Is flexible ureteroscopy (Flexible Ureteroscopy) with laser fragmentation and Double J (DJ) stent insertion indicated for multiple right renal stones, with the largest stone located in the mid calyceal position, measuring 7 x 5 mm in dimensions and 1100 Hounsfield Units (HU) in density?

Management of Multiple Right Renal Stones with Mid-Calyceal Stone of 7 x 5 mm

Flexible ureteroscopy with laser fragmentation and DJ stent insertion is an appropriate and effective treatment option for the described 7 x 5 mm mid-calyceal renal stone with 1100 HU density. 1, 2

Treatment Decision Algorithm

Stone Characteristics Assessment:

• Stone size: 7 x 5 mm (less than 10 mm)
• Location: Mid-calyceal position
• Density: 1100 HU (relatively hard stone)
• Multiple stones present
• No significant back pressure obstructive changes

Recommended Approach:

1. First-line treatment: Flexible ureteroscopy (FURS) with laser fragmentation and DJ stent insertion

   • High success rate for mid-calyceal stones of this size (86-91% stone-free rate) 1
   • Particularly effective for stones with high density (1100 HU) that may be resistant to SWL
   • Allows treatment of multiple stones in a single session

2. Alternative option: Shock Wave Lithotripsy (SWL)

   • Less invasive but potentially less effective for mid-calyceal stones
   • Mid-ureteral stones pose targeting challenges for SWL due to overlying bone 1
   • Lower success rates for stones with high density (>1000 HU)

Evidence Supporting This Decision

The American Urological Association guidelines indicate that ureteroscopic management of mid-ureteral stones is highly successful, with stone-free rates of 86% for stones in this location 1. For stones <10 mm like the one described (7 x 5 mm), the success rate is even higher at approximately 91% 1.

Flexible ureteroscopy offers several advantages in this case:

• Allows direct visualization of all stones
• Provides access to mid-calyceal location
• Effective fragmentation of high-density stones (1100 HU) using laser
• Permits removal of multiple stones in a single procedure
• Low complication rates (ureteral perforation <5%, stricture formation <2%) 1

Technical Considerations

• Access: A flexible ureteroscope is ideal for accessing mid-calyceal stones
• Fragmentation: Holmium:YAG laser is effective for high-density stones
• DJ stent placement: Recommended post-procedure to prevent obstruction from residual fragments and edema
• Expected outcomes: High likelihood of complete stone clearance (86-91%) in a single procedure 1

Potential Complications and Mitigation

• Ureteral injury: Risk is <5% and can be minimized with careful technique 1
• Long-term stricture: Occurs in <2% of cases 1
• Infection: Appropriate perioperative antibiotics if indicated
• Stent discomfort: Temporary and manageable with analgesics

Follow-up Recommendations

• Imaging (KUB X-ray or ultrasound) within 1-2 weeks to monitor stone position and clearance 2
• DJ stent removal typically after 2-3 weeks
• Increased fluid intake (>2L/day) to help prevent recurrent stone formation 2

The high stone-free rates, minimal invasiveness, and ability to treat multiple stones make flexible ureteroscopy with laser fragmentation and DJ stent insertion the most appropriate treatment option for this patient's mid-calyceal stone.