Al-Abadi E et al, 2013: Extracorporal shock wave lithotripsy in the management of stones in children with oxalosis-still the first choice?
Al-Abadi E, Hulton SA
Department of Paediatric Nephrology and Urology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, West Midlands, UK
BACKGROUND: Primary hyperoxaluria (PH) is a recognised cause of nephrolithiasis. The aim of this study was to evaluate the success of extracorporal shock wave lithotripsy (ESWL) in treating nephrolithiasis in children with PH.
METHODS: This was a retrospective review of patient characteristics, treatments and outcomes of 36 children with oxalate stones due to PH.
RESULTS: A total of 52 stones were formed in 28 patients, of which 23 stones were treated with ESWL. Of these 23 stones, ten improved and 13 did not; nine were located in the upper pole, nine in the lower pole and four and one in the pelvic and ureteric areas, respectively. All pelvic and ureteric stones improved, while 66.7 % of upper pole stones and 89.9 % of lower pole stones did not; 20% of PH type 1 stones improved compared to 47 % of PH type 2 stones. The mean pre- and post-eGFR in stone-improvers was 98.82 and 104.7 ml/min/1.73 m2, respectively; in the non-improvers, these values were 100.75 and 95.68 ml/min/1.73 m2, respectively. Mean pre-ESWL stone size in the improved and nonimproved groups was 7.3 mm and 8.5 mm respectively.
CONCLUSIONS: Based on our results, ESWL is not the ideal method of stone therapy for patients with PH. ESWL was more effective in treating pelvic and ureteric stones, with upper pole stone response being better than lower pole response. PH2 patients were more than twice as likely to respond to ESWL treatment. Stone size and prior preventive treatment did not affect outcome. eGFR was not affected by ESWL.
Pediatr Nephrol. 2013 Feb 9. [Epub ahead of print]
PMID:23397522 [PubMed - as supplied by publisher]
This is a report on a series of rare but severe cases of urolithiasis seen in 22 years between 1987 and 2009. Primary hyperoxaluira caused stone formation in 28 children at a mean age of 77,1 months.
These were the aims of the study: " to evaluate the success of ESWL in treating nephrolithiasis in children with hyperoxaluria in order to: (1) identify factors that may affect the success or failure of treatment, (2) identify the effect of ESWL on the estimated (e) GFR and (3) suggest criteria for the use of ESWL in children with oxalosis."
Both authors are not Urologists, probably did not do the treatment and it is not stated with what machine and how these children were treated. "Successful treatment was defined as a ≥50 % reduction in stone bulk or complete resolution of stone based on a post-intervention radiology examination."
Why and how a preventive treatment was done in 10 cases is not stated. All ureteral (1) and pelvic (4) stones "improved". Only three of 9 upper pole stones and 1 of nine lower pole stones "improved". It was probably not known by the authors that stones in these cases are frequently extensively fixed to and within the papillary tissue resulting in no or incomplete disintegration and fragment discharge.
Their conclusion is: "We recommend that for patients with PH and a stone size of >1 cm located in the renal parenchyma or lower pole other methods should be considered, as success is not guaranteed with ESWL. Available resources that may help improve outcomes should be used."
Specific recommendations for the ESWL treatment of PH patients are not made. My suspicion is that a good cooperation between pediatric nephrologists and urologists could probably have improved the results.