ESWL is Appropriate for This 6mm Proximal Ureteral Stone
Yes, this 6mm hyperdense stone (665 HU) in the left proximal ureter with moderate hydronephrosis is indicated for ESWL, though the stone density suggests you should counsel the patient about potentially reduced fragmentation efficiency and consider ureteroscopy as an equally appropriate first-line alternative.
Stone Size and Location Support ESWL
- For proximal ureteral stones ≤10mm, both ESWL and ureteroscopy are acceptable first-line treatment options 1, 2.
- ESWL achieves an 82% stone-free rate for proximal ureteral stones overall, with additional procedures required in only 0.62 procedures per patient 1.
- The 6mm size falls well within the optimal range for ESWL, as stones <10mm demonstrate 90% stone-free rates 1.
Stone Density is a Critical Consideration
The 665 HU density is moderately concerning but not prohibitive for ESWL success:
- Stones with attenuation values <500 HU achieve 100% clearance with ESWL, while those 500-1000 HU achieve 95.7% clearance 3.
- Your stone at 665 HU falls in the favorable middle range where ESWL remains highly effective 3.
- Stones ≥956 HU are not ideal candidates for ESWL, but your stone is well below this threshold 3.
- Higher density stones (cystine, brushite, calcium oxalate monohydrate) demonstrate reduced fragmentation, though the specific composition matters more than density alone 1.
Hydronephrosis Does Not Negatively Impact ESWL Success
- The presence and degree of hydronephrosis does not affect ESWL success rates or time to stone clearance for proximal ureteral stones 4.
- In a study of 130 patients with proximal ureteral stones, stone-free rates were 74.4% regardless of hydronephrosis severity (none, mild, moderate, or severe) 4.
- The moderate hydronephrosis in this case should not deter you from offering ESWL 4.
Alternative Treatment: Ureteroscopy
If you anticipate the stone density may compromise ESWL efficiency, ureteroscopy offers superior stone-free rates:
- Ureteroscopy achieves 81% stone-free rates for proximal ureteral stones with the majority rendered stone-free in a single procedure 1.
- Modern holmium:YAG laser technology readily fragments high-density stones that resist shock-wave energy 1.
- Complication rates for ureteroscopy are low (<5% perforation, <2% stricture) 1.
Treatment Algorithm for This Case
Proceed with ESWL as first-line if:
- Patient prefers minimal anesthesia (ESWL can be performed with IV sedation) 1
- Patient accepts potential for repeat procedures
- No contraindications exist (pregnancy, bleeding disorders) 2
Consider ureteroscopy as first-line if:
- Patient prioritizes single-procedure stone clearance
- Stone composition analysis suggests resistant stone type
- Patient has failed prior ESWL
Important Caveats
- Rule out infection before any intervention - if sepsis or anuria is present, urgent decompression via nephrostomy or stent is required before definitive treatment 2.
- Routine stenting before ESWL offers no advantage and is not recommended 1.
- Fluoroscopic targeting is preferred over ultrasound for ureteral stones to ensure accurate shock-wave focusing 1.
- Expect stone passage within 28 days if ESWL is successful, with 90% of stone-free cases clearing fragments in this timeframe 5.