What is the recommended treatment for a patient with a staghorn calculus?

Treatment of Staghorn Calculi

Percutaneous nephrolithotomy (PNL) is the recommended primary treatment for staghorn calculi, achieving stone-free rates more than three times greater than SWL monotherapy (84.2% vs 51.2%). 1

Treatment Algorithm

First-line Treatment:

• PNL-based therapy is the gold standard for most staghorn calculi 1
  • Provides direct visualization of the collecting system
  • Allows for more complete stone removal
  • Stone-free rate of 84.2% 1, 2
  • Can be performed as monotherapy or in combination with other modalities

Treatment Selection Based on Stone Characteristics:

1. Standard Staghorn Calculi:

   • PNL monotherapy or PNL followed by SWL for residual fragments

2. Stone Size Considerations:

   • Stones <500 mm²: PNL achieves 94.4% stone-free rate vs 63.2% with SWL monotherapy 2
   • Stones 501-1000 mm²: PNL achieves 86% stone-free rate vs 45.7% with SWL 2
   • Stones >1000 mm²: PNL achieves 82.4% stone-free rate vs only 22.2% with SWL 2

3. Special Situations:

   • Cystine staghorn calculi: PNL-based therapy is preferred (SWL monotherapy should be avoided) 1
   • Non-functioning kidney: Consider nephrectomy 3, 1
   • Extremely large stones (≥2500 mm²), unfavorable collecting system anatomy, or patients with extreme obesity: Consider open surgery (anatrophic nephrolithotomy) 1

PNL Procedure Details

1. Access and Positioning:

   • Patient typically in prone position
   • Lower calyx is most commonly used access point (64.1%), followed by upper calyx (18.5%) and middle calyx (17.4%) 4
   • 16% of cases require multiple access tracts 4

2. Stone Removal:

   • Tract dilation to 24-30 French
   • Stone fragmentation using ultrasonic, pneumatic, electrohydraulic lithotripsy or holmium:YAG laser
   • Flexible nephroscopy to access stones unreachable with rigid instruments
   • Placement of nephrostomy tube (size and duration vary by practice)

3. Combination Approach ("Sandwich Therapy"):

   • Initial PNL for bulk stone removal
   • SWL for residual stones if needed
   • Final percutaneous nephroscopy to retrieve remaining fragments 1

Outcomes and Complications

Stone-Free Rates:

• PNL monotherapy: 78% at discharge, 91% at 3 months 4
• PNL-based approaches: 84.2% overall 1, 2
• SWL monotherapy: 51.2% overall 2

Complications:

• PNL: Bleeding requiring transfusion (0.8-9.4%), renal collecting system injury 4, 2, 5
• SWL: Obstruction (30.5%), pyelonephritis, sepsis 2
• Conservative non-operative approach: 30% mortality from renal failure and/or sepsis 6

Important Pitfalls to Avoid

1. Avoid SWL monotherapy for most staghorn calculi due to significantly lower stone-free rates 1

2. Don't neglect infection control - staghorn calculi often contain bacterial colonies that can cause sepsis when crushed 7

3. Consider stone composition - cystine and uric acid stones are harder to fragment and may benefit from combination therapy with alkali solution irrigation 7

4. Don't end combination therapy with SWL - final percutaneous nephroscopy is crucial for optimal stone-free rates 1

5. Ensure adequate drainage before any SWL treatment if that approach is selected 1

6. Don't overlook the need for follow-up - regular imaging is necessary to detect early recurrence 1