Urolithiasis/Endourology

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Use of Ureteral Stent in Extracorporeal Shock Wave

Lithotripsy for Upper Urinary Calculi: A Systematic Review

and Meta-Analysis

Shen Pengfei, Jiang Min, Yang Jie, Li Xiong, Li Yutao, Wei Wuran, Dai Yi, Zeng Hao* and Wang Jia*

From the Department of Urology, West China Hospital (SP, YJ, LX, LY, WW, DY, ZH, WJ) and Department of Health Statistics, West China School of Public Health (JM), Sichuan University, Chengdu, China

Abbreviations and Acronyms

D-J stent⫽ Double-J® stent ESWL®⫽ extracorporeal shock wave lithotripsy

LUTS⫽ lower urinary tract symptoms

RCTs⫽ randomized controlled trials

UTI⫽ urinary tract infection Submitted for publication January 25, 2011. Nothing to disclose.

Supplementary material for this article can be obtained at http://eng.cd120.com/ArticleShow. asp?ArtID⫽443.

* Correspondence: Department of Urology, West China Hospital, Sichuan University, Guo-XueXiang37, Chengdu, 610041 China (telephone: ⫹8618980601427; e-mail:[email protected]). Editor’s Note:This article is the fourth of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages1562 and 1563.

Purpose: This systematic review was performed to assess the necessity and complications of stenting before extracorporeal shock wave lithotripsy in the management of upper urinary stones.

Materials and Methods: A systematic research of PubMed®, EMBASE® and the Cochrane Library was performed to identify all randomized controlled trials. The comparisons were about the outcomes and complications of extracorporeal shock wave lithotripsy in the management of upper urinary stones with or without Double-J stenting before extracorporeal shock wave lithotripsy, including stone-free rate, Steinstrasse, lower urinary tract symptoms, hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, and nausea and vomit-ing. We used the Cochrane Collaboration’s Review Manager (RevMan) 5.0.2 software for statistical analysis.

Results: Eight randomized controlled trials were included in analysis that re-ported 876 patients in total, divided into the stented group of 453 and the stentless group of 423. All studies recorded the stone-free rate and the results of the meta-analysis showed no difference between the groups (RR 0.97, 95% CI 0.91–1.03, p⫽ 0.27). The total incidence of Steinstrasse in the stented group was similar to that of the stentless group with the exception of 1 study. However, the incidence of lower urinary tract symptoms was significantly higher in the stented group than in the stentless group (RR 4.10, 95% CI 2.21–7.61, p ⬍0.00001). Significant differences could not be found in hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, or nausea and vomiting be-tween the groups.

Conclusions: The systematic review suggested significant advantages of stent-ing before extracorporeal shock wave lithotripsy compared to in situ extracorpo-real shock wave lithotripsy in terms of Steinstrasse. However, stenting did not benefit stone-free rate and auxiliary treatment after extracorporeal shock wave lithotripsy, and it induced more lower urinary tract symptoms. More high qual-ity, randomized controlled trials are needed to address this issue.

Key Words: kidney calculi, ureteral calculi, lithotripsy, stents, randomized

controlled trial

UROLITHIASISis one of the most

preva-lent urological disorders1_{and the}

preva-lence of urinary stones has increased

in most countries. In the United King-dom at least 1 renal stone will form in approximately 8% of male and 4% of

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0022-5347/11/1864-1328/0 Vol. 186, 1328-1335, October 2011

THE JOURNAL OF UROLOGY® _{Printed in U.S.A.}

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female patients, and in the United States the male lifetime prevalence has increased to 15%.2_The

man-agement of urinary calculi was revolutionized by the introduction of extracorporeal shockwave lithotripsy in 1980. ESWL is a safe, effective and minimally invasive method, and is now the first choice of treat-ment for most upper urinary calculi.3,4 _Most

frag-ments pass uneventfully through the urinary tract after ESWL.

However, fragments may obstruct the ureter, thus leading to post-ESWL complications such as acute renal pain, hydronephrosis, infection and re-nal failure.5 _{Success rates and complications are}

determined by the size, location and composition of the stone in the urinary tract, the type of litho-tripter, shock wave energy and rate, and anatomical characteristics.4 _{Fragments may become impacted}

in the ureter and form Steinstrasse after ESWL, but no agreement has yet been reached that ureteral stenting could be used to prevent Steinstrasse and other post-ESWL complications.6_{The European}

As-sociation of Urology (2010) recommends pre-ESWL stenting for renal stones with a diameter greater than 20 mm (approximately 300 mm2_{), and a D-J}

stent to reduce obstructive and infective complica-tions after the use of ESWL.7_{However, stenting is}

considered a relatively invasive procedure and sev-eral studies have reported that D-J stent insertion does not improve ESWL results.8_{Stents are}

associ-ated with significant symptoms of discomfort such as urinary frequency, urgency, dysuria, hematuria etc. Joshi et al suggested that indwelling ureteral stents resulted in a negative functional capacity and utility values, and a decreased quality of life in up to 80% of patients.9 _{Whether stents should be}

consid-ered routinely before ESWL for treating upper uri-nary calculi is still controversial.

We conducted this systematic review to assess the necessity and complications of pre-ESWL stenting in the management of urinary stones, and to verify whether stenting would influence the effectiveness of therapy by collecting all published RCTs. To our knowledge this is the first systematic review of pre-ESWL stenting in the management of upper urinary calculi.

METHODS Search Strategy

We searched the databases PubMed (from 1980 to Decem-ber 2010), EMBASE (from 1980 to DecemDecem-ber 2010), the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews. The search process was initially designed to find all trials involving the terms “renal calculi,” “ureteral calculi,” “extracorpo-real shock wave lithotripsy,” “ESWL,” “double-J stent,” “ureteral stent” and “randomized controlled trial” (and

multiple synonyms for each term). Reference lists from retrieved documents were also searched. Computer searches were supplemented with a manual search. Two authors (SP, YJ) independently screened all citations and abstracts selected by the search strategy to identify poten-tially eligible studies.

Participants

The inclusion criteria were adult patients (male or female) who had renal calculi or ureteral calculi with normal serum creatinine. All patients were suitable for ESWL and stone size varied with the criteria of each included trial. Patients with radiolucent stones, bleeding disorders, congenital renal abnormalities, increased serum creati-nine, metabolic abnormalities, symptomatic urinary tract infection, unilateral stone disease, excretory urogram showing evidence of ureteropelvic junction obstruction and residual fragments after previous ESWL, open sur-gery or endoscopy were excluded from these RCTs.

Interventions

All patients were treated with ESWL, and were divided into the 2 groups of stented and stentless. Each group included 3 subgroups of renal stone, ureteral stone, or renal or ureteral stone subgroup. Comparisons were made regarding outcomes and complications of ESWL in the management of upper urinary stones with or without D-J stent before ESWL.

Outcome Measures

Several outcomes and complications were measured in this review, including stone-free rate, Steinstrasse, LUTS (urinary frequency, urgency, dysuria, nocturia, inconti-nence), hematuria (microscopic hematuria, gross hematu-ria, transient hematuria), fever, UTI (pyuhematu-ria, pyelonephri-tis and others), pain (suprapubic pain, loin pain, flank pain, bladder pain and penile pain) and need for analge-sia, nausea and vomiting, and auxiliary treatment. Ac-cording to the included trials, objective followup data were obtained by sending a questionnaire or other ways in the clinic and followup was at least 3 months. The interval of each followup was determined by the researchers. Stone clearance was defined as the absence of residual stones by plain radiographic film, ultrasonography or excretory urography after ESWL. Cases needing an auxiliary pro-cedure were considered treatment failures.

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Data Extraction

Data were extracted independently by both authors using a pre-designed data extraction form. Data extraction in-cluded data source, eligibility, methods, participant char-acteristics, interventions and results. The 2 authors then met to synthesize their findings and the information sub-sequently was entered into RevMan 5.0.2. Any discrepan-cies among the extracted data were resolved by discussion, and if the disagreements could not be resolved by

discus-sion they were resolved in consultation with another au-thor (WJ).

Quality Assessment

The quality of included studies was assessed by 2 authors according to the Cochrane Collaboration reviewers’ hand-book and the QUOROM (Quality of Reporting of Meta-analyses) guidelines.10,11_{The quality items were composed}

of generation of randomization sequences, allocation

conceal-Study or Subgroup 1.1.1 renal stone Al-Awadi 1999 Bierkens 1991 Musa 2008 Mustafa 2009 Subtotal (95% CI) Total events

Heterogeneity: Chi² = 1.62, df = 3 (P = 0.65); I² = 0% Test for overall effect: Z = 0.29 (P = 0.77)

1.1.2 ureteral stone

Chang 1993 Ghoneim 2010

Subtotal (95% CI)

Total events

1.1.3 renal or ureteral stone

Chandhoke 2002 Pryor 1990

Total events

Total (95% CI)

Total events

Test for subgroup differences: Not applicable

Events 172 18 53 9 252 16 27 43 47 12 59 354 Total 200 41 60 11 312 26 30 56 60 25 85 453 Events 174 8 54 26 262 20 26 46 26 17 43 351 Total 200 23 60 27 310 27 30 57 31 25 56 423 Weight 49.7% 2.9% 15.4% 4.3% 72.3% 5.6% 7.4% 13.0% 9.8% 4.9% 14.6% 100.0% M-H, Fixed, 95% CI 0.99 [0.91, 1.07] 1.26 [0.65, 2.44] 0.98 [0.87, 1.11] 0.85 [0.64, 1.13] 0.99 [0.92, 1.06] 0.83 [0.57, 1.21] 1.04 [0.86, 1.25] 0.95 [0.79, 1.14] 0.93 [0.76, 1.15] 0.71 [0.43, 1.15] 0.86 [0.70, 1.05] 0.97 [0.91, 1.03]

stent stentless Risk Ratio Risk Ratio

M-H, Fixed, 95% CI

0.2 0.5 1 2 5

Favours stent Favours stentless

Subgroups

renal stone ureteral stone renal or ureteral stone

0.1 0.2 0.5 1 2 5 10 0 0.1 0.2 0.3 0.4 0.5 RR SE(log[RR]) B A

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ment, description of withdrawals and dropouts, intent to treat analysis, and baseline assessed by adequate, unclear or not used/reported. The blinding method was not ana-lyzed in this review because it was not suitable for surgi-cal clinisurgi-cal trials.

Data Analysis

Data analysis was performed using RevMan 5.0.2. For all eligible studies dichotomous data were presented as rela-tive risk with 95% CI. Meta-analysis was performed using fixed effects or random effects methods depending on the presence or absence of significant heterogeneity. Statisti-cal heterogeneity among trials was evaluated by the I-square test with significance set at p⬍0.05. In the absence of statistically significant heterogeneity the fixed effects method was used to combine the results. Otherwise the random effects method was used. Additionally, sensitiv-ity analysis was performed if low qualsensitiv-ity trials were included. All data analysis was directed by a statistical specialist (JM).

RESULTS

Description of Studies

A total of 897 reports were identified by the searchers. By scanning titles and abstracts 889

re-dundant publications, reviews and meta-analyses were excluded from study. After referring to full texts 8 studies were left for analysis involving 876 patients in total,6,12–18_{of whom 453 were designated}

the stented group and 423 the stentless group. All trials were published in English. The systematic review study characteristics, types of outcome mea-surement, quality of included trials and 4-phase search flow diagram are presented infigure 1.

Stone-Free Rate

The stone-free rate data were available from all included clinical trials. The total stone-free rate was 78.1% (354 of 453) in the stented group and 83.0% (351 of 423) in the stentless group. There was no significant difference in stone-free rate between the groups (RR 0.97, 95% CI 0.91–1.03, p⫽ 0.27,fig.2).

Steinstrasse

Steinstrasse was reported in 5 (62.5%) studies. Al-Awadi et al treated renal stones (15 to 35 mm) with ESWL and most cases involved Steinstrasse in this review.15 _{However, the authors did not report the}

number of subgroups so this study was analyzed as a subgroup for this outcome. There was no

signifi-Study or Subgroup 2.1.1 renal stone Bierkens 1991 Mustafa 2009 Subtotal (95% CI) Total events

Ghoneim 2010

Total events

Heterogeneity: Not applicable

Test for overall effect: Z = 0.68 (P = 0.50)

Chandhoke 2002

Total events

2.1.4 subgroup 4

Al-Awadi 1999

Total events

Total (95% CI)

Total events

Events 6 1 7 0 0 1 1 12 12 20 Total 41 11 52 30 30 60 60 200 200 342 Events 3 1 4 1 1 4 4 26 26 35 Total 23 27 50 30 30 31 31 200 200 311 Weight 10.3% 1.6% 11.9% 4.0% 4.0% 14.2% 14.2% 69.9% 69.9% 100.0% M-H, Fixed, 95% CI 1.12 [0.31, 4.07] 2.45 [0.17, 35.86] 1.30 [0.41, 4.09] 0.33 [0.01, 7.87] 0.33 [0.01, 7.87] 0.13 [0.02, 1.11] 0.13 [0.02, 1.11] 0.46 [0.24, 0.89] 0.46 [0.24, 0.89] 0.51 [0.30, 0.86]

0.001 0.1 1 10 1000

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cant difference in Steintrasse incidence between the stented group and the stentless group in other sub-group analyses (p ⫽ 0.66, 0.50 and 0.06, respec-tively). However, there was a significant difference in the study by Al-Awadi et al (RR 0.46, 95% CI 0.24 – 0.89, p⫽ 0.02,fig. 3).

LUTS and Hematuria

LUTS include storage, voiding and post-micturition symptoms affecting the lower urinary tract, and they can significantly reduce quality of life. In the review 3 (37.5%) studies recorded LUTS including urinary frequency, urgency, dysuria, nocturia and

Study or Subgroup Ghoneim 2010 Mustafa 2009 Pryor 1990 Total (95% CI) Total events

Heterogeneity: Chi² = 3.06, df = 2 (P = 0.22); I² = 35% Test for overall effect: Z = 4.47 (P < 0.00001)

Events 18 1 18 37 Total 30 11 25 66 Events 7 0 2 9 Total 30 27 25 82 Weight 75.3% 3.2% 21.5% 100.0% M-H, Fixed, 95% CI 2.57 [1.26, 5.24] 7.00 [0.31, 159.85] 9.00 [2.33, 34.77] 4.10 [2.21, 7.61]

0.001 0.1 1 10 1000

A Study or Subgroup Ghoneim 2010 Musa 2008 Pryor 1990 Total (95% CI) Total events

Heterogeneity: Tau² = 2.69; Chi² = 8.64, df = 2 (P = 0.01); I² = 77% Test for overall effect: Z = 1.01 (P = 0.31)

Events 4 15 10 29 Total 30 60 25 115 Events 1 19 0 20 Total 30 60 25 115 Weight 31.1% 43.4% 25.6% 100.0% M-H, Random, 95% CI 4.00 [0.47, 33.73] 0.79 [0.44, 1.40] 21.00 [1.30, 340.02] 3.02 [0.35, 25.95]

M-H, Random, 95% CI

0.001 0.1 1 10 1000

B

Figure 4. LUTS (A) and hematuria (B) in patients with and without stent before ESWL

Study or Subgroup Bierkens 1991 Chandhoke 2002 Ghoneim 2010 Musa 2008 Pryor 1990 Total (95% CI) Total events

Events 7 2 1 3 0 13 Total 41 60 30 60 25 216 Events 3 4 2 1 0 10 Total 23 31 30 60 25 169 Weight 31.7% 43.5% 16.5% 8.3% 100.0% M-H, Fixed, 95% CI 1.31 [0.37, 4.58] 0.26 [0.05, 1.33] 0.50 [0.05, 5.22] 3.00 [0.32, 28.03] Not estimable 0.86 [0.40, 1.86]

stent stentless Risk Ratio Risk Ratio M-H, Fixed, 95% CI

0.01 0.1 1 10 100

Favours stent Favours stentless A B Study or Subgroup Bierkens 1991 Chandhoke 2002 Ghoneim 2010 Total (95% CI) Total events

Events 1 0 25 26 Total 41 60 30 131 Events 1 2 13 16 Total 23 31 30 84 Weight 7.3% 18.7% 74.0% 100.0% M-H, Fixed, 95% CI 0.56 [0.04, 8.55] 0.10 [0.01, 2.12] 1.92 [1.24, 2.98] 1.48 [0.98, 2.25]

0.1 0.2 0.5 1 2 5 10

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incontinence. There was a significant difference in LUTS between the 2 groups (RR 4.10, 95% CI 2.21– 7.61, p ⬍0.00001). The major LUTS recorded in studies by Pryor and Jenkins12 _{and Mustafa and}

Ali-El-Dein18_{were urinary frequency and urgency,}

but the symptom reported by Ghoneim et al was dysuria (fig. 4, A).6 _{Hematuria was also a common}

symptom after ESWL, and 3 (37.5%) trials in this review reported data on microscopic hematuria, gross hematuria and transient hematuria. There was no statistically significant difference in the in-cidence of hematuria after ESWL between the stented and stentless group (RR 3.02, 95% CI 0.35– 25.95, p⫽ 0.31,fig. 4, B).

Fever and UTI

Fever was reported in 4 (50.0%) studies and no pa-tients had a fever in the study by Pryor and Jen-kins.12_{The difference in fever incidence between the}

stented group and the stentless group was not signif-icant (RR 0.86, 95% CI 0.40 –1.86, p⫽ 0.70,fig. 5, A).

UTI, including pyelonephritis and pyuria, was re-corded in 3 (37.5%) studies. There was no statisti-cally significant difference in UTI incidence after ESWL between the stented and stentless group (RR 1.48, 95% CI 0.98 –2.25, p⫽ 0.06,fig. 5, B).

Additional Complications

Pain (suprapubic, loin, flank, bladder and penile pain) was reported in 5 (62.5%) studies and the need for analgesia was reported in 3. Mustafa and Ali-El-Dein did not record the number of patients experi-encing pain but they reported no patients needed analgesia.18 The difference in pain between the groups was not statistically significant (RR 1.37, 95% CI 0.90 –2.07, p⫽ 0.14). Only 1 study showed that patients needed analgesia after ESWL but the difference was not significant (RR 0.75, 95% CI 0.39 –1.45, p ⫽ 0.39, fig. 6, A).17 _{There were 3}

(37.5%) studies that reported nausea and vomiting after ESWL, and the difference was not

statisti-Study or Subgroup 7.1.1 Pain Al-Awadi 1999 Bierkens 1991 Ghoneim 2010 Musa 2008 Pryor 1990 Subtotal (95% CI) Total events

7.1.2 Analgesia Bierkens 1991 Musa 2008 Mustafa 2009 Subtotal (95% CI) Total events

Test for overall effect: Z = 0.86 (P = 0.39) Events 5 18 11 9 7 50 0 12 0 12 Total 200 41 30 60 25 356 41 60 11 112 Events 8 3 9 11 1 32 0 16 0 16 Total 200 23 30 60 25 338 23 60 27 110 Weight 24.4% 11.7% 27.4% 33.5% 3.0% 100.0% 100.0% 100.0% M-H, Fixed, 95% CI 0.63 [0.21, 1.88] 3.37 [1.11, 10.22] 1.22 [0.59, 2.51] 0.82 [0.37, 1.83] 7.00 [0.93, 52.80] 1.37 [0.90, 2.07] Not estimable 0.75 [0.39, 1.45] Not estimable 0.75 [0.39, 1.45]

stent stentless Risk Ratio Risk Ratio M-H, Fixed, 95% CI

0.01 0.1 1 10 100

A B Study or Subgroup Al-Awadi 1999 Musa 2008 Pryor 1990 Total (95% CI) Total events

Events 3 10 4 17 Total 200 60 25 285 Events 4 14 3 21 Total 200 60 25 285 Weight 19.0% 66.7% 14.3% 100.0% M-H, Fixed, 95% CI 0.75 [0.17, 3.31] 0.71 [0.34, 1.48] 1.33 [0.33, 5.36] 0.81 [0.45, 1.46]

0.01 0.1 1 10 100

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cally significant (RR 0.81, 95% CI 0.45–1.46, p⫽ 0.48, fig. 6, B).

Auxiliary Treatment

Auxiliary treatment included ureteroscopy, uretero-lithotomy, nephrectomy and percutaneous nephros-tomy. There were 6 (75.0%) trials that recorded in-formation about auxiliary treatment after ESWL. Ghoneim et al6 _{and Mustafa and Ali-El-Dein}18

re-ported no patients received further treatment after ESWL. There was no statistically significant differ-ence between the groups in terms of total inciddiffer-ence of auxiliary treatment (RR 1.43, 95% CI 0.70 –2.92, p⫽ 0.33,fig. 7).

DISCUSSION

Most guidelines recommend ESWL as the first line treatment for ureteral and renal calculi smaller than 20 mm.7,19 Successful stone-free rates with ESWL were reported by several authors.20,21 The evaluation of success after ESWL implies not only the complete disintegration of the calculus but also the subsequent spontaneous passage of the frag-ments. Therefore, the success of ESWL is closely

related to the problem of residual fragments after ESWL. Steinstrasse is possible and may constitute a potentially serious complication if not investigated carefully. The methods of reducing residual frag-ments after ESWL are strongly influenced by the decisions of the urologist.22,23_{In the last few years}

several centers have investigated the effects of ure-teral stenting before ESWL on Steinstrasse and other post-ESWL complications.6,17

However, according to the results of this review D-J stenting before ESWL provided no additional benefit compared to in situ ESWL. Stenting did not improve the stone-free rate. The results of our sub-group analysis show that the incidence of Stein-strasse in the stented group was similar to that in the stentless group. We could not conclude that D-J stenting before ESWL had an advantage compared to another group because most patients with Stein-strasse were reported in the study by Al-Awadi et al and the stone size was larger than 20 mm.15These data may introduce bias and influence the results of our review. In conjunction with ESWL most urolo-gists prefer to use a stent for stones larger than 20 mm to prevent the risk of Steinstrasse.24,25

Study or Subgroup 9.1.1 renal stone Al-Awadi 1999 Bierkens 1991 Mustafa 2009 Subtotal (95% CI) Total events

Chang 1993 Ghoneim 2010

Total events

Pryor 1990

Total events

Total (95% CI)

Total events

Events 6 5 0 11 6 0 6 1 1 18 Total 200 41 11 252 26 30 56 25 25 333 Events 7 2 0 9 2 0 2 0 0 11 Total 200 23 27 250 27 30 57 25 25 332 Weight 58.2% 21.3% 79.5% 16.3% 16.3% 4.2% 4.2% 100.0% M-H, Fixed, 95% CI 0.86 [0.29, 2.51] 1.40 [0.30, 6.66] Not estimable 1.00 [0.42, 2.41] 3.12 [0.69, 14.06] Not estimable 3.12 [0.69, 14.06] 3.00 [0.13, 70.30] 3.00 [0.13, 70.30] 1.43 [0.70, 2.92]

0.001 0.1 1 10 1000

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Moreover in our review the incidence of LUTS was significantly higher in the stented group than in the nonstented group. Thus, patients with a D-J stent have frequent and evident LUTS which may be attributed to bladder irritation by the stent itself acting as a foreign body. Furthermore, these symp-toms may be sufficiently severe to affect patient quality of life. In this review significant differences were not found in hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, and nausea and vomiting between the 2 groups. Some of the included trials reported that patients may be prescribed an antibiotic for UTI before ESWL or routinely prescribed analgesics after ESWL.6,18

However, these data would influence our results. We searched the literature in electronic data-bases without language restrictions but we could not find RCTs concerning ESWL in languages other

than English. As studies with large samples and positive results are more easily reported in English than those with small samples and negative results, this might have introduced language bias and pub-lication bias.

CONCLUSIONS

The randomized controlled clinical trials in this sys-tematic review suggested significant advantages of pre-ESWL stenting compared to in situ ESWL in terms of Steinstrasse, but stenting did not improve the stone-free rate and auxiliary treatment after ESWL. In addition, stenting before ESWL could in-duce more LUTS. Whether ureteral stents should be used in ESWL remains controversial. More high quality, well designed, randomized, controlled mul-ticenter trials that are adequately powered are needed to address this issue.

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