For the 2018 edition of the EAU Urolithiasis Guidelines the Guidelines Office have transitioned to a modified GRADE methodology. For each recommendation within the guidelines there is an accompanying online strength rating form which addresses a number of key elements namely:

the overall quality of the evidence which exists for the recommendation;
the magnitude of the effect (individual or combined effects);
the certainty of the results (precision, consistency, heterogeneity and other statistical or study related factors);
the balance between desirable and undesirable outcomes;
the impact of patient values and preferences on the intervention;
the certainty of those patient values and preferences.

These key elements are the basis which panels use to define the strength rating of each recommendation. The strength of each recommendation is determined by the balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence, and nature and variability of patient values and preferences. The strength of each recommendation is represented by the words ‘strong’ or ‘weak’.

In addition, new and relevant evidence has been identified, collated and appraised through a structured assessment of the literature. A broad and comprehensive literature search, covering all sections of the Urological Trauma Guidelines was performed. Additional references and text updates have been incorporated throughout the text as a result of this search. Furthermore, all recommendations have been rephrased throughout the current document to aid in their implementation.

The literature for the entire document has been assessed and updated, whenever relevant (see Methods section).

New sections and recommendations have been included in the 2018 publication in sections:

3.4.1.1 Summary of evidence and guidelines for the management of renal colic

Summary of evidence	LE
Non-steroidal anti-inflammatory drugs are very effective in treating renal colic and are superior to opioids.	1b

Recommendations	Strength rating
Non-steroidal anti-inflammatory drugs are very effective in treating renal colic and are superior to opioids.	Strong

3.4.4.1 Summary of evidence and guidelines for chemolysis

Summary of evidence	LE
Irrigation chemolysis has been in limited clinical use to dissolve struvite stones.	3
Uric acid stones can be dissolved based on oral alkalinisation of the urine above 7.0.	3
For obstructing uric acid stones, a combination of oral chemolysis with Tamsulosin is more effective than each substance alone, in particular in stones > 8 mm.	1b

Recommendations (oral chemolysis of uric acid stones)	Strength Rating
Combine oral chemolysis with Tamsulosin in case of (larger) ureteral stones (if active intervention is not indicated).	Weak

3.4.6.1 Summary of evidence and guidelines for retrograde URS, RIRS and antegrade ureteroscopy

Summary of evidence	LE
Medical expulsion therapy following Ho:YAG laser lithotripsy accelerates the spontaneous passage of fragments and reduces episodes of colic.	1b
The most effective lithotripsy system for flexible ureteroscopy is the Ho:YAG laser.	2a
Pneumatic and US systems can be used with high disintegration efficacy in rigid URS.	2a
Medical expulsion therapy following Ho:YAG laser lithotripsy increases SFRs and reduces colic episodes.	1b
Percutaneous antegrade removal of proximal ureter stones or laparoscopic ureterolithotomy are feasable alternatives to retrograde ureteroscopy in selected cases.	1a

Recommendations	Strength rating
Offer MET for patients suffering from stent-related symptoms and after Ho:YAG laser lithotripsy for the passage of fragments.	Strong

3.4.9.4.1 Summary of evidence and guidelines for selection of procedure for active removal of ureteral stones

Summary of evidence	LE
Observation is feasible in informed patients who develop no complications (infection, refractory pain, deterioration of renal function).	1a
Compared with SWL, URS was associated with a significantly greater SFR up to four weeks, but the difference was not significant at three months in the included studies.	1a
Ureterorenoscopy was associated with fewer re-treatments and need for secondary procedures, but with a higher need for adjunctive procedures, greater complication rates and longer hospital stay.	1a

Recommendations	Strength rating
Offer α-blockers as MET as one of the treatment options for (distal)ureteral stones ≥ 5 mm.	Strong
In cases of severe obesity use ureterorenoscopy as first-line therapy for ureteral (and renal) stones.	Strong

3.4.13.1 Summary of evidence and guideline for management of patients with residual stones

Summary of evidence	LE
To detect residual fragments after SWL, URS or PNL deferred imaging is more appropriate than immediate imaging post intervention.	3

Recommendation	Strength rating
Perform imaging after SWL, URS or PNL to determine presence of residual fragments.	Strong

3.4.15.6 Summary of evidence and guidelines for the management of stones in children

Summary of evidence	LE
Ureterenoscopy has become the treatment of choice for larger distal ureteral stones in children.	1a

Recommendations

Strength rating

Offer children with ureteral stones shockwave lithotripsy as first line option but consider uretero-renoscopy if SWL is not possible and larger distal ureteral stones.

Strong

Offer children with renal pelvic or calyceal stones with a diameter > 20 mm ( ̴300 mm²) percutaneous nephrolithotomy.

Strong

4.7.4 Summary of evidence and guideline for the management of uric acid- and ammonium urate stones

Summary of evidence	LE
Potassim citrate can be beneficial to alkalinise the urine in urate stone formers.	3
Allopurinol can be beneficial in hyperuricosuric urate stone formers.	1b

Recommendations	Strength rating
Prescribe potassim citrate to alkalinise the urine in urate stone formers.	Strong
Prescribe allopurinol in hyperuricosuric urate stone formers.	Strong