A mechanistic analysis of stone fracture in lithotripsy

Sapozhnikov, Oleg A.; Maxwell, Adam D.; MacConaghy, Brian; Bailey, Michael R.

doi:10.1121/1.2404894

Cited by 134 publications

(95 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This correlation between stone appearance by CT and susceptibility to SW's is consistent with results from numerical modeling showing that irregularities in the structure of the stone can act as sites for focusing of SW energy [27], so that the stone may break more easily. Stone shape can also have profound effects on the interaction of SW's with a stone [28,29].…”

Section: Discussionmentioning

confidence: 99%

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

et al. 2007

View full text Add to dashboard Cite

COM stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW's. For this study, 47 COM stones (4-10 mm in diameter) were scanned with micro CT to verify composition and also for assessment of heterogeneity (presence of pronounced lobulation, voids, or apatite inclusions) by blinded observers. Stones were then placed in water and scanned using 64-channel helical CT. As with micro CT, heterogeneity was assessed by blinded observers, using high-bone viewing windows. Then stones were broken in a lithotripter (Dornier Doli-50) over 2 mm mesh, and SW's counted. Results showed that classification of stones using micro CT was highly repeatable among observers (κ=0.81), and also predictive of stone fragility. Stones graded as homogeneous required 1874±821 SW/g for comminution, while stones with visible structure required half as many SW/g, 912±678. Similarly, when stones were graded by appearance on helical CT, classification was repeatable (κ=0.40), and homogeneous stones required more SW's for comminution than did heterogeneous stones (1702±993 SW/g, compared to 907±773). Stone fragility normalized to stone size did not correlate with Hounsfield units (p=0.85). In conclusion, COM stones of homogeneous structure require almost twice as many SW's to comminute than stones of similar mineral composition that exhibit internal structural features that are visible by CT. This suggests that stone fragility in patients could be predicted using pre-treatment CT imaging. The findings also show that Hounsfield unit values of COM stones did not correlate with stone fragility. Thus, it is stone

show abstract

Section: Discussionmentioning

confidence: 99%

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

et al. 2007

View full text Add to dashboard Cite

show abstract

“…In this method, a single shock wave of several dozen MPa on a focal plane is focused onto a kidney stone from outside the body repeatedly, once in 1-2 s. 1,2) Unlike abdominal surgery, this method does not require incision. However, it has two problems.…”

Section: Introductionmentioning

confidence: 99%

Effect of annular focusing of ultrasound on rate of stone erosion using cavitation bubbles

Yura

Lafond

Yoshizawa

et al. 2018

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Shock wave lithotripsy has been one of the first-line treatments to fragment kidney stones. One disadvantage of this method is that some residual stone fragments can be too large to pass through the ureters. Stone fragments can be made small enough by ultrasonically induced cavitation erosion, but the erosion rate, with conventional single-spot focusing, tends to be low owing to ultrasound attenuation by excessively generated cavitation bubbles upstream of the stone surface. Sector vortex annular focusing can generate cavitation bubbles widely and thinly. We propose exposure sequences utilizing this focusing scheme and investigated their effect on erosion rate using a stone model. Sector vortex annular focusing showed an erosion rate significantly higher than that of single-spot focusing. Among them, switching between the two focusing schemes provided the highest rate, higher than the mathematical sum of those of the two schemes, and even higher than that of sector vortex focusing at the same pulse repetition.

show abstract

“…May 6, 2015|Volume 4|Issue 2| WJN|www.wjgnet.com [47][48][49][50] . Another setting recommendation for SWL is pre-treating the stone at a low energy for 100-200 shock waves and then pausing for several minutes prior to going to a higher energy [50,51] .…”

mentioning

confidence: 99%

Strategies to optimize shock wave lithotripsy outcome: Patient selection and treatment parameters

Semins

Matlaga

2015

WJN

View full text Add to dashboard Cite

Shock wave lithotripsy (SWL) was introduced in 1980, modernizing the treatment of upper urinary tract stones, and quickly became the most commonly utilized technique to treat kidney stones. Over the past 5-10 years, however, use of SWL has been declining because it is not as reliably effective as more modern technology. SWL success rates vary considerably and there is abundant literature predicting outcome based on patient-and stone-specific parameters. Herein we discuss the ways to optimize SWL outcomes by reviewing proper patient selection utilizing stone characteristics and patient features. Stone size, number, location, density, composition, and patient body habitus and renal anatomy are all discussed. We also review the technical parameters during SWL that can be controlled to improve results further, including type of anesthesia, coupling, shock wave rate, focal zones, pressures, and active monitoring. Following these basic principles and selection criteria will help maximize success rate. Core tip: Shock wave lithotripsy is a commonly utilized technology for kidney stone treatment that has declining efficacy over the past decade. The paper outlines how to optimize outcomes with proper patient selection and control of treatment parameters.

show abstract

A mechanistic analysis of stone fracture in lithotripsy

Cited by 134 publications

References 37 publications

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

Effect of annular focusing of ultrasound on rate of stone erosion using cavitation bubbles

Strategies to optimize shock wave lithotripsy outcome: Patient selection and treatment parameters

Contact Info

Product

Resources

About