To cite this guideline:
Assimos D, Krambeck A, Miller NL et al: Surgical management of stones: American Urological Association/Endourological Society Guideline, part II. J Urol 2016; 196: 1161.

The purpose of this clinical guideline is to provide a clinical framework for the surgical management of patients with kidney and/or ureteral stones. Index patients discussed include adult, pediatric, and pregnant patients with ureteral or renal stones.

Unabridged version of this Guideline [pdf]
Español translated guideline courtesy of Confederacion Americana de Urologia (CAU) [pdf]

Dean Assimos, MD; Amy Krambeck, MD; Nicole L. Miller, MD; Manoj Monga, MD; M. Hassan Murad, MD, MPH; Caleb P. Nelson, MD, MPH; Kenneth T. Pace, MD; Vernon M. Pais Jr., MD; Margaret S. Pearle, MD, Ph.D; Glenn M. Preminger, MD; Hassan Razvi, MD; Ojas Shah, MD; Brian R. Matlaga, MD, MPH

Purpose

The purpose of this Guideline is to provide a clinical framework for the surgical management of patients with kidney and/or ureteral stones.

Methodology

A systematic review of the literature using the Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus databases (search dates 1/1/1985 to 5/31/15) was conducted to identify peer-reviewed studies relevant to the surgical management of stones. The review yielded an evidence base of 1,911 articles after application of inclusion/exclusion criteria. These publications were used to create the guideline statements. If sufficient evidence existed, then the body of evidence for a particular treatment was assigned a strength rating of A (high quality evidence; high certainty), B (moderate quality evidence; moderate certainty), or C (low quality evidence; low certainty). Evidence-based statements of Strong, Moderate, or Conditional Recommendation, which can be supported by any body of evidence strength, were developed based on benefits and risks/burdens to patients. Additional information is provided as Clinical Principles and Expert Opinions when insufficient evidence existed.

Guideline Statements

Imaging, Pre-operative Testing

1. Clinicians should obtain a non-contrast CT scan on patients prior to performing PCNL. Strong Recommendation; Evidence Level Grade C

2. Clinicians may obtain a non-contrast CT scan to help select the best candidate for SWL versus URS. Conditional Recommendation; Evidence Level Grade C

3. Clinicians may obtain a functional imaging study (DTPA or MAG‐3) if clinically significant loss of renal function in the involved kidney or kidneys is suspected. Conditional Recommendation; Evidence Level Grade C

4. Clinicians are required to obtain a urinalysis prior to intervention. In patients with clinical or laboratory signs of infection, urine culture should be obtained. Strong Recommendation; Evidence Level Grade B

5. Clinicians should obtain a CBC and platelet count on patients undergoing procedures where there is a significant risk of hemorrhage or for patients with symptoms suggesting anemia, thrombocytopenia, or infection; serum electrolytes and creatinine should be obtained if there is suspicion of reduced renal function. Expert Opinion

6. In patients with complex stones or anatomy, clinicians may obtain additional contrast imaging if further definition of the collecting system and the ureteral anatomy is needed. Conditional Recommendation; Evidence Level Grade C

Treatment of Adult Patients with Ureteral Stones

7. Patients with uncomplicated ureteral stones ≤10 mm should be offered observation, and those with distal stones of similar size should be offered MET with α-blockers. (Index Patient 3) Strong Recommendation; Evidence Level Grade B

8. Clinicians should offer reimaging to patients prior to surgery if passage of stones is suspected or if stone movement will change management. Reimaging should focus on the region of interest and limit radiation exposure to uninvolved regions. Clinical Principle

9. In most patients, if observation with or without MET is not successful after four to six weeks and/or the patient/clinician decide to intervene sooner based on a shared decision making approach, clinicians should offer definitive stone treatment. (Index Patients 1-3) Moderate Recommendation; Evidence Level Grade C

10. Clinicians should inform patients that SWL is the procedure with the least morbidity and lowest complication rate, but URS has a greater stone-free rate in a single procedure. (Index Patients 1-6) Strong Recommendation; Evidence Level Grade B

11. In patients with mid or distal ureteral stones who require intervention (who were not candidates for or who failed MET), clinicians should recommend URS as first-line therapy. For patients who decline URS, clinicians should offer SWL. (Index Patients 2,3,5,6) Strong Recommendation; Evidence Level Grade B

12. URS is recommended for patients with suspected cystine or uric acid ureteral stones who fail MET or desire intervention. Expert Opinion

13. Routine stenting should not be performed in patients undergoing SWL. (Index Patients 1-6) Strong Recommendation; Evidence Level Grade B

14. Following URS, clinicians may omit ureteral stenting in patients meeting all of the following criteria: those without suspected ureteric injury during URS, those without evidence of ureteral stricture or other anatomical impediments to stone fragment clearance, those with a normal contralateral kidney, those without renal functional impairment, and those in whom a secondary URS procedure is not planned. (Index Patients 1-6) Strong Recommendation; Evidence Level Grade A

15. Placement of a ureteral stent prior to URS should not be performed routinely. (Index Patient 1-6) Strong Recommendation; Evidence Level Grade B

16. Clinicians may offer α-blockers and antimuscarinic therapy to reduce stent discomfort. (Index patients 1-6) Moderate Recommendation; Evidence Level Grade B

17. In patients who fail or are unlikely to have successful results with SWL and/or URS, clinicians may offer PCNL, laparoscopic, open, or robotic assisted stone removal. (Index patient 1-6) Moderate Recommendation; Evidence Level Grade C

19. Clinicians should not utilize EHL as the first-line modality for intra-ureteral lithotripsy. (Index patients 1-6,13,15) Expert Opinion

20. In patients with obstructing stones and suspected infection, clinicians must urgently drain the collecting system with a stent or nephrostomy tube and delay stone treatment. Strong Recommendation; Evidence Level Grade C

Treatment of Adult Patients with Renal Stones

21. In symptomatic patients with a total non-lower pole renal stone burden ≤ 20 mm, clinicians may offer SWL or URS. (Index Patient 7) Strong Recommendation; Evidence Level Grade B

22. In symptomatic patients with a total renal stone burden >20 mm, clinicians should offer PCNL as first-line therapy. (Index Patient 8) Strong Recommendation; Evidence Level Grade C

25. In patients with total renal stone burden >20 mm, clinicians should not offer SWL as first-line therapy. (Index Patient 8) Moderate Recommendation; Evidence Level Grade C

27. Clinicians may perform nephrectomy when the involved kidney has negligible function in patients requiring treatment. (Index Patients 1-14) Conditional Recommendation; Evidence Level Grade C

28. For patients with symptomatic (flank pain), non-obstructing, caliceal stones without another obvious etiology for pain, clinicians may offer stone treatment. (Index Patient 12) Moderate Recommendation; Evidence Level Grade C

29. For patients with asymptomatic, non-obstructing caliceal stones, clinicians may offer active surveillance. Conditional Recommendation; Evidence Level Grade C

30. Clinicians should offer SWL or URS to patients with symptomatic ≤ 10 mm lower pole renal stones. (Index Patient 9) Strong Recommendation; Evidence Level Grade B

31. Clinicians should not offer SWL as first-line therapy to patients with >10mm lower pole stones. (Index Patient 10) Strong Recommendation; Evidence Level Grade B

32. Clinicians should inform patients with lower pole stones >10 mm in size that PCNL has a higher stone-free rate but greater morbidity. (Index patient 10). Strong Recommendation; Evidence Level Grade B

33. In patients undergoing uncomplicated PCNL who are presumed stone-free, placement of a nephrostomy tube is optional. Conditional Recommendation; Evidence Level Grade C

34. Flexible nephroscopy should be a routine part of standard PCNL. Strong Recommendation; Evidence Level Grade B

35. Clinicians must use normal saline irrigation for PCNL and URS. Strong Recommendation; Evidence Level Grade B

39. In patients not considered candidates for PCNL, clinicians may offer staged URS. Moderate Recommendation; Evidence Level Grade C

40. Clinicians may prescribe α-blockers to facilitate passage of stone fragments following SWL. Moderate Recommendation; Evidence Level Grade B

43. SWL should not be used in the patient with anatomic or functional obstruction of the collecting system or ureter distal to the stone. Strong Recommendation; Evidence Level Grade C

44. In patients with symptomatic caliceal diverticular stones, endoscopic therapy (URS, PCNL, laparoscopic, robotic) should be preferentially utilized. Strong Recommendation; Evidence Level Grade C

45. Staghorn stones should be removed if attendant comorbidities do not preclude treatment. Clinical Principle

Treatment for Pediatric Patients with Ureteral or Renal Stones

46. In pediatric patients with uncomplicated ureteral stones ≤10 mm, clinicians should offer observation with or without MET using α-blockers. (Index Patient 13) Moderate Recommendation; Evidence Level Grade B

47. Clinicians should offer URS or SWL for pediatric patients with ureteral stones who are unlikely to pass the stones or who failed observation and/or MET, based on patient-specific anatomy and body habitus. (Index Patient 13) Strong Recommendation; Evidence Level Grade B

48. Clinicians should obtain a low-dose CT scan on pediatric patients prior to performing PCNL. (Index Patient 13) Strong Recommendation; Evidence Level Grade C

49. In pediatric patients with ureteral stones, clinicians should not routinely place a stent prior to URS. (Index Patient 13) Expert Opinion

50. In pediatric patients with a total renal stone burden ≤20mm, clinicians may offer SWL or URS as first-line therapy. (Index Patient 14) Moderate Recommendation; Evidence Level Grade C

51. In pediatric patients with a total renal stone burden >20mm, both PCNL and SWL are acceptable treatment options. If SWL is utilized, clinicians should place an internalized ureteral stent or nephrostomy tube. (Index Patient 14) Expert Opinion

52. In pediatric patients, except in cases of coexisting anatomic abnormalities, clinicians should not routinely perform open/laparoscopic/robotic surgery for upper tract stones. (Index Patients 13, 14) Expert Opinion

53. In pediatric patients with asymptomatic and non-obstructing renal stones, clinicians may utilize active surveillance with periodic ultrasonography. (Index Patient 14) Expert Opinion

Treatment for Pregnant Patients with Ureteral or Renal Stones

54. In pregnant patients, clinicians should coordinate pharmacological and surgical intervention with the obstetrician. (Index Patient 15) Clinical Principal

55. In pregnant patients with ureteral stones and well controlled symptoms, clinicians should offer observation as first-line therapy. (Index Patient 15) Strong recommendation; Evidence Level Grade B

56. In pregnant patients with ureteral stones, clinicians may offer URS to patients who fail observation. Ureteral stent and nephrostomy tube are alternative options with frequent stent or tube changes usually being necessary. (Index Patient 15) Strong Recommendation; Evidence Level Grade C

Treatment for all Patients with Ureteral or Renal Stones

23. When residual fragments are present, clinicians should offer patients endoscopic procedures to render the patients stone free, especially if infection stones are suspected. (Index Patient 11) Moderate Recommendation; Evidence Level Grade C

24. Stone material should be sent for analysis. Clinical Principle

26. Open/ laparoscopic /robotic surgery should not be offered as first-line therapy to most patients with stones. Exceptions include rare cases of anatomic abnormalities, with large or complex stones, or those requiring concomitant reconstruction. (Index Patients 1-15) Strong Recommendation; Evidence Level Grade C

36. A safety guide wire should be used for most endoscopic procedures. (Index Patients 1-15) Expert Opinion

37. Antimicrobial prophylaxis should be administered prior to stone intervention and is based primarily on prior urine culture results, the local antibiogram, and in consultation with the current Best Practice Policy Statement on Urologic Surgery Antibiotic Prophylaxis. Clinical Principle

38. Clinicians should abort stone removal procedures, establish appropriate drainage, continue antibiotic therapy, and obtain a urine culture if purulent urine is encountered during endoscopic intervention. (Index Patients1-15) Strong Recommendation; Evidence Level Grade C

41. If initial SWL fails, clinicians should offer endoscopic therapy as the next treatment option. (Index Patient 1-14) Moderate Recommendation; Evidence Level Grade C

42. Clinicians should use URS as first-line therapy in most patients who require stone intervention in the setting of uncorrected bleeding diatheses or who require continuous anticoagulation/antiplatelet therapy. (Index Patients1-15) Strong Recommendation; Evidence Level Grade C

Background

Kidney stones are a common and costly disease; it has been reported that over 8.8% of the United States population will be affected by this malady, and direct and indirect treatment costs are estimated to be several billion dollars per year in this country.^1-3 The surgical treatment of kidney stones is complex, as there are multiple competitive treatment modalities, and in certain cases more than one modality may be appropriate. Proper treatment selection, which is directed by patient- and stone-specific factors, remains the greatest predictor of successful treatment outcomes. The Panel used information from the literature to formulate actionable guideline statements to assist clinicians in providing the best care for their patients requiring stone elimination. 

This Guideline includes revisions of the previously published AUA Guidelines titled 'Staghorn Calculi (2005)'⁴ and 'Ureteral Calculi (2007)'⁵ and is expanded to incorporate the management of patients with non-staghorn renal stones. The Update Literature Review (ULR) process for AUA Guidelines was used to determine that updates were warranted for both the Staghorn Calculi and Ureteral Calculi Guidelines. A guideline for the management of non-staghorn renal stones had previously not been generated by the AUA. The AUA and the Endourological Society felt that a single, all-encompassing guideline document would provide the greatest value to the clinician for patient management. This Guideline also compliments the AUA Guideline on 'Medical Management of Kidney Stones' published in 2014.⁶

The surgical management of patients with various stones is described below and divided into 13 respective patient profiles. Index Patients 1-10 are non-morbidly obese; non-pregnant adults (≥ 18 years of age) with stones not thought to be composed of uric acid or cystine; normal renal, coagulation and platelet function; normally positioned kidneys; intact lower urinary tracts without ectopic ureters; no evidence of sepsis; and no anatomic or functional obstruction distal to the stone(s). Index Patients 13 and 14 are children (<18 years if age) with similar characteristics to Index Patients 1-10. Index Patient 15 is a pregnant female with symptomatic renal or ureteral stone(s) with normal renal function without urinary tract infection (UTI). The proximal ureter is defined as the segment distal to the ureteropelvic junction (UPJ) and above the upper border of the sacroiliac joint. The middle ureter is that which overlies the sacroiliac joint and the distal ureter that lies below it.

Index Patients

Index Patient 1: Adult, <10mm proximal ureteral stone

Index Patient 2: Adult, <10mm mid ureteral stone

Index Patient 3: Adult, <10mm distal ureteral stone

Index Patient 4: Adult, >10mm proximal ureteral stone

Index Patient 5: Adult, >10mm mid ureteral stone

Index Patient 6: Adult, > 10 mm distal ureteral stone

Index Patient 7: Adult, ≤20mm total non-lower pole renal stone burden

Index Patient 8: Adult, >20mm total renal stone burden

Index Patient 9: Adult, ≤10mm lower pole renal stone(s)

Index Patient 10: Adult, >10mm lower pole renal stone(s)

Index Patient 11: Adult, with residual stone(s)

Index Patient 12: Adult, renal stone(s) with pain and no obstruction

Index Patient 13: Child, not known to have cystine or uric acid ureteral stone(s)

Index Patient 14: Child, not known to have cystine or uric acid renal stone(s)

Index Patient 15: Pregnant female, renal or ureteral stone(s)

Methodology

Process for Initial Literature Selection
Consistent with the published AUA Guideline methodology framework,⁷ the process started by conducting a comprehensive systematic review. The AUA commissioned an independent group to conduct a systematic review and meta-analysis of the published literature on various options for the surgical management of stones.⁸ The protocol of the systematic review was developed a priori by the methodology team in conjunction with the expert panel. A systematic review was conducted to identify published articles relevant to the surgical management of renal or ureteral stones. Literature searches were performed on English-language publications using the Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from 1/1/1985 to 5/31/2015. Preclinical studies (e.g., animal models), commentary, and editorials were excluded. Studies on patients with lower tract stones were excluded (including bladder stones and diversions). Bibliographies of review articles were checked to ensure inclusion of all possibly relevant studies. Multiple reports on the same patient group were carefully examined to ensure inclusion of only non-redundant information. The systematic review yielded a total of 1,911 studies. The Panel and methodology group continued to monitor the literature for relevant randomized trials thereafter and added several newer trials published through 2015.

The Panel judged that there was a sufficient evidence base from which to construct the Guideline. Data on study type (e.g., randomized controlled trial [RCT], controlled clinical trial [CCT], observational study), perioperative testing, treatment parameters (e.g., type of treatment), patient characteristics (e.g., age, stone size and location), outcomes (e.g., stone-free rate, residual fragments, quality of life [QoL]) and complications were extracted.

Almost all the studies that reported on preoperative testing (99 computed tomography [CT] scan, 10 renal scan, 128 renal ultrasound [US], 188 KUB, 156 intravenous pyelogram [IVP], 68 complete blood count [CBC], 29 stone analysis and 112 urine culture) did not report the purpose of performing these tests. There were no reliable data on the utility or incremental value of testing. The procedures of interest were percutaneous nephrolithotomy (PCNL), ureteroscopy (URS), laparoscopy, shock-wave lithotripsy (SWL), open surgery, robotic surgery, ureteral stent, or nephrostomy. Comparison of any of these active treatments against each other or against medical management was done when possible. Medical expulsive therapy (MET) was evaluated in terms of efficacy against placebo. Outcomes included stone-free rate (as determined by KUB, US, IVP, nephrotomogram, CT, endoscopy); residual fragments (by size); secondary procedures needed (stone-removing versus ancillary); QoL; pain; analgesic requirements; length of hospitalization; comparative recurrence rates; renal function; and procedure complications (e.g., death, sepsis/sirs, transfusion, loss of kidney, readmission rates, overall rates). When multiple studies evaluated the same outcome and had similar population, intervention, and comparison, meta-analysis was conducted using the random effects model, when appropriate.8 Stone-free rate was stratified based on stone size and location.

The methodology team independently rated the methodological quality of the studies and provided an overall judgment of the whole body of evidence based on confidence in the available estimates of effect.

The methodology team summarized the data with explicit description of study characteristics, methodological quality, main findings, and quality of the evidence (confidence in the estimates). The methodology team attended panel meetings and facilitated incorporation of the evidence into the Guideline.

Quality of Individual Studies and Determination of Evidence Strength

The quality of individual studies that were either RCTs or CCTs was assessed using the Cochrane Risk of Bias tool.⁹ The quality of CCTs and comparative observational studies was rated using the Newcastle-Ottawa Quality (NOQ) Assessment Scale.¹⁰ Because there is no widely-agreed upon quality assessment tool for single cohort observational studies, the quality of these studies was not assessed.

The categorization of evidence strength is conceptually distinct from the quality of individual studies (the latter is also called the risk of bias). Evidence strength refers to the body of evidence available for a particular question and includes not only individual study quality but consideration of study design; consistency of findings across studies; adequacy of sample sizes; and generalizability of samples, settings, and treatments for the purposes of the Guideline. The AUA categorizes body of evidence strength as Grade A (well-conducted and highly-generalizable RCTs or exceptionally strong observational studies with consistent findings), Grade B (RCTs with some weaknesses of procedure or generalizability or moderately strong observational studies with consistent findings), or Grade C (RCTs with serious deficiencies of procedure or generalizability or extremely small sample sizes or observational studies that are inconsistent, have small sample sizes, or have other problems that potentially confound interpretation of data). By definition, Grade A evidence is evidence about which the Panel has a high level of certainty, Grade B evidence is evidence about which the Panel has a moderate level of certainty, and Grade C evidence is evidence about which the Panel has a low level of certainty.⁷

AUA Nomenclature: Linking Statement Type to Evidence Strength

The AUA nomenclature system links statement type to body of evidence strength, level of certainty, magnitude of benefit or risk/burdens, and the Panel's judgment regarding the balance between benefits and risks/burdens (see Table 1). Strong Recommendations are directive statements that an action should (benefits outweigh risks/burdens) or should not (risks/burdens outweigh benefits) be undertaken because net benefit or net harm is substantial. Moderate Recommendations are directive statements that an action should (benefits outweigh risks/burdens) or should not (risks/burdens outweigh benefits) be undertaken because net benefit or net harm is moderate. Conditional Recommendations are non-directive statements used when the evidence indicates that there is no apparent net benefit or harm or when the balance between benefits and risks/burden is unclear. All three statement types may be supported by any body of evidence strength grade. Body of evidence strength Grade A in support of a Strong or Moderate Recommendation indicates that the statement can be applied to most patients in most circumstances and that future research is unlikely to change confidence. Body of evidence strength Grade B in support of a Strong or Moderate Recommendation indicates that the statement can be applied to most patients in most circumstances but that better evidence could change confidence. Body of evidence strength Grade C in support of a Strong or Moderate Recommendation indicates that the statement can be applied to most patients in most circumstances but that better evidence is likely to change confidence. Body of evidence strength Grade C is rarely used in support of a Strong Recommendation. Conditional Recommendations also can be supported by any body of evidence strength. When body of evidence strength is Grade A, the statement indicates that benefits and risks/burdens appear balanced, the best action depends on patient circumstances, and future research is unlikely to change confidence. When body of evidence strength Grade B is used, benefits and risks/burdens appear balanced, the best action also depends on individual patient circumstances and better evidence could change confidence. When body of evidence strength Grade C is used, there is uncertainty regarding the balance between benefits and risks/burdens, alternative strategies may be equally reasonable, and better evidence is likely to change confidence.

For some clinical issues, particularly diagnosis, there was little or no evidence from which to construct evidence-based statements. Where gaps in the evidence existed, the Panel provides guidance in the form of Clinical Principles or Expert Opinions with consensus achieved using a modified Delphi technique if differences of opinion emerged.¹¹ A Clinical Principle is a statement about a component of clinical care that is widely agreed upon by urologists or other clinicians for which there may or may not be evidence in the medical literature. Expert Opinion refers to a statement, achieved by consensus of the Panel, that is based on members' clinical training, experience, knowledge, and judgment for which there is no evidence.

Panel Selection and Peer Review Process

The Surgical Management of Stones Panel was created in 2013 by the American Urological Association Education and Research, Inc. (AUA). The Practice Guidelines Committee (PGC) of the AUA selected the Panel Chair who in turn appointed the additional panel members with specific expertise in this area. The Endourological Society also nominated two representatives to serve on the panel. Once nominated, all panel members were asked to record their conflict of interest (COI) statements, providing specific details on the AUA interactive web site. These details are first reviewed by the Guidelines Oversight Committee (GOC), a member sub-committee from the PGC consisting of the Vice Chair of the PGC and two other members. The GOC determines whether the individual has potential conflicts related to the guideline. If there are conflicts, then the nominee's COI is reviewed and approved by the AUA Judicial and Ethics (J&E) committee. A majority of panel members may not have relationships relevant to the Guideline topic.

The AUA conducted a thorough peer review process. The draft guidelines document was distributed to 109 peer reviewers, 54 of whom provided comments. The Panel reviewed and discussed all submitted comments and revised the draft as needed. Once finalized, the Guideline was submitted for approval to the PGC and Science and Quality Council (S&Q). Then it was submitted to the AUA Board of Directors and the Endourological Society Board of Directors for final approval. Funding of the panel was provided by the AUA, with support from The Endourological Society; panel members received no remuneration for their work.

Limitations of the Literature

Evidence to guide perioperative diagnostic evaluation was sparse and of low quality, affecting recommendations on laboratory testing and imaging. Data on stone-free rate (lithotripsy, URS and PCNL) when stratified by location and stone size were also limited in clinical trials; therefore, rates were also derived from large registries that provided precise, although likely biased, estimates. Comparative effectiveness of MET was derived from a large number of trials that overall has a moderate risk of bias. Only a very small number of studies were available to provide comparative effectiveness inferences in children.

Clinicians should obtain a non-contrast CT scan on patients prior to performing PCNL. Strong Recommendation; Evidence Level Grade C

Clinicians may obtain a non-contrast CT scan to help select the best candidate for SWL versus URS. Conditional Recommendation; Evidence Level Grade C

Clinicians may obtain a functional imaging study (DTPA or MAG‐3) if clinically significant loss of renal function in the involved kidney or kidneys is suspected. Conditional Recommendation; Evidence Level Grade C

Clinicians are required to obtain a urinalysis prior to intervention. In patients with clinical or laboratory signs of infection, urine culture should be obtained. Strong recommendation; Evidence Level Grade B

Clinicians should obtain a CBC and platelet count on patients undergoing procedures where there is a significant risk of hemorrhage or for patients with symptoms suggesting anemia, thrombocytopenia, or infection; serum electrolytes and creatinine should be obtained if there is suspicion of reduced renal function. Expert Opinion

In patients with complex stones or anatomy, clinicians may obtain additional contrast imaging if further definition of the collecting system and the ureteral anatomy is needed. Conditional recommendation; Evidence Level Grade C

Patients with uncomplicated ureteral stones ≤10 mm should be offered observation, and those with distal stones of similar size should be offered MET with α-blockers. (Index Patient 3) Strong Recommendation; Evidence Level Grade B

Clinicians should offer reimaging to patients prior to surgery if passage of stones is suspected or if stone movement will change management. Reimaging should focus on the region of interest and limit radiation exposure to uninvolved regions. Clinical Principle

In most patients, if observation with or without MET is not successful after four to six weeks and/or the patient/clinician decide to intervene sooner based on a shared decision making approach, the clinicians should offer definitive stone treatment. (Index Patients 1-3) Moderate Recommendation; Evidence Level Grade C

Clinicians should inform patients that SWL is the procedure with the least morbidity and lowest complication rate, but URS has a greater stone-free rate in a single procedure. (Index Patients 1-6) Strong Recommendation, Evidence Level Grade B

In patients with mid or distal ureteral stones who require intervention (who were not candidates for or who failed MET), clinicians should recommend URS as first-line therapy. For patients who decline URS, clinicians should offer SWL. (Index Patients 2,3,5,6) Strong Recommendation; Evidence Level Grade B

URS is recommended for patients with suspected cystine or uric acid ureteral stones who fail MET or desire intervention. Expert Opinion

Routine stenting should not be performed in patients undergoing SWL. (Index Patients 1-6) Strong Recommendation; Evidence Level Grade B

Following URS, clinicians may omit ureteral stenting in patients meeting all of the following criteria

those without suspected ureteric injury during URS, those without evidence of ureteral stricture or other anatomical impediments to stone fragment clearance, those with a normal contralateral kidney, those without renal functional impairment, and those in whom a secondary URS procedure is not planned. (Index Patients 1-6) Strong Recommendation; Evidence Level Grade A

Placement of a ureteral stent prior to URS should not be performed routinely. (Index Patient 1-6) Strong Recommendation; Evidence Level Grade B

Clinicians may offer α-blockers and antimuscarinic therapy to reduce stent discomfort. (Index patients 1-6) Moderate Recommendation; Evidence Level Grade B

In patients who fail or are unlikely to have successful results with SWL and/or URS, clinicians may offer PCNL, laparoscopic, open, or robotic assisted stone removal. (Index patient 1-6) Moderate Recommendation; Evidence Level Grade C

Clinicians performing URS for proximal ureteral stones should have a flexible ureteroscope available. (Index Patients 1, 4) Clinical Principle

Clinicians should not utilize EHL as the first-line modality for intra-ureteral lithotripsy. (Index patients 1-6,13,15) Expert Opinion

In patients with obstructing stones and suspected infection, clinicians must urgently drain the collecting system with a stent or nephrostomy tube and delay stone treatment. Strong Recommendation; Evidence Level Grade C

In symptomatic patients with a total non-lower pole renal stone burden < 20 mm, clinicians may offer SWL or URS. (Index Patient 7) Strong Recommendation; Evidence Level Grade B

In symptomatic patients with a total renal stone burden >20 mm, clinicians should offer PCNL as first-line therapy. (Index Patient 8) Strong Recommendation; Evidence Level Grade C

In patients with total renal stone burden >20 mm, clinicians should not offer SWL as first-line therapy. (Index Patient 8) Moderate Recommendation; Evidence Level Grade C

Clinicians may perform nephrectomy when the involved kidney has negligible function in patients requiring treatment. (Index Patients 1-14) Conditional Recommendation; Evidence Level Grade C

For patients with symptomatic (flank pain), non-obstructing, caliceal stones without another obvious etiology for pain, clinicians may offer stone treatment. (Index Patient 12) Moderate Recommendation; Evidence Level Grade C

For patients with asymptomatic, non-obstructing caliceal stones, clinicians may offer active surveillance. Conditional Recommendation; Evidence Level grade C

Clinicians should offer SWL or URS to patients with symptomatic ≤ 10 mm lower pole renal stones. (Index Patient 9) Strong Recommendation; Evidence Level Grade B

Clinicians should not offer SWL as first-line therapy to patients with >10mm lower pole stones. (Index Patient 10) Strong Recommendation; Evidence Level Grade B

Clinicians should inform patients with lower pole stones >10 mm in size that PCNL has a higher stone-free rate but greater morbidity. (Index patient 10). Strong Recommendation; Evidence Level Grade B

In patients undergoing uncomplicated PCNL who are presumed stone-free, placement of a nephrostomy tube is optional. Conditional Recommendation; Evidence Level Grade C

Flexible nephroscopy should be a routine part of standard PCNL. Strong recommendation; Evidence Level Grade B

Clinicians must use normal saline irrigation for PCNL and URS. Strong Recommendation; Evidence Level Grade B

In patients not considered candidates for PCNL, clinicians may offer staged URS. Moderate Recommendation; Evidence Level Grade C

Clinicians may prescribe α-blockers to facilitate passage of stone fragments following SWL. Moderate Recommendation; Evidence Level Grade B

SWL should not be used in the patient with anatomic or functional obstruction of the collecting system or ureter distal to the stone. Strong Recommendation; Evidence Level Grade C

In patients with symptomatic caliceal diverticular stones, endoscopic therapy (URS, PCNL, laparoscopic, robotic) should be preferentially utilized. Strong Recommendation; Evidence Level Grade C

Staghorn stones should be removed if attendant comorbidities do not preclude treatment. Clinical Principle

In pediatric patients with uncomplicated ureteral stones ≤10 mm, clinicians should offer observation with or without MET using α-blockers. (Index Patient 13) Moderate Recommendation; Evidence Level Grade B

Clinicians should offer URS or SWL for pediatric patients with ureteral stones who are unlikely to pass the stones or who failed observation and/or MET, based on patient-specific anatomy and body habitus. (Index Patient 13) Strong Recommendation; Evidence Level Grade B

Clinicians should obtain a non-contrast, low-dose CT scan on pediatric patients prior to performing PCNL. (Index Patient 13) Strong Recommendation; Evidence Level Grade C

In pediatric patients with a total renal stone burden ≤20mm, clinicians may offer SWL or URS as first-line therapy. (Index Patient 14) Moderate Recommendation; Evidence Level Grade C

In pediatric patients with a total renal stone burden >20mm, both PCNL and SWL are acceptable treatment options. (Index Patient 14) Moderate Recommendation; Evidence Level Grade C

In pediatric patients, except in cases of coexisting anatomic abnormalities, clinicians should not routinely perform open/laparoscopic/robotic surgery for upper tract stones. (Index Patients 13, 14) Expert Opinion

In pediatric patients with asymptomatic and non-obstructing renal stones, clinicians may utilize active surveillance with periodic ultrasonography. (Index Patient 14) Expert Opinion

In pregnant patients, clinicians should coordinate pharmacological and surgical intervention with the obstetrician. (Index Patient 15) Clinical Principal

In pregnant patients with ureteral stone(s) and well controlled symptoms, clinicians should offer observation as first-line therapy. (Index Patient 15) Strong recommendation; Evidence Level Grade B

In pregnant patients with ureteral stones, clinicians may offer URS to patients who fail observation. Ureteral stent and nephrostomy tube are alternative options with frequent stent or tube changes usually being necessary. (Index Patient 15) Strong Recommendation; Evidence Level Grade C

When residual fragments are present, clinicians should offer patients endoscopic procedures to render the patients stone-free, especially if infection stones are suspected. (Index Patient 11) Moderate Recommendation; Evidence Level Grade C

Stone material should be sent for analysis. Clinical Principle

Open/laparoscopic/robotic surgery should not be offered as first-line therapy to most patients with stones. Exceptions include rare cases of anatomic abnormalities, with large or complex stones, or those requiring concomitant reconstruction. (Index Patients 1-15) Strong Recommendation; Evidence Level Grade C

A safety guide wire should be used for most endoscopic procedures. (Index Patients 1-15) Expert Opinion

Antimicrobial prophylaxis should be administered prior to stone intervention and is based primarily on prior urine culture results, the local antibiogram, and in consultation with the current Best Practice Policy Statements on Antibiotic Prophylaxis. Clinical Principle

Clinicians should abort stone removal procedures, establish appropriate drainage, continue antibiotic therapy, and obtain a urine culture if purulent urine is encountered during endoscopic intervention. (Index Patients1-15) Strong Recommendation; Evidence Level Grade C

If initial SWL fails, clinicians should offer endoscopic therapy as the next treatment option. (Index Patient 1-14) Moderate Recommendation; Evidence Level Grade C

Clinicians should use URS as first-line therapy in most patients who require stone intervention in the setting of uncorrected bleeding diatheses or who require continuous anticoagulation/antiplatelet therapy. (Index Patients1-15) Strong Recommendation; Evidence Level Grade C

It is unfortunate that the surgical treatment of kidney stones, a disease with such a great prevalence, has not been studied with greater rigor in previous years. One of the most disappointing aspects of the systematic review performed herein is the small number of high quality research studies identified. There is an extreme paucity of high quality RCTs comparing competitive surgical interventions for stone disease. However, this is not surprising, given that other urologic fields are also underpopulated with such studies.

Going forward, it will be beneficial to standardize the reporting of stone treatment studies. At present, there is great heterogeneity in the definitions of such important metrics as stone size, stone location, stone-free status, complications and economic outcomes. This terminology should be standardized as this will allow more reliable comparisons among studies, and make systematic reviews and meta-analyses more powerful.

Clinicians' ability to utilize imaging studies to predict treatment outcomes for differing stone interventions is limited at present. As a result, we cannot completely counsel patients on their likely course following a stone removal intervention. This is particularly true for SWL, where our pre-treatment understanding of stone fragility is lacking. It would be most welcome for the clinician to be better able to predict treatment outcomes from presently available imaging modalities. Furthermore, efforts should also be focused on identifying and advancing the utility of imaging modalities that do not rely on ionizing radiation such as MRI and ultrasonography.

Many patients with a symptomatic ureteral stone will pass their stones spontaneously. From a patient-centered standpoint, time course to passage, as well as maneuvers to increase the probability of spontaneous passage are exceedingly important. Clinicians' ability to counsel patients on how long it will take for a stone to pass is limited due in great part to a lack of research focused on answering this question. With regards to augmenting stone passage utilizing pharmacotherapy, our understanding is unclear as the literature is conflicted. Future studies better defining the ability of MET to promote stone passage will be important to improving the patient experience. In addition, the development of agents with better efficacy and tolerability to facilitate stone passage is warranted.

The mechanical action of stone fragmentation and removal is the primary driver of intra-operative time allocation during a stone removal procedure. For URS and PCNL, the technologies accomplish the same end, but via different mechanisms. For patients undergoing URS, in particular flexible URS, the Holmium laser is currently the lithotrite of choice. In some cases the laser may be used to fragment the stone into small pieces that can be individually retrieved; in other cases the laser may be used to fragment the stone into fine powder, which will spontaneously drain from the kidney. At present, it is not known which of these approaches yields superior outcomes, but such information would be immediately useful to the practicing urologist.

There is also a need to improve the devices that are used in the stone fragmentation and evacuation process during endoscopic surgery. With respect to URS, there is a need for mechanical devices that more efficiently and safely fragment and evacuate stone material; at present, this process is cumbersome and potentially dangerous as ureteral injury may occur during stone extraction. With respect to PCNL, advances in stone removal technology will enable a more rapid and efficient evacuation of larger burdens of stone.

Ureteral stent placement is commonly performed following stone interventions. In some cases, stent placement may not be necessary, such as in the case of an uncomplicated ureteroscopic procedure. However, in many of those cases, stents are still placed. It is well recognized that ureteral stents are the source of significant morbidity. Future efforts should be devoted to better identifying which patients may safely avoid stent placement. In addition, advances in stent technology, with a particular focus on identifying the nature and source of stent morbidity, as well as design advances to minimize these bothersome symptoms will also improve surgical care.

Stone disease in the pediatric population has been reported to be increasing. At present, our understanding of stone management among children is somewhat rudimentary, as the published literature is sparse. Future efforts to better define the effects of surgical stone treatment in this population will also be important.

Figure 1. Forest plot: Odds ratio of stone-free rate for distal ureteral stones <10 mm in patients receiving any α-Blocker vs. Control

Figure 2. Forest plot: Odds ratio of stone-free rate for distal ureteral stones in patients receiving Tamsulosin 0.4 mg vs. Control

Figure 3. Forest plot: Odds ratio of stone-free rate for distal ureteral stones < 10 mm in patients receiving Nifedipine vs. Control

Figure 4. Forest plot: Odds ratio of stone-free rate for proximal ureteral stones in patients receiving any α-Blocker vs. Control

Figure 5. Forest plot: Odds ratio of stone-free rate for middle ureteral stones in patients receiving any α-Blocker vs. Control

Figure 6. Stone-free rate in adults, SWL vs. URS

Abbreviations

1. Saigal CS, Joyce G and Timilsina AR: Urologic diseases in America project: Direct and indirect costs of nephrolithiasis in an employed population: opportunity for disease management? Kidney Int 2005; 68:1808.
2. Scales CD Jr, Smith AC, Hanley JM et al: Prevalence of kidney stones in the United States. Eur Urol 2012; 62: 160.
3. Pearle MS, Calhoun EA, Curhan GC et al: Urologic diseases in America project: urolithiasis. J Urol 2005; 173: 848.
4. Preminger GM, Assimos DG, Lingeman JE et al: Chapter 1: AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations. J Urol 2005; 173: 1991.
5. Preminger GM, Tiselius HG, Assimos DG et al: 2007 guideline for the management of ureteral calculi. J Urol 2007; 178: 2418.
6. Pearle MS, Goldfarb DS, Assimos DG et al: Medical management of kidney stones: AUA guideline. J Urol 2014; 192: 316.
7. Faraday M, Hubbard H, Kosiak B et al: Staying at the cutting edge: a review and analysis of evidence reporting and grading; the recommendations of the American Urological Association. BJU Int 2009; 104: 294.
8. Barrionuevo Moreno P, Asi N, Benkhadra K et al: Surgical management of kidney stones: a systematic review. Mayo Clinic 2015.
9. Higgins JDA: Assessing quality of included studies in Cochrane Reviews. The Cochrane Collaboration Methods Groups Newsletter 2007; 11.
10. Wells GA, Shea B, O'Connell D et al: The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomized studies in meta-analyses. 2009: http://www.ohri.ca/programs/clinical_epidemiology/oxford.htm.
11. Hsu C and Sandford BA: The Delphi Technique: Making Sense of Consensus. Practical Assessment, Research & Evaluation 2007; 12: 1.
12. Akbulut F, Kucuktopcu O, Ucpinar B et al: A rare complication of extracorporeal shock wave lithotripsy: intrarenal hematoma mimicking pelvis renalis tumor. Case Reports in Urology 2015; 2015: 1.
13. Chalasani V, Bissoon D, Bhuvanagir AK et al: Should PCNL patients have a CT in the prone position preoperatively? Can J Urol 2010; 17; 5082.
14. Ghani KR, Patel U and Anson K: Computed tomography for percutaneous renal access. J Endourol 2009; 23: 1633.
15. Hopper KD, Sherman JL, Luethke JM et al: The retrorenal colon in the supine and prone patient. Radiology 1987; 162: 443.
16. Labadie K, Okhunov A, Akhavein D et al: Evaluation and comparison of urolithiaisis scoring systems in percutaneous kidney stone surgery. J Urol 2015; 193; 154.
17. Prassopoulos P, Gourtsoyiannis N, Cavouras D et al: A study of the variation of colonic positioning in the pararenal space as shown by computed tomography. Eur J Radiol 1990; 10: 44.
18. Okhunov Z, Friedlander JI, George AK et al: S.T.O.N.E. nephrolithometry: novel surgical classification system for kidney calculi. Urology 2013; 81: 1154.
19. Smith A, Averch TD, Shahrour K et al: A nephrolithometric nomogram to predict treatment success of percutaneous nephrolithotomy. J Urol 2013; 190; 149.
20. Thomas K, Smith NC, Hegarty N et al: The Guy’s stone score—grading the complexity of percutaneous nephrolithotomy procedures. Urology 2011; 78: 277.
21. Wickham JEA, Fry IK and Wallace DMA: Computerised tomography localization of intrarenal calculi prior to nephrolithotomy. BJU Int 1980; 52: 422.
22. Poletti PA, platon A, Ruschmann OT et al: Low-dose versus standard-dose CT protocol in patients with clinically suspected renal colic. AJR Am J Roentgenol 2007; 188: 927.
23. Brehmer M, Beckman MO and Magnusson A: 3-dimensional CT planning improves percutaneous stone surgery. Scan J Urol 2014; 48: 316.
24. Fulgham PF, Assimos DG, Pearle MS et al: Clinical effectiveness protocols for imaging in the management of ureteral calculous disease: AUA technology assessment. J Urol 2013; 189: 1230.
25. Coursey CA, Casalino DD, Reimer EM et al: ACR appropriateness criteria: acute onset flank pain- suspicion of stone disease. Ultrasound Q 2012; 28: 227.
26. Smith-Bindman R, Aubin C, Bailitz J et al: Ultrasonography versus computed tomography for suspected nephrolithiaisis. N Eng J Med 2014; 371: 1100.
27. Perks AE; Schuler TD, Lee J et al: Stone attenuation and skin-to-stone distance on computed tomography predicts for stones fragmentation by shock wave lithotripsy. Urology 2008; 72: 765.
28. El-Nahas AR, El-Assmy AM, Mansour O et al: A prospective multivariate analysis of factors predicting stone disintegration by extracorporeal shock wave lithotripsy: the value of high-resolution noncontrast computed tomography. Eur Urol 2007; 51: 1688.
29. Patel T, Kozakowski K, Hruby G et al: Skin to stone distance is an independent predictor of stone-free status following shock wave lithotripsy. J Endourol 2009; 23: 1383.
30. Pareek G, Hedican SP, Lee FT Jr et al: Shock wave lithotripsy success determined by skin-to-stone distance on computed tomography. Urology. 2005; 66: 941.
31. Tran TY, McGillen K, Cone EB et al: Triple D Score is a reportable predictor of shockwave lithotripsy stone-free rates. J Endourol 2015; 29: 226.
32. Vakalopoulos I: Development of a mathematical model to predict extracorporeal shockwave lithotripsy outcome. J Endourol. 2009; 23: 891.
33. Feder MT, Blitstein J, Mason B et al: Predicting differential renal function using computerized tomography measurements of renal parenchymal area. J Urol 2008; 180: 2110.
34. Gupta S, Singh AH, Shabbir A et al: Assessing renal parenchymal volume on unenhanced CT as a marker for predicting renal function in patients with chronic kidney disease. Acad Radiol 2012; 19: 654.
35. Herts BR, Sharma N, Lieber M et al: Estimating glomerular filtration rate in kidney donors: a model constructed with renal volume measurements from donor CT scans. Radiology 2009; 252: 109.
36. Morrisroe SN, Su RR, Bae KT et al: Differential renal function estimation using computerized tomography based renal parenchymal volume measurement. J Urol 2010; 183: 2289.
37. Ramaswamy K, Marien T, Mass A et al: Simplified approach to estimating renal function based on computerized tomography. Can J Urol 2013; 20: 6833.
38. Benson AD, Juliano TM and Miller NL: Infectious outcomes of nephrostomy drainage before percutaneous nephrolithotomy compared to concurrent access. J Urol 2014; 192: 770.
39. Korets R, Graversen JA, Kates M et al: Post-percutaneous nephrolithotomy systemic inflammatory response: a prospective analysis of preoperative urine, renal pelvic and stone cultures. J Urol 2011; 186: 1899.
40. Margel D, Ehrlich Y, Brown N et al: Clinical implication of routine stone culture in percutaneous nephrolithotomy, a prospective study. Urology 2006; 67: 26.
41. Mariappan P, Smith G, Bariol SV et al: Stone and pelvic urine culture are better than bladder urine as predictors of urosepsis following percutaneous nephrolithotomy: a prospective clinical study J Urol 2005; 173: 1610.
42. Marien T, Mass AY and Shah O: Antimicrobial resistance patterns in cases of obstructive pyelonephritis secondary to stones. Urology 2015; 85: 64.
43. Committee on Standards and Practice Parameters: Practice advisory for preanesthesia evaluation: an updated report by the American Society of Anesthesiologists Task Force on preanesthesia evaluation. Anesthesology 2012; 116: 1.
44. Patel IJ, Davidson JC, Nikolic B et al: Consensus guidelines for periprocedural management of coagulation status and hemostasis risk in percutaneous image-guideline interventions. J Vasc Interv Radiol 2012; 23: 727.
45. Frank S, Oleyar MJ, Ness PM, et al: Reducing unnecessary preoperative blood orders and costs by implementing an updated institution specific maximum surgical blood order schedule and a remote electronic blood release system. Anesthesiology 2014; 121: 501.
46. Patel U, Walkden RM, Ghani KR et al: Three-dimensional CT pyelography for planning of percutaneous nephrostolithotomy: accuracy of stone measurement, stone depiction and pelvicalyceal reconstruction. Eur Radiol 2009; 19: 1280.
47. Thiruchelvam N, Mostafid H and Ubhayakar G: Planning percutaneous nephrolithotomy using multidetector computed tomography urography, multiplanar reconstruction and three-dimensional reformatting. BJU Int 2005; 95: 1280.
48. Hubner WA, Irby P and Stoller ML: Natural history and current concepts for the treatment of small ureteral calculi. Eur Urol 1993; 24: 172.
49. Miller OF and Kane CJ: Time to stone passage for observed ureteral calculi: a guide for patient education. J Urol 1999; 162: 688.
50. Park HK, Choi EY, Jeong BC et al: Localizations and expressions of alpha-1A, alpha-1B and alpha-1D adrenoceptors in human ureter. Urol Res 2007; 35: 325.
51. Sasaki S, Tomiyama Y, Kobayashi S et al: Characterization of alpha1-adrenoceptor subtypes mediating contraction in human isolated ureters. Urology 2011; 77: e13.
52. Furyk JS, Chu K, Banks C et al: Distal ureteric stones and tamsulosin: a double-blind, placebo-controlled, randomized, multicenter trial. Ann Emerg Med 2016; 67: 86.
53. Pickard R, Starr K, MacLennan G et al: Medical expulsive therapy in adults with ureteric colic: a multicenter, randomized, placebo-controlled trial. Lancet 2015; 386: 341.
54. Kreshover JE, Dickstein RJ, Rowe C et al: Predictors for negative ureteroscopy in the management of upper urinary tract stone disease. Urology 2011; 78: 748.
55. Vaughan ED and Gillenwater JY: Recovery following complete chronic unilateral ureteral occlusion: functional, radiographic and pathologic alterations. J Urol 1973; 100: 27.
56. Pedro RN, Hinck B, Hendlin K et al: Alfuzosin stone expulsion therapy for distal ureteral calculi; a double-blind, placebo controlled study. J Urol 2008; 179: 2244.
57. Aboumarzouk OM, Kata SG, Keeley FX et al: Extracorporeal shock wave lithotripsy (ESWL) versus ureteroscopic management for ureteric calculi. Cochrane Database Syst Rev. [Meta-Analysis Research Support, Non-U.S. Gov't Review]. 2012; 5: CD006029.
58. Makarov DV, Trock BJ, Allaf ME et al: The effect of ureteral stent placement on post-ureteroscopy complications: a meta-analysis. Urology 2008; 71: 796.
59. Lasser MS and Pareek G: Smith’s Textbook of Endourology 3rd Edition,Wiley-Blackwell, 2012; 273.
60. Segura JW, Preminger GM, Assimos DG et al: Ureteral Stones Clinical Guidelines Panel summary report on the management of ureteral calculi. J Urol 1997; 158: 1915.
61. Shen P, Jiang M, Yang J et al: Use of ureteral stent in extracorporeal shock wave lithotripsy for upper urinary calculi: a systematic review and meta-analysis. J Urol 2011; 186: 1328.
62. Al- Ba’adani T, Ghilan A, El-Nono I et al: Whether post-ureteroscopy stenting is necessary or not? Saudi Med J 2006; 27: 845.
63. Borboroglu PG, Amling CL, Schenkman NS et al: Ureteral stenting after ureteroscopy for distal ureteral calculi: a multi-institutional prospective randomized controlled study assessing pain, outcomes and complications. J Urol 2001; 166: 1651.
64. Chen YT, Chen J, Wong WY et al: Is ureteral stenting necessary after uncomplicated ureteroscopic lithotripsy? A prospective, randomized controlled trial. J Urol 2002; 167: 1977.
65. Cheung MC, Lee F, Leung YL et al: A prospective randomized controlled trial on ureteral stenting after ureteroscopic holmium laser lithotripsy. J Urol 2003; 169: 1257.
66. Denstedt JD, Wollin TA, Sofer M et al: A prospective randomized controlled trial comparing nonstented vs stented ureteroscopic lithotripsy. J Urol 2001; 165: 1419.
67. Ibhrahim HM, Al-Kandari AM, Shaaban HS et al: Role for ureteral stenting after uncomplicated ureteroscopy for distal ureteral stones: a randomized controlled trial. J Urol 2008; 180: 961.
68. Isen K, Bogatekin S, Em S et al: Is routine ureteral stenting necessary after uncomplicated ureteroscopic lithotripsy for lower ureteral stones larger than 1 cm? Urol Res 2008; 36: 115.
69. Gunlusoy B, Degirmenci T, Arslan M et al: Is ureteral cauterization necessary after ureteroscopic lithotripsy for uncomplicated upper ureteral stones? J Endourol 2008; 22: 1645.
70. Jeong H, Kwak C and Lee SE: Ureteric stenting after ureteroscopy for ureteric stones: a prospective randomized study assessing symptoms and complications. BJU Int 2003; 93: 1032.
71. Mustafa M: The role of stenting in relieving loin pain following ureteroscopic stone therapy for persisting renal colic with hydronephrosis. International Urol and Nephrol 2007; 39: 91.
72. Shao Y, Zhuo J, Sun XW et al: Nonstented vs routine stented ureteroscopic holmium laser lithotripsy: a prospective randomized trial. Urol Res 2008; 36: 259.
73. Srivastava A, Gupta R, Kumar A et al: Routine stenting after ureteroscopy for distal ureteral calculi is unnecessary: results of a randomized controlled trial. J Endourol 2003; 17: 871.
74. Nabi G, Cook J, N’Dow J et al: Outcome of stenting after uncomplicated ureteroscopy: systematic review and meta-analysis. BMJ 2007; 334: 544.
75. Pengfei S, Yutao L, Jie Y et al: The results of ureteral stenting after ureteroscopic lithotripsy for ureteral calculi: a systematic review and meta-analysis. J Urol 2011; 186: 1904.
76. Rubenstein RA, Zhao LC, Loeb S et al: Prestenting improves ureteroscopic stone-free rates. J Endourol 2007; 21: 1277.
77. Chu L, Farris CA, Corcoran AT et al: Preoperative stent placement decreases cost of ureteroscopy. Urology 2011; 78: 309.
78. Netsch C, Knipper S, Bach T et al: Impact of preoperative ureteral stenting on stone-free rates of ureteroscopy for nephroureterolithiasis: a matched-paired analysis of 286 patients. Urology 2012; 80: 1214.
79. Zhou L, Cai X, Li H et al: Effects of α-blockers, antimuscarinics, or combination therapy in relieving ureteral stent-related symptoms: a meta-analysis. J Endourol 2015; 29: 650.
80. Lamb AD, Vowler SL, Johnston R et al: Meta-analysis showing the beneficial effect of α-blockers on ureteric stent discomfort. BJU Int 2011; 108: 1894.
81. Kwon JK, Cho KS, Oh CK et al. The beneficial effect of alpha-blockers for ureteral stent-related discomfort: systematic review and network meta-analysis for alfuzosin versus tamsulosin versus placebo. BMC Urol 2015; 15: 55.
82. Yakoubi R, Lemdani M, Monga M et al: Is there a role for α-blockers in ureteral stent related symptoms? A systematic review and meta-analysis. J Urol 2011; 186: 928.
83. Roberts WW, Cadeddu JA, Micali S et al: Ureteral stricture formation after removal of impacted calculi. J Urol 1998; 159: 723.
84. Abbas B, Nasser S, Amirmohsen Z et al: Retrograde, antegrade, and laparoscopic approaches for the management of large, proximal ureteral stones: a randomized clinical trial. J Endourol 2008; 22: 2677.
85. Muslumanoglu AY, Karadag MS, Tefekli AH et al: When is open ureterolithotomy indicated for the treatment of ureteral stones? Int J Urol 2006; 13: 1385.
86. Berczi C, Flasko T, Lorincz L et al: Results of percutaneous endoscopic ureterolithotomy compared to that of ureteroscopy. J Laparoendosc Adv Surg Tech A 2007; 17: 285.
87. Dretler SP, Keating MA and Riley J: An algorithm for the management of ureteral calculi. J Urol 1986; 136: 1190.
88. Moufid K, Abbaka N, Touiti D et al: Large impacted upper ureteral calculi: A comparative study between retrograde ureterolithotripsy and percutaneous antegrade ureterolithotripsy in the modified lateral position. Urol Ann 2013; 5: 140.
89. Tan HM, Liew RP, Chan CC et al: Multimodal approach in the management of 1163 ureteric stone cases. Med J Malaysia 1995; 50: 87.
90. Yang Z, Song L, Xie D et al: Comparative study of outcome in treating upper ureteral impacted stones using minimally invasive percutaneous nephrolithotomy with aid of patented system or transurethral ureteroscopy. Urology 2012; 80: 1192.
91. Siavash F, Iradj K, Aliakbar A et al: Open surgery, laparoscopic surgery, or transureteral lithotripsy--which method? Comparison of ureteral stone management outcomes. J Endourol 2011; 25: 31.
92. Lopes Neto AC, Korkes F, Silva JL 2nd et al: Prospective randomized study of treatment of large proximal ureteral stones: extracorporeal shock wave lithotripsy versus ureterolithotripsy versus laparoscopy. J Urol 2012; 187: 164.
93. Fang YQ, Qiu JG, Wang DJ et al: Comparative study on ureteroscopic lithotripsy and laparoscopic ureterolithotomy for treatment of unilateral upper ureteral stones. Acta Cir Bras 2012; 27: 266.
94. Seeger AR, Rittenberg MH and Bagley DH: Ureteropyeloscopic removal of ureteral calculi. J Urol 1988; 139: 1180.
95. Cohen J, Cohen S and Grasso M: Ureteropyeloscopic treatment of large, complex intrarenal and proximal ureteral calculi. BJU Int 2013; 111: E127.
96. Hyams E, Monga M, Pearle MS et al: A prospective, multi-institutional study of flexible ureteroscopy for proximal ureteral stones smaller than 2 cm. J Urol 2015; 193: 165.
97. Perez Castro E, Osther PJ, Jinga V et al: Differences in ureteroscopic stone treatment and outcomes for distal, mid-, proximal, or multiple ureteral locations: the Clinical Research Office of the Endourological Society ureteroscopy global study. Eur Urol 2014; 66: 102.
98. Raney AM: Electrohydraulic ureterolithotripsy. Urology 1978; 13: 284.
99. Hofbauer J, Hobarth K and Marberger M: Electrohydraulic versus pneumatic disintegration in the treatment of ureteral stones: a randomized, prospective trial. J Urol 1995; 153: 623.
100. Vorreuther R, Corleis R, Klotz T et al: Impact of shock wave pattern and cavitation bubble size on tissue damage during ureteroscopic electrohydraulic lithotripsy. J Urol 1995; 153: 849.
101. Santa-Cruz RW, Leveillee RJ and Krongrad A: Ex vivo comparison of four lithotripters commonly used in the ureter: what does it take to perforate? J Endourol 1998; 12: 417.
102. Teichman JM, Rao RD, Rogenes VJ et al: Ureteroscopic management of ureteral calculi: electrohydraulic versus holmium:YAG lithotripsy. J Urol 1997; 158: 1357.
103. Pearle MS, Pierce HL, Miller GL et al: Optimal method of urgent decompression of the collecting system for obstruction and infection due to ureteral calculi. J Urol 1998; 160: 1260.
104. Borofsky MS, Walter D, Shah O et al: Surgical decompression is associated with decreased mortality in patients with sepsis and ureteral calculi. J Urol 2013; 189: 946.
105. Srisubat A, Potisat S, Lojanapiwat B et al: Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones. Cochrane Database Syst Rev 2014; 11.
106. Matlaga BR, Jansen JP, Meckley LM et al: Treatment of ureteral and renal stones: a systematic review and meta-analysis of randomized, controlled trials. J Urol 2012; 188: 130.
107. Bryniarski P, Paradysz A, Zyczkowski M et al: A randomized controlled study to analyze the safety and efficacy of percutaneous nephrolithotripsy and retrograde intrarenal surgery in the management of renal stones more than 2 cm in diameter. J Endourol 2012; 26: 52.
108. Karakoyunlu N, Goktug G, Sener NC et al: A comparison of standard PCNL and staged retrograde FURS in pelvis stones over 2 cm in diameter: a prospective randomized study. Urolithiasis 2015; 43: 283.
109. De S, Autorino R, Kim FJ et al: Percutaneous nephrolithotomy versus retrograde intrarenal surgery: a systematic review and meta-analysis. Eur Urol 2015; 67: 125.
110. de la Rosette J, Assimos D, Desai M et al: The Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study: indications, complications, and outcomes in 5803 patients. J Endourol 2011;25: 11.
111. Seitz C, Desai M, Hacker A et al: Incidence, prevention, and management of complications following percutaneous nephrolitholapaxy. Eur Urol 2012; 61: 146.
112. Al-Kohany KM, Shokeir AA, Mosbah A et al: Treatment of complete staghorn stones: a prospective randomized comparison of open surgery versus percutaneous nephrolithotomy. J Urol 2005; 173: 469.
113. Meretyk S, Gofrit ON, Gafni O et al: Complete staghorn calculi: random prospective comparison between extracorporeal shock wave lithotripsy monotherapy and combined with percutaneous nephrostolithotomy. J Urol 1997; 157: 780.
114. Eisenberger F, Rassweiler J, Bub P et al: Differentiated approach to staghorn calculi using extra-corporeal shock wave lithotripsy and percutaneous nephro-lithotomy: An analysis of 151 consecutive cases. World J Urol 1987; 5: 248.
115. Teichman JM, Long RD and Hulber JC: Long term renal fate and prognosis after staghorn management. J Urol 1995; 153: 1403.
116. Raman JD, Bagrodia A, Gupta A et al: Natural history of residual fragments following percutaneous nephrostolithotomy. J Urol 2009; 181: 1163.
117. Chew BH, Brotherhood HL, Sur RL et al: Natural history, complications and re-intervention rates of asymptomatic residual stone fragments after ureteroscopy: a report from the EDGE research consortium. J Urol 2015; [Epub ahead of print]
118. Michaels EK and Fowler JE, Jr.:Extracorporeal shock wave lithotripsy for struvite renal calculi: prospective study with extended followup. J Urol 1991; 146: 728.
119. Blandy JP and Singh M.: The case for a more aggressive approach to staghorn stones. J Urol 1976; 115: 505.
120. Koga S, Arakaki Y, Matsuoka M et al: Staghorn calculi—long-term results of management. Br J Urol 1991; 68: 122.
121. Priestly JT and Dunn JH: Branched renal calculi. J Urol 1949; 61: 194.
122. Rous SN and Turner WR: Retrospective study of 95 patients with staghorn calculus disease. J Urol 1977; 118: 902.
123. Vargas AD, Bragin SD and Mendez R: Staghorn calculus: its clinical presentation, complications and management. J Urol 1982; 127: 860.
124. Lam HS, Lingeman JE, Barron M et al: Staghorn calculi: analysis of treatment results between initial percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy monotherapy with reference to surface area. J Urol 1992; 147: 1219.
125. Joseph P, Mandal AK, Singh SK et al: Computerized tomography attenuation value of renal calculus: can it predict successful fragmentation of the calculus by extracorporeal shock wave lithotripsy? A preliminary study. J Urol 2002;167: 1968.
126. Perks AE, Schuler TD, Lee J et al: Stone attenuation and skin-to-stone distance on computed tomography predicts for stone fragmentation by shock wave lithotripsy. Urology 2008; 72: 765.
127. Madbouly K, Sheir KZ and Elsobky E: Impact of lower pole renal anatomy on stone clearance after shock wave lithotripsy: fact or fiction? J Urol 2001; 165: 1415.
128. Sumino Y, Mimata H, Tasaki Y et al: Predictors of lower pole renal stone clearance after extracorporeal shock wave lithotripsy. J Urol 2002; 168: 1344.
129. Ruggera L, Beltrami P, Ballario R et al: Impact of anatomical pielocaliceal topography in the treatment of renal lower calyces stones with extracorporeal shock wave lithotripsy. Int J Urol 2005; 12: 525.
130. Soyupek S, Armagan A, Kosar A et al: Risk factors for the formation of a steinstrasse after shock wave lithotripsy. Urol Int 2005; 74: 323.
131. Madbouly K, Sheir KZ, Elsobky E et al: Risk factors for the formation of a steinstrasse after extracorporeal shock wave lithotripsy: a statistical model. J Urol 2002; 167: 1239.
132. Al-Awadi KA, Abdul Halim H, Kehinde EO et al: Steinstrasse: a comparison of incidence with and without J stenting and the effect of J stenting on subsequent management. BJU Int 1999; 84: 618.
133. Li S, Liu TZ, Wang XH et al: Randomized controlled trial comparing retroperitoneal laparoscopic pyelolithotomy versus percutaneous nephrolithotomy for the treatment of large renal pelvic calculi: a pilot study. J Endourol 2014; 28: 946.
134. Qin C, Wang S, Li P et al: Retroperitoneal laparoscopic technique in treatment of complex renal stones: 75 cases. BMC Urol 2014; 14: 16.
135. Singh V, Sinha RJ, Gupta DK et al: Prospective randomized comparison of retroperitoneoscopic pyelolithotomy versus percutaneous nephrolithotomy for solitary large pelvic kidney stones. Urol Int 2014; 92: 392.
136. Zheng J, Yan J, Zhou Z et al: Concomitant treatment of ureteropelvic junction obstruction and renal calculi with robotic laparoscopic surgery and rigid nephroscopy. Urology 2014; 83: 237.
137. Aminsharifi A, Hosseini MM and Khakbaz A. Laparoscopic pyelolithotomy versus percutaneous nephrolithotomy for a solitary renal pelvis stone larger than 3 cm: a prospective cohort study. Urolithiasis 2013; 41: 493.
138. Wang X, Li S, Liu T et al: Laparoscopic pyelolithotomy compared to percutaneous nephrolithotomy as surgical management for large renal pelvic calculi: a meta-analysis. J Urol 2013; 190: 888.
139. Kuo CC, Wu CF, Huang CC et al: Xanthogranulomatous pyelonephritis: critical analysis of 30 patients. Int Urol Nephrol 2011; 43: 15.
140. Zelhof B, McIntyre IG, Folwer SM et al: Nephrectomy for benign disease in the UK: results from the British Association of Urological Surgeons nephrectomy database. BJU Int 2015; 117: 138.
141. Goldberg H, Holland R, Tal R et al: The impact of retrograde intrarenal surgery for asymptomatic renal stones in patients undergoing ureteroscopy for a symptomatic ureteral stone. J Endourol 2013; 27: 970.
142. Gdor Y, Faddegon S, Krambeck AE et al: Multi-institutional assessment of ureteroscopic laser papillotomyfor chronic flank pain associated with papillary calcifications. J Urol 2011; 185: 192.
143. Keeley FX Jr, Tilling K, Elves A et al: Preliminary results of a randomized controlled trial of prophylactic shock wave lithotripsy for small asymptomatic renal caliceal stones. BJU Int 2001; 87: 1.
144. Bilgasem S, Pace KT, Dyer S et al: Removal of asymptomatic ipsilateralrenal stones following rigid ureteroscopy for ureteral stones. J Endourol 2003; 17: 397.
145. Glowacki LS, Beecroft ML, Cook RJ et al: The natural history of asymptomatic urolithiasis. J Urol 1992; 147: 319.
146. Burgher A, Beman M, Holzman JL et al: Progression of nephrolithiasis: long-term outcomes with observation of asymptomatic calculi. J Endourol 2004; 18: 534.
147. Koh LT, Ng FC and Ng KK: Outcomes of long-term follow-up of patients with conservative management of asymptomatic renal calculi. BJU Int 2012; 109: 622.
148. Inci K, Sahin A, Islamoglu E et al: Prospective long-term followup of patients with asymptomatic lower pole caliceal stones. J Urol 2007; 177: 2189.
149. Yuruk E, Binbay M, Sari E et al: A prospective, randomized trial of management for asymptomatic lower pole calculi. J Urol 2010; 183: 1424.
150. Pearle MS, Lingeman JE, Leveillee R et al: Prospective, randomized trial comparing shock wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1 cm or less. J Urol 2005; 173: 2005.
151. Schuster TG, Hollenbeck BK, Faerber GJ et al: Ureteroscopic treatment of lower pole calculi:comparison of lithotripsy in situ and after displacement. J Urol 2002; 168: 43.
152. L’esperance JO, Ekeruo WO, Scales CD Jr. et al: Effect of ureteral access sheath on stone-free rates in patients undergoing ureteoscopic management of renal calculi. Urology 2005; 66: 252.
153. Albala DM, Assimos DG, Clayman RV et al: Lower pole I: a prospective randomized trial of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy for lower pole nephrolithiasis-initial results. J Urol 2001; 166: 2072.
154. BhattuAS, Mishra S, Ganpule A et al: Outcomes in a large series of minipercs: analysis of consecutive 318 patients. J Endourol 2015; 29: 283.
155. Crook TJ, Lockyer CR, Keoghane SR et al: A randomized controlled trial of nephrostomy placement versus tubeless percutaneous nephrolithotomy. J Urol 2008; 180: 612.
156. Maheshwari PN, Andankar M, Hegde S et al: Bilateral single-session percutaneous nephrolithotomy: a feasible and safe treatment. J Endourol 2000; 14: 285.
157. Liatsikos EN, Hom D, Dinlenc CZ et al: Tail stent versus re-entry tube: A randomized comparison after percutaneous stone extraction. Urology 2002; 59: 15.
158. Pietrow PK, Auge BK, Lallas K et al: Pain after percutaneous nephrolithotomy: impact of nephrostomy tube size. J Endourol 2003; 17: 411.
159. Osman Y, Harraz AM, El-Nahas AR et al: Clinically insignificant residual stone fragments: an acceptable term in the computed tomography era? Urology 2013; 81: 723.
160. Altunrende F, Tefekli A, Stein RJ et al: Clinically insignificant residual fragments after percutaneous nephrolithotomy: medium-term follow-up. J Endourol 2011; 25:941.
161. Gücük A, Kemahli E, Uyeturk U et al: Routine flexible nephroscopy for percutaneous nephrolithotomy for renal stones with low density: a prospective randomized study. J Urol 2013; 190: 144.
162. Zeltser I, Pearle MS and Bagley DH: Saline is our friend. Urology. 2009; 1: 28.
163. Aghamir SM, Alizadeh F, Meysamie A et al: Sterile water versus isotonic saline solution as irrigation fluid in percutaneous nephrolithotomy.Urol J 2009; 6: 249.
164. Hosseini MM, Hassanpour A, Manaheji F et al: Percutaneous nephrolithotomy: is distilled water as safe as saline for irrigation? Urol J 2014; 11: 1551.
165. Chen SS, Lin AT, Chen KK et al: Hemolysis in transurethral resection of the prostate using distilled water as the irrigant. J Chin Med Assoc 2006; 69: 270.
166. Auge BK, Pietrow PK Lallas et al: Ureteral access sheath provides protection against elevated renal pressures during routine flexible ureteroscopic stone manipulation. J Endourol 2004; 18: 33.
167. Wolf JS Jr, Bennett CJ, Dmochowski RR et al: Best Practice Policy Statement on Urologic Surgery Antimicrobial Prophylaxis. J Urol 2008; 179: 1379.
168. Charlton M, Vallancien G, Veillon B et al: Urinary tract infections in percutaneous surgery for renal calculi. J Urol 1986; 135: 15.
169. Darenkov AF, Derevianko Il, Martov AG et al: The prevention of infectious-inflammatory complications in the postoperative period in percutaneous surgical interventions in patients with urolithiasis. Urol Nefro 1994; 2: 24.
170. Mariappan P, Smith G, Moussa SA et al: One week of ciprofloxacin before percutaneous nephrolithotomy significantly reduces the upper tract infection and urosepsis: a prospective controlled study. BJU Int 2006; 98: 1075.
171. Bag S, Kumar S, Taneja N et al: One week of nitrofurantoin before percutaneous nephrolithotomy significantly reduces upper tract infection and urosepsis: a prospective controlled study. Urology 2011; 77: 45.
172. Viers BR, Cockerill PA, Mehta RA et al: Extended antimicrobial use in patients undergoing percutaneous nephrolithotomy and associated antibiotic related complications. J Urol 2014; 192: 1667.
173. Grasso M, Conlin M and Bagley DH: Retrograde ureteropyeloscopic treatment of 2cm or greater upper urinary tract and minor staghorn calculi. J Urol 1998; 160: 346.
174. El-Anany FG, Hammouda HM, Maghraby HA et al: Retrograde ureteropyeloscopic holmium laser lithotripsy for large renal calculi. BJU Int 2001; 88: 850.
175. Breda A, Ogunyemi O, Leppert JT et al: Flexible ureteroscopy and laser lithotripsy for single intrarenal stones 2cm or greater – is this the new frontier? J Urol 2008; 179: 981.
176. Riley JM, Stearman L and Troxel S: Retrograde ureteroscopy for renal stones larger than 2.5cm. J Endourol 2009; 23: 1395.
177. Hyams E, Munver R, Bird V et al: Flexible ureterorenoscopy and holmium laser lithotripsy for the management of renal stone burdens that measure 2�3cm: a multiinstitutional experience. J Endourol 2010; 24: 1583.
178. Ricchiuti DJ, Smaldone MC, Jacobs BL et al: Staged retrograde endoscopic lithotripsy as alternative to PCNL in select patients with large renal calculi. J Endourol 2007; 21: 1421.
179. Bagley DH, Healy KA and Kleinmann N: Ureteroscopic treatment of larger renal calculi (>2cm). Arab J Urol 2012; 10: 296.
180. Pace KT, Weir MJ, Tariq N et al: Low success rate of repeat shock wave lithotripsy for ureteral stones after failed initial treatment. J Urol 2000; 164: 1905.
181. Giblin JG, Lossef S and Pahira JJ: A modification of standard percutaneous nephrolithotripsy technique for the morbidly obese patient. Urology. 1995; 46: 491.
182. Jackman SV, Docimo SG, Cadeddu JA et al: The "mini-perc" technique: a less invasive alternative to percutaneous nephrolithotomy. World J Urol 1998; 16: 371.
183. Tepeler A, Armagan A, Sancakturar AA et al: The role of microperc in the treatment of symptomatic lower pole renal calculi. J Endourol 2013; 27: 13.
184. Zhu H, Ye X, Xiao X et al: Retrograde, antegrade, and laparoscopic approaches to the management of large upper ureteral stones after shockwave lithotripsy failure: a four-year retrospective study. J Endourol 2014; 28: 100.
185. Abu Ghazaleh LA, Shunaigat AN and Budair Z: Retrograde intrarenal lithotripsy for small renal stones in prepubertal children. Saudi J Kidney Dis Transpl 2011; 22: 492.
186. Ji C, Gan W, Guo H et al: A prospective trial on ureteral stenting combined with secondary ureteroscopy after an initial failed procedure. Urol Res 2012; 40: 593.
187. Jones BJ, Ryan PC, Lyons O et al: Use of the double pigtail stent in stone retrieval following unsuccessful ureteroscopy. Br J Urol 1990;66: 254.
188. Singal RK, Razvi HA and Denstedt JD: Secondary ureteroscopy: results and management strategy at a referral center. J Urol 1998; 159: 52.
189. Tugcu V, Gurbuz G, Aras B et al: Primary ureteroscopy for distal-ureteral stones compared with ureteroscopy after failed extracorporeal lithotripsy. J Endourol 2006; 20: 1025.
190. Turna B, Stein RJ, Smaldone MC et al: Safety and efficacy of flexible ureterorenoscopy and holmium:YAG lithotripsy for intrarenal stones in anticoagulated cases. J Urol 2008; 179: 1415.
191. Elkoushy MA, Violette PD and Adnonian S: Ureteroscopy in patients with coagulopathies is associated with lower stone-free rate and increased risk of clinically significant hematuria. International Braz J Urol 2012; 38: 195.
192. Gallucci M, Vincenzoni A, Schettini M et al: Extracorporeal shock wave lithotripsy in ureteral and kidney malformations. Urol Int 2001; 66: 61.
193. El-Assmy A, El-Nahas AR, Mohsen T et al: Extracorporeal shock wave lithotripsy of upper urinary tract calculi in patients with cystectomy and urinary diversion. Urology 2005; 66: 510.
194. Khalil M: Management of impacted proximal ureteral stone: extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy. Urol Ann 2013;5: 88.
195. Renner C and Rassweiler J: Treatment of renal stones by extracorporeal shock wave lithotripsy. Nephron 1999; 81: 71.
196. Meretyk I, Leretyk S and Clayman RV: Endopyelotomy: comparison of ureteroscopic retrograde and antegrade percutaneous techniques. J Urol 1992; 148: 775.
197. Waingankar N, Hayek S, Smith AD et al: Caliceal diverticula: a comprehensive reviewRevUrol 2014; 16: 29.
198. Turna B, Raza A, Moussa S et al: Management of calyceal diverticular stones with extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy: long-term outcome. BJU Int 2007; 100: 151.
199. Constantinople NL, Waters WB and Yalla SV: Operative versus non-operative management of patients with staghorn calculi and neurogenic bladder. J Urol 1979; 121: 716.
200. Viprakasit DP, Sawyer MD, Herrell SD et al: Changing composition of staghorn calculi. J Urol 2011; 186: 2285.
201. Aydogdu O, Burgu B, Gucuk A et al: Effectiveness of doxazosin in treatment of distal ureteral stones in children. J Urol 2009; 182: 2880.
202. Erturhan S, Bayrak O, Sarica K et al: Efficacy of medical expulsive treatment with doxazosin in pediatric patients. Urology 2013; 81: 640.
203. Mokhless I, Zahran AR, Youssif M et al: Tamsulosin for the management of distal ureteral stones in children: A prospective randomized study. J Pediatr Urol 2012; 8: 544.
204. Brenner D, Elliston C, Hall E et al: Estimated risks of radiation-induced fatal cancer from pediatric CT. AJR Am J Roentgenol 2001; 176: 289.
205. Brenner DJ and Hall EJ: Computed tomography—an increasing source of radiation exposure. N Engl J Med 2007; 357: 2277.
206. Strauss KJ and Goske MJ. Estimated pediatric radiation dose during CT. Pediatr Radiol 2011; 41: S472.
207. Linet MS, Slovis TL, Miller DL et al: Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin 2012; 62: 75.
208. Paterson A, Frush DP and Donnelly LF: Helical CT of the body: are settings adjusted for pediatric patients? AJM Am J Roentgenol 2001; 176: 297.
209. Sohn W, Clayman RV, Lee JY et al: Low-dose and standard computed tomography scans yield equivalent stone measurements. Urology 2013; 81: 231.
210. Zilberman DE, Tsivian M, Lipkin ME et al: Low dose computerized tomography for detection of urolithiasis—its effectiveness in the setting of the urology clinic. J Urol 2011; 185: 910.
211. Hubert KC and Palmer JS: Passive dilation by ureteral stenting before ureteroscopy: eliminating the need for active dilation. J Urol 2005; 174: 1079.
212. Corcoran AT, Smaldone MC, Mally D et al: When is prior ureteral stent placement necessary to access the upper urinary tract in prepubertal children? J Urol 2008; 180: 1861.
213. Badawy AA, Saleem MD, Abolyosr A et al: Extracorporeal shock wave lithotripsy as first line treatment for urinary tract stones in children: outcome of 500 cases. Int Urol Nephrol 2012; 44: 661.
214. Brinkmann OA, Griehl A, Kuwertz-Bröking E et al: Extracorporeal shock wave lithotripsy in children. Efficacy, complications and long-term follow up. Eur Urol 2001; 39: 591.
215. Ishii H, Griffin S and Somani BK: Flexible ureteroscopy and lasertripsy (FURSL) for paediatric renal calculi: results from a systematic review. J Pediatr Urol 2014; 10: 1020.
216. Sen H, Seckiner I, Bayrak O et al: Treatment alternatives for urinary system stone disease in preschool aged children: results of 616 cases. J Pediatr Urol 2015; 11:34.
217. Rodrigues Netto N Jr, Longo JA, Ikonomidis JA et al: Extracorporeal shock wave lithotripsy in children. J Urol 2002; 167: 2164.
218. Shouman AM, Ziada AM, Ghoneim IA et al: Extracorporeal shock wave lithotripsy monotherapy for renal stones >25 mm in children. Urology 2009;74: 109.
219. Orsola A, Diaz I, Caffaratti J et al: Staghorn calculi in children: treatment with monotherapy extracorporeal shock wave lithotripsy. J Urol 1999; 162: 1229.
220. Al-Busaidy SS, Prem AR and Medhat M: Pediatric staghorn calculi: the role of extracorporeal shock wave lithotripsy monotherapy with special reference to ureteral stenting. J Urol 2003; 169: 629.
221. Schuster TK, Smaldone MC, Averch TD et al: Percutaneous nephrolithotomy in children. J Endourol 2009; 23: 1699.
222. Dede O, Sancaktutar AA, Dağguli M et al: Ultra-mini-percutaneous nephrolithotomy in pediatric nephrolithiasis: both low pressure and high efficiency. J Pediatr Urol 2015; 11: 253.
223. Sabnis RB, Chhabra JS, Ganpule AP et al: Current role of PCNL in pediatric urolithiasis. Curr Urol Rep 2014; 15: 423.
224. Wah TM, Kidger L, Kennish S et al: MINI PCNL in a pediatric population. Cardiovasc Intervent Radiol 2013; 36: 249.
225. Zeng G, Zhao Z, Wan SP et al: Minimally invasive percutaneous nephrolithotomy for simple and complex renal caliceal stones: a comparative anlaysis of more than 10,000 cases. J Endourol 2013; 27: 1203.
226. Basiri A, Tabibi A, Nouralizadeh A et al: Comparison of safety and efficacy of laparoscopic pyelolithotomy versus percutaneous nephrolithotomy in patients with renal pelvic stones: a randomized clinical trial. Urol J 2014; 11: 1932.
227. Lee RS, Passerotti CC, Cendron M et al: Early results of robot assisted laparoscopic lithotomy in adolescents. J Urol 2007;177: 2306.
228. DeFoor W, Minevich E, Jackson E et al: Urinary metabolic evaluations in solitary and recurrent stone forming children. J Urol 2008; 179: 2369.
229. Spivacow FR, Negri AL, del Valle EE et al: Metabolic risk factors in children with kidney stone disease. Pediatr Nephrol 2008; 23: 1129.
230. The American Congress of Obstetricians and Gynecologists: Committee Opinion No. 656 summary: guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol 2016; 127: 418.
231. Johnson EB, Krambeck AE, White WM et al: Obstetric complications of ureteroscopy during pregnancy. J Urol 2012; 188: 151.
232. Swartz MA, Lydon-Rochelle MT, Simon D et al: Admission for nephrolithiasis in pregnancy and risk of adverse birth outcomes. Obstet Gynecol 2007; 109: 1099.
233. Rosenberg E, Sergienko R, Abu-Ghanem S et al: Nephrolithiasis during pregnancy: characteristics, complications, and pregnancy outcome. World J Urol 2011; 29: 743.
234. Bailey G, Vaughan L, Rose C et al: perinatal outcomes with tamsulosin therapy for symptomatic urolithiasis. J Urol 2015; 195: 99.
235. Semins MJ, Trock BJ and Matlaga BR: The safety of ureteroscopy during pregnancy: a systematic review and meta-analysis. J Urol 2009; 181: 139.

This document was written by the Surgical Management of Stones Guideline Panel of the American Urological Association Education and Research, Inc., which was created in 2014. The Practice Guidelines Committee (PGC) of the AUA selected the committee chair. Panel members were selected by the chair. Membership of the panel included specialists in urology with specific expertise on this disorder. The mission of the panel was to develop recommendations that are analysis-based or consensus-based, depending on panel processes and available data, for optimal clinical practices in the treatment of stones. Funding of the panel was provided by the AUA and Endo. Panel members received no remuneration for their work. Each member of the panel provides an ongoing conflict of interest disclosure to the AUA. While these guidelines do not necessarily establish the standard of care, AUA seeks to recommend and to encourage compliance by practitioners with current best practices related to the condition being treated. As medical knowledge expands and technology advances, the guidelines will change. Today these evidence-based guidelines statements represent not absolute mandates but provisional proposals for treatment under the specific conditions described in each document. For all these reasons, the guidelines do not pre-empt physician judgment in individual cases. Treating physicians must take into account variations in resources, and patient tolerances, needs, and preferences. Conformance with any clinical guideline does not guarantee a successful outcome. The guideline text may include information or recommendations about certain drug uses ('off label') that are not approved by the Food and Drug Administration (FDA), or about medications or substances not subject to the FDA approval process. AUA urges strict compliance with all government regulations and protocols for prescription and use of these substances. The physician is encouraged to carefully follow all available prescribing information about indications, contraindications, precautions and warnings. These guidelines and best practice statements are not in-tended to provide legal advice about use and misuse of these substances. Although guidelines are intended to encourage best practices and potentially encompass available technologies with sufficient data as of close of the literature review, they are necessarily time-limited. Guidelines cannot include evaluation of all data on emerging technologies or management, including those that are FDA-approved, which may immediately come to represent accepted clinical practices. For this reason, the AUA does not regard technologies or management which are too new to be addressed by this guideline as necessarily experimental or investigational.