Hwang I et al, 2014: Factors influencing the failure of extracorporeal shock wave lithotripsy with Piezolith 3000 in the management of solitary ureteral stone
Hwang I, Jung SI, Kim KH, Hwang EC, Yu HS, Kim SO, Kang TW, Kwon DD, Park K
Department of Urology, Chonnam National University, 42, Jebongno, Gwangju, Donggu, 501-757, Republic of Korea
Studies of predictive factors of extracorporeal shockwave lithotripsy (ESWL) failure in patients with ureteral stones have not yielded results sufficient to prevent ESWL failure. The present study investigated patients with ureteral stone and analyzed the predictive factors of ESWL failure. Ninety patients with ureteral stone treated from January 2006 to June 2012 using ESWL for ureteral stone were enrolled. Patient's demographic data including age, gender, body mass index (BMI), symptoms and calculous characteristics including location, size, episode and the grade of hydronephrosis were recorded. Statistical results were performed using univariate and multivariate analyses for the predictive factors of ESWL failure. In univariate analysis, calculous location, size, and grade of hydronephrosis between two groups displayed significant differences (p 25 kg/m2 [Odds ratio (OR) = 3.5, 95 % confidence interval (CI) 1.1-11.0], calculous size ≥1 cm (OR = 10.5, 95 % CI 3.0-36.2), calculous location (mid-ureter; OR = 8.49, 95 % CI 1.5-45.7) and severe grade of hydronephrosis (OR = 12.3, 95 % CI 1.9-79.5). In conclusions, ESWL failure can be predicted in cases of obesity, calculous size exceeding 1 cm, mid-ureteral stone and severe hydronephrosis. When we consider calculous management in patients with these risk factors, initial surgical approach is recommended instead of ESWL.
Urolithiasis. 2014 Feb 5. [Epub ahead of print]
PMID:24496560[PubMed - as supplied by publisher]
The authors report data from 90 patients with ureteral stones treated during a period of 78 months. This means that in average only slightly more than one patient (1.15) was treated each month or not more than 14 patients per year. In this group it was concluded that 56% were failures.
The failure rate is higher than expected and higher than in most other studies. The definition of failure is, however, difficult to understand, because disintegration of stones to fragments with a size of even 4 or 5 mm (in the ureter) are usually associated with a good chance of spontaneous passage and thus without the need of repeated intervention.. Although high BMI, large stone size and location in the mid ureter might have affected the outcome, it seems likely that improved results can be anticipated with increased operator experience and by optimizing the technique.