From the Guidelines
I strongly recommend proceeding with Extracorporeal Shock Wave Lithotripsy (ESWL) for this 5 x 4.5 mm right proximal ureteric stone at L3 level, given its size and location, which are associated with high stone-free rates of 82% as reported in the 2007 guideline for the management of ureteral calculi 1. The stone's density of 340 Hounsfield Units (HU) and its location in the proximal ureter make it an appropriate candidate for ESWL treatment. Prior to the procedure, ensure adequate hydration and consider prescribing tamsulosin 0.4 mg daily to facilitate stone passage after fragmentation. Pain management with NSAIDs like diclofenac 50 mg three times daily or ketorolac 10 mg every 6 hours as needed is recommended. The mild back pressure changes indicate early hydronephrosis, suggesting intervention is timely before kidney damage occurs. ESWL works by delivering focused shock waves that break the stone into smaller fragments that can pass naturally through the urinary tract. Success rates for proximal ureteric stones of this size are generally good, though multiple sessions may occasionally be required, with additional procedures being infrequently necessary, at a rate of 0.62 procedures per patient for proximal ureteral stones 1. Following ESWL, increased fluid intake of at least 2-3 liters daily will help flush out stone fragments, and follow-up imaging in 2-4 weeks is essential to confirm complete stone clearance. Key considerations include:
- The use of newer generation lithotriptors with higher peak pressures and smaller focal zones, which should theoretically be ideal for treating stones in the ureter, although they have not been associated with an improvement in stone-free rates or a reduction in the number of procedures needed 1.
- The potential for performing the procedure with minimal anesthesia, making it an attractive option for patients who desire treatment with minimal sedation 1.
- The importance of informed consent, particularly for women of childbearing age, regarding the theoretical possibility of damage to unfertilized eggs and/or ovaries, although no objective evidence has been discovered to support such concerns 1.
From the Research
Indications for ESWL
- The patient has a right proximal ureteric obstructive stone seen at the level of L3, measuring about 5 x 4.5 mm (density value 340 HU), causing mild back pressure changes 2.
- ESWL is generally the first line treatment for proximal ureteral stones, especially for stones less than 1cm 2, 3.
- The stone size in this case is less than 1cm, which makes ESWL a suitable treatment option 2, 4.
Comparison with Ureteroscopy
- Ureteroscopy with holmium laser lithotripsy is a viable and safe alternative to ESWL for the management of proximal ureteric calculi 3.
- Ureteroscopy has a higher stone-free rate and lower re-treatment rate compared to ESWL for proximal ureteric stones 3, 5.
- However, ESWL is still a recommended treatment option for proximal ureteric stones less than 1cm 2, 4.