Accessing the Proximal Ureter in Complete Staghorn Calculi
In complete staghorn calculi, you access the proximal ureter and calyces through percutaneous nephrolithotomy (PCNL) using flexible nephroscopy—the calyces are NOT sealed off, they're just filled with stone that you systematically fragment and remove. 1
Understanding the Technical Approach
The concern about "sealed off" calyces reflects a misunderstanding of staghorn anatomy. While the stone fills the collecting system, the calyces remain patent spaces that can be accessed once you establish a percutaneous tract. Here's how it works:
Initial Access Strategy
- Upper pole entry is preferred for staghorn stones because it typically provides access to the majority of the collecting system and may allow complete removal through a single site 1
- The guidewire is manipulated under fluoroscopic or ultrasound guidance "into the kidney and down the ureter" during initial access 1
- Multiple access sites (2 or more) may be required when collecting system anatomy is complex 1
Reaching All Stone Components
The key is flexible nephroscopy combined with modern lithotripsy:
- After initial rigid nephroscope fragmentation of bulk stone, flexible nephroscopy accesses stones that cannot be reached with the rigid scope 1
- Holmium:YAG laser or electrohydraulic lithotripsy fragments stones in difficult-to-reach calyces 1
- The tract can be kept open indefinitely, allowing repeated inspections 1
- Recent advances in flexible nephroscopy and holmium laser have decreased the number of accesses needed to remove staghorn stones 1
Combined Approaches for Complete Access
When a single tract proves insufficient:
- Combined antegrade-retrograde approach: A ureteral access sheath can be placed retrograde while performing PCNL, allowing simultaneous access from above and below 2
- Endoscopic combined intrarenal surgery (ECIRS): Integrates PCNL with retrograde intrarenal surgery for stones in difficult-to-reach calyces 3, 4
- Antegrade flexible ureteroscopy through the nephrostomy tract can reach previously inaccessible areas 3
Clinical Reality Check
Stone-free rates of 74-83% are achievable with PCNL for staghorn stones 1, which wouldn't be possible if calyces were truly "sealed off." The challenge isn't that calyces are inaccessible—it's that:
- Complex stones may require 1.3 procedures on average 1
- 10-50% of patients need additional PCNL procedures depending on stone complexity 1
- Second-look nephroscopy through the established tract is often more efficient than combination therapy 1
Important Caveats
- If combination therapy with SWL is used, percutaneous nephroscopy should be the final procedure because fragment passage after SWL is incomplete 1
- Direct inspection of the collecting system identifies small fragments that imaging may miss 1
- The proximal ureter is accessed by advancing instruments through the renal pelvis—not a separate challenge once you have renal access
The bottom line: Complete staghorn stones are challenging because of their volume and complexity, not because of anatomical inaccessibility. Modern flexible endoscopy through a well-positioned percutaneous tract provides comprehensive access to the entire collecting system.