Management of 1.1 cm Kidney Stone
For a 1.1 cm (11 mm) kidney stone, ureteroscopy (URS) should be offered as first-line therapy, with percutaneous nephrolithotomy (PCNL) as an alternative option depending on stone location and patient factors. 1
Treatment Selection Algorithm
Primary Recommendation by Stone Size
- Stones >10 mm should NOT be treated with shock wave lithotripsy (SWL) as first-line therapy due to significantly lower success rates 1
- For stones 10-20 mm (which includes your 1.1 cm stone), the median success rates are:
Location-Specific Considerations
If the stone is in the lower pole:
- URS is preferred over SWL for stones >10 mm, as SWL success drops dramatically to 58% for 10-20 mm lower pole stones 1
- PCNL achieves 87% stone-free rates for lower pole stones in this size range 1
If the stone is in the renal pelvis or upper/middle calyx:
- URS remains the preferred first-line option with 81% success 1
- These locations have better drainage than lower pole, but SWL is still inadequate at this size 1
Urgent Exclusions Before Definitive Treatment
Before proceeding with any surgical intervention, you must rule out:
- Obstructing stone with infection - if present, urgent drainage with stent or nephrostomy tube is mandatory before definitive treatment 1
- Purulent urine requires immediate procedure abortion, drainage placement, urine culture, and continued antibiotics 1
Procedural Details
Ureteroscopy (URS) Approach
- Flexible ureteroscopy with holmium:YAG laser lithotripsy is the gold standard technique 1
- Safety guidewire should be used to facilitate re-access 1
- Antimicrobial prophylaxis is required 1
- Routine post-procedure stenting is unnecessary after uncomplicated URS and may increase morbidity 1
PCNL Considerations (if chosen)
- Reserved for stones >20 mm as first-line, but acceptable for 10-20 mm stones when URS is not feasible 1
- Normal saline irrigation must be used to prevent electrolyte abnormalities 1
- Flexible nephroscopy should be routine to access fragments in areas inaccessible by rigid nephroscope 1
- Nephrostomy tube placement after uncomplicated PCNL is optional 1
Factors Affecting Success
Patient factors that reduce SWL success (reinforcing why it should be avoided):
- Obesity and increased skin-to-stone distance 1
- Unfavorable collecting system anatomy (narrow infundibulum, acute infundibulopelvic angle) 1
- High stone density on CT 1
Common Pitfalls to Avoid
- Do not offer SWL as first-line therapy - success rates are unacceptably low (58%) for stones >10 mm, requiring multiple treatments and higher failure rates 1
- Do not perform blind basket extraction - always use direct ureteroscopic vision 1
- Do not delay treatment if infection is present - urgent drainage takes priority over definitive stone removal 1
Post-Treatment Management
- Stone analysis is mandatory to guide prevention strategies 1
- All patients should increase fluid intake to achieve urine volume of at least 2.5 liters daily 2
- Metabolic testing with 24-hour urine collection should be performed for high-risk or recurrent stone formers 2
- Dietary counseling: limit sodium to 2,300 mg/day, consume 1,000-1,200 mg/day of dietary calcium 2