What is the recommended management for a left renal upper pole infundibular stone with mild hydronephrosis?

Management of Left Renal Upper Pole Infundibular Stone with Mild Hydronephrosis

For an upper pole renal stone with mild hydronephrosis, flexible ureteroscopy (fURS) or shock wave lithotripsy (SWL) should be offered as first-line treatment if the stone is symptomatic or if intervention is chosen, with the specific modality depending on stone size. 1

Initial Assessment and Imaging

• Obtain stone size and precise location using low-dose CT without contrast if not already characterized, as this information is essential for surgical planning 1
• The presence of mild hydronephrosis does not significantly impact treatment success rates with flexible ureteroscopy, though grade 2 or higher hydronephrosis may reduce stone-free rates 2
• Upper pole stones have distinct behavior compared to lower pole stones—they are more likely to become symptomatic (40.6% vs 24.3%) and more likely to pass spontaneously (14.5% vs 2.9%) 3

Treatment Algorithm Based on Stone Size

For Stones ≤10 mm:

• Both SWL and fURS are acceptable first-line options 1
• fURS provides higher single-procedure stone-free rates but with slightly higher complication rates 1
• SWL offers better quality of life measures in the immediate postoperative period 1
• Upper pole location is favorable for both modalities compared to lower pole 1

For Stones 10-20 mm:

• fURS and SWL remain first-line treatments for non-lower pole locations 1
• PCNL may be considered as an alternative option for stones in this size range 1
• Stone-free rates: fURS approximately 81%, SWL approximately 58% for this size range 1

For Stones >20 mm:

• PCNL should be offered as first-line therapy 1
• PCNL provides stone-free rates of 94% compared to 75% with ureteroscopy for stones >20 mm 1
• SWL should not be offered as first-line therapy due to significantly reduced stone-free rates 1

Management of Infundibular Stenosis Component

• If infundibular stenosis is present with stone burden ≤2 cm, retrograde intrarenal surgery (RIRS) with dilation/incision of the stenotic opening is highly effective 4
• Successful identification and treatment of stenotic openings is achieved in 94% of cases 4
• For stones 2-3 cm with infundibular stenosis, combined RIRS with SWL provides 75% stone-free rates 4
• Upper pole infundibular stenosis is more amenable to endoscopic management than lower pole lesions 4

Conservative Management Considerations

• Active surveillance is an option for asymptomatic, non-obstructing stones up to 15 mm 1
• However, upper pole stones have a 40.6% chance of becoming symptomatic over 3+ years of follow-up 3
• Stones ≥4 mm are 26% more likely to fail observation than smaller stones 5
• If observation is chosen, periodic imaging follow-up is mandatory to detect silent obstruction, which occurs in approximately 2-3% of cases 1, 3

Key Clinical Pitfalls

• Do not perform blind basket extraction without direct ureteroscopic visualization, as this carries significant risk of ureteral injury 1
• The mild hydronephrosis present does not contraindicate any treatment modality and should not delay intervention if the stone is symptomatic 2
• Upper pole stones are less likely to cause silent obstruction compared to lower pole stones but still require monitoring if observed 3
• Flexible nephroscopy should be routine during PCNL to ensure complete stone clearance from all calyces 1

Specific Technical Recommendations

• Use normal saline irrigation for any endoscopic procedure to prevent electrolyte abnormalities 1
• Routine ureteral stent placement is not recommended pre- or post-operatively unless specific indications exist 1
• If stenting is performed, consider alpha-blockers to reduce stent-related discomfort 1
• For PCNL, nephrostomy tube placement is optional in uncomplicated cases 1