Limitation of shockwave-induced enhanced crystal deposition in traumatized tissue by verapamil in rabbit model

To evaluate the possible protective effect of verapamil (a calcium channel blocking agent) against the traumatizing effects of high-energy shockwaves (HESW) and new stone formation, as indicated by crystal deposition in the renal parenchyma, an experimental study was performed in rabbits.

A total of 65 rabbits were included. During severe hyperoxaluria induced by continuous ethylene glycol (EG) (0.75%) administration, animals in the first group (N = 15) received EG only, and animals in the second group underwent administration of 500 to 1500 shockwaves, animals in the third group (N = 15) received verapamil (0.1 mg/kg) for 3 days prior to HESW application, a control group (N = 15) received various numbers (500 to 1500) of shockwaves alone. Sham-treated animals (N = 5) constituted the last group in our study. Three months after shockwave application, tissue sections obtained from treated and untreated kidneys were evaluated histopathologically under light microscopy and transmission electron microscopy (TEM) for the presence and degree of crystal deposition in the cortical parenchymal region subjected to HESW.

Whereas crystal deposition was evident in the intercellular region and intratubular parts of the parenchyma in animals receiving EG and HESW, especially in those receiving relatively higher numbers of shockwaves), animals receiving verapamil demonstrated limited or no crystal formation. No significant crystal deposition could be noted in specimens from animals undergoing either EG or SWL alone, and sham-treated animals demonstrated no significant alteration, as expected.

Using this model, the traumatic effects of HESW could be evaluated as a factor in new stone formation after SWL. Verapamil has been found to be protective against crystal deposition.