What is the process of retrieving kidney stones with a basket?

Kidney Stone Retrieval with a Basket

Kidney stone retrieval with a basket must always be performed under direct ureteroscopic visualization and never as a blind procedure to prevent ureteral injury and ensure optimal patient outcomes. 1

Procedure Overview

The process of retrieving kidney stones with a basket involves several key steps:

• Ureteroscopy is performed first to visualize the stone directly, using either rigid or flexible ureteroscopes depending on stone location 1
• Normal saline is used as the irrigation solution during the procedure to prevent electrolyte abnormalities 1
• A specialized stone basket (typically nitinol) is passed through the ureteroscope's working channel 2
• The basket is opened near the stone and manipulated to capture it under direct visualization 1
• Once captured, the stone is carefully extracted through the ureter 1, 2

Types of Baskets and Equipment

• Tipless nitinol baskets are commonly used due to their flexibility and reduced risk of ureteral injury 3
• Basket size selection depends on the stone size and location 3
• Successful stone retrieval correlates with the stone's endoscopic size - stones appearing approximately one-third of the screen size can typically be retrieved successfully 3
• For larger stones, fragmentation may be required prior to basket retrieval 4

Indications and Contraindications

Indications:

• Small to moderate-sized stones (typically <10mm) 1, 5
• Stones located in accessible areas of the collecting system 2
• Failed spontaneous passage of stones 1
• Stones causing obstruction, pain, or infection 1

Contraindications:

• Untreated urinary tract infection (requires antibiotic therapy before intervention) 1
• Stones too large to be safely removed intact (>10mm may require fragmentation first) 5
• Anatomical abnormalities preventing safe access 1

Technical Considerations

• Stone location matters: Distal ureteral stones are more easily retrieved than proximal or renal stones 6, 5
• Stone size is critical: Stones larger than 10mm generally require fragmentation before basket retrieval 5
• Access sheaths: Using ureteral access sheaths facilitates multiple passes of the basket 3
• Stone repositioning: For lower pole renal stones, a nitinol basket can be used to reposition the stone to a more accessible location before fragmentation or removal 2

Potential Complications

• Ureteral injury (3-6% depending on stone location) 1
• Ureteral stricture formation (1-4%) 1
• Urinary tract infection (2-4%) 1
• Sepsis (2-5%) 1
• Failure to retrieve the stone 5

Safety Precautions

• Never perform blind basketing: Stone extraction with a basket without endoscopic visualization of the stone is contraindicated due to high risk of ureteral injury 1
• Fluoroscopy alone is insufficient: Direct ureteroscopic visualization is required for safe stone manipulation 1
• Infection prevention: Urine culture should be obtained prior to the procedure, and appropriate antibiotics administered if infection is suspected 1
• Stone size assessment: Careful evaluation of stone size relative to ureter and access sheath diameter is essential 3

Alternative Approaches

For stones not amenable to simple basket retrieval:

• Holmium laser lithotripsy can be used to fragment larger stones before basket retrieval 1, 2
• Ultrasonic lithotripsy is another option for fragmenting stones that are too large for direct extraction 4
• For complex or large stones, percutaneous nephrolithotomy (PNL) may be preferred 1
• Shock wave lithotripsy (SWL) may be considered for certain stone locations 1

Outcomes

• Success rates for basket retrieval are highest for distal ureteral stones less than 10mm in size 5
• Stone-free rates of approximately 85% can be achieved with proper technique and patient selection 2
• Complication rates are generally low when performed by experienced urologists under direct visualization 1