Shock Wave Lithotripsy in Ureteral Stones: Evaluation of Patient and Stone Related Predictive Factors

Abstract

Purpose:To evaluate the patient and stone related factors which may influence the final outcome of SWL in the management of ureteral stones.Materials and Methods:Between October 2011 and October 2013, a total of 204 adult patients undergoing SWL for single ureteral stone sizing 5 to 15 mm were included into the study program. The impact of both patient (age, sex, BMI,) and stone related factors (laterality, location, longest diameter and density as CT HU) along with BUN and lastly SSD (skin to stone distance) on fragmentation were analysed by univariate and multivariate analyses. Results: Stone free rates for proximal and distal ureteral stones were 68.8% and 72.7%, respectively with no statistically significant difference between two groups (p=0.7). According to univariate and multivariate analyses, while higher BMI (mean: 26.8 and 28.1, p=0.048) and stone density values (mean: 702 HU and 930 HU, p<0.0001) were detected as statistically significant independent predictors of treatment failure for proximal ureteral stones, the only statistically significant predicting parameter for the success rates of SWL in distal ureteral stones was the higher SSD value (median: 114 and 90, p=0.012).Conclusions:Our findings have clearly shown that while higher BMI and increased stone attenuation values detected by NCCT were significant factors influencing the final outcome of SWL treatment in proximal ureteral stones; opposite to the literature, high SSD was the only independent predictor of success for the SWL treatment of distal ureteral stones.

Role of clinical and radiological parameters in predicting the outcome of shockwave lithotripsy for ureteric stones

“…Higher BMI is found to be a significant factor affecting the success of SWL in some studies. [ 15 16 ] Conversely, in another study, BMI failed to predict successful SWL outcomes, whereas SSD remained a significant predictor. [ 17 ] Wiesenthal et al .…”

“…In a recent study by Yazici et al . [ 16 ] SSD was the only independent predictor of failure or success for the treatment of distal ureteral stones treated with SWL. In our study, BMI was not a significant predictor of the outcome of SWL ( P = 0.913), whereas, SSD was found to be significant ( P < 0.001) in predicting the outcome of SWL.…”

Management of ‘forgotten’ encrusted JJ stents using extracorporeal shockwave lithotripsy: A single-centre experience

“…Recent studies have shown that HU values affect ESWL results (number of shocks, session, and success) [19]. In our present study, the mean (SD) density of encrustation was 707.6 (113.8) HU in patients with forgotten stents left in situ for <2 years, compared to a mean (SD) of 863.6 (187.4) HU in patients with forgotten stents left in situ for longer (P < 0.001).…”

Treatment of Distal Ureteral Calculi Using Extracorporeal Physical Vibrational Lithecbole Combined with Tamsulosin: A New Option to Speed Up Obstruction Relief

“…5 SWL is used to indirectly relieve the obstruction, 19 but it also has risks such as bleeding, fever, and ureterostenosis. 6,7,20 Surgery, such as ureterorenoscopy, is an option to relieve the obstruction directly, but patients face the risk of complications and high costs. [21][22][23] Since the wave is divergent, the location where the vibrator meets the skin is the point of highest effect.…”

“…4,5 When SWL was first invented, it was used to relieve pain and it was effective. 6,7 However, SWL is a noninvasive therapy, and although it is reasonably safe, severe complications and bleeding may occur. 8,9 Recently, a new extracorporeal physical vibrational lithecbole (EPVL) device named Friend-I EPVL (Zhengzhou Fu Jian Da Medical Instrument Co., Zhengzhou, China) has proven to be an effective treatment for upper urinary tract residual calculi.…”