Login to Access Video or Poster Abstract: MP62-04
Sources of Funding: None

Introduction

We previously reported that the success rates of extracorporeal shock wave lithotripsy (ESWL) were increased from 66.3% to 87.2% by technical training (Okada et al. Urolithiasis 2013). In the present study, we analyzed how the technical skills acquired by this training directly affected subsequent ESWL results.

Methods

Among 335 ESWL treatments performed at Nagoya City University Hospital from December 2011 to August 2016, we analyzed the 324 cases that could be evaluated by CT three months post-ESWL treatment. All 17 urologists in charge of treatment attended the technical training. We analyzed associations between success rate and the following parameters: patient factors (age and body mass index), kidney stone factors (size, CT value, constituents, intervening period and skin-to-stone distance), conformity to the recommended techniques from training, number of ESWL sessions, grade of hydronephrosis, indwelling of ureteral stents, therapeutic position, use of stretcher wedges, targeting methods, air removal between cushion and skin, type of ESWL apparatus (Gemini or Lithotripter S, Dornier MedTech, Japan), shock wave frequency, and period from apparatus adjustment (stone model tests). The techniques recommended in training were 1) combined use of fluoroscopy and ultrasonography for targeting renal and proximal ureter stones, 2) use of stretcher wedges for middle ureter stones, and 3) semi-supine position with stretcher wedges for distal ureter stones.

Results

The average total success rate was 84.3% over the study period. Average conformity to the training techniques was 80.2%, and the average success rates of the conformity and nonconformity groups were 86.2% and 76.6%, respectively (p<0.0001). There was a significant difference in the success rates between the types of apparatuses used, where the Gemini group success rate was 90.1% and the Lithotripter S group success rate was 82.0% (p<0.0001). The number of the selected cases with conformity of the recommended techniques, air removal, low CT values (≤1000HU), appropriate stone size (≤10mm), and the first therapy were 90 and their success rate was 95.6%.

Conclusions

Conforming to recommended techniques, air removal, and appropriate case selection can all lead to higher success rates in ESWL.

Funding

None