El-Nahas et al, 2012: Are there long-term effects of extracorporeal shockwave lithotripsy in paediatric patients?
El-Nahas AR, Awad BA, El-Assmy AM, Abou El-Ghar ME, Eraky I, El-Kenawy MR, Sheir KZ
Urology Department, Urology and Nephrology Centre, Mansoura University, Mansoura, Egypt
Abstract
Study Type - Therapy (outcomes) Level of Evidence 2b What's known on the subject? and What does the study add? Extracorporeal shockwave lithotripsy is effective for the treatment of paediatric renal stones with favourable short-term safety. Extracorporeal shockwave lithotripsy for treatment of paediatric renal stones is also safe for the kidney and the child on long-term follow-up.
OBJECTIVE: To evaluate the long-term effects of extracoporeal shockwave lithotripsy (SWL) for treatment of renal stones in paediatric patients.
PATIENTS AND METHODS: A database of paediatric patients who underwent SWL monotherapy for treatment of renal stones from September 1990 through to January 2009 was compiled. This study included only patients with follow-up for more than 2 years. The long-term effects of SWL were evaluated at the last follow-up with measurement of patients' arterial blood pressure, estimation of random blood sugar and urine analysis. The results of diastolic blood pressure were plotted against a standardized age reference curve. The treated kidney was examined by ultrasonography for measurement of renal length and detection of stones. The measured renal lengths were plotted against age-calculated normal renal lengths in healthy individuals.
RESULTS: The study included 70 patients (44 boys (63%) and 26 girls) with mean age at the time of SWL 6.5 ± 3.6 years (range 1-14). The mean follow-up period was 5.2 ± 3.6 years (range 2.1-17.5). The mean age at last follow-up was 11.7 ± 5.3 years (range 4.4-27.5). No patients developed hypertension or diabetes. Only one treated kidney was smaller than one standard deviation of the calculated length. The cause of this was obstruction by a stone in the pelvic ureter 3 years after SWL.
CONCLUSION: The long-term follow-up after SWL for treatment of renal stones in paediatric patients showed no effect on renal growth and no development of hypertension or diabetes.
© 2012 BJU INTERNATIONAL.
BJU Int. 2012 Aug 23. doi: 10.1111/j.1464-410X.2012.11420.x. [Epub ahead of print]
PMID:22924860 [PubMed - as supplied by publisher]
Comments 1
Whenever you need very large numbers to prove or disprove a relationship between a procedure and the effects or side effects the impact of that procedure is probably small. So the news of this manuscript is good.
But determining and comparing hypertension in children and adolescents is not without problems.
Ethnicity, pubertal maturation and body weight are important determinants of blood pressure levels and temporal trends of blood pressure in populations must be taken into account when comparing data over long time periods (Blood Pressure Differences between Blacks and Whites in Relation to Body Size among US Children and Adolescents. Rosner B et al. Am J Epidemiol Vol. 151, No. 10, (2000) 1007-1119; Trends in Blood Pressure Among Children and Adolescents. Muntner P et al. JAMA, Vol 291(2004) 2107-2113).
In this paper: 30 out of 100 eligible patients were lost to follow-up. This is more than 40 % of the reported cases and a truly confounding problem when trying to make valid conclusions from the data.
The author states: “If there was no disintegration of the stone after three sessions, the case was considered an SWL failure.” But 11,4 % of the patients had 4 sessions. Would the number of session and total number of shots have an influence on the blood pressure?
What was the follow-up time in those 4/62 children who developed prehypertension? 4/62 is 6%. Is that the expected rate of prehypertension in a comparable population?
A matched pair analysis would probably have been more effective to answer the permanently repeated question on the relation between ESWL and hypertension.
Peter Alken