Is stenting advisable for patients with staghorn stones (kidney stones that fill the renal pelvis and extend into the calyces)?

Is Stenting Advisable for Staghorn Stones?

Yes, stenting is advisable for staghorn stones when shock wave lithotripsy (SWL) is used, but stenting decisions vary based on the primary treatment modality selected.

Stenting Recommendations Based on Treatment Approach

When SWL is Used (Small Volume Staghorn Stones Only)

If SWL monotherapy is undertaken for small volume staghorn calculi (<500 mm²), adequate drainage via either ureteral stenting or percutaneous nephrostomy MUST be established before initiating treatment. 1

• Placement of internal ureteral stent or percutaneous nephrostomy tube facilitates fragment passage, prevents severe obstruction, and limits sepsis following stone fragmentation 1
• This drainage requirement is critical because staghorn stones generate large fragment burdens that risk steinstrasse and ureteral obstruction 1
• However, SWL monotherapy should NOT be used for most staghorn stones due to significantly inferior stone-free rates compared to percutaneous nephrolithotomy (PNL) 1, 2

When Percutaneous Nephrolithotomy (PNL) is Used - The Gold Standard

PNL should be the first-line treatment for most staghorn calculi, and routine pre-stenting is not required for this approach. 1, 2

• PNL achieves stone-free rates more than three times greater than SWL monotherapy 1, 2
• Stenting decisions for PNL are made intraoperatively based on findings rather than routinely 3, 4
• Post-procedure nephrostomy tube placement is standard with PNL, providing drainage without need for ureteral stent 1, 3

When Ureteroscopy (URS) is Used for Residual Fragments

Stenting following uncomplicated URS is optional, but clear indications exist for mandatory stenting. 1

Mandatory stenting indications after URS include: 1

• Ureteral injury
• Ureteral stricture
• Solitary kidney
• Renal insufficiency
• Large residual stone burden

Routine stenting after uncomplicated URS should be avoided because it causes bothersome lower urinary tract symptoms, pain, and temporary quality of life impairment, plus complications including stent migration, UTI, breakage, encrustation, and obstruction. 1

Treatment Algorithm for Staghorn Stones

Step 1: Primary Treatment Selection

Choose PNL as first-line treatment for most staghorn stones 1, 2

• Modern PNL with flexible nephroscopy achieves 95% stone-free rates with mean 1.6 procedures per patient 5, 2
• Single randomized trial (Meretyk) demonstrated PNL stone-free rates >3 times higher than SWL 1, 2

Step 2: Consider SWL Only for Highly Selected Cases

SWL monotherapy may be considered ONLY for: 1

• Small volume staghorn calculi (<500 mm²)
• Normal collecting system anatomy (no or minimal dilatation)
• MANDATORY requirement: Place ureteral stent or percutaneous nephrostomy BEFORE SWL

Step 3: Combination Therapy Sequence

If combination therapy is used, follow this specific sequence: 2

1. Initial PNL debulking
2. SWL for residual fragments unreachable by nephroscopy
3. Final percutaneous nephroscopy (never end with SWL alone - yields only 23% stone-free rates) 2

Critical Pitfalls to Avoid

Never use SWL monotherapy without establishing drainage first - this risks severe obstruction and sepsis from fragment burden 1

Never use SWL monotherapy for cystine staghorn stones - associated with poor stone-free rates for stones ≥25mm 1

Do not routinely stent with standard SWL for ureteral calculi - provides no improved fragmentation and increases morbidity, but staghorn stones are the exception requiring drainage 1

Avoid ending combination therapy with SWL - always perform final nephroscopy to assess stone-free status accurately 2

Special Populations

Pediatric Patients

Either SWL monotherapy or PNL may be considered, with stone-free rates approaching 80% for SWL in children (higher than adults) 1

• If SWL is chosen, drainage via stenting or nephrostomy remains mandatory 1

Solitary Kidney

PNL is safe and effective with demonstrated improvement in creatinine and GFR at 1-year follow-up 6

• Stenting indications are particularly important in solitary kidney cases 1

Complications Related to Stenting Decisions

When adequate drainage is NOT established before SWL for staghorn stones: 1

• Risk of severe obstruction from fragment burden
• Risk of sepsis (reported at 0.15% with proper precautions) 1
• Steinstrasse formation (4% incidence) 1

When routine stenting is performed unnecessarily: 1

• Bothersome lower urinary tract symptoms
• Pain requiring analgesia
• UTI risk
• Need for secondary cystoscopy for removal (unless pull-string attached)