Editing AUA: Stone Surgery (2016) (section)

== Treatment of Renal Stones ==

=== UrologySchool.com summary ===
* '''<span style="color:#ff0000">Asymptomatic, non-obstructing caliceal stones: active surveillance</span>'''
* '''<span style="color:#ff0000">Symptomatic, total stone burden < 20mm</span>'''
** '''<span style="color:#ff0000">Non-lower pole: either SWL or URS</span>''' are preferred over PCNL
** '''<span style="color:#ff0000">Lower pole:</span>'''
*** '''<span style="color:#ff0000">≤10mm: SWL or URS</span>'''
*** '''<span style="color:#ff0000">10-20mm: PCNL (first-line) or URS (no SWL)</span>'''
* '''<span style="color:#ff0000">Symptomatic, total stone burden >20mm: PCNL (first-line) or URS (option) (no SWL)</span>'''
[[File:2019auastonesxpathway.jpg|alt=2019 AUA Guideline Algorithm of Selecting Surgical Treatment of Stones|center|thumb|734x734px|2019 AUA Guideline Algorithm of Selecting Surgical Treatment of Stones]]

=== Asymptomatic, non-obstructing caliceal stones ===
* '''Active surveillance may be offered'''
** Observation of asymptomatic, non-obstructing caliceal stones is appropriate as long as the patient is counseled about the risk of stone growth, passage, and pain.
** '''There is conflicting data on the natural history of asymptomatic renal stones'''
*** '''≈50% of asymptomatic stones will progress, a much smaller percentage will require surgical intervention.'''
**** Lower pole stone location and isolated stone ≥ 4 mm were associated with a higher likelihood of failing observation.
** '''Treatment of asymptomatic, non-obstructing caliceal stones should be considered in:'''
**# '''Cases of associated infection'''
**# '''Vocational reasons (e.g. airline pilots, military)'''
**# '''Poor access to medical care'''
** If observation is chosen for asymptomatic, non-obstructing caliceal stones, '''follow-up imaging studies to assess for stone growth or new stone formation is recommended'''. Dietary modifications and medical therapy may be considered, especially if new stone formation occurs

=== Symptomatic ===
* '''Total stone burden ≤20mm'''
** '''Non-lower pole stone'''
*** '''Recommended options: SWL or URS'''
**** '''Treatment options for patients with a <20 mm non-lower pole renal stone burden include SWL, URS, and PCNL'''. Of these, PCNL stone-free rates are the least affected by stone size, while stone-free rates of both SWL and URS decline with increasing stone burden. However, '''for stone burdens <20mm, stone-free rates of both URS and SWL are acceptable and have less morbidity compared to PCNL'''.
** '''Lower pole stone'''
*** '''≤ 10 mm'''
**** '''Recommended options: SWL or URS'''
***** An RCT found that there was no significant difference between the stone-free rates with URS vs. SWL. Intraoperative complications were higher with URS, and patient-derived QoL measures were better with SWL in this trial.
***** '''CT imaging parameters should be used for patient selection.'''
*** '''> 10mm'''
**** '''Recommended options: PCNL (preferred) or URS; SWL not recommended'''
***** '''Clinicians should inform patients with lower pole stones >10 mm in size that PCNL has a higher stone-free rate but greater morbidity [than URS].'''
***** '''PCNL should be considered the primary treatment'''
* '''Stone burden > 20 mm'''
** '''Recommended options: PCNL (first-line) or URS (option); SWL not recommended as first-line'''
*** Significantly reduced stone-free rates and increased need for multiple treatments for SWL compared to PCNL for patients with a total renal stone burden > 20 mm
**** Success of SWL is dependent on several other factors, including obesity, skin-to-stone distance, collecting system anatomy, stone composition and stone density/attenuation, which could also contribute to lower stone-free rates
**** The benefit of a higher stone-free rate must be weighed against the increased invasiveness and risk of complications for PCNL compared to URS or SWL.
***** 15% overall complication rate with PNCL, majority categorized as Clavien Grade I. '''Bleeding necessitating blood transfusion (7%) is the most common complication'''
**** The risk of ureteral obstruction from stone fragments (steinstrasse) increases
* '''Staghorn calculi'''
** '''PCNL is the first-line treatment''' 

=== 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'''
*** '''Requiring concomitant reconstruction, such as those with''' '''concomitant UPJ obstruction or ureteral stricture.'''

=== Nephrectomy ===

* '''In patients requiring treatment, nephrectomy may be performed when the involved kidney has negligible function'''

* '''Observation may be appropriate for some asymptomatic patients. However, poorly functioning kidneys can often be a source of persistent infection, pain, and pyelonephritis. In these cases, nephrectomy may be the best treatment option to relieve symptoms and prevent systemic complications, such as sepsis and xanthogranulomatous pyelonephritis.'''
* When considering nephrectomy for the poorly functioning kidney, overall renal function and the condition of the kidney on the contralateral side should be considered.
* '''Nephrectomy should be avoided, if possible, in pregnant patients until after they deliver.'''