Definitions for the levels of evidence (LE = 1a-4) and grades of recommendation (GR = A-C) are provided at the end of the "Major Recommendations" field.
Note from European Association of Urology: In several statements presented throughout the text the methods considered have been assigned Preference numbers, 1, 2, 3, etc. Preference numbers are used to indicate which treatment alternative was considered most appropriate or preferred, according to the literature or consensus reached. If two procedures were considered equally useful, they were given the same preference number. The first treatment alternative always has the preference number 1.
Classification
A system for subgrouping stone-forming patients into different categories according to type of stone and severity of the disease is shown in the following table.
| Table: Categories of Stone Formers |
| |
Definition |
Category |
| Non-calcium Stones |
Infection stone: magnesium ammonium phosphate, carbonate apatite or ammonium urate* |
INF |
| Uric acid/ammonium urate*/sodium urate stone |
UR |
| Cystine stone |
CY |
| Calcium Stones |
First time stone former without residual stone or fragments |
So |
| First time stone former with residual stone or fragments |
Sres |
| Recurrent stone former with mild disease without residual stone(s) or fragments |
Rmo |
| Recurrent stone former with mild disease with residual stone(s) or fragments |
Rm-res |
| Recurrent stone former with severe disease with or without residual stone(s) or fragments or stone forming patient with specific risk factor(s) irrespective of otherwise defined category (see "Specific Risk Factors for Stone Formation" below) |
Rs |
* It is of note that ammonium urate stones form when a urease-producing infection occurs in patients with urine that is supersaturated with uric acid/urate.
Specific Risk Factors for Stone Formation
- Onset of disease early in life (i.e., below 25 years of age)
- Stones containing brushite (calcium hydrogen phosphate; CaHPO4·2H2O)
- Strong family history of stone formation
- Only one functioning kidney (although only one kidney does not mean an increased risk of stone formation, these patients should be particularly considered for measures to prevent stone recurrence)
- Diseases associated with stone formation
- Hyperparathyroidism
- Renal tubular acidosis (partial/complete)
- Cystinuria
- Primary hyperoxaluria
- Jejunoileal bypass
- Crohn's disease
- Intestinal resection
- Malabsorptive conditions
- Sarcoidosis
- Medication associated with stone formation
- Calcium supplements
- Vitamin D supplements
- Acetazolamide
- Ascorbic acid in megadoses (>4 g/day)
- Sulfonamides
- Triamterene
- Indinavir
- Anatomical abnormalities associated with stone formation
- Tubular ectasia (medullary sponge kidney)
- Pelvi-ureteral junction obstruction
- Caliceal diverticulum/caliceal cyst
- Ureteral stricture
- Vesico-ureteral reflux
- Horseshoe kidney
- Ureterocele
|
Diagnostic Procedures
Diagnostic Imaging
| Imaging is imperative in patients with fever or a solitary kidney and when the diagnosis of stone is in doubt |
LE = 4
GR = C
|
| Table: Imaging Modalities in the Diagnostic Work-Up of Patients with Acute Flank Pain |
| Preference Number |
Examination |
LE |
GR |
References |
| 1 |
Non-contrast computed tomography (CT) |
1 |
A |
Smith et al., 1995; Smith et al., 1996; Kobayashi et al., 2003; Sudah et al., 2002; Homer, Davies-Payne, & Peddinti, 2001; Shokeir & Abdulmaaboud, 2001; Gray Sears et al, 2002; Miller et al., 1998; Dalrymple et al., 1998; Worster et al., 2002; Shine, 2008; Mindelzun & Jeffrey, 1997 |
| 1 |
Excretory urography |
Standard procedure |
| 2 |
Plain film of kidney, ureters and bladder (KUB) + ultrasonography (US) |
2a |
B |
Shokeir & Abdulmaaboud, 2001 |
| Table: General Considerations Regarding the Use of Contrast Medium |
| Contrast medium should not be given to, or avoided, in the following circumstances |
LE/GR |
GR |
Selected References |
- Patients with an allergy to contrast media
|
– |
– |
Morcos, Thomsen & Webb, 2001; Thomsen & Morcos, 2003 |
- When the serum or plasma creatinine level is >150 micromoles/L
|
4 |
C |
Thomsen & Morcos, 2003 |
- To patients on medication with metformin
|
3 |
B |
Thomsen & Morcos, 2003; Nawaz et al., 1998; McCartney et al., 1999; Thompson et al., 2000 |
- Untreated hyperthyroidism
|
3 |
B |
– |
- To patients with myelomatosis
|
3 |
B |
Thomsen & Morcos, 2003 |
Analysis of Stone Composition
Stones that pass spontaneously, are removed surgically, or excreted as fragments following disintegration, should be subjected to stone analysis to determine their composition (Asper, 1990; Herring, 1962; Daudon & Jungers, 2004; Otnes, 1983; Leusmann, Blaschke, & Schmandt, 1990). The preferred analytical procedures are X-ray crystallography and infrared spectroscopy.
Biochemical Investigations
Analytical Work-up in the Acute Phase
| Table: Biochemical Analyses Recommended for Patients with an Acute Stone Episode |
| For all patients |
Urinary sediment/dipstick test for demonstration of red cells White cells. Test for bacteriuria (nitrite) and urine culture in case of a positive reaction
Serum creatinine should be analysed as a measure of the renal function
|
| For patients with fever |
C-reactive protein and blood cell count |
| For patients who vomit |
Serum/plasma sodium
Serum/plasma potassium
|
| Optional useful information |
Approximate pH levela
Serum/plasma calciumb
All other examinations that might be necessary in case of intervention
|
a Knowledge of pH might reflect the type of stone that the patient has formed.
b This might be the only occasion on which patients with hypercalcaemia are identified.
Analysis of Urine in Search for Risk Factors of Stone Formation
Two urine collections for each set of analyses are recommended. The urine collections are repeated when necessary (Hobarth, Hofbauer, & Szabo, 1994; Hess et al., 1997; Straub et al., 2005).
A Simplified Overview of the Principles of Analytical Work-Up in Patients
A correct categorization of the patients requires both information on the stone composition and an actual imaging procedure. The principles shown in the table below can be applied to all patients provided a reasonable assumption of the category can be made. If this is not possible an alternative analytical approach has to be chosen until more data have been collected.
| Table: Recommendations Regarding Analysis of Stones, Blood and Urine in Different Categories of Stone Forming Patients |
| Category of Stone Former* |
Stone |
Blood |
Urine |
| INF |
Yes |
Creatinine |
Culture
Urease (in positive urine cultures)
pH
|
| UR |
Yes |
Urate
Creatinine
|
Urate
pH
Volume
|
| CY |
Yes |
Creatinine |
Cystine
pH
Volume
|
Calcium stone
So Rmo
|
Yes |
Calcium
Albumin
Creatinine
(Urate)
|
Bacteria
Nitrate test
pH
|
Calcium stone
Sres Rm-res
Calcium stone
Rs
|
Yes |
Calcium
Albumin
Creatinine
(Urate)
|
Bacteria
Nitrate test
pH
----------------------
Calcium
Oxalate
Citrate
Creatinine
Volume
(Magnesium)
(Phosphate)
(Urea)
(Urate)
|
*See the table "Categories of Stone Formers" in the Classification section above for definitions of categories.
Treatment of Patients with Renal Colic
Pain Relief
The relief of pain is usually the most urgent therapeutic step in patients with an acute stone episode (see table below).
| Table: Pain Relief for Patients with Acute Stone Colic |
| Preference |
Pharmacological Agent |
LE |
GR |
References |
| 1 |
Diclofenac sodium |
1b |
A |
Holmlund & Sjodin, 1978; Lundstam, et al., 1982; Lundstam, Wahlander, & Kral, 1980; Walden, Lahtinen, & Elvander, 1993 |
| 1 |
Indomethacin
Ibuprofen
|
|
|
|
| 2 |
Hydromorphine hydrochloride + atropine
Methamizol
Pentazocine
Tramadol
|
4 |
C |
|
The recommendation is to start with diclofenac whenever possible (see table below) and change to an alternative drug if the pain persists. Because of the increased risk of vomiting, avoid giving hydromorphone and other opiates without simultaneous administration of atropine.
Effects of Diclofenac on Renal Function
Although the renal function can be affected in patients with an already reduced function this is not the case for normally functioning kidneys (Lee et al. 2007) (LE = 1b; GR = A).
| Table: Recommendations and Considerations Regarding Treatment of the Patient with Renal Colic |
| Recommendations |
LE |
GR |
Selected References |
| Treatment should be started with an non-steroidal anti-inflammatory drug (NSAID) |
1b |
A |
Holmlund & Sjodin, 1978; Lundstam et al, 1982; Lundstam, Wahlander, & Kral, 1980; Walden, Lahtinen, & Elvander, 1993 |
| Diclofenac sodium affects glomerular filtration rate (GFR) in patients with reduced renal function, but not in patients with normal renal function |
2a |
2a |
Lee et al., 2007 |
| Diclofenac sodium is recommended as a method to counteract recurrent pain after an episode of ureteral colic |
1b |
A |
Laerum et al., 1995 |
Indications for Active Stone Removal
The size, site, and shape of the stone at the initial presentation are factors that influence the decision to remove the stone (see table below):
| Table: Indications for Active Stone Removal |
| Indications for Considering Active Stone Removal |
LE |
GR |
Selected References |
- When stone diameter is >7 mm because of a low rate of spontaneous passage
|
2a |
B |
Sandegard, 1956; Morse & Resnick, 1991; Ibrahim et al., 1991; Miller & Kane, 1999; Andersson & Sylven 1983 |
- When adequate pain relief cannot be achieved
|
4 |
B |
|
- When stone obstruction is associated with infection*
|
4 |
B |
|
- When there is a risk of pyonephrosis or urosepsis*
|
4 |
B |
|
- In single kidneys with obstruction*
|
4 |
B |
|
|
|
4 |
B |
|
* Diversion of urine with a percutaneous nephrostomy catheter or bypassing the stone with a stent are minimal requirements in these patients.
Active Removal of Stones in the Kidney
Extracorporeal Shock-Wave Lithotripsy (ESWL) for Removal of Stones in the Kidney
| In the case of infected stones or bacteriuria, antibiotic therapy should be given before ESWL treatment and continued for at least 4 days after the treatment |
LE = 4
GR = C
|
| Shorter intervals between treatment sessions are usually acceptable for stones in the ureter. Clinical experience supports this view |
LE = 4
GR = C
|
| It has been concluded, however, that a frequency of 1 to 1.5 Hz is acceptable and optimal (Yilmaz et al., 2005) |
LE = 3
GR = C
|
| Insertion of an internal stent before ESWL is recommended for stones with a diameter >20 mm (~300 mm2) (Sulaiman, Buchholz & Clark, 1999) |
LE = 3
GR = B
|
A study concluded that the routine use of internal stents does not improve the outcome (Musa, 2008) (LE = 1b, GR = A).
A multicentre randomized comparison between ESWL and ureteroscopic removal of stones from the lower calix system failed to show a significantly better result with ureteroscopy (Pearle et al., 2005) (LE = 1b; GR = A).
Percutaneous Removal of Renal Stones
The majority of renal stones can be removed by percutaneous surgery. However, if ESWL is available, the indications for percutaneous nephrolithotomy (PNL) should be limited to those cases likely to have a less favourable outcome after ESWL.
Pre-procedural plain film of kidney, ureters and bladder (KUB) and intravenous urography or computed tomography (CT) scan should be used to plan access.
The percutaneous puncture may be facilitated by the preliminary placement of a balloon ureteral catheter to dilate and opacify the collecting system.
In lower pole stones, ESWL, PNL and flexible uretero-nephroscopy are competing procedures with different success and complication rates and patient acceptance (Pearle et al., 2005; Albala et al., 2001) (LE = 1b; GR = A).
Stones can be extracted straightaway, or following disintegration by US-, electro-hydraulic-, laser- or hydro-pneumatic probes. To reduce the number of residual fragments, continuous removal of small fragments by suction or extraction is preferred. After completion of the procedure, a self-retaining balloon nephrostomy tube tamponading the tract and maintaining access to the collecting system is preferred in complicated procedures or when a second intervention is necessary. Tubeless percutaneous nephrolithotomy, with or without tract fulguration, application of a sealant or double-J stenting, is a safe alternative in uncomplicated cases (Feng et al., 2001; Desai et al., 2004) (LE = 1b; GR = A).
Retrograde Removal of Ureteral and Renal Stones (Retrograde Intrarenal Surgery [RIRS])
| Antibiotic prophylaxis should be administered before the procedure to ensure sterile urine (Knopf, Graff, & Schulze, 2003; Grabe, 2001) |
LE = 4
GR = C
|
| Stone extraction with a basket without endoscopic visualization of the stone (blind basketing) should not be performed (see Chapter 9 of the original guideline document) |
LE = 4
GR = C
|
Holmium:yttrium aluminium garnet (Ho:YAG) laser lithotripsy is a reliable method for the treatment of urinary calculi, regardless of the hardness of the stone (Grasso, 1996; Grasso & Chalik, 1998; Jeon, Hyun, & Lee, 2005; Gupta, 2007). It is the preferred method when performing flexible ureteroscopy (URS) (Smith & Patel, 2007; Gupta, 2007; Gould, 1998; Tawfiek & Bagley, 1999) (LE = 3; GR = B/C).
| Nitinol baskets preserve tip deflection of flexible ureterorenoscopes and the tipless design reduces the risk of mucosa injury (Michel et al., 2002). They are therefore most suitable for use in flexible URS |
LE = 2b/3
GR = B
|
| Stenting following uncomplicated URS is optional (see also Chapter 9 in the original guideline document) |
LE = 1a
GR = A
|
| Flexible URS has been demonstrated to be an effective treatment for ESWL-refractory calculi (Johnson, Portela, & Grasso, 2006; Mariani, 2007). |
| Ureteroscopy can also be applied when ESWL might be contraindicated or ill-advised |
LE = 4
GR = C |
Open Surgery for Removal of Renal Stones
Indications for open and laparoscopic surgery
Indications for open surgery for stone removal include:
- Complex stone burden
- Treatment failure with ESWL and/or PNL or failed ureteroscopic procedure
- Intrarenal anatomical abnormalities: infundibular stenosis, stone in the caliceal diverticulum (particularly in an anterior calyx), obstruction of the ureteropelvic junction, stricture
- Morbid obesity
- Skeletal deformity, contractures and fixed deformities of hips and legs
- Co-morbid medical disease
- Concomitant open surgery
- Non-functioning lower pole (partial nephrectomy), non-functioning kidney (nephrectomy)
- Patient choice following failed minimally invasive procedures (i.e., single procedure in preference to possibly more than one PNL procedure)
- Stone in an ectopic kidney where percutaneous access and ESWL may be difficult or impossible.
- Cystolithotomy for giant bladder calculus
- A large stone burden in children because of easy surgical access and the need for only one anaesthetic procedure
Operative Procedures
Operative procedures that can be carried out include:
- Simple and extended pyelolithotomy
- Pyelo-nephrolithotomy
- Anatrophic nephrolithotomy
- Ureterolithotomy
- Radial nephrolithotomy
- Pyeloplasty
- Partial nephrectomy and nephrectomy
- Removal of calculus with re-implantation of the ureter (i.e., ureteroneocystotomy)
The superiority of open surgery over less invasive therapy in terms of stone-free rates is based on considerable historical experience, but (as yet) there are no comparative studies available (LE 4).
Clearly, laparoscopic surgery is a highly specialized skill and should only be carried out by surgeons trained in the technique, in well-equipped, dedicated centres. The advantages are low post-operative morbidity, reduced hospital stay and minimal blood loss. However, the procedure takes considerably longer than conventional surgery.
| Where the expertise is available the laparoscopic approach should be an alternative before proceeding to open surgery (Marberger, 1999) |
LE = 4
GR = C
|
Recommendations for Removal of Renal Stones
Recommendations on the most appropriate method for removal of stones from the kidney are based on several important considerations. The available options are ESWL, PNL, retrograde intrarenal surgery (RIRS) with a flexible ureteroscope, as well as video-endoscopic laparoscopic and open surgery. All these methods are applicable. However, for any given stone situation, it is logical to select a method with low invasiveness and low morbidity.
More than 20 years of experience with low invasive methods have clearly shown that open surgery is necessary only in exceptional cases and mainly for those patients in whom anatomical reconstruction is necessary. Video-endoscopic retroperitoneal or laparoscopic surgery has no place as a standard procedure for removal of stones from the kidney. However, this technique should be considered as an alternative before proceeding to open surgery, and it is advantageous in some types of reconstructive surgery.
For small stones (up to a maximum diameter of 20 mm or a surface area of approximately 300 mm2), ESWL has been established as the standard procedure because it is non-invasive, has a low rate of complications and there is (at least for adults) no need for regional or general anaesthesia.
There continues to be a debate about whether large renal stones are best treated with ESWL or with PNL. Although larger stones can also be treated successfully with ESWL, the drawbacks of ESWL are a frequent need for repeated treatments and the relatively common occurrence of residual fragments. Although PNL might be preferable to ESWL for faster debulking of the stone, it must be emphasized that considerable expertise and experience is required for complete clearance of stones from the caliceal system. Unless percutaneous surgery is carried out with a meticulous technique, residual fragments of the stone may also be left behind following PNL.
Residual fragments of infection stones, associated with the most pronounced risk of recurrent stone formation, can be eliminated with PNL, with or without percutaneous chemolysis. Such a step might also be used as an auxiliary procedure in the treatment of cystine stones.
For uric acid stones, oral chemolysis is the first choice of treatment for stone elimination. However, an increased rate of dissolution can be obtained by combining stone disintegration and chemolysis, and treatment in this way may be considered for removal of large uric acid stones. The approximate estimates of surface area corresponding to oval stone projections with certain diameters are given in Appendix 2 of the original guideline document.
An overview of treatment recommendations according to size and stone type as discussed above is shown in the following tables.
| Table: Active Removal of Radiopaque (Calcium) Renal Stones with a Largest Diameter < 20 mm (Surface Area ~ < 300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
Extracorporeal shock-wave lithotripsy (ESWL), also including piezolithotripsy |
1b |
A |
| 2 |
Percutaneous nephrolithotomy |
1b |
A |
| 3 |
Retrograde intrarenal surgery |
2a |
C |
| 4 |
Laparoscopic surgery |
2a |
C |
| 5 |
Open surgery |
4 |
C |
Infection stones are also radiopaque and usually contain calcium in the form of carbonate apatite and hydroxyapatite. These stones should be treated in the same way as sterile calcium stones, provided there is no obstruction and that a symptomatic infection has been adequately treated.
| For all patients with infection stones or recent history of urinary tract infection, bacteriuria antibiotics should be administered before the stone removing procedure for at and continued least 4 days afterwards |
LE = 4
GR = C
|
| Table: Active Removal of Uric Acid Renal Stones with a Largest Diameter < 20 mm (Surface Area ~ < 300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
Oral chemolysis |
2a |
B |
| 2 |
ESWL + oral chemolysis |
2a |
B |
For patients with uric acid stones and a percutaneous nephrostomy catheter in place, stone disintegration with ESWL can advantageously be combined with percutaneous chemolysis (see Section 7.5 of the original guideline document).
| Table: Active Removal of Cystine Stones with a Largest Diameter < 20 mm (Surface Area ~ < 300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
ESWL |
2a |
B |
| 1 |
Percutaneous nephrolithotomy |
2a |
B |
| 2 |
Retrograde intrarenal surgery |
4 |
C |
| 3 |
Laparoscopic surgery |
4 |
C |
| 4 |
Open surgery |
4 |
C |
| Table: Active Removal of Radiopaque (Calcium) Renal Stones with a Largest Diameter >20 mm (Surface Area >300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
Percutaneous nephrolithotomy |
1b |
A |
| 2 |
ESWL |
1b |
A |
| 3 |
Percutaneous nephrolithotomy + ESWL |
2b |
B |
| 4 |
Laparoscopic surgery |
4 |
C |
| 4 |
Open surgery |
4 |
C |
| Table Active Removal of Uric Acid Renal Stones with a Largest Diameter >20 mm (Surface Area ~ >300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
Oral chemolysis |
2a |
B |
| 2 |
ESWL + oral chemolysis |
2a |
B |
| 3 |
Percutaneous nephrolithotomy |
3 |
C |
| 3 |
Percutaneous + chemolysis |
3 |
C |
For patients with uric acid stones and a percutaneous nephrostomy catheter in place, stone disintegration with ESWL combined with percutaneous chemolysis is a good alternative to quickly dissolve the stone material (see Section 7.5 of the original guideline document).
| Table: Active Removal of Cystine Stones with a Largest Diameter >20 mm (Surface Area >300 mm2) |
| Preference |
Procedure |
LE |
GR |
| 1 |
Percutaneous nephrolithotomy |
2a |
B |
| 1 |
Percutaneous nephrolithotomy + ESWL |
2a |
B |
| 1 |
Percutaneous nephrolithotomy + chemolysis |
3 |
C |
| 2 |
ESWL + chemolysis |
3 |
C |
| 3 |
Laparoscopic surgery |
4 |
C |
| 3 |
Open surgery |
4 |
C |
| Patients, who are planned for ESWL-treatment of stones with a diameter exceeding (20 mm ~300 mm2), should have an internal stent to avoid problems related to Steinstrasse |
LE = 3
GR = B
|
Staghorn Stones
A staghorn stone is defined as a stone with a central body and at least one caliceal branch. Whereas a partial staghorn stone fills up only part of the collecting system, a complete staghorn stone fills all the calices and the renal pelvis.
| Patients with staghorn stones can usually be treated according to the principles given for large stones (diameter >20 mm/300 mm2) (see Chapter 7 of the original guideline document) |
LE = 1b
GR = A/B
|
In patients with small staghorn stones and a non-dilated system, repeated ESWL sessions with a stent can be a reasonable treatment alternative. Nephrectomy should be considered in the case of a non-functioning kidney. In selected cases with infection, cystine, uric acid and calcium phosphate stones, the combined use of ESWL or other stone-removing procedures and chemolysis may be useful. The principles of chemolytic treatment are discussed in Chapter 7 of the original guideline document.
Management of Patients with Stones in the Ureter
For recommendations for the management of patients with stones in the ureter, see the National Guideline Clearinghouse (NGC) summary of the European Association of Urology (EAU) and American Urological Association (AUA) Education and Research, Inc. 2007 guideline for the management of ureteral calculi.
General Recommendations and Precautions for Stone Removal
Infections
A test for bacteriuria should be carried out in all patients in whom stone removal is planned. Screening with dipsticks might be sufficient in uncomplicated cases. In others, urine culture is necessary. In cases with clinically significant infection and obstruction, several days of drainage procedures by a stent or a percutaneous nephrostomy should precede the active intervention for stone removal.
Aspects of Anticoagulation and Stone Treatment
Patients with bleeding diathesis or medical anticoagulation should be referred to an internist for appropriate therapeutic measures prior to, and during, the stone-removing procedure.
| Avoiding electro-hydraulic lithotripsy seems to be crucial to decrease bleeding complications (Watterson et al., 2002; Kuo et al., 1998) |
LE = 4
GR = C
|
Pacemaker
It is recommended that the patient's cardiologist is consulted before undertaking ESWL treatment. Patients with implanted cardioverter defibrillators need to be treated with special care because some of these devices need deactivation during ESWL.
Recommendations for Special Considerations
| Table: Recommendations for Special Considerations |
| Special Considerations |
LE |
GR |
| Treatment with antibiotics should precede stone-removing procedures in case of a positive urine culture, positive dip-stick test or suspicion of an infective component |
3 |
B |
| Treatment with salicylates should be stopped 10 days before the planned stone removal |
3 |
B |
| Extracorporeal shock-wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) are contraindicated in pregnant women |
4 |
C |
| ESWL is possible in patients with a pacemaker |
4 |
C |
Management of Stone Problems During Pregnancy
Diagnostic Evaluation
| Ultrasonography (using the change in resistive index and transvaginal ultrasound [US] when necessary) has become the primary radiological diagnostic tool |
LE = 1a
GR = A
|
Management of the Stone Problem
| In 70 to 80% of patients, the stones will pass spontaneously |
LE = 1a
GR = A
|
| Preference 1 |
Conservative management with bed rest, appropriate hydration and analgesia should be the first line treatment for all pregnant women with non-complicated urolithiasis |
LE = 4
GR = C
|
If spontaneous passage does not occur or if complications develop (commonly the induction of premature labour), some certain established treatment options should be considered:
| Preference 2 |
The placement of an internal stent or a percutaneous nephrostomy catheter are suggested first line treatment alternatives |
LE = 4
GR = C
|
| Preference 3 |
Ureteroscopy, although more invasive, has been accepted as a minimally invasive treatment alternative (Stothers & Lee 1992; Parulkar et al., 1998; Lewis et al., 2003; Cormier et al., 2006; Denstedt & Razvi, 1992) |
LE = 1b
GR = A
|
| When conservative management fails and urinary diversion is desired, both nephrostomy tube placement and internal ureteral insertion are appropriate alternatives |
LE = 3
GR = B
|
Caution must be exercised when performing URS during pregnancy with a solitary kidney. Ureteroscopy in experienced hands can be an effective treatment alternative to removal of ureteral stones during pregnancy (LE = 1b; GR = B).
| Due to the established risks of radiation exposure on the growing fetus, ESWL and PNL are contraindicated in pregnancy |
LE = 4b
GR = C
|
Management of Stone Problems in Children
Investigations
Paediatric patients with urinary stones are considered to be a high-risk group for developing recurrent stones.
| Therefore, investigations for stone diagnosis as well as metabolic abnormalities are crucial (Straub et al., 2005). |
LE = 2a
GR = B
|
| A urine culture is mandatory (Straub et al., 2005) |
LE = 2
GR = A
|
Imaging
When selecting diagnostic procedures to identify urolithiasis in paediatric patients, the investigator must consider the fact that the patients may be uncooperative, require anaesthesia for some modalities, or be sensitive to ionizing rays.
Ultrasound
| Ultrasound evaluation should include the kidney the filled bladder and adjoining portions of the ureter (Palmer, 2006) |
LE = 4
GR = B
|
In addition, colour-Doppler US showing differences in the ureteric jet (Darge & Heidemeier, 2005) (LE = 4; GR = C) and differences in the resistive index of the arciform arteries of both kidneys are indicative of the grade of obstruction (Pepe et al., 2005) (LE = 4; GR = C).
Thus, US is able to provide information about the presence, size and location of a stone, the grade of dilatation and obstruction. It is also able to indicate signs of abnormalities that facilitate the formation of stones. Ultrasound also is a part of the metaphylactic work-up.
Nevertheless US fails to identify stones in more than 40% of paediatric patients (Oner et al., 2004; Palmer et al., 2005) (LE = 4) and provides no information about renal function.
Recently developed CT protocols may further reduce the radiation exposure (Cody et al., 2004) (LE = 4; GR = C). However, the radiation dose and the extent of information about renal function must be considered when using non-enhanced helical CT.
Intravenous Urography (IVU)
| Conventional imaging models are indispensable in some cases (Riccabona, Lindbichler, & Sinzig, 2002; Chateil et al., 2004) |
LE = 4
GR = C
|
Helical Computed Tomogram (CT)
| In paediatric patients, only 5% of stones escape detection by non-enhanced helical CT (Djelloul et al., 2006; Palmer et al., 2005; Thomson et al., 2001) |
LE = 4 |
| Sedation or anaesthesia is rarely needed when a modern high speed CT apparatus is used (Palmer, 2006) |
LE = 4 |
Magnetic Resonance Urography (MRU)
Magnetic resonance urography is unable to demonstrate a urinary stone. However, it may provide detailed information about the anatomy of the urinary collecting system, the location of an obstruction or stenosis in the ureter, and the morphology of renal parenchyma (Leppert et al., 2002) (LE = 4).
Nuclear Imaging
A diuretic renogram with injection of a radiotracer (mercaptoacetyltriglycine [MAG3] or diethylene triamine penta-acetic acid [DPTA]) and furosemide are able to demonstrate renal function, identify obstruction in the kidney after injection of furosemide, as well as indicate the anatomical level of the obstruction (Palmer, 2006) (LE = 4; GR = C or B).
Metaphylactic Investigations
| The most common non metabolic disorders are vesico ureteral reflux, ureteropelvic junction obstruction, a neurogenic bladder, or other voiding difficulties (Sternberg et al., 2005) |
LE = 4 |
If suspected, suitable investigations must be performed (see appropriate chapter of the original guideline document).
| Metabolic investigations are based on a proper stone analysis. According to the current standard, infrared spectroscopy or X-ray diffraction are mandatory for adult patients. A wet chemistry analysis is insufficient (Hesse et al., 2005) |
LE = 2b
GR = B
|
Based on the composition of stones (see also the appropriate Chapter 16 in the original guideline document).
| Additional serum chemistry and 24 hour urine collections may be required (Straub et al., 2005) |
LE = 2
GR = A
|
Stone Removal
In principle, the same treatment modalities are used for adults and children. However, the specific circumstances of paediatric therapy must be taken into account when treating children.
| Spontaneous passage of a stone is more likely to occur in children than in adults (Sternberg et al., 2005) |
LE = 4
GR = C
|
For invasive stone removal in paediatric patients, both ESWL and endourologic procedures are effective alternatives. Several factors must be considered when selecting the therapeutic procedure:
- Compared to adults, children pass fragments more rapidly after ESWL.
- For endourological procedures, the smaller organ size must be considered when selecting instruments for PNL or URS.
- Use of US for localization during ESWL in order to eliminate radiation exposure.
- Anticipated stone composition (cystine stones are more resistant to ESWL).
- Co-morbidity involving the use of concomitant treatment.
- The need for general anaesthesia for ESWL (depending on the patient's age and the lithotripter used).
Endourological Procedures
The improvement of intracorporeal lithotripsy devices and the development of smaller instruments facilitate both PNL and URS in children. For PNL, nephroscopes that are sized 15F or less are available (Jackman et al., 1998; Lahme, 2006) (LE = 4; GR = C). Smaller 'needle ureteroscopes' and flexible scopes are also available.
| During URS, dilatation of the ureteral orifice is rarely needed (Gedik et al., 2007) |
LE = 4
GR = C
|
As in adults (see Chapters 7 and 9 of the original guideline document).
| The Ho:YAG laser is the preferred device for intracorporeal lithotripsy (Gupta, 2007) |
LE = 4
GR = C
|
| For PNL or URS with larger instruments US or pneumatic lithotripsy are appropriate alternatives (Desai, 2005) |
LE = 3
GR = C
|
| The indications for ESWL are similar to those in adults. Children with renal pelvic stones or caliceal stones with a diameter up to 20 mm (~300mm2) are ideal cases for this form of stone removal. The success rates tend to decrease as the stone burden increases. |
LE = 1a
GR = A
|
Open or Laparoscopic Surgery
The rate of open procedures in stone patients has dropped significantly in all age groups. Open surgery, if required, may be replaced by laparoscopic procedures. Indications for surgery include failure of primary therapy for stone removal (Casale et al., 2004), abnormal position of the kidney (Holman & Toth, 1998), or an additional target of therapy apart from stone removal, such as the treatment of stones in a primary obstructive megaureter (Hemal et al., 2003) (LE = 4; GR = C).
Residual Fragments
| Patients with residual fragments or stones should be regularly followed up to monitor the course of their disease |
LE = 4
GR = C
|
| Identification of biochemical risk factors and appropriate stone prevention is particularly indicated in patients with residual fragments or stones (Kang et al., 2007) |
LE = 1b
GR = A
|
In symptomatic patients, it is important to rule out obstruction and to treat this problem if present. In other cases, necessary therapeutic steps need to be taken to eliminate symptoms. In asymptomatic patients where the stone is unlikely to pass, treatment should be applied according to the relevant stone situation.
| For well-disintegrated stone material residing in the lower calix, it might be worthwhile considering inversion therapy during high diuresis and mechanical percussion (Chiong et al., 2005) |
LE = 1a
GR = A
|
| Table: Recommendations for the Treatment of Residual Fragments |
| Residual Fragments, Stones (Largest Diameter) |
Symptomatic Residuals |
Asymptomatic Residuals |
| <4-5 mm |
Stone removal |
Reasonable follow-up |
| >6-7 mm |
Stone removal |
Consider appropriate method for stone removal |
Steinstrasse
| Table: Recommendations for Treatment of Steinstrasse |
| Position of Stone |
Unobstructed |
Obstructed and/or Symptomatic |
LE |
GR |
| Proximal ureter |
1. Extracorporeal shock-wave lithotripsy (ESWL) |
1. Percutaneous nephrostomy catheter
(PN) |
| 2. Ureteroscopy (URS) |
1. Stent |
4 |
C |
| 1. URS |
| 1. ESWL |
| Mid-ureter |
1. ESWL |
1. PN |
| 2. URS |
1. Stent |
4 |
C |
| 1. URS |
| 1. ESWL |
| Distal ureter |
1. ESWL |
1. PN |
| 1. URS |
1. Stent |
4 |
C |
| 1. URS |
| 1. ESWL |
Internal Stenting – When and Why
The Use of Stents in the Ureter
The indications for stenting for urgent relief of obstruction are:
- Presence of infection with urinary tract obstruction
- Urosepsis
- Intractable pain or vomiting or both
- Obstruction in a solitary or transplanted kidney
- Bilateral obstructing stones
- Relief of ureteral calculus obstruction in pregnancy, pending definitive therapy in the post-partum period
| For decompression of the renal collecting system ureteral catheters, stents and percutaneous nephrostomy catheters are apparently equally effective |
LE = 1b
GR = A |
The recommendation is that stent insertion prior to shock wave lithotripsy (SWL) for obstructing ureteral stones 2 cm or less provides no advantage and is unnecessary.
The recommendation is that ureteric stents are not necessary following uncomplicated URS for stones.
Recurrence Preventive Treatment
Recurrence Preventive Treatment of Patients with Calcium Stone Disease
| Table: Dietary and Pharmacological Treatment Regimens for Prevention of Recurrent Calcium Stone Formation |
| Treatment |
Biochemical Effects |
References |
LE |
GR |
| Increased fluid intake |
Dilution of urine |
Borghi et al., 1996; Curhan et al., 1997 |
1b |
A |
| Reduced intake of oxalate |
Reduced excretion of oxalate |
|
|
|
| Reduced intake of animal protein |
Reduced excretion of:
Increased excretion of:
Increased pH
|
Borghi et al., 2002 |
1b |
A |
| Reduced intake of sodium |
Reduced excretion of calcium
Increased excretion of citrate
|
Borghi et al., 2002 |
1b |
A |
| Increased intake of fibres |
|
Hess et al., 1999; Ebisuno et al., 1991 |
2b |
B |
| Increased intake of vegetables, provided there is a simultaneous adequate intake of calcium |
|
Siener & Hesse, 2002 |
3 |
B |
| Avoid excessive intake of vitamin C |
Reduced urinary oxalate |
Taylor, Stampfer, & Curhan, 2004 |
2b |
B |
| Thiazide |
Reduced excretion of calcium |
Wilson, Strauss & Manuel, 1984; Robertson et al., 1985; Ettinger et al., 1988; Ohkawa et al., 1992; Borghi et al., 1993; Ahlstrand, Sandwall, & Tiselius, 1996; Ala-Opas et al., 1987; Coe & Kavalach, 1974; "Do thiazides," 1981; Ljunghall et al., 1981; Ahlstrand et al., 1984; Marangella et al., 1999; Tiselius et al., 1993 |
1a |
A |
| Potassium citrate |
Increased excretion of citrate
Increased urine pH
Increased inhibition of crystal growth and crystal agglomeration
|
Hofbauer et al., 1994; Ettinger et al., 1997 |
1b |
A |
| Potassium magnesium citrate |
Increased urine pH
Increased excretion of citrate
Increased inhibition of crystal growth and crystal agglomeration
Reduced supersaturation with calcium oxalate (CaOx) as a result of increased urinary magnesium
Increased inhibition of calcium phosphate (CaP) crystal growth and aggregation
|
Pak & Fuller, 1986 |
1b |
A |
| Allopurinol (in patients with hyperuricuric calcium oxalate stone formation) |
Reduces urinary urate
Decreased risk of calcium oxalate crystal formation
|
Fellstrom et al., 1985 |
1b |
A |
| Pyridoxine |
In patients with primary hyperoxaluria: reduced excretion of oxalate |
Takei et al., 1998 |
3 |
C |
Drinking Recommendations
The general recommendation for calcium stone formers is to maintain a high urine flow by a generous intake of fluids. The aim should be to obtain a 24-hour urine volume of at least 2 L (LE 1b; GR A).
Although most beverages can be drunk to increase fluid intake and help prevent stone formation, grapefruit juice has been shown to be associated with an increased risk of stone formation (Curhan et al., 1998) (LE 3; GR C).
| Table: Suggested Treatment for Patients with Specific Abnormalities in Urine Composition |
| Urinary Risk Factor |
Suggested Treatment |
LE |
GR |
| Hypercalciuria |
Thiazide + potassium citrate |
1a |
A |
| Hyperoxaluria |
Oxalate restriction |
2b |
A |
| Hypocitraturia |
Potassium citrate |
1b |
A |
| Enteric hyperoxaluria |
Potassium citrate |
3-4 |
C |
| Calcium supplement |
2 |
B |
| Oxalate complex formation |
3 |
B |
| High excretion of sodium |
Restricted intake of salt |
1b |
A |
| Small urine volume |
Increased fluid intake |
1b |
A |
| Urea level indicating a high intake of animal protein |
Avoid excessive intake of animal protein |
1b |
A |
| Distal renal tubular acidosis |
Potassium citrate |
2b |
B |
| Primary hyperoxaluria |
Pyridoxine |
3 |
B |
| No abnormality identified |
High fluid intake |
2b |
B |
| Table: When Should Calcium Stone Formers Be Offered Recurrence Preventive Treatment and How? |
| Category** |
Analysis of Urinary Risk Factors |
Recurrence Prevention |
| First time stone former without residual stone or fragments (So) |
No |
General advice |
| First time stone former with residual stone or fragments (Sres) |
Yes* |
Specific advice, with or without a pharmacological agent |
| Recurrent stone former with mild disease and without residual stone(s) or fragments (Rmo) |
No |
General advice |
| Recurrent stone former with mild disease with residual stone(s) or fragments (Rm-res) |
Yes* |
Specific advice, with or without a pharmacological agent |
| Recurrent stone former with severe disease with or without residual stone(s) or fragments or stone forming patient with specific risk factor(s) irrespective of otherwise defined category (see "Specific Risk Factors for Stone Formation" below) (Rs) |
Yes |
Specific advice, with or without a pharmacological agent |
* Optional procedure that is recommended if it is likely that the information obtained can be useful for designing the subsequent treatment.
| Table: Pharmacological Treatment of Uric Acid Stone Disease |
| Objective |
Therapeutic Measures |
References |
LE |
GR |
| Prevention |
Urine Dilution
A high fluid intake; 24-hour urine volume exceeding 2-2.5 L
|
Rodman, Sosa & Lopez, 1996; Low & Stoller, 1997; Shekarriz & Stoller, 2002; Hesse, Tiselius, & Jahnen, 2002 |
3 |
B |
Alkalinization
Potassium citrate 3-7 mmol x 2-3
|
Coe, Evan, & Worcester, 2005; Welch et al., 2006; Pak et al., 1977; Wilcox et al., 1972 |
2b |
B |
In patients with a high serum or urine level of urate
Allopurinol 300 mg x 1
|
Pak, Sakhaee, & Fuller, 1986 |
3 |
B |
| Medical dissolution of uric acid stones |
Urine dilution
A high fluid intake; 24-hour urine volume exceeding 2-2.5L
|
|
4 |
C |
Alkalinization
Potassium citrate 6-10 mmol x 2-3
|
Mattle & Hess, 2005; Shekarriz & Stoller, 2002 |
1b |
A |
Always reduce urate excretion
Allopurinol 300 mg x 1
|
|
4 |
C |
Medical Treatment of Cystine Stone Disease
| Table: Pharmacological Treatment of Patients with Cystine Stone Disease |
| Therapeutic Measures |
References |
LE |
GR |
Urine Dilution
A high fluid intake should be recommended so that the 24-hour urine volume exceeds 3000 mL. To achieve this goal, the intake should be at least 150 mL/h
|
Ng & Streem, 1999; Biyani & Cartledge, 2006; Dent & Senior, 1955 |
3 |
B |
Alkalinization
For patients with a cystine excretion below 3 mmol/24 h:
Potassium citrate 3-10 mmol x 2-3 should be given to achieve a pH >7.5
|
Ng & Streem, 1999; Biyani & Cartledge, 2006; Dent & Senior, 1955 |
3 |
B |
Complex Formation with Cystine
For patients with a cystine excretion above 3 mmol/24 h or when other measures are insufficient
Tiopronin (α-mercaptopropionyl glycine), 250-2000 mg/day
or
Captopril, 75-150 mg
|
Ng & Streem, 1999; Biyani & Cartledge, 2006; Dent & Senior, 1955; Tiselius, 1996; Freed, 1975; Rogers et al., 2007; Chow & Streem, 1998 |
3 |
B |
Management of Patients with Infection Stones
| It is fundamental that the renal collecting system is cleared from stone material |
LE = 3
GR = C
|
| Table: Pharmacological Treatment of Infection Stone Disease |
| Therapeutic Measures |
References |
LE |
GR |
Stone Removal
Surgical removal of the stone material as completely as possible
|
Wilson, 1989 |
4 |
C |
| Antibiotic Treatment |
| Short-term antibiotic course |
Wong, Riedl, & Griffith, 1996 |
3 |
B |
| Long-term antibiotic course |
|
3 |
B |
| Acidification |
| Ammonium chloride 1 g x 2-3 |
Wall & Tiselius, 1990 |
3 |
B |
| Methionine 500 mg 1-2 x 3 |
Jarrar, Boedeker, & Weidner, 1996 |
3 |
B |
| Urease Inhibition |
Griffith et al., 1991; Williams, Rodman, & Peterson, 1984 |
1b |
A* |
| In very selected cases with severe infections, treatment with acetohydroxamic acid (Lithostat) might be a therapeutic option |
* Although treatment with acetohydroxamic acid (Lithostat) has proven effective in controlled studies, due to the potentially severe side effects, this form of treatment is used only in selected cases with severe infections.
Definitions:
Levels of Evidence
1a Evidence obtained from meta-analysis of randomized trials
1b Evidence obtained from at least one randomized trial
2a Evidence obtained from one well-designed controlled study without randomization
2b Evidence obtained from at least one other type of well-designed quasi-experimental study
3 Evidence obtained from well-designed non-experimental studies, such as comparative studies, correlation studies and case reports
4 Evidence obtained from expert committee reports or opinions or clinical experience of respected authorities
Grades of Recommendation
- Based on clinical studies of good quality and consistency addressing the specific recommendations and including at least one randomized trial
- Based on well-conducted clinical studies, but without randomized clinical trials
- Made despite the absence of directly applicable clinical studies of good quality
