BACKGROUND: Kidney stones are uncommon in children, but increasing in incidence. We reviewed our experience treating urolithiasis in children with ESWL using a modern portable lithotriptor.
METHODS: With IRB approval, a medical record review was performed of all ESWL cases in patients under 20 years old (1998-2007). Patients were treated on a Dornier Compact Delta Lithotriptor with ultrasound and fluoroscopic imaging. Subjects were defined as stone-free if imaging within 12 months showed no evidence of stones with no additional treatment. Patient and treatment factors associated with successful outcomes were analyzed.
RESULTS: A total of 150 lithotripsy sessions were completed on 114 stone-bearing renal units. Mean age at treatment was 10.5 +/- 4.5 years; 53% were in females. Mean stone diameter was 0.8 +/- 0.3 cm. Treatment was for solitary stones in 76%, 2 stones in 17%, and 3 or more in 7% (mean shock count: 2247). Subjects underwent 1 treatment session in 78%, 2 sessions in 16%, and 3 or more sessions in 6%. Overall stone-free rate (assessed at median 2.6 months after treatment started) was 58.6%. However, among children with a history of anatomic urological conditions or urological surgery (n=16), stone-free rate was only 12.5% (p<.0001). Excluding the children with urological conditions, the overall stone-free rate increased to 67%. Other factors associated with decreased likelihood of being stone-free after SWL included size over 1 cm (25% vs. 63%, p=0.01). Complications requiring acute re-evaluation or treatment occurred after 7% of treatment sessions. Most common complications were nausea/vomiting (3), febrile UTI (3), and ureteral obstruction (3). Readmission was required after 3.4% of treatment sessions.
CONCLUSIONS: Contemporary ESWL is effective in many children with urolithiasis, and is well-tolerated. However, in some children, particularly those with a history of urological surgery or congenital genitourinary conditions, success rates are very low and these children may be best treated with other modalities.