Senyucel MF et al, 2013: Evaluation of contralateral kidney, liver and lung after extracorporeal shock wave lithotripsy in rabbits
Senyucel MF, Boybeyi O, Ayva S, Aslan MK, Soyer T, Demet AI, Kısa U, Basar M, Cakmak MA
Department of Pediatric Surgery, Faculty of Medicine, Kırıkkale University, Kırıkkale, Turkey
An experimental study was carried out to evaluate the effects of extracorporeal shock wave lithotripsy (ESWL) on contralateral kidney, liver and lung by histopathological and biochemical methods. Twelve New Zealand rabbits were allocated to two groups (n = 6). Tissues of control group (CG, n = 6) were harvested without any intervention. In ESWL group (EG), right kidneys were exposed to 3,000 shock waves at 14 kV energy using electro-hydraulic type ESWL device three times every other day. Both kidneys, liver, and right lobe of lung tissues in EG were harvested on seventh day. Kidneys were examined histopathologically for presence of glomerular and tubular injury, interstitial edema, congestion, inflammation and fibrosis. Livers were examined for hepatocyte vacuolization, congestion, portal inflammation and fibrosis. Lung tissues were examined for loss of normal structure, emphysema, interstitial congestion-edema, prominent alveolar septal vessels, interstitial inflammation, intra-alveolar hemorrhage, intraluminal hemorrhage, peribronchial edema, congestion, inflammation in bronchial wall and epithelial desquamation. Biochemical analysis of tissue samples was performed for oxidative injury markers. Histopathological evaluations revealed that tubular injury was found in both shocked and contralateral kidneys (p < 0.05). EG showed higher grades of portal fibrosis in liver and higher grades of peribronchial congestion in lung when compared to CG (p < 0.05). Biochemical evaluations of both kidneys showed that malondialdehyde levels were higher in EG than in CG (p < 0.05). ESWL causes histopathologic alterations both in shocked and contralateral kidneys. Extrarenal tissues such as liver and lung can be affected by shock waves histopathologically and oxidative injury of contralateral kidney may occur acutely after ESWL.
Urolithiasis. 2013 Jun 1. [Epub ahead of print]
PMID:23728121 [PubMed - as supplied by publisher]
This study has several problems in its design:
1. It is not stated if the control group (CG) had 3 times anesthesia like the treatment group (EG).
2. Three treatment sessions with each 3000 shots within 6 days on the same kidney should definitively cause a trauma, but what
purpose does it serve? Even the authors state: "Although its clinical relevance is questionable, it seems that energy was sufficient to cause reasonable histological changes in the tissues."
3. Of the 15 histopathological parameters evaluated in lung, liver and kidneys 10 were not different in the CG and the EG. So the animals that were used obviously had pre-experimental changes.
4. The authors used small animals and concluded: "The results of the present study might be related to the direct effect of shock waves which would be the limitation of our study." This probably explains a lot of their findings including the similar changes in the treated and not treated kidneys of the EG group.
5. The authors do not give any data on the geometry of the shockwave direction, focus and the focal depth and where within the animal the shock wave was directed. The changes seen may all be attributable to the direct effect of shock wave on the different organs.
Probably the rabbit is not a useful animal to study the side effects of shock waves on neighboring organs.