The role of lithotripsy and its side effects

Is extracorporeal lithotripsy a first-line treatment for urinary stones today?

OBJECTIVE

To evaluate the efficacy and complications of extracorporeal lithotripsy (SWL) as a first-line treatment for renal and ureteral stones METHODS: Retrospective and observational study of all the patients treated with lithotripsy in a third level center between January 2014 and January 2021; characteristics of the patients, the stones, complications and results of SWL is recollected. Multivariate logistic regression of the factors associated with stone size reduction was performed. A statistical analysis of the factors associated with additional treatment after SWL and factors associated with complications is also executed.

RESULTS

1727 patients are included. Stone mean size was 9,5mm. 1540 (89.4%) patients presented reduction in stone size. In multivariate analysis, stone size (OR=1.13; p=0.00), ureteral location of the lithiasis (OR=1.15; p=0.052) and number of waves (p=0.002; OR=1.00) used in SWL are the factors associated with reduction of stone size. Additional treatment after lithotripsy was needed in 665 patients (38.5%). The factors associated with the need for retreatment were stone size (OR=1.131; p=0.000), number of waves (OR=1.000; p=0.000), energy (OR=1.005; p=0.000). 153 patients (8.8%) suffered complications after SWL. A statistically significant association was found between the size of the lithiasis (p=0.024, OR=1.054) and the previous urinary diversion (P=0.004, OR=0.571).

CONCLUSION

Lithotripsy remains an effective treatment as the first line of therapy for reno-ureteral lithiasis with a low percentage of complications.

Cavitation cloud formation and surface damage of a model stone in a high-intensity focused ultrasound field

This work investigates the fundamental role of cavitation bubble clouds in stone comminution by focused ultrasound. The fragmentation of stones by ultrasound has applications in medical lithotripsy for the comminution of kidney stones or gall stones, where their fragmentation is believed to result from the high acoustic wave energy as well as the formation of cavitation. Cavitation is known to contribute to erosion and to cause damage away from the target, yet the exact contribution and mechanisms of cavitation remain currently unclear. Based on in situ experimental observations, post-exposure microtomography and acoustic simulations, the present work sheds light on the fundamental role of cavitation bubbles in the stone surface fragmentation by correlating the detected damage to the observed bubble activity. Our results show that not all clouds erode the stone, but only those located in preferential nucleation sites whose locations are herein examined. Furthermore, quantitative characterizations of the bubble clouds and their trajectories within the ultrasonic field are discussed. These include experiments with and without the presence of a model stone in the acoustic path length. Finally, the optimal stone-to-source distance maximizing the cavitation-induced surface damage area has been determined. Assuming the pressure magnitude within the focal region to exceed the cavitation pressure threshold, this location does not correspond to the acoustic focus, where the pressure is maximal, but rather to the region where the acoustic beam and thereby the acoustic cavitation activity near the stone surface is the widest.

Global trends in research on extracorporeal shock wave therapy (ESWT) from 2000 to 2021

BACKGROUND

This study intended to analyze the application of extracorporeal shock wave therapy in medicine and to evaluate the quality of related literature.

METHODS

All publications were extracted from 2000 to 2021 from the Web of Science Core Collection (WoSCC). The literature characteristics were depicted by VOSviewer (version 1.6.15) and the online bibliometric website ( http://bibliometric.com/ ). The future trends and hotspots were conducted by Bibliographic Item Co-occurrence Matrix Builder (version 2.0) and gCLUTO software.

RESULTS

We analyzed 1774 articles corresponding to the criteria for ESWT publications from 2000 to 2021. Most studies were conducted within the United States and China which besides have the most cooperation. The most published research institutions are Chang Gung University, Kaohsiung Chang Gung Memorial Hospital, and Kaohsiung Medical University. Six research hotspots were identified by keyword clustering analysis: Cluster0: The effects of ESWT on muscle spasticity; Cluster1: The application of ESWT in osteoarthritis (OA); Cluster2: Therapeutic effect of ESWT on tendon diseases; Cluster3: Early application of ESWT/ESWL in urolithiasis; Cluster4: The Role of angiogenesis in ESWT and the efficiency of ESWT for penile disease; Cluster5: The Special value of radial extracorporeal shock wave therapy (rESWT).

CONCLUSIONS

A comprehensive and systematic bibliometric analysis of ESWT was conducted in our study. We identified six ESWT-related research hotspots and predicted future research trends. With the gradual increase of research on ESWT, we find that ESWT is used more and more extensively, such in musculoskeletal disease, bone delay union, neurological injury, andrology disorders, lymphedema, and so on. In addition, the mechanism is not destructive damage, as initially thought, but a restorative treatment. Furthermore, delayed union, cellulite, burn, and diabetic foot ulcers may be the future direction of scientific study.

The effects of Cynodon dactylon (Poaceae family) and Dolichos biflorus (Fabaceae family) extracts on decreasing size and excretion of kidney and urinary tract stones: a randomized, double-blind controlled trial

OBJECTIVES

Given high and growing prevalence rate of urolithiasis in most societies as well as the problems caused by this issue, it is necessary to apply more cost-effective and safer therapeutic methods, which are accessible for all the individuals worldwide. Therefore, this study aimed to investigate efficacy of herbal medicines named Cynodon dactylon and Dolichos biflorus on solving and excretion of renal and urinary tract stones in patients with urolithiasis.

METHODS

This study included 96 patients with urolithiasis who were randomly allocated into three groups. The first group received the extract of D. biflorus seeds (1,600 mg), the second group received extract of C. dactylon rhizome (1,600 mg) and the third group received placebo for 21 days. In this study, we used an hydroalcoholic extract of D. biflorus and C. dactylon prepared by Soxhlet method. For each patient, the size of the stones, the amount of calcium in the urine, the number of stones excreted and their chemical substance type were measured.

RESULTS

In this study, changes were observed at the significance level in the interventions groups of 1 and 2, and the placebo group in the left kidney, so that changes in size of the stone in left kidney as intergroup were significantly different in these three groups (p=0.02). The mean of changes in stone size in left kidney in the group C. dactylon was 3.78 ± 7.1 and in the group D. biflorus, it was 0.27 ± 0.6.

CONCLUSIONS

A significant difference in the results of this study show that C. dactylon rhizome and D. biflorus seed extracts are able to decrease the size of the stone and can be effective on kidney stones excretion.

Epidemiology of Kidney Stones

In the past two decades, major breakthroughs that improve our understanding of the pathophysiology and therapy of kidney stones (KS) have been lacking. The disease continues to be challenging for patients, physicians, and healthcare systems alike. In this context, epidemiological studies are striving to elucidate the worldwide changes in the patterns and the burden of the disease and identify modifiable risk factors that contribute to the development of kidney stones. Our expanding knowledge of the epidemiology of kidney stones is of paramount importance and largely upgrades the modern management of the disease. In this paper, we review the variables affecting prevalence and incidence, including age, gender, race, ethnicity, occupation, climate, geography, systemic diseases, diabetes, vascular disease, chronic kidney disease, and dietary risk factors relevant to kidney stones.

An experimentally-calibrated damage mechanics model for stone fracture in shock wave lithotripsy

A damage model suggested by the Tuler-Butcher concept of dynamic accumulation of microscopic defects is obtained from experimental data on microcrack formation in synthetic kidney stones. Experimental data on appearance of microcracks is extracted from micro-computed tomography images of BegoStone simulants obtained after subjecting the stone to successive pulses produced by an electromagnetic shock-wave lithotripter source. Image processing of the data is used to infer statistical distributions of crack length and width in representative transversal cross-sections of a cylindrical stone. A high-resolution finite volume computational model, capable of accurately modeling internal reflections due to local changes in material properties produced by material damage is used to simulate the accumulation of damage due to successive shocks. Comparison of statistical distributions of microcrack formation in computation and experiment allows calibration of the damage model. The model is subsequently used to compute fracture of a different aspect-ratio cylindrical stone predicting concurrent formation of two main fracture areas as observed experimentally.

A randomised controlled trial evaluating renal protective effects of selenium with vitamins A, C, E, verapamil, and losartan against extracorporeal shockwave lithotripsy-induced renal injury

OBJECTIVE

To evaluate the protective effects of selenium with vitamins A, C and E (selenium ACE, i.e. antioxidants), verapamil (calcium channel blocker), and losartan (angiotensin receptor blocker) against extracorporeal shockwave lithotripsy (ESWL)-induced renal injury.

PATIENTS AND METHODS

A randomised controlled trial was conducted between August 2012 and February 2015. Inclusion criteria were adult patients with a single renal stone (<2 cm) suitable for ESWL. Patients with diabetes, hypertension, congenital renal anomalies, moderate or marked hydronephrosis, or preoperative albuminuria (>300 mg/L) were excluded. ESWL was performed using the electromagnetic DoLiS lithotripter. Eligible patients were randomised into one of four groups using sealed closed envelopes: Group1, control; Group 2, selenium ACE; Group 3, losartan; and Group 4, verapamil. Albuminuria and urinary neutrophil gelatinase-associated lipocalin (uNGAL) were estimated after 2-4 h and 1 week after ESWL. The primary outcome was differences between albuminuria and uNGAL. Dynamic contrast-enhanced magnetic resonance imaging was performed before ESWL, and at 2-4 h and 1 week after ESWL to compare changes in renal perfusion.

RESULTS

Of 329 patients assessed for eligibility, the final analysis comprised 160 patients (40 in each group). Losartan was the only medication that showed significantly lower levels of albuminuria after 1 week (P < 0.001). For perfusion changes, there was a statistically significant decrease in the renal perfusion in patients with obstructed kidneys in comparison to before ESWL (P = 0.003). These significant changes were present in the control or antioxidant group, whilst in the losartan and verapamil groups renal perfusion was not significantly decreased.

CONCLUSIONS

Losartan was found to protect the kidney against ESWL-induced renal injury by significantly decreasing post-ESWL albuminuria. Verapamil and losartan maintained renal perfusion in patients with post-ESWL renal obstruction.

Evaluation of acute post-shock wave lithotripsy renal changes by dynamic magnetic resonance imaging: a prospective clinical study

PURPOSE

We studied acute renal morphological and hemodynamic changes after shock wave lithotripsy of renal stones.

MATERIALS AND METHODS

A total of 60 adult patients with a single renal stone 25 mm or less in a radiologically normal urinary tract were eligible for shock wave lithotripsy and included in analysis. Study exclusion criteria were hypertension, diabetes mellitus, previous recent stone management and other contraindications to shock wave lithotripsy. Renal perfusion and morphological changes were evaluated by dynamic magnetic resonance imaging before, and 2 to 4 hours and 1 week after lithotripsy.

RESULTS

In all cases there was a statistically significant decrease in renal perfusion 1 week after shock wave lithotripsy compared to before and 2 to 4 hours after lithotripsy (66% vs 71% and 72% of the aortic blood flow, respectively, p <0.05). At 1-week followup 39 unobstructed renal units (65%) showed no significant difference in renal perfusion at any time while 21 (35%) obstructed renal units showed a significant decrease in renal perfusion compared to before and 2 to 4 hours after lithotripsy (63% vs 76% and 75%, p = 0.003 and 0.005, respectively). Hematomas were observed in 7 cases (12%) 2 to 4 hours after lithotripsy, of which 5 were subcapsular and 2 were intrarenal. Three subcapsular hematomas resolved after 1 week. Localized loss of corticomedullary differentiation was observed in 2 patients (3.3%) with intrarenal hematoma 2 to 4 hours after treatment. Generalized loss of corticomedullary differentiation was observed 1 week after lithotripsy in 5 cases (8.3%).

CONCLUSIONS

Shock wave lithotripsy alone induces minimal, reversible acute renal morphological changes and does not induce significant changes in renal perfusion. Posttreatment obstruction has a major effect on renal perfusion on the treated side and must be managed urgently.

Interleukin-18 and NGAL in assessment of ESWL treatment safety in children with urolithiasis

Urolithiasis is recurrent chronic disease and a complex nephro-urological problem. Currently it is diagnosed in very young children, even infants in the first quarter of life. Until recently the main method of treatment for stones, which for various reasons did not pass spontaneously, was open surgery. At present, the main method replacing open surgery is extracorporeal shock wave lithotripsy (ESWL). Usefulness of common known indicators of the renal function to assess the safety of ESWL procedure is evaluated and verified. The basic markers are serum creatinine, cystatin C, urea, glomerular filtration rate and albuminuria assessment. Unfortunately all these methods show little sensitivity in the case of acute injury processes. There are efforts to use new biomarkers of renal tubular activity, which include among others interleukin 18 (IL-18) and neutrophil gelatinase-associated lipocalin (NGAL). The aim of the study was to assess the safety of ESWL by means of albumin to creatinine ratio, serum cystatin C levels and concentration of two new markers: IL -18 and NGAL. Albumin to creatinine ratio (p = 0.28) and serum cystatin C (p = 0.63) collected before and 48 hours after ESWL did not show statistically significant differences. Similarly, both new markers (IL -18 and NGAL) showed no significant differences (urine IL -18 p = 0.31; serum NGAL p = 0.11; urine NGAL p = 0.29). In conclusion, serum cystatin C tests, urine albumin to creatinine ratio and new early markers of renal tubular injury confirmed the safety of the extracorporeal shock wave lithotripsy (ESWL) and show that the procedure does not cause any episode of acute renal injury.

Does extracorporeal shock wave lithotripsy cause hearing impairment in children?

PURPOSE

We evaluated the possible effects of noise created by high energy shock waves on the hearing function of children treated with extracorporeal shock wave lithotripsy.

MATERIALS AND METHODS

A total of 65 children with normal hearing function were included in the study. Patients were divided into 3 groups, ie those becoming stone-free after 1 session of shock wave lithotripsy (group 1, 22 children), those requiring 3 sessions to achieve stone-free status (group 2, 21) and healthy children/controls (group 3, 22). Extracorporeal shock wave lithotripsy was applied with patients in the supine position with a 90-minute frequency and a total of 2,000 shock waves in each session (Compact Sigma, Dornier MedTech, Wessling, Germany). Second energy level was used with a maximum energy value of 58 joules per session in all patients. Hearing function and possible cochlear impairment were evaluated by transient evoked otoacoustic emissions test at 1.0, 1.4, 2.0, 2.8 and 4.0 kHz frequencies before the procedure, 2 hours later, and 1 month after completion of the first shock wave lithotripsy session in groups 1 and 2. In controls the same evaluation procedures were performed at the beginning of the study and 7 weeks later.

RESULTS

Regarding transient evoked otoacoustic emissions data, in groups 1 and 2 there was no significant alteration in values obtained after shock wave lithotripsy compared to values obtained at the beginning of the study, similar to controls.

CONCLUSIONS

A well planned shock wave lithotripsy procedure is a safe and effective treatment in children with urinary stones and causes no detectable harmful effect on hearing function.

Preliminary investigation on ultra high diluted B. vulgaris in experimental urolithiasis

PURPOSE

The study focuses on the anti-urolithiasis potential of ultra-diluted homeopathic potency of Berberis vulgaris (B. vulgaris) root bark, commonly used in homeopathic system to treat renal calculi.

METHODOLOGY

B. vulgaris root bark (200c, 20 μl/100 g body weight/day, p.o, for 28 days) was tested in an animal model of urolithiasis. Urolithiasis was induced in male Wistar rats by adding 0.75% ethylene glycol (EG) to drinking water. Urine and serum samples were analyzed for calcium, magnesium, phosphorus, uric acid and creatinine. Enzymic makers of renal damage (alkaline phosphatase, lactate dehydrogenase, leucine aminopeptidase and γ-glutamyl transpeptidase) were assessed in kidney and urine. Renal tissues were analyzed for oxalate content.

RESULTS

Administration of EG to rats increased the levels of the stone-forming constituents calcium, phosphorus and uric acid, in urine. Levels were normalized by B. vulgaris treatment. The decrease in the urolithiasis inhibitor magnesium in urine was prevented by treatment with B. vulgaris. Serum creatinine levels were largely normalized by B. vulgaris treatment. Hyperoxaluria induced renal damage was evident from the decreased activities of tissue marker enzymes and an apparent escalation in their activity in the urine in control animals; this was prevented by B. vulgaris treatment.

CONCLUSION

Homeopathic B. vulgaris root bark has strong anti-urolithiasis potential at ultra-diluted dose.

The protective role of coenzyme Q10 in renal injury associated with extracorporeal shockwave lithotripsy: a randomised, placebo-controlled clinical trial

OBJECTIVE

To determine the efficacy of coenzyme Q10 (CoQ10) in preventing renal injury in patients with lithiasis undergoing extracorporeal shockwave lithotripsy (ESWL).

PATIENTS AND METHODS

Prospective, randomised, double-blind, placebo-controlled clinical trial of 100 patients with renal lithiasis who were treated with ESWL. The patients were distributed randomly into two groups receiving either placebo or CoQ10 (200 mg/day), a powerful antioxidant with vasoactive properties, orally administered during the week before ESWL and for 1 week after. Renal dysfunction markers, vasoactive hormones, oxidative stress, plasma levels of several interleukins and vascular resistance index (VRI) using Doppler ultrasound were evaluated the week before ESWL, 2 h before ESWL and at 2 h, 24 h and 7 days after ESWL.

RESULTS

There was a significant increase in glomerular filtration (P = 0.013), as well as a decrease in the albumin/creatinine ratio and the β2 -microglobulin level (P = 0.02) after 1 week of treatment in the CoQ10 group. These changes were maintained at the follow-up after ESWL. The administration of CoQ10 was associated with improvement in vasoactive hormone parameters, VRI and interleukin levels. These improvements were maintained until the end of the follow-up period. However, the administration of CoQ10 was not associated with significant changes in the oxidative stress parameters.

CONCLUSION

Our results indicate that CoQ10 administration improves renal function and vasoactive and inflammation parameter values, allowing for preconditioning before the tissue insult caused by ESWL.

Antioxidant signal and kidney injury molecule-1 levels in shockwave lithotripsy induced kidney injury

PURPOSE

Shockwave lithotripsy (SWL) induces acute kidney injury (AKI) that extends from the papilla to the outer cortex by causing ischemia and the production of nephrotoxic agents. Direct ischemic damage and the generation of free radicals cause injury to the proximal tubular cells. Kidney injury molecule-1 (KIM-1) is a transmembrane glycoprotein that is upregulated in proximal tubular cells after ischemic or nephrotoxic injury and is not expressed in healthy kidneys. We evaluated the extent of free radical production in response to SWL by measuring urinary total antioxidant capacity (TAC) and total oxidant status (TOS). Furthermore, we investigated the severity of SWL-induced kidney injury by measuring KIM-1 expression levels.

PATIENTS AND METHODS

The study population comprised 30 patients who were carefully selected and 30 age and sex matched control subjects. All patients received the same SWL procedure. Midstream urine samples were collected from patients before SWL and at 120 minutes after SWL. Urine KIM-1 levels were measured by enzyme-linked immunosorbent assay, and TAC and TOS were measured via spectrophotometry.

RESULTS

Mean levels of TAC (2.88±0.56 mmolTxEq/L),TOS (8.27±1.57 μmolH2O2Eq/L), and KIM-1 (0.55±0.08 ng/mL) before SWL were not significantly different from mean TAC, TOS, and KIM-1 levels measured from the control group at 2.81±0.42 mmolTxEq/L, 10.73±1.4 μmolH2O2Eq/L, and 0.51±0.07 ng/mL, respectively. Two hours after SWL, mean urine TAC levels (2.81±0.85 mmolTxEq/L, P=0.02) were decreased and mean KIM-1 expression (0.85±0.11 ng/mL, P=0.01) was significantly increased, but there was no significant difference in mean TOS levels (11.24±1.9 μmolH2O2Eq/L, P=0.627) compared with the control group.

CONCLUSIONS

The increased burden of free radical oxidants in the setting of decreasing antioxidant capacity may be one of the initial indicators of AKI after SWL. Moreover, KIM-1 demonstrates great potential as an early and noninvasive biomarker of SWL-induced kidney injury.

Renal deterioration index: preoperative prognostic model for renal functional outcome after treatment of bilateral obstructive urolithiasis in patients with chronic kidney disease

BACKGROUND AND PURPOSE

Patients who present with varying severity of obstructive urolithiasis behave differently after the treatment. Some patients recover with improved renal function while others progress to renal failure. Our objective was to objectively quantify which patients would progress to renal failure after treatment for obstructive urolithiasis.

PATIENTS AND METHODS

A prospective analysis of 167 patients with renal failure from bilateral obstructive urolithiasis who were treated and subsequently followed for at least 1 year was performed. Failure was defined as glomerular filtration rate (GFR) values less than 15 mL/min at 1 year follow-up. All patients had preoperative placement of a percutaneous nephrostomy tube for at least 5 days before treatment with either ureteroscopy or percutaneous nephrolithotomy. Multiple logistic regression analysis of affecting parameters was performed. A renal deterioration index (RDI) was constructed based on scores assigned to varying severity of multivariate significant factors and the receiver operating characteristic (ROC) curve was analyzed.

RESULTS

There were 48(28.7%) patients who progressed to CKD stage V at 1-year follow-up. Combined cortical width (≤ 0.001), proteinuria (0.01), positive urine culture (0.004), and nadir preoperative GFR postbilateral percutaneous nephrostomy (0.016) were statistically significant factors affecting renal deterioration on multivariate analysis. RDI has a high ROC curve (AUC=0.90) for predicting renal functional outcome. Combining these parameters in a prediction table yielded a RDI score ≥ 12 being associated with high odds risk (odds ratio=11.2) of treatment failure.

CONCLUSION

RDI ≥ 12 is associated with renal deterioration after appropriate treatment of bilateral obstructive urolithiasis.

Design of the dual stone locating system on an extracorporeal shock wave lithotriptor

Extracorporeal Shock Wave Lithotriptors are very popular for the treatment of urinary stones all over the world. They depend basically upon either X-ray fluoroscopy or ultrasound scans to detect the stones before therapy begins. To increase the effectiveness of treatment this study took advantage of both X-ray and ultrasound to develop a dual stone locating system with image processing modules. Its functions include the initial stone locating mode with stone detection by fluorescent images and the follow-up automatic stone tracking mode made by constant ultrasound scanning. The authors have integrated both apparatus and present the operating principles for both modes. The system used two in vitro experiments to justify its abilities of stone location in all procedures.

Optimal shock wave rate for shock wave lithotripsy in urolithiasis treatment: a prospective randomized study

PURPOSE

We aimed to compare the effects of a fast shock wave rate (120 shocks per minute) and a slow shock wave rate (60 shocks per minute) on the shock wave lithotripsy (SWL) success rate, patient's pain tolerance, and complications.

MATERIALS AND METHODS

A total of 165 patients with radiopaque renal pelvis or upper ureter stones were included in the study. Patients were classified by use of a random numbers table. Group I (81 patients) received 60 shock waves per minute and group II (84 patients) received 120 shock waves per minute. For each session, the success rate, pain measurement, and complication rate were recorded.

RESULTS

No statistically significant differences were observed in the patients according to age, sex, body mass index, stone size, side, location, total energy level, or number of shocks. The success rate of the first session was greater in group I than in group II (p=0.002). The visual analogue pain scale was lower in group I than in group II (p=0.001). The total number of sessions to success and the complication rate were significantly lower in group I than in group II (p=0.001).

CONCLUSIONS

The success rate of SWL is dependent on the interval between the shock waves. If the time between the shock waves is short, the rate of lithotripsy success decreases, and the pain measurement score and complications increase. We conclude slow SWL is the optimal shock wave rate.

[Ischemic lesions in kidneys after extracorporeal shock wave lithotripsy demonstrated by Proton NMR spectroscopy of urine samples]

PURPOSE

The aim of this prospective study was to investigate the effect of extracorporeal shock wave lithotripsy (SWL) on kidneys of patients with pyelic stone disease. The effects of SWL were assessed by high-resolution proton nuclear magnetic resonance (HNMR) spectroscopy of urine samples.

METHODS

Twenty-three patients, aged 31-80years (mean: 55years), with pyelic stone disease were investigated before and after SWL. Multiparameter analysis was performed by HNMR spectroscopy of urine samples collected before and 5h after SWL (second miction post-SWL).

RESULTS

The most relevant resonances determined by HNMR spectroscopy were acetate, lactate, trimethylamine N-oxide and amino acids. Excretion of these markers increased significantly in comparison with pre-SWL urinary samples.

CONCLUSION

These results show that early ischemic damage occurs after SWL. Post-SWL. HNMR spectroscopy is an effective tool for noninvasive follow-up of renal damage.

[Horseshoe kidney stones: benefit of flexible ureterorenoscopy with holmium laser]

OBJECTIVES

We aim to assess the outcome of the flexible ureterorenoscopy (F-URS) with holmium laser in treating horseshoe kidney (HSK) stones.

PATIENTS AND METHODS

We reviewed retrospectively the records of 18 patients with HSK stone (18 renal units) who underwent F-URS using holmium laser from December 2004 to October 2009. The mean age was 37.7±6.9 years. The F-URS used after the extracorporeal shock wave lithotripsy (ESWL) failure in eight patients (44.4%) and four patients (22.2%) had PCNL failure. The follow up visit range were between 4 and 6 weeks with plain radiograph (KUB) and renal ultrasound or non contrast computed tomography scan (NCCT). Success rate was defined as stone free or residual fragment less than 3 mm. Use of auxiliary procedures like ESWL were considered as treatment failure.

RESULTS

Eighteen patients, three females and 15 males with mean age was 37.7±6.9 years with HSK calculi underwent ureteroscopic management. The presenting symptoms were renal colic, urinary tract infection or hematuria. We found different HSK stone location (11 mixed calyceal, three mixed pelvic and calyceal and four pelvic). The average stone burden was 15.5±7.3 mm and the mean operative time was 112±9.4 minutes. All over procedures were 27, with mean average of 1.5 procedures per patient. The success rate was 89%.

CONCLUSION

The F-URS with holmium laser is an efficient minimal invasive procedure in treating HSK stones.

Urine cytology to evaluate urinary urothelial damage of shock-wave lithotripsy

Our aim is to study the prospective trial where urine cytology was used to detect the acute urothelial mucosal damage in patients who undergo extracorporeal shock waves lithotripsy (SWL). The study included 48 consecutive patients (28 male, 20 female) with mean age of 49.02 years (range 18-66) who were treated with SWL due to renal stones (30 patients) or upper ureter stones (18 patients). The mean calculi diameter was 12.44 mm (range 5-20). Urinary cytologic examinations were done for all patients immediately before and after SWL therapy and 10 days latter. The average numbers of transitional cells, red blood cells and myocytes were counted under 40 × magnification. In overall patients the average numbers of transitional cells at the cytologic examinations done immediately before and after SWL therapy were 1.6 and 7.53 cell/field, respectively (p = 0.001). The increment in transitional cells at cytologic examination after SWL was significantly influenced only by number of shock waves applied (p = 0.003). No muscle cell was detected in all cytologic examinations. The cytologic examinations which were done after 10 days of SWL therapy showed recovery from all cytologic abnormalities. The acute increment in number of transitional cells after the SWL is not clinically important and it is a temporary change. Urothelial lesion is limited to mucosal layer and there is no evidence of damage to basal membrane or deeper muscle layer. SWL safety on urothelial and muscular layer was demonstrated. However, evaluation of larger series with use of other lithotripters is necessary before reaching any definitive conclusions.

Shock wave lithotripsy for distal ureteric stones: supine or prone

Shock wave lithotripsy (SWL) has become the preferred first-line approach to most patients with symptomatic urolithiasis. The purpose of this study is to assess the ideal patient position during SWL for the treatment of distal ureter stones. A total of 342 patients included in this retrospective study. 148 (108 men, 40 women) patients were included in the first group and were treated in supine position. The remaining 194 (143 men, 51 women) patients were included to second group and were treated in prone position. This study designed retrospectively. The procedure was accepted as a success if the patient was stone free or had only clinically insignificant fragments (≤3 mm) for 3 months or more after the last SWL session. Before SWL, the mean is one area in the first group was 61.32 mm2 while the mean stone area in the second group was 59.04 mm2 (p = 0.208). Mean energy, Mean energy maximum and mean number of applied shock waves of the first group was 4.65, 3.19 and 3,960, respectively. The same parameters in second group were 4.26, 3.03 and 2,953, respectively. These results show that there are statistically significant differences between two groups with respect to mean energy, mean energy maximum and mean number of applied shock waves (p = 0.003, p = 0.010, p = 0.000, respectively). Success rate was 85.1% in group 1 and 72.7% in group 2 (p = 0.006). Our results suggest that supine position is effective and better than prone position for SWL in patients with distal ureteric stones.

Flexible ureterorenoscopy with holmium laser in horseshoe kidneys

OBJECTIVES

To assess the outcome of flexible ureterorenoscopy (F-URS) with the holmium laser in treating stones in the horseshoe kidney (HSK).

METHODS

We retrospectively reviewed the records of 17 patients with a HSK stone (17 renal units) who had undergone F-URS with the holmium laser from December 2004 to May 2009. The presenting symptoms were renal colic, urinary tract infection, or hematuria. F-URS was used in as an alternative after the failure of shock wave lithotripsy in 8 patients (47%) and percutaneous nephrolithotomy failure in 4 patients (23.5%). Follow-up examination was performed after 4-6 weeks with plain radiography and either renal ultrasonography or noncontrast computed tomography. Success was defined as stone-free status or residual fragments <3 mm. The use of auxiliary procedures was considered to indicate treatment failure.

RESULTS

A total of 17 patients were included in the present study (3 females and 14 males). Their age was 16-52 years (mean age ± SD 34.7 ± 6.3). The HSK stone location was 7 mixed caliceal, 3 mixed pelvic and caliceal, and 7 pelvic. The average stone burden was 16 mm (range 7-35). The overall number of procedures was 25 (mean 1.5 procedures/patient). Of the 17 patients, 15 (88.2%) were rendered stone free.

CONCLUSIONS

The results of our study have shown that F-URS with the holmium laser is an efficient minimal invasive procedure for treating HSK stones.

Retroperitoneal laparoscopic pyelolithotomy: how does it compare with percutaneous nephrolithotomy for larger stones?

Our 10-year experience of retroperitoneal laparoscopic pyelolithotomy, a rarely performed minimally invasive operative procedure, is presented. The results are compared with our own experience of percutaneous nephrolithotomy for larger renal stones. Forty-two patients with a mean age of 39.12 years underwent 43 retroperitoneal laparoscopic pyelolithotomies using Gaur's balloon technique. The total number of stones was 65 (44 pelvic and 21 calyceal) and they ranged in size between 5 and 48 mm. Two patients had chronic renal failure due to bilateral impacted renal calculi. Forty-eight percutaneous nephrolithotomies performed in the same unit during the last 2 years in patients with non-staghorn calculi > 2 cm were included for a comparative study. The open conversion rate and the drainage period for retroperitoneal laparoscopic pyelolithotomy were much higher. However, the operative time, blood loss, analgesic intake, hospital stay, residual stone rate, re-treatment rate and major complication rates were lower, compared with percutaneous nephrolithotomy.

Impact of percutaneous nephrolithotomy on estimated glomerular filtration rate in patients with chronic kidney disease

BACKGROUND AND PURPOSE

We investigated the impact of percutaneous renal procedures on estimated glomerular filtration rate (GFR) of patients with chronic kidney disease (CKD).

PATIENTS AND METHODS

The GFRs of adult patients were calculated using the Modification of Diet in Renal Disease formula, and the patients were staged according to the Kidney Disease Outcome Quality Initiative CKD classification system. The study included 185 patients with preoperative GFR values less than 60 mL/min/1.73 m(2). The impact of percutaneous nephrolithotomy (PCNL) on GFR was analyzed by comparing the preoperative GFR with the GFR before discharge and at postoperative month 3.

RESULTS

Patients with CKD had a significant increase in the GFR after the procedure. In postoperative month 3, the mean GFR was more than 60 mL/min/1.73 m(2) in 25% of the patients with CKD and less than 60 mL/min/1.73 m(2) in 75%. While all patients with stage 5 CKD improved to better stages, some other patients' conditions declined to stage 5 from better stages at the end of postoperative month 3. No patient needed dialysis. The presence of urinary tract infections tended to affect GFR negatively.

CONCLUSION

Estimated GFR, as a better indicator of renal function, is significantly affected by the PCNL procedure. While significant improvement was observed in late-stage patients with CKD, unexpected deterioration could occur in patients at earlier stages.

Treatment of renal calculi by lithotripsy: minimizing short-term shock wave induced renal damage by using antioxidants

Treatment with extracorporeal shock wave lithotripsy (ESWL), the preferred method of treating kidney stones <3 cm in size, has been shown to induce silent and often self-limiting acute and chronic lesions in the kidneys and adjacent organs. We conducted a randomized clinical trial to determine whether ESWL produces ischaemia and reperfusion injury in the kidneys and whether oral administration of antioxidants reduces the degree of short-term renal injury in patients treated with ESWL. The study included 120 patients with renal stones (1-3 cm in size) treated with ESWL. The patients were divided into three groups--patients in group A (n=39) served as a control group and were not given any antioxidants; patients in group B (n=41) were given two capsules of antioxidants "Nature Made R: " 2 h before ESWL, and 2 and 8 h after ESWL; and patients in group C (n=40) were given two capsules of the antioxidants 2 and 8 h after ESWL. Double 'J' stents were inserted in patients before treatment with ESWL. Blood and urine samples were obtained from all patients just before the start of treatment with ESWL, and at 2 and 24 h and on 7th and 28th day after ESWL. Serum levels of malondialdehyde (MDA), alpha-tocopherol, cholesterol, albumin and ascorbic acid, and alpha-tocopherol/cholesterol ratio were determined. Urinary levels of albumin and beta(2) microglobulin were also determined as measures of renal tubular injury. At 24 h after ESWL, patients given antioxidants (groups B + C) had significantly reduced mean serum concentration of MDA (P<0.001); higher levels of serum ascorbic acid (P<0.001) and serum albumin (P<0.001); lower alpha-tocopherol/cholesterol ratio, lower urinary albumin and beta(2 )microglobulin levels compared with patients who did not receive antioxidants (group A). These findings suggest that treatment with ESWL generates free radicals through ischaemic/reperfusion injury mechanism, and that oral administration of antioxidant may protect these patients from short term renal injury caused by ESWL.

Multimodal evaluation of renal perfusional changes due to extracorporeal shock wave lithotripsy

OBJECTIVES

To examine the effect of extracorporeal shock wave lithotripsy (ESWL) on renal perfusion before and after treatment, by assessing renal resistive index (RI) using colour Doppler ultrasonography (CDUS), magnetic resonance perfusion imaging (MRPI), radionuclide renography and big-endothelin-1 values (Big-ET-1).

PATIENTS AND METHODS

In 69 normotensive patients the RI was measured before, 1, 3, 6 and 24 h after ESWL using CDUS. The RI values, measured in interlobar/arcuate arteries, were correlated with the findings on MRPI, done before and within 24 h after ESWL. In addition, renal plasma flow (RPF, assessed on radionuclide renography) and Big-ET-1 levels (a potent vasoconstrictor peptide), served as a control for evaluating renal perfusion. The patients were stratified in three age groups, i.e. <or=39, 40-59 and >or=60 years, with 23 patients in each group.

RESULTS

The mean (sd) RI increased significantly in the treated kidneys, from 0.64 (0.05) before to 0.72 (0.08) after ESWL (P = 0.001). Only in patients aged >or=60 years did the RI continue to increase over the 24 h. MRPI showed a decrease of renal blood flow (RBF) in all age groups, but most significantly in those aged >or=60 years. The radionuclide renography and big-ET-1 levels changed significantly only in the oldest group. The best correlation was between RI and RBF changes detected by MRPI.

CONCLUSIONS

ESWL obviously causes disturbances of renal perfusion, particularly in elderly patients (>or=60 years). Measurement of RI with Doppler techniques might provide useful information for the clinical diagnosis of renal damage.

ESWL Prediction of Outcome and Failure Prevention

Based on our own experiences and a review of the recent literature, this article evaluates recent developments in predicting outcomes and failures of shockwave lithotripsy when treating patients with urinary tract stones. After a detailed MEDLINE research, the authors identified several variables that influence and predict extracorporeal shockwave lithotripsy (ESWL) success. These variables may be categorized as stone variables, patient variables and operator variables. Only multivariate analysis on a large number of homogenous patients may offer an objective evaluation of the factors conditioning ESWL outcome.

Renal stone epidemiology in Rochester, Minnesota: an update

Studies in Western countries have suggested an increasing incidence of nephrolithiasis (NL) in the latter part of the 20th century. Therefore, we updated NL epidemiology data for the Rochester population over the years 1970-2000. All Rochester residents with any diagnostic code that could be linked to NL in the years of 1970, 1980, 1990, and 2000 were identified, and the records reviewed to determine if they met the criteria for a symptomatic kidney stone as defined in a previous Rochester, MN study. Age-adjusted incidence (+/-s.e.) of new onset symptomatic stone disease for men was 155.1 (+/-28.5) and 105.0 (+/-16.8) per 100,000 per year in 1970 and 2000, respectively. For women, the corresponding rates were 43.2 (+/-14.0) and 68.4 (+/-12.3) per 100,000 per year, respectively. On average, rates for women increased by about 1.9% per year (P=0.064), whereas rates for men declined by 1.7% per year (P=0.019). The overall man to woman ratio decreased from 3.1 to 1.3 during the 30 years (P=0.006). Incident stone rates were highest for men aged 60-69 years, whereas for women, they plateaued after age 30. Therefore, since 1970 overall NL incidence rates in Rochester have remained relatively flat. However, NL rates for men have declined, whereas rates for women appear to be increasing. The reasons remain to be determined.

Efficacy of the Duet lithotripter using two energy sources for stone fragmentation by shockwaves: an in vitro study

PURPOSE

To evaluate the efficacy of the Duet lithotripter's novel design of two independent spark-plug generator/reflector systems focused at a common F2. The apparatus allows either simultaneous delivery of shockwaves from both generators (resulting in a per-shock energy delivery at F2 equal to that delivered by its single generator at about 24 kV), alternating (between the two generators), or single-generator delivery of shockwaves at various energy levels and rates.

MATERIALS AND METHODS

Eighty-five phantom gypsum stones (volume 786 mm3 each) were placed in a net-like basket and immersed in a specially designed waterbath coupled with the Duet lithotripter (Direx Medical Systems Ltd., Petach Tikva, Israel). Shockwaves were delivered at rates of either 60 or 120 per minute and at intensities of 16 or 22.8 kV (electrohydraulic). Energy was delivered either separately from each generator, in an alternating mode, or simultaneously from both generators. The number of shocks required to fragment the stones sufficiently to allow all of the pieces to fall through the basket holes (complete fragmentation) was recorded.

RESULTS

The number of shocks required for complete fragmentation in the alternate mode (120 shocks/min, each generator rate 60/min; 22.8kV) was lower than with the single generator, 112 +/- 19 v 134 +/- 18 (at a rate of 120/min; 22.8 kV). The simultaneous mode of dual generator shockwave delivery was more effective than the traditional single generator (114 +/- 28 shocks at a rate of 120/min, 16 kV v 159 +/- 40 shocks at a rate 120/min; 22.8kV).

CONCLUSION

The Duet lithotripter is more effective when used in a simultaneous or alternating mode than is the classical single mode of shock delivery, with the added benefit of shorter treatment time.

Efficacy of extracorporeal shock wave lithotripsy for solitary lower calyceal stone: a statistical model

OBJECTIVE

To evaluate the effect of inferior calyceal radiographic anatomy, number of extracorporeal shock wave lithotripsy (ESWL) sessions and stone size on the successful clearance of solitary inferior calyceal calculi after ESWL.

PATIENTS AND METHODS

In a prospective study between January 2001 and November 2002, 66 renal units with a solitary inferior calyceal calculus of < or = 2 cm were treated with electrohydraulic ESWL. The infundibulopelvic angle (two definitions), infundibulovertebral angle, inferior calyceal infundibular diameter, infundibular length, cortical thickness over the lower pole, number of minor calyces and stone size were determined from intravenous urography before treatment. The number of ESWL sessions was also included in the analysis. Treatments which produced residual fragments not clearing within 3 months of satisfactory fragmentation were considered as failures. All patients in whom the treatment failed were treated successfully by percutaneous nephrolithotomy. The data were then analysed using two different statistical methods; first by intravariable differences using the test of proportion (Fisher's test) and then all the variables together using logistic regression.

RESULTS

At 3 months 78.8% of the renal units were clear of stone. All intravariable differences were statistically significant except stone size (<1 cm, 1-2 cm). In a multivariate analysis of all variables, only stone size was the most important predictor for successful stone clearance (P = 0.03).

CONCLUSIONS

ESWL is the initial treatment of choice in selected patients with inferior calyceal stones. The stone size appears to be the most important predictor for stone clearance.

Shockwave Lithotripsy: Anecdotes and Insights

Shockwave lithotripters have evolved considerably since the introduction of the Dornier HM3 machine 20 years ago. Although shockwave lithotripsy (SWL) remains the preferred treatment for the majority of symptomatic upper urinary-tract calculi, newer lithotripters are not as effective and may have a higher risk of side effects. Lack of progress in lithotripter evolution is attributable to inadequate understanding of how and why shockwaves produce effects on stone and tissue. Current knowledge suggests that stones fragment by the mechanisms of compression fracture, spallation, squeezing, and acoustic cavitation, while tissue damage from shockwaves is secondary to cavitation and non-cavitational forces such as sheer stress. It appears likely that most tissue damage from shockwaves is caused by cavitation. As the understanding of SWL matures, new lithotripter designs may emerge that truly represent an improvement on the original Dornier HM3 machine.

Prediction of Fragility of Urinary Calculi by Dual X-Ray Absorptiometry

PURPOSE

Stone fragility is a key factor for the success of shock wave lithotripsy (SWL). Dual x-ray absorptiometry is the gold standard for measuring bone mineral content and density, which helps in determining bone mass and the fracture risk. The same principle was applied to determine the relationship of stone mineral content (SMC) and density (SMD) to predict the fragility of stone before SWL.

MATERIALS AND METHODS

A total of 102 patients with a solitary renal and upper ureteral stone of less than 3 cm treated at a single center with a lithotriptor were included. Prior to SWL all patients underwent dual x-ray absorptiometry evaluation for SMC and SMD. Plain x-ray documented disintegration after SWL. Stone size and site, the number of shock waves and energy levels were recorded. Failure was defined as no fragmentation to a size of less than 4 mm, which would pass unaided, up to a maximum of 3,000 shock waves.

RESULTS

Overall 94 patients with renal stones were included. Mean stone size was 16.68 +/- 7 mm (range 5 to 30). Mean and median SMC was 0.63 +/- 0.83 and 0.34 gm (range 0.01 to 5.54), and mean and median SMD was 0.48 +/- 0.19 and 0.46 gm/cm2 (range 0.05 to 1.12), respectively. Overall 67 patients (71%) had successful fragmentation and clearance at a mean of 1,623.58 +/- 658.77 shock waves (range 355 to 3,000). On logistic regression analysis only SMC was the significant factor affecting the outcome in terms of fragmentation. At a SMC of more than 1.27 gm 95% of the stones would not fragment or needed more than 3,000 shock waves.

CONCLUSIONS

Patients with high stone mineral content (SMC greater than 1.27 gm) could be directly offered percutaneous nephrolithotomy, thus, avoiding the unnecessary cost of prior SWL.

Efficacy and outcome of surgical intervention in patients with nephrolithiasis and chronic renal failure

AIM

To prospectively evaluate the efficacy and outcome of surgical intervention in patients with renal stones and chronic renal insufficiency.

METHODS

The study was carried out from January 1999 till January 2001. Only patients with chronic renal failure without medical renal disease were taken up for study. All patients were subjected to an ultrasound assessment of the kidney, ureter and bladder. In case of obstructed and infected systems a preliminary percutaneous nephrostomy was carried out. After correction of dyselectrolytemia, acid base imbalance and dialysis (if indicated) patients were subjected to surgical intervention (open surgery or percutaneous nephrolithotomy). ESWL was offered for stones persisting after surgery. The stone burden, composition, therapeutic procedures required to render patients stone free were assessed. The outcome of stone removal on renal function was also evaluated by serial renal dynamic scans and creatinine clearance estimations.

RESULTS

Out of 90 patients operated for staghorn or calyceal calculi, complete follow up data was available in 70. Pyelo-nephrolithotomy and percutaneous nephrolithotomy was carried out in 63 and 7 patients respectively. Out of 15 patients with residual stones ESWL was successfully performed in 9 cases. Mixed, calcium oxalate monohydrate, calcium oxalate dihydrate, and struvite stones were encountered in 48%, 14%, 17% and 21% respectively. The average pre operative serum creatinine was 4.76 (1.9-16) mg%. The maximum duration of follow up was 9 months. By the 9th post operative month the average fall in serum creatinine values was 1.53 mg/dl (32%) and the average functional improvement by renal dynamic scans stood at 20.665%. 41 patients were saved from further dialysis.

CONCLUSION

Patients with mild to moderate renal failure showed maximal improvement in renal function forestalling or reducing the need for dialysis/renal replacement therapy.

Retroperitoneal Laparoscopic Pyelolithotomy for Staghorn Stones

PURPOSE

To establish the feasibility of the retroperitoneal laparoscopic approach for treatment of patients with staghorn renal calculi who are under consideration for an open pyelolithotomy.

PATIENTS AND METHODS

Retroperitoneal laparoscopic pyelolithotomy was performed in three patients with impacted staghorn renal calculi between 22 and 45 mm in largest diameter. One of the patients also had multiple caliceal stones. These patients wanted an open procedure but had agreed to have their stone removal done laparoscopically in view of our experience. The previously described retroperitoneal laparoscopic approach was used, and the handling of some of the specific problems in such patients is described in the text.

RESULTS AND CONCLUSION

The stones were removed successfully in all the three patients, and there were no complications. Although no definitive conclusion can be drawn from this small series, the paper shows the feasibility of the retroperitoneal laparoscopic approach in a select group of patients with staghorn renal calculi.

Lower pole I: a prospective randomized trial of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy for lower pole nephrolithiasis-initial results

PURPOSE

The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined.

MATERIALS AND METHODS

A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less.

RESULTS

Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur.

CONCLUSIONS

Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity.

Vertebral fracture associated with shockwave lithotripsy in a patient with granulomatous spondylitis

Extracorporeal shockwave lithotripsy (SWL) is an accepted treatment modality in the treatment of urinary stone disease. Many complications have been reported secondary to high-energy shockwaves, but the effects of SWL on the skeletal system have rarely been investigated. We represent the first case of a burst-type vertebral fracture after SWL in an elderly osteoporotic patient with granulomatous spondylitis.

CD4(+) T-lymphocytopenia and Pneumocystis carinii pneumonia in a patient with miliary tuberculosis

We report a case of miliary tuberculosis (MTB) occurring after extracorporeal shock-wave lithotripsy in a 51-year-old man. The MTB was complicated by pancytopenia and CD4(+) T-lymphocytopenia, which was responsible for Pneumocystis carinii pneumonia. Hematological parameters returned to normal in response to antituberculous treatment.

Mini-percutaneous nephrolithotomy

Standard percutaneous nephrolithotomy is highly effective for the removal of renal calculi. However, significant morbidity has been associated with this procedure. Consequently, many urologists inappropriately defer to a less effective procedure to reduce patient morbidity. This practice may increase the total number of procedures needed for treatment and result in a substantial increase in health care costs. Mini-percutaneous nephrolithotomy using a 13F ureteroscopy sheath is described to reduce the morbidity associated with standard percutaneous nephrolithotomy while maintaining its efficiency and effectiveness for stone removal. The indications and technique for mini-percutaneous nephrolithotomy and our results are summarized.