Ceylan C et al, 2013: Evaluation of the Process of Recycling and Renal Parenchymal Injury after ESWL with Metabolites Excreted in the Urine
Ceylan C, Dogan S, Saydam G, Kocak MZ, Doluoglu OG.
Department of Urology Clinic of Turkiye, Yuksek Ihtisas Training and Research Hospital , Ankara , Turkey
Abstract
OBJECTIVES: To show renal parenchymal injury depending on extracorporeal shock wave lithotripsy (ESWL).
METHODS: The patients with one renal stone and in whom ESWL is planned among the patients in whom renal stone was determined. Their 24-h urine samples were collected just before and after the ESWL treatment. Cit (citrate), UrA (uric acid), RBP (retinol-binding protein), NAG (N-acetyl-β-Đ-glucosaminidase), Cr (creatinine), Na (sodium), K (potassium), P (phosphor), Ca (calcium), and Cl (chlorine) metabolites excreted in urine were evaluated after urine samples were taken on the study day. Changes in the metabolites excreted; the number, frequency, and duration of ESWL shock wave; the energy; and the body mass index were recorded. The results for p < 0.05 will be accepted as statisticallysignificant.
RESULTS: Two sessions of ESWL were applied to a total of 20 patients. When metabolites excreted in the urine before (B1E) and after (A1E) the first session of ESWL, and before (B2E) and after (A2E) the second session of ESWL, were evaluated, no statistically significant result for Ca and Cl excretion was noted. For NAG and Cr, a significant difference was observed in terms of metabolite excretion between B1E and B2E. For other metabolites, we saw that there is no difference between B1E and B2E. While a significant metabolite change was observed for RBP, NAG, Cr, and Na as long as A1E and A2E ESWL session number increases, other metabolites were not significant.
CONCLUSION: Shock waves induce significant damage to the renal and adjacent tissues as indicated by a significant increase in cell-escaped enzymes and electrolytes and the extent of damage depends on the energy and the number of shock wave exposure.
Ren Fail. 2013;35(4):466-71. doi: 10.3109/0886022X.2013.766574. Epub 2013 Feb 18
PMID:23413820 [PubMed - in process]
Comments 1
It is well recognized that SWL results in transient damage to the renal parenchyma. In this regard the authors measured a number of urine variables before and after two SWL sessions carried out with an interval of 15 days. According to the article, all stones were located in the UPJ and it is thus difficult to know how much shock wave energy that did hit the renal parenchyma. As far as I can see it is not mentioned why this subgroup of patients was chosen. Neither is it mentioned which lithotripter that was used and therefore the shock wave features are unknown.
The most interesting finding was that more than 15 days apparently were necessary in order to normalize NAG and creatinine. It is commented in the Discussion that, as expected, low energy treatment was associated with milder tissue effects, but I was unable to localize those data in the results section.
If any lesson should be learnt from this study it is that SWL-sessions for renal stones, when possible should be carried out with intervals longer than 15 days.
The results are indeed interesting, but the problem is that all urine variables are expressed per volume (L, ml, dL) and there is no information on how the 24h urine volumes varied between the four collection periods.
Hans-Göran Tiselius