BOO) at various threshold values; and to investigate the diagnostic value of low‐volume voids. Patients and methods  The study comprised 1271 men aged between 45 and 88 years recruited from 12 centres in Europe, Australia, Canada, Taiwan and Japan over a 2‐year period. Symptom questionnaires, voiding diaries, uroflowmetry and pressure‐flow data were recorded. The relationship between uroflow variables and symptoms, Qmax and BOO, and the diagnostic performance of low volume voids were analysed. Results  The relationship between symptoms and uroflow variables was poor. The mean difference between home‐recorded and clinic‐recorded voided volumes was −48 mL. Qmax was significantly lower in those with BOO (9.7 mL/s for void 1) than in those with no obstruction (12.6 mL/s; P<0.001) and Qmax was negatively correlated with obstruction grade (Spearman’s correlation coefficient −0.3, P<0.001), even when controlling for the negative correlation between age and Qmax (Spearman’s partial correlation coefficient −0.29, P<0.001). A threshold value of Qmax of 10 mL/s had a specificity of 70%, a positive predictive value (PPV) of 70% and a sensitivity of 47% for BOO. The specificity using a threshold Qmax of 15 mL/s was 38%, the PPV 67% and the sensitivity 82%. Those voiding <150 mL (n=225) had a 72% chance of BOO (overall prevalence of BOO 60%). In those voiding >150 mL the likelihood of BOO was 56%. The addition of a specific threshold of 10 mL/s to these higher volume voiders improved the PPV for BOO to 69%. Conclusion  While uroflowmetry cannot replace pressure‐flow studies in the diagnosis of BOO, it can provide a valuable improvement over symptoms alone in the diagnosis of the cause of lower urinary tract dysfunction in men presenting with LUTS. This study provides performance statistics for Qmax with respect to BOO; such statistics may be used to define more accurately the presence or absence of BOO in men presenting with LUTS, so avoiding the need for formal pressure‐flow studies in everyday clinical practice, while improving the likelihood of a successful outcome from prostatectomy. This study also shows that low‐volume uroflowmetry can provide useful diagnostic information and that, as such, the data from such voids should not be discarded.