Do patients expect too much from extracorporeal shock wave lithotripsy?

BACKGROUND: The era of patient-focused care has brought a new dimension to medical treatment. Now, as well as looking for therapies that work effectively, they must also be acceptable to patients. Previous studies in this department have shown that stone clearance rates with lithotripsy compare favourably with national standards, but very little work has been done regarding patient's own perception of the experience. METHODS: A postal survey was conducted of all patients attending the lithotripsy unit over a period of 1 year, questioning their opinion of all aspects of the treatment. The results were analysed by conversion to a numerical score. RESULTS: On the whole, patients expressed satisfaction, but they were more dissatisfied with the stone clearance than any other aspect of their treatment. In the light of a previous study, it was felt that the patients' expectations were unrealistic. As a result, we changed our practice such that patients attending the unit have a better idea of the likelihood of success. CONCLUSIONS: This was a simple and cost-effective exercise, that has generated some valuable data which can be used to improve the entire patient experience.     

Is extracorporeal shock wave lithotripsy in pediatrics a safe procedure?

Removal of urinary calculi is an essential element in the successful treatment of patients with urinary stone disease. The new generation of lithotriptors allows the treatment without the need for general anesthesia. The patients, often outpatients, have a faster discharge from the hospital with a reduction of hospitalization time and operating costs. Shock wave lithotripsy (SWL) is currently considered a safe technique for treatment of pediatric urinary lithiasias, with a low percentage of complications and subsequent surgical retreatments. But can we define SWL as a safe procedure in pediatrics? Herein, we will review the literature to justify SWL safety in children, focusing on important parameters as the insertion of preoperative stenting, side effects, and complications after the procedure.     

Renal and hypertensive complications of extracorporeal shock wave lithotripsy: who is at risk?

Extracorporeal shock wave lithotripsy (ESWL) is now used in the treatment of about 90% of renal and ureteral stones. Because of the non-punctual delivery of energy to the stone, a small volume of renal parenchyma is injured giving place to a fibrous scar which can be shown by highly resolutive imaging techniques like magnetic nuclear resonance. Isotopic clearances point to a reduction of 15% in the renal plasma flow on the side of the lithotripsy, but this alteration appears to be transient in nature. In a few cases an abrupt onset of transient hypertension has been reported in clear relation to a compressive perirenal hematoma. The responsibility of ESWL in the late occurrence of permanent hypertension is, however, still uncertain, probably because of the difficulty in showing that this occurrence is not only related to the older age of the patient. The American Food and Drug Administration-sponsored multicentric study begun in 1992 should solve this issue in the future. Recent articles suggest that altered renal function prior to ESWL would predict the late occurrence of hypertension and worsening of renal failure. Furthermore, age and the resistance index of arcuate or interlobar renal arteries (measured by Doppler) could help to screen patients at risk of developing hypertension. In practice in patients over 60 years of age and/or with a plasma creatinine of >to 300 micromol/l, ESWL should be performed with caution, and renal function and blood pressure should be carefully monitored.     

Does the rate of shock wave delivery affect outcomes in patients receiving shock wave lithotripsy for urinary calculi?

This Practice Point discusses a meta-analysis performed by Semins and colleagues, which included a total of 589 patients from four studies who were randomized to receive shock wave lithotripsy (SWL) delivered at either 120 shock waves per minute (fast rate) or 60 shock waves per minute (slow rate). The slow-rate group had a 10.2% increased chance of successful treatment compared with the fast-rate group (P = 0.002). Whilst this paper adds to existing evidence suggesting improved outcomes for slow-rate versus fast-rate SWL, the small sample size and heterogeneity of the studies included make it difficult to draw definitive conclusions. Varying the shock wave delivery rate according to patient, lithotripter system and stone characteristics, might form an important part of individualizing SWL treatment protocols. The potential advantages of slow-rate SWL must be weighed against the disadvantages of increased treatment times. Large multicenter studies will be required to determine how best to tailor SWL treatment to the individual patient.     

What makes a shock wave efficient in lithotripsy?

The aim of this investigation was the connection of quantitative shock wave parameters to stone fragmentation in lithotripsy. We developed an in vitro procedure where eroded craters in artificial stones could be measured with respect to their geometric outlines. By altering the components of an electrodynamic ultrasonic source we obtained a multitude of shock wave foci with physical parameters covering a wide range. With these foci different craters were formed and measured. With a correlation method the quantitative stone erosion could be connected with single physical parameters of the shock waves. As a result we found strict linear dependence of the volume erosion on the effective energy. On the other hand, the peak pressure in the focus revealed to be a poor parameter to qualify the fragmentation efficiency of a lithotripter. Additionally the contribution of the rise time of the shock wave to stone erosion is of negligible influence.     

Can Phyllanthus niruri affect the efficacy of extracorporeal shock wave lithotripsy for renal stones? A randomized, prospective, long-term study

PURPOSE: Phyllanthus niruri is a plant used in Brazilian folk medicine for the treatment of urolithiasis. We assessed the efficacy of P. niruri after extracorporeal shock wave lithotripsy for renal stones. MATERIALS AND METHODS: We prospectively evaluated 150 patients with renal stones that were as large as 25 mm and composed of calcium oxalate. All patients received 1 to 3 extracorporeal shock wave lithotripsy sessions by Dornier Lithotriptor S. After treatment 78 of 150 patients (52%) underwent therapy with Uriston, a P. niruri extract (2 gm daily) for at least 3 months (group 1). Otherwise 72 of 150 patients (48%) were used as a control group (group 2). No significant difference in stone size between the 2 groups was found. Stone clearance was assessed after 30, 60, 90 and 180 days by abdominal x-ray and ultrasound scan. RESULTS: Stone-free rate (stone-free defined as the absence of any stone or residual fragments less than 3 mm) was 93.5% in group 1 and 83.3% in group 2 (p = 0.48) at the end point of the followup (180 days). For lower caliceal stones (56 patients) the stone-free rate was 93.7% in the treatment group and 70.8% in the control group (p = 0.01). Re-treatment need for group 1 was 39.7% and for group 2 it was 43.3% (p = 0.2). No side effects were recorded with extracorporeal shock wave lithotripsy or P. niruri therapy. CONCLUSIONS: Regular self-administration of P. niruri after extracorporeal shock wave lithotripsy for renal stones results in an increased stone-free rate that appears statistically significant for lower caliceal location. Its efficacy and the absolute lack of side effects make this therapy suitable to improve overall outcomes after extracorporeal shock wave lithotripsy for lower pole stones.     

Ureteroscopic therapy of “steinstrasse” after extracorporeal shock wave lithotripsy (ESWL)

We were interested in the efficacy and morbidity of the ureteroscopy (URS) in the treatment of "steinstrasse" after ESWL. From 1991 to 1996, 27 patients with "steinstrasse" were treated with a total of 32 ureteroscopic procedures. The URS alone had a stonefree success rate of 43.7% (n = 14). URS combined with ESWL was effective in 43.7% (n = 14), leading to an overall success rate of 87.4%. In 4 cases (12.6%) a second therapy was necessary (in 3 cases a second URS + ESWL and in one patient a nephrectomy due to septic pyonephrosis. The overall rate of auxiliary ESWL after URS was 53.1%. Mean operating time was 72 minutes (20-180 min). The rate of complications was 21.8% (n = 7) and mainly due to ureteral perforations or postoperative fever but none suffered from late complications like ureteral stricture. All treated patients received a double-J-stent and antibiotics. The treatment of "steinstrasse" in the middle portion of the ureter proved to be more difficult due to the anatomical position of the ureter and lasted in a longer operating time as the upper or distal "steinstrasse". The stone extraction and the lithoclast-lithotripsy alone or in combination were the most frequent used ureteroscopic procedures to eliminate stone fragments. The URS alone or in combination with the ESWL for the treatment of "steinstrasse" is a highly effective and safe approach.     

Radiological determination of stone density and skin-to-stone distance—Can it predict the success of extracorporeal shock wave lithotripsy?

ObjectivesTo determine the role of stone density and skin-to-stone distance (SSD) by non-contrast computed tomography of the kidneys, ureters and bladder (CT-KUB) in predicting the success of extracorporeal shock wave lithotripsy (ESWL).MethodsWe evaluated 89 patients who received ESWL for renal and upper ureteric calculi measuring 5–20 mm, over a 12 month period. Mean stone density in Hounsfield units (HU) and mean SSD in millimetres (mm) was determined on pre-treatment CT-KUB at the CT workstation. ESWL was successful if post-treatment residual stone fragments were ≤3 mm.ResultsESWL success was observed in 68.5% of the patients. Mean stone densities were 505 ± 153 and 803 ± 93 HU in ESWL successful and failure groups, respectively; this was statistically significant (p < 0.001, student's t-test). Mean SSD were 10.6 ± 2.0 and 11.2 ± 2.6 cm in ESWL successful and failure groups, respectively, this was not statistically significant.ConclusionsThis study shows that stone density can help in predicting the outcome of ESWL. We propose that stone densities <500 HU are highly likely to result in successful ESWL. Conversely, stone densities ≥800 HU are less likely to do so. This should be accounted for when considering ESWL.     

Is lower pole caliceal anatomy predictive of extracorporeal shock wave lithotripsy success for primary lower pole kidney stones?

PURPOSE: The management of lower pole kidney stones is controversial. We examined whether lower pole caliceal anatomy could predict the success of extracorporeal shock wave lithotripsy of primary lower pole kidney stones 20 mm. or less. MATERIALS AND METHODS: From December 1997 to June 2001, 246 adults with a single, 20 mm. or less radiopaque lower pole renal stone were treated with the Doli 50 lithotriptor (Dornier Medical Systems, Marietta, Georgia) while under general anesthesia. Of the 246 patients 190 (77%) had excretory urography available for review. Lower pole infundibular length and width, lower pole infundibulopelvic angle and caliceal-pelvic height were measurable on 161 (85%), 129 (68%), 128 (67%) and 163 (86%) excretory urograms, respectively. Extracorporeal shock wave lithotripsy was considered a failure if residual stone fragments remained after 1 month, or an auxiliary procedure or re-treatment was required.RESULTS The overall stone-free rate was 78% (32 of 41) for stones 5 mm. or less, 73% (98 of 135) for stones 6 to 10 mm., 43% (22 of 51) for stones 11 to 15 mm. and 30% (7 of 19) for stones 16 to 20 mm. in maximum linear dimension. The stone-free rates grouped according to stone surface area were 76% (48 of 63 stones) for stone surface area 25 mm.2 or less, 69% (97 of 141) for 26 to 100 mm.2 and 33% (14 of 42) for 101 to 400 mm.2. Caliceal anatomy was not predictive of success even with stones grouped as 10 or less or 11 to 20 mm. Grouping patients with favorable (lower pole infundibulopelvic angle 70 degrees or greater, lower pole infundibular length 30 mm. or less and lower pole infundibular width greater than 5 mm.) versus unfavorable (70 degrees or less, greater than 30 mm. and 5 mm. or less, respectively) anatomy was also not predictive of success. CONCLUSIONS: On the Doli 50 machine stone size rather than caliceal anatomy is predictive of treatment outcome. Initial treatment failures with this machine should be managed by alternative endoscopic procedures if necessary rather than by repeat shock wave lithotripsy.     

The dose–effect relationship in extracorporeal shock wave therapy: the optimal parameter for extracorporeal shock wave therapy

Background

Extracorporeal shock wave therapy (ESWT) has been demonstrated to have the angiogenic effect on ischemic tissue. We hypothesize that ESWT exerts the proangiogenesis effect with an energy density–dependent mode on the target cells.

Materials and methods

Endothelial progenitor cells (EPCs) of rats were obtained by cultivation of bone marrow–derived mononuclear cells. EPCs were divided into five groups of different energy densities, and each group was furthermore subdivided into four groups of different shock numbers. Thus, there were 20 subgroups in total. The expressions of angiogenic factors, apoptotic factors, inflammation mediators, and chemotactic factors were examined, and the proliferation activity was measured after ESWT.

Results

When EPCs were treated with low-energy (0.04–0.13 mJ/mm²) shock wave, the expressions of endothelial nitric oxide synthase, angiopoietin (Ang) 1, Ang-2, and B-cell lymphoma 2 increased and those of interleukin 6, fibroblast growth factor 2, C-X-C chemokine receptor type 4, vascular endothelial growth factor a, Bcl-2-associated X protein, and caspase 3 decreased. stromal cell-derived factor 1 changed without statistical significance. When cells were treated with high-energy (0.16 mJ/mm²) shock wave, most of the expressions of cytokines declined except the apoptotic factors and fibroblast growth factor 2, and cells lead to apoptosis. The proliferation activity and the ratio of Ang-1/Ang-2 reached their peak values, when cells were treated with ESWT with the intensity ranging from 0.10–0.13 mJ/mm² and shock number ranging from 200–300 impulses. Meanwhile, a minimal value of the ratio of Bax/Bcl-2 was observed.

Conclusions

There is a dose–effect relationship in ESWT. The shock intensity ranging from 0.10–0.13 mJ/mm² and shock number ranging from 200–300 impulses were the optimal parameters for ESWT to treat cells in vitro.     

How effective is extracorporeal shock wave lithotripsy of ureteral stones with Dornier Lithotripter S EMSE 220F-XXP? A prospective and preliminary assessment

Aim  

To report our preliminary series with the Doli S EMSE 220F-XXP, the upgraded version of the previous Dornier Lithotripter S EMSE 220, for treatment of ureteral stones.     

Is quantitative diffusion-weighted MRI a valuable technique for the detection of changes in kidneys after extracorporeal shock wave lithotripsy?

Objective

The aim of this study was to evaluate the capability and the reliability of diffusion-weighted imaging (DWI) in the changes of kidneys occurring after extracorporeal shock wave lithotripsy (ESWL) treatment for renal stones.

Materials and Methods

A total of 32 patients who underwent ESWL treatment for renal stone disease between June and December 2011 were enrolled in this prospective study. Color Doppler ultrasonography (CDUS) and DWI were performed before and within 24 hours after ESWL. DWI was obtained with b factors of 0, 500 and 1000 s/mm² at 1.5 T MRI. Each of Resistive index (RI) and ADC values were calculated from the three regions of renal upper, middle and lower zones for both of the affected and contralateral kidneys. Paired sample t test was used for statistical analyses.

Results

After ESWL, the treated kidneys had statistically significant lower ADC values in all different regions compared with previous renal images. The best discriminative parameter was signal intensity with a b value of 1000 s/mm². The changes of DWI after ESWL were noteworthy in the middle of the treated kidney (p<0.01). There were no significant difference between RI values in all regions of treated and contralateral kidneys before and after treatment with ESWL (p>0.05).

Conclusion

DWI is a valuable technique enables the detection of changes in DWI after ESWL treatment that may provide useful information in prediction of renal damage by shock waves, even CDUS is normal.     

Does a slower treatment rate impact the efficacy of extracorporeal shock wave lithotripsy for solitary kidney or ureteral stones?

PURPOSE: We compared the efficacy of an SR (70 to 80 shocks per minute) and an FR (120 shocks per minute) for ESWL for solitary stones less than 2 cm located in the kidney or proximal ureter. MATERIALS AND METHODS: A total of 349 patients with a solitary, radiopaque kidney or ureteral stone underwent ESWL on a DoLi(R) 50 lithotriptor. Patients were grouped based on stone size, stone location and whether SR or FR treatment was performed. Of the 349 patients 135 had a renal stone between 1and 2 cm, 137 had a renal stone less than 1 cm and 77 had a proximal ureteral stone with a surface area of between 30 and 90 mm. SFRs were determined at approximately 1 month by plain x-ray of the kidneys, ureters and bladder. RESULTS: In comparison to the FR groups SR groups required fewer shocks and had significantly lower power indexes. Of patients with renal stones between 1 and 2 cm 24 of 52 (46%) in the FR group were stone-free compared to 56 of 83 (67%) in the SR group (p <0.05). For stones with a surface area of 30 to 90 mm located in the kidney or proximal ureter there was a trend toward an improved SFR in the SR group but differences between the SR and FR groups were not statistically significant. CONCLUSIONS: For solitary renal stones between 1 and 2 cm an SR results in a better treatment outcome than an FR for ESWL. However, when stone size is less than 1 cm, SFR differences in the SR and FR treatment groups become less significant.     

Flexible ureterorenoscopy versus extracorporeal shock wave lithotripsy for treatment of lower pole stones of 10-20 mm

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Shock wave lithotripsy and flexible ureterorenoscopy are acceptable treatment options for lower pole stones smaller than 10 mm, while percutaneous nephrolithotomy is the favoured treatment for stones larger than 20 mm. For treatment of lower pole stones of 10–20 mm, flexible ureterorenoscopy has a significantly higher stone‐free rate and lower retreatment rate than shock wave lithotripsy.

OBJECTIVE

• ? To compare the outcomes of flexible ureterorenoscopy (F‐URS) and extracorporeal shock wave lithotripsy (ESWL) for treatment of lower pole stones of 10–20 mm.

PATIENTS AND METHODS

• ? The database of patients with a single lower pole stone of 10–20 mm was examined to obtain two matched groups who were treated with F‐URS or ESWL. Matching criteria were stone length, side and patient gender.
• ? Stone‐free rates were evaluated 3 months after the last treatment session by non‐contrast computed tomography. Both groups were compared for retreatment rate, complications and stone‐free rate.

RESULTS

• ? The matched groups included 37 patients who underwent F‐URS and 62 patients who underwent ESWL. Retreatment rate was significantly higher for ESWL (60% vs 8%, P < 0.001).
• ? Complications were more after F‐URS (13.5% vs 4.8%), but the difference was not significant (P= 0.146). All complications were grade II or IIIa on modified Clavien classification.
• ? The stone‐free rate was significantly better after F‐URS (86.5% vs 67.7%, P= 0.038). One failure of F‐URS (2.7%) and five failures (8%) of ESWL were treated with percutaneous nephrolithotomy.
• ? Significant residual fragments in three patients (8%) after F‐URS were treated with ESWL, while significant residual fragments after ESWL in five patients (8%) were treated with F‐URS. Residual fragments (<4 mm) were followed every 3 months in one patient (2.7%) after F‐URS and in 10 patients (16%) after ESWL.

CONCLUSIONS

• ? For treatment of lower pole stones of 10–20 mm, F‐URS provided significantly higher stone‐free rate and lower retreatment rate compared with ESWL.
• ? The incidence of complications after F‐URS was not significantly more than after ESWL.

     

Is there a role for tamsulosin in shock wave lithotripsy for renal and ureteral calculi?

PURPOSE: We evaluated the effect of the alpha-blocker tamsulosin on stone clearance, analgesic requirements and steinstrasse in shock wave lithotripsy for solitary renal and ureteral calculus. MATERIALS AND METHODS: A prospective, double-blind, randomized placebo controlled study was performed during 1 year involving 60 patients with a solitary renal or ureteral calculus undergoing shock wave lithotripsy. The control group (30) received 0.4 mg tamsulosin and the study group (30) received placebo daily until stone clearance or for a maximum of 30 days. An oral preparation of dextropropoxyphene hydrochloride and acetaminophen was the analgesic used on an on-demand basis. The parameters assessed were stone size, position, clearance time, effect on steinstrasse and analgesic requirement. RESULTS: The overall clearance rate was 96.6% (28 of 29) in the study group and 79.3% (23 of 29) in the control group (p = 0.04). With larger stones 11 to 24 mm the difference in the clearance rate was significant (p = 0.03) but not so with the smaller stones 6 to 10 mm (p = 0.35). The average dose of analgesic used was lower with tamsulosin than with controls, without statistical significance. Steinstrasse resolved spontaneously in the tamsulosin group whereas 25% (2 of 8) required intervention in the placebo group. There was no difference between the 2 groups with regard to age, stone size or location. CONCLUSIONS: The alpha-blocker tamsulosin seemed to facilitate stone clearance, particularly with larger stones during shock wave lithotripsy for renal and ureteral calculus. It also appeared to improve the outcome of steinstrasse. Tamsulosin may have a potential role in routine shock wave lithotripsy.     

Is pre-shock wave lithotripsy stenting necessary for ureteral stones with moderate or severe hydronephrosis?

PURPOSE: We performed a prospective, randomized clinical trial to evaluate the outcome of ureteral stents for solitary ureteral stones 2 cm or less in moderately or severely obstructed systems using shock wave lithotripsy. MATERIALS AND METHODS: Between 2001 and 2004, 186 patients who met study criteria were randomized into 2 groups. Group 1 received a pre-shock wave lithotripsy 6Fr Double-J stent and group 2 had no stent. Patients were treated with a Dornier MFL 5000 lithotripter. Results were compared in terms of clearance rates, number of shock waves and sessions, irritative voiding symptoms, incidence of complications and secondary interventions. Failure was defined as the need for additional procedure(s) for stone extraction. RESULTS: Overall 164 patients (88.2%) became stone-free after shock wave lithotripsy. Complete stone fragmentation was achieved after 1 to 3 and more than 3 session in 108 (58.1%), 30 (16.1%), 13 (7%) and 14 patients (7.5%), respectively. Ureteral stent insertion did not affect the stone-free rate, which was 84.9% and 91.4% in groups 1 and 2, respectively (p = 0.25). There was no statistical difference in the re-treatment rate, flank pain or temperature in the 2 groups. However, all patients in the stented group significantly complained of side effects attributable to the stent, including dysuria, suprapubic pain, hematuria, pyuria and positive urinary culture. CONCLUSIONS: Pretreatment stenting provides no advantage over in situ shock wave lithotripsy for significantly obstructing ureteral calculi. Shock wave lithotripsy is reasonable initial therapy for ureteral stones 2 cm or less that cause moderate or severe hydronephrosis.