Impact of Case Volume on Shock Wave Lithotripsy Outcomes: Data from the National Shock Wave Lithotripsy Database of New Zealand.

Purpose: To assess the impact of individual operator case volume on shock wave lithotripsy (SWL) treatment outcomes in more than 9000 stone cases over a 20-year period in New Zealand. Materials and Methods: Stone cases treated with SWL on the Mobile Medical Technology (MMT) vehicle between June 19, 1995, and December 1, 2014, were identified. Data collection was undertaken prospectively for patient, stone, and treatment characteristics, and retrospectively for treatment outcomes. Multivariate analysis using binary logistic regression was undertaken to assess whether radiographer stone case volume (stones/year) was an independent predictor of SWL success (stone free or clinically insignificant residual fragments ≤4 mm at follow-up). Results: Sixteen radiographers delivered treatment to the included cohort (9039 stone cases), with a median case volume (stones/year) of 73 (range: 37-197) and median total of 425 stones treated (range: 71-1721). The two radiographers with highest case volumes achieved the highest success rates. Radiographer case volume (stones/year) was independently associated with SWL success (odds ratio [OR]: 1.004, 95% confidence interval [CI]: 1.003-1.005, p < 0.0001) and reduced need for post-SWL hospital admission (OR: 0.997, 95% CI: 0.994-1.000, p = 0.028), but there was no associated decrease in post-SWL urosepsis (OR: 0.999, 95% CI: 0.974-1.025, p = 0.941), perinephric hematoma (OR: 1.003, 95% CI: 0.985-1.020, p = 0.778), or need for auxiliary procedures (OR: 1.000, 95% CI: 0.998-1.002, p = 0.871). Conclusions: SWL success rates can be improved by increasing the frequency of cases performed by individual operators. In this multicenter cohort of more than 9000 stone cases treated over a 20-year period, the best outcomes were seen for those radiographers performing >150 cases per year.

Routine Antibiotic Prophylaxis Is Not Required for Patients Undergoing Shockwave Lithotripsy: Outcomes from a National Shockwave Lithotripsy Database in New Zealand.

PURPOSE: To assess the effectiveness of routine prophylactic antibiotics in the prevention of urinary tract infection (UTI) after extracorporeal shockwave lithotripsy (SWL) and identify predictors of UTI development in a multicenter series of over 10,000 stone cases treated in New Zealand over a 20-year period. MATERIALS AND METHODS: Patients treated with SWL on the Mobile Medical Technology vehicle between June 19, 1995 and December 1, 2014 were identified. Data collection was undertaken prospectively for patient, stone and treatment characteristics, and, retrospectively, for treatment outcomes. The primary outcome was clinical UTI, defined as development of UTI symptoms requiring antibiotic therapy. Secondary outcomes included urinary sepsis, need for hospital admission due to infectious complications, and length of hospital stay. Multivariate analysis was undertaken to identify factors independently associated with the development of post-SWL UTI. RESULTS: Antibiotic prophylaxis was used in 62.1% (n = 6710) of cases. On comparing patients who received prophylactic antibiotics to those in whom antibiotics were withheld, no significant differences were observed in terms of post-SWL UTI (1.1% vs 1.3%, p = 0.335) or urinary sepsis (0.04% vs 0.15%, p = 0.075). The use of prophylactic antibiotics was not independently associated with post-SWL UTI (OR: 1.269, 95% CI: 0.886-1.818, p = 0.194). Female gender, larger stone size, and higher number of delivered shocks were predictive of UTI development, but antibiotic prophylaxis did not appear to offer any benefit in this subgroup. CONCLUSIONS: Routine antibiotic prophylaxis was not associated with a reduction in clinical UTI after SWL in this cohort of over 10,000 stone cases in New Zealand.