Extracorporeal Shock Wave Lithotripsy For Ureteral Stones Research Articles

Relative benefits of extracorporeal shockwave lithotripsy (ESWL) compared to observation in acute renal colic

Miss Catherine Lovegrove1,2Mandy Spencer1Prof Ben Turney1,2Ms Naomi Neal1
 1 Department of Urology, Oxford University Hospitals NHS Trust, Oxford, Oxfordshire, UK2 University of Oxford Nuffield Department of Surgical Sciences, Oxford, Oxfordshire, UK
 
 Background NICE guidance recommends patients with renal colic be offered surgical treatment, including extracorporeal shockwave lithotripsy (ESWL), within 48 hours if pain is uncontrolled or stones unlikely to pass. We compared outcomes for ureteric stone passage after ESWL with those of observation to ascertain the relative benefits of ESWL.
 Methods We collected data on stone location, size and number of ESWL treatments required prospectively over 18 months. Stone passage was confirmed radiologically. Data were compared with MIMIC, a multi-centre collaborative study examining spontaneous stone passage after observation alone.
 Results 166 patients had ESWL for ureteric stones. Median size was 6.5mm (IQR 5.0-8.0mm). 57.2% (N=95) were proximal stones. Smaller stones required fewer treatments (P=0.003). Patients with a ureteric stone <5mm required median 1.0 ESWL treatments (IQR 1.0-2.0). Ureteric stones 5-7mm had median 1.0 treatments (IQR 1.0-2.0) and stones >7mm median 2.0 treatments (IQR 1.0-2.0). Compared to MIMIC, patients with ESWL for stones <5mm were 11% more likely to achieve stone clearance (100.0% vs 89.0%, P=0.001). ESWL for 5-7mm stones had 28.1% greater clearance compared to observation (77.1% vs. 49.0%, P<0.001) and ESWL for stones >7mm 21% greater likelihood of clearance (50.0% vs. 29.0%, P<0.001). Proximal ureteric stones were 16.4% more likely to pass with ESWL than observation (68.4% vs 52%, P=0.02). Distal stones showed similar passage with ESWL (77.5%) and observation (83.0%), P=0.43.
 Conclusions Proximal ureteric stones and those >5mm stones benefit most from ESWL. Results aid identification of patients whose stones are less likely to pass and warrant urgent review to consider ESWL.

327 Relative Benefits of Extracorporeal Shockwave Lithotripsy (ESWL) Compared to Observation in Acute Renal Colic

Abstract Aim NICE guidance recommends patients with renal colic be offered surgical treatment, including extracorporeal shockwave lithotripsy (ESWL), within 48 hours if pain is uncontrolled or stones unlikely to pass. We compared outcomes for ureteric stone passage after ESWL with those of observation to ascertain the relative benefits of ESWL. Method We collected data on stone location, size, and number of ESWL treatments required prospectively over 18 months. Stone passage was confirmed radiologically. Data were compared with MIMIC, a multi-centre collaborative study examining spontaneous stone passage after observation alone. Results 166 patients had ESWL for ureteric stones. Median size was 6.5mm (IQR 5.0-8.0mm). 57.2% (N = 95) were proximal stones. Smaller stones required fewer treatments (P = 0.003). Patients with a ureteric stone <5mm required median 1.0 ESWL treatments (IQR 1.0-2.0). Ureteric stones 5-7mm had median 1.0 treatments (IQR 1.0-2.0) and stones >7mm median 2.0 treatments (IQR 1.0-2.0). Compared to MIMIC, patients with ESWL for stones <5mm were 11% more likely to achieve stone clearance (100.0% vs 89.0%, P = 0.001). ESWL for 5-7mm stones had 28.1% greater clearance compared to observation (77.1% vs. 49.0%, P < 0.001) and ESWL for stones >7mm 21% greater likelihood of clearance (50.0% vs. 29.0%, P < 0.001). Proximal ureteric stones were 16.4% more likely to pass with ESWL than observation (68.4% vs 52%, P = 0.02). Distal stones showed similar passage with ESWL (77.5%) and observation (83.0%), P = 0.43. Conclusions Proximal ureteric stones and those >5mm stones benefit most from ESWL. Results aid identification of patients whose stones are less likely to pass and warrant urgent review to consider ESWL.

Factors influencing the failure of extracorporeal shock wave lithotripsy with Piezolith 3000 in the management of solitary ureteral stone

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 < 0.05). The predictive factors of ESWL failure were BMI >25 kg/m(2) [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.

The efficacy of tamsulosin therapy after extracorporeal shock-wave lithotripsy for ureteric calculi: A prospective randomised, controlled study

ObjectiveTo evaluate whether tamsulosin hydrochloride is effective as an adjunctive medical therapy to increase the effectiveness of extracorporeal shock-wave lithotripsy (ESWL) for treating ureteric stones, and minimises the use of analgesic drugs after the procedure. Patients and methodsTo treat single ureteric stones of 5–15mm in diameter, 130 patients were treated with ESWL. After treatment, equal numbers of patients were randomly assigned to receive either the standard medical therapy alone (controls) or combined with 0.4mg tamsulosin daily for ⩽12weeks. All patients were followed up for 3months or until an alternative treatment was offered. ResultsAt 3months the treatment was considered to be clinically successful in 55/65 (85%) of those receiving tamsulosin and in 58/65 (89%) of the controls (P=0.34). When patients were classified according to stone size the success rate was similar in both groups (P=0.22) for those with a stone of >10mm. However, ureteric colic was reported in 12% of patients treated with standard therapy but in only 5% of those treated with tamsulosin (P=0.006). The mean cumulative diclofenac dose was 380mg/patient in the tamsulosin group and 750mg/patient in the control group (P=0.004). ConclusionsThis study showed the effectiveness of tamsulosin as an adjunctive medical therapy after ESWL for ureteric stones, but it did not improve stone clearance when treating ureteric stones. However, it decreased the use of analgesics and reduced the complication rate, especially for steinstrasse.

CAN WE IMPROVE THE PREDICTION OF STONE-FREE STATUS AFTER EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR URETERAL STONES? A NEURAL NETWORK OR A STATISTICAL MODEL?

We evaluated whether an artificial neural network (ANN) can improve the prediction of stone-free status after extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia) for ureteral stones compared to a logistic regression (LR) model. Between February 1989 and December 1998, 984 patients with ureteral stones, including 780 males and 204 females with a mean age +/- SD of 40.85 +/- 10.33 years, were treated with ESWL. Stone-free status at 3 months was determined by urinary tract plain x-ray and excretory urography. Of all patients 919 (93.3%) were free of stones. The impact of 10 factors on stone-free status was studied using an LR model and ANN. These factors were patient age and sex, renal anatomy, stone location, side, number, length and width, whether stones were de novo or recurrent, and stent use. An LR model was constructed and ANN was trained on 688 randomly selected patients (70%) to predict stone-free status at 3 months. The 10 factors were used as covariates in the LR model and as input parameters to ANN. Performance of the trained net and developed logistic model was evaluated in the remaining 296 patients (30%), who served as the test set. The sensitivity (percent of correctly predicted stone-free cases), specificity (percent of correctly predicted nonstonefree cases), positive predictive value, overall accuracy and average classification rate of the 2 techniques were compared. Relevant variables influencing the construction of the 2 models were compared. Evaluating the performance of the LR and ANN models on the test set revealed a sensitivity of 100% and 77.9%, a specificity of 0.0% and 75%, a positive predictive value of 93.2% and 97.2%, an overall accuracy of 93.2% and 77.7%, and an average classification rate of 50% and 76.5%, respectively. LR failed to predict any nonstone free cases. LR and ANN identified stone location and stent use as important factors in determining the outcome, while ANN also identified stone length and width as influential factors. ANN and LR could predict adequately those who would be stone-free after ESWL for ureteral stones. The neural network has a higher ability to predict those who fail to respond to ESWL.

The Effect of Extracorporeal Electromagnetic Shock Waves on the Morphology and Contractility of Rabbit Ureter

Purpose Although extracorporeal shock wave lithotripsy (ESWL) is known to cause pathologic changes in various organs, little is known about its effects on the ureter, the target organ in ESWL of ureteral stones in situ. In this study, we sought to determine the short-term effects of ESWL on the ureter. Materials and Methods Left lower ureteral segments of 21 rabbits were removed to serve as the control group and 2000 shocks were applied to the right lower ureters. Groups of 7 rabbits were sacrificed 1, 3 and 5 days after shock wave exposure. While histomorphological alterations were examined under light and transmission electron microscopy, contractility of all ureters was determined in organ baths. Results The epithelial cells disclosed no change after shock wave application. Histologically the muscular layer was the most affected part of the ureter. There was interstitial and intracellular edema on light microscopy and marked chromatin and mitochondrial changes at the subcellular level. The adventitial layer was also edematous. These changes were prominent on days 1 and 3 and returned to normal on day 5. The contractility of the ureters on day 1 was significantly reduced (p less than 0.05). However, the contractility of the samples on days 3 and 5 were not significantly different from controls. Conclusion Our findings demonstrate that electromagnetic shock waves produce reversible morphological and functional changes in rabbit ureteric muscle.

Studies on changes in parameters of the coagulation and fibrinolysis in association with extracorporeal shock wave lithotripsy.

Tissue damage by extracorporeal shock wave lithotripsy (ESWL) is assumed to be attributable to ischemic changes in the treated region surrounding the particular vessel which is first ruptured by shock waves. Such changes cannot take place without being accompanied by acceleration of coagulation and fibrinolysis. In the literature on renal damage by ESWL, no parameters of the coagulation and fibrinolysis of blood were used. The present study was designed to investigate renal damage by shock waves through the quantification of sequential changes in the following parameters between before and after ESWL: thrombin antithrombin III complex (TAT), alpha 2-plasmin inhibitor-plasmin complex (PIC), fibrin and fibrinogen degradation products (FDP) and D-dimer (D-D). In ESWL for renal stones, a significant acceleration of TAT occurred on the 1st postoperative day, followed by acceleration of PIC on the 3rd postoperative day. A transient acceleration was observed for FDP and D-D after operation. The levels of these parameters, however, returned to normal by the 1st postoperative week. In ESWL for ureteral stones, unlike for renal stones, none of the parameters showed statistically significant acceleration. In the construction of percutaneous nephrostomy (PNS) cases for ureteral stones before ESWL, none of the parameters showed significant acceleration either. Changes in these parameters of coagulation and fibrinolysis due to ESWL for renal stones were greater than those of construction of PNS or ESWL for ureteral stones. The reason for the difference of the alteration in these parameters between renal stones and ureteral stones were more abundant vessels in the kidney than the ureter. All these changes in the parameters, however, disappeared within almost 1 week.