Login to Access Video or Poster Abstract: MP62-10
Sources of Funding: NIH grants PO1 DK-43881, and R44 DK-089703

Introduction

An innovative electrohydraulic discharge device has been developed to fracture kidney stones. This device is composed of an array of 18 sparker units, each generating an acoustic pulse, which coalesce to produce a single shock wave front. We report on preliminary tests to determine if the sparker array can fracture stones (in vitro) and if sparker array treatment produces a renal hemorrhagic lesion in our pig model of lithotripsy injury (in vivo).

Methods

U-30 model stones were placed at the focus of the sparker array in a holder with 2-mm mesh openings. 600 shock waves (SWs) were then administered to each stone using a charging voltage of 21.6 kV at 60 SWs/min. All large stone fragments (≥ 2-mm) retained in the holder were collected, dried and weighed to determine percent of stone breakage. The renal lesion analysis portion of the study consisted of treating the left kidney of anesthetized female pigs (35-40 kg) with 2400 SWs using 21.6 kV at 60 SWs/min. Immediately after sparker array treatment the kidneys were perfusion fixed with glutaraldehyde, excised and processed to quantitate the parenchymal hemorrhagic lesion of that kidney.

Results

On average, 71.3±1.9% (mean±S.E., n=6) of each model stone was fractured to < 2-mm in size. Renal injury analysis revealed that none of the kidneys treated with 2400 SWs (n=3) showed evidence of hemorrhagic injury.

Conclusions

The sparker array consistently comminuted model stones demonstrating its ability to fracture stones similar to other lithotripters. However, unlike most other lithotripters, the sparker array did not cause renal injury at the settings used in this study. These findings suggest further research is warranted to determine the potential of this device.

Funding

NIH grants PO1 DK-43881, and R44 DK-089703