The most common treatment for acute renal colic is conservative therapy (adequate fluid intake, analgesics (pain relievers), and the alpha-blocker tamsulosin) with the goal of spontaneous stone clearance (expulsion; medical expulsive therapy, MET). See “Drug therapy” for more information. In asymptomatic kidney stones, conservative stone therapy also includes “watchful waiting”. According to the current S2k guideline, patients with a newly diagnosed ureteral stone up to 7 mm in diameter can wait for spontaneous discharge under regular monitoring. Pregnant women with uncomplicated urolithiasis should primarily be treated conservatively. In asymptomatic, stone-bearing children, a metabolic workup should be performed primarily. For uric acid stones, drug-oral chemolitholysis should be performed as first-line therapy.
Urinary Diversion
In cases of colic that cannot be controlled with medication, high-grade obstruction (occlusion) with consecutive urinary retention kidney and /or increasing retention levels/accumulation of urinary substances (postrenal renal failure), urinary diversion is required. This is based on the location and type of obstruction.
- Obstruction in the urinary bladder: transurethral (through the urethra) or suprapubic (above the pubic bone) urinary diversion (suprapubic catherization).
- Suprapubic obstruction: ureteral stenting (ureteral stenting) or percutaneous nephrostomy (synonym: pyelostomy; this is the external diversion of urine (percutaneous, i.e., through the skin) from the renal pelvis through a nephrostomy catheter). The two procedures are considered equivalent in terms of urinary diversion.
Percutaneous urinary diversion should also be performed in the presence of stone road and fever/urinary tract infection. Alternatively, the insertion of a ureteral stent can be made. In pregnant women, if intervention is needed, urinary diversion should be performed primarily. Definitive stone therapy should then be performed post partum.
Active stone therapy
Indications for urologic stone removal (stone extraction):
- Pronounced urinary retention
- Pain resistant to therapy
- Concomitant urinary tract infection and stones that cannot spontaneously pass due to their size.
In children, indications for primary therapy are symptomatic stones, effusion stones and infection stones. Depending on the type of stone and stone localization, the following surgical measures can be used in urolithiasis:
1st order
- Extracorporeal shock wave lithotripsy (ESWL) – disintegration of urinary stones by shock waves generated outside the body.
- Ureteroscopic lithotripsy – endoscopic examination of the ureter (ureter) by means of ureteroscope incl. disintegration of urinary stones by shock waves if necessary also by means of laser lithotripsy (LL): gold standard is the holmium:yttrium-aluminum-garnet (Ho:YAG) laser* ; indications: Means of choice for stones of the mid and distal ureter* Note: Thulium fiber laser (TFL) is more effective than Ho:YAG laser: four times higher stone ablation in dusting mode and two times faster ablation in fragmentation mode.
- Percutaneous nephrolithotomy (PCNL, PCN, PNL; synonym: percutaneous nephrolitholapaxy) – after puncture of the kidney crushing of the stone and removal via an endoscope.
- Flexible ureterorenoscopy (URS) – urinary stone removal with the help of a reflection of the ureter (ureter) and kidney.
- Laparoscopic or open surgery; indications:
- For stone therapy with concomitant need for correction of anatomic drainage obstructions (e.g., subpelvic ureteral stenosis/narrowing of the ureter at its junction with the renal pelvis) or anatomic features.
- Large renal and ureteral stenosis (exceptional indication).
- Nephrectomy (surgical removal of the kidney) – in extreme cases (eg, acute situation in infected urinary stasis kidney).
Important note
- After ureteroscopy, residual stone fragments that are <4 mm still pass spontaneously in 26% of patients. These progressed as follows: size increase with a complication rate of 59% (vs. 28% for smaller stone remnants) and reintervention rate 38% (vs. 18%); stone fragments > 2 mm (also grew) but did not lead to complications or require reintervention.
- Kidney stone extraction unreliably prevented UTIs: 52% continued to have recurrent UTIs. Associated with an increased risk of infection were:
- Black skin color (OR 13.7)
- Arterial hypertension (OR 2.8).
- Diabetes mellitus (odds ratio, OR 1.73).
Interventional procedures depending on stone location (modified after)
Interventional urinary stone treatment usually requires contrast imaging (i.v. urography or contrast-enhanced CT, as well as ureteropyelography) to gain knowledge of the configuration of the voiding system. Prior to active stone therapy, acute urinary tract infection should be ruled out or antibiotic therapy appropriate for resistance should be initiated. Anticoagulation should be suspended before interventional therapy. Acetylsalicylic acid (ASA) may be continued after careful indication evaluation.
| Localization | Operative measure |
| Stones of the renal pelvis and upper/middle calyx group. |
|
| Kidney stones of the lower calyx group |
|
| Spout stones |
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| Proximal ureteral stones |
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| Distal ureteral stones |
|
Legend
- ESWL (extracorporeal shock wave therapy).
- PCNL (percutaneous nephrolithotomy)
- SFR (stone-free rate at 3 months).
- URS (ureterorenoscopy)
Further notes
- ESWL in children shows higher stone-free rates than in adults for all stone localizations.