Management of Obstructing Urinary Stones

Initial Assessment and Management

The European Association of Urology recommends urgent decompression of the collecting system via either percutaneous nephrostomy (PCN) or ureteral stenting in patients with obstructing urinary stones and suspected infection, with definitive stone treatment delayed until sepsis is resolved 1
For patients with obstructing stones without signs of infection, medical management with fluids and pain control can be considered, especially for smaller stones that may pass spontaneously, as recommended by the American College of Radiology 2, 3
The European Urology guidelines suggest that NSAIDs are the first-line treatment for renal colic pain management, with opioids as second-line agents 1
Medical expulsive therapy with alpha-blockers is recommended for patients with stones >5mm in the distal ureter to facilitate stone passage, according to the European Urology guidelines 1

Immediate decompression of the collecting system is required in cases of sepsis and/or anuria with an obstructed kidney, as recommended by the European Urology and the Journal of Urology guidelines 1, 4
Retrograde ureteral stenting is a first-line approach in most cases, associated with decreased hospital stay and ICU admission rates compared to PCN, according to the American College of Radiology 2, 3
Percutaneous nephrostomy (PCN) is considered when retrograde stenting fails or in specific scenarios, with a technical success rate approaching 100%, as reported by the Journal of the American College of Radiology 2, 5

For stones ≤20mm, either shock wave lithotripsy (SWL) or ureteroscopy (URS) is recommended, while for stones >20mm, percutaneous nephrolithotomy (PCNL) is the first-line therapy, according to the Journal of Urology guidelines 4
Patients treated initially with PCN are more likely to receive definitive treatment via a percutaneous approach, while those with ureteral stents typically undergo ureteroscopic treatment, as reported by the American College of Radiology 2, 3

In pregnant patients, ultrasound is the first-line imaging modality, followed by MRI if needed, and retrograde stenting with minimal or no fluoroscopy is preferred, according to the European Urology and the Journal of the American College of Radiology guidelines 1, 6, 7
The American College of Radiology recommends that if stone disease with infection is suspected in pregnant patients, decompression is necessary 6

Delaying decompression in obstructing stones with infection can lead to sepsis, and definitive stone treatment should not be attempted before resolving infection, as recommended by the European Urology and the Journal of Urology guidelines 1, 4
The Journal of Urology guidelines suggest that shock wave lithotripsy (SWL) should not be used as first-line therapy for stones >20mm due to reduced stone-free rates and increased need for multiple treatments 4

The European Association of Urology and American Urological Association recommend waiting until sepsis resolves before proceeding with definitive laser stone treatment 8
Laser fragmentation can be performed at the same session or immediately thereafter if the stent was placed for ureteral access or identification 8
Patients treated with Double J stents are typically destined for ureteroscopic (laser) treatment as their definitive approach 9

Routine placement of ureteral stents is not recommended preoperatively for ureteroscopy, suggesting that when stents are placed, they serve immediate purposes rather than requiring maturation time 8
The European Association of Urology guidelines mention that prestenting has been shown to improve outcomes particularly for renal stones, but this does not imply a mandatory waiting period 8
For stones less than 20mm, flexible ureteroscopy (fURS) with laser lithotripsy is first-line treatment 8
Laser lithotripsy is the preferred fragmentation method for flexible ureteroscopy 8
Holmium:YAG laser is specifically recommended for stone fragmentation during both ureteroscopy and percutaneous procedures 8, 10

Flexible ureteroscopy with holmium laser lithotripsy is the recommended first‑line treatment for a 14 mm distal ureteral stone, falling within the size range where ureteroscopy shows excellent efficacy according to the 2025 European Association of Urology (EAU) guidelines (strong recommendation). [11][12]
The 2025 EAU guidelines state that for ureteral stones < 20 mm, either shock‑wave lithotripsy (SWL) or ureteroscopy may be used as first‑line therapy, with ureteroscopy increasingly favored because of technical advances (strong recommendation). 13

A stone density of ≈ 1000 HU indicates a hard composition, which markedly lowers ESWL success rates and often requires multiple treatment sessions (high‑level evidence). 11
Rough surface morphology of the calculus further reduces its amenability to fragmentation by shock waves (high‑level evidence). 11
Distal ureteral location (≈ 30 mm from the vesicoureteric junction) is readily accessible with flexible ureteroscopy, supporting its selection over ESWL (high‑level evidence). [11][12]

Routine post‑ureteroscopy stenting is not required after an uncomplicated flexible ureteroscopy and may increase patient morbidity (moderate‑level evidence). [11][12]
DJ‑stent insertion is advised when any of the following intra‑operative conditions occur: significant ureteral trauma, residual stone fragments that will need staged treatment, or intra‑procedural bleeding/perforation (moderate‑level evidence). 12

When a DJ‑stent is placed, prescribing an α‑blocker improves stent tolerability and reduces discomfort (moderate‑level evidence). [11][12]13
After laser lithotripsy, an α‑blocker can be used as medical expulsive therapy to facilitate passage of stone fragments and lessen colic (moderate‑level evidence). [11][12]

Holmium:YAG laser remains the gold‑standard energy source for stone fragmentation during flexible ureteroscopy (high‑level evidence). [11][12]
Thulium‑fiber laser provides comparable efficacy and may be used as an alternative energy source (high‑level evidence). 11

Use of a safety guidewire during flexible ureteroscopy is recommended to maintain access and reduce the risk of loss of ureteral entry (moderate‑level evidence). 13
Laser lithotripsy is the preferred modality for stone fragmentation when performing flexible ureteroscopy (moderate‑level evidence). 13