Effect of initial shock wave voltage on shock wave lithotripsy-induced lesion size during step-wise voltage ramping

Bret A. Connors, Andrew Evan, Philip M. Blomgren, Rajash Handa, Lynn R. Willis, Sujuan Gao

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

OBJECTIVE: To determine if the starting voltage in a step-wise ramping protocol for extracorporeal shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS: To address this question, one kidney from 19 juvenile pigs (aged 7-8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3-4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS: Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS: The data suggest that initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the initial shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.

Original languageEnglish
Pages (from-to)104-107
Number of pages4
JournalBJU International
Volume103
Issue number1
DOIs
StatePublished - Jan 2009

Fingerprint

Lithotripsy
Kidney
Swine
Wounds and Injuries
Shock
Therapeutics
Hemorrhage

Keywords

  • Animal models
  • Renal protection
  • Tissue injury

ASJC Scopus subject areas

  • Urology

Cite this

Effect of initial shock wave voltage on shock wave lithotripsy-induced lesion size during step-wise voltage ramping. / Connors, Bret A.; Evan, Andrew; Blomgren, Philip M.; Handa, Rajash; Willis, Lynn R.; Gao, Sujuan.

In: BJU International, Vol. 103, No. 1, 01.2009, p. 104-107.

Research output: Contribution to journalArticle

@article{9407ff5cb1394adaaae13edd1c565714,
title = "Effect of initial shock wave voltage on shock wave lithotripsy-induced lesion size during step-wise voltage ramping",
abstract = "OBJECTIVE: To determine if the starting voltage in a step-wise ramping protocol for extracorporeal shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS: To address this question, one kidney from 19 juvenile pigs (aged 7-8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3-4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS: Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29){\%} functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01){\%} FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14){\%} FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS: The data suggest that initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the initial shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.",
keywords = "Animal models, Renal protection, Tissue injury",
author = "Connors, {Bret A.} and Andrew Evan and Blomgren, {Philip M.} and Rajash Handa and Willis, {Lynn R.} and Sujuan Gao",
year = "2009",
month = "1",
doi = "10.1111/j.1464-410X.2008.07922.x",
language = "English",
volume = "103",
pages = "104--107",
journal = "BJU International",
issn = "1464-4096",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Effect of initial shock wave voltage on shock wave lithotripsy-induced lesion size during step-wise voltage ramping

AU - Connors, Bret A.

AU - Evan, Andrew

AU - Blomgren, Philip M.

AU - Handa, Rajash

AU - Willis, Lynn R.

AU - Gao, Sujuan

PY - 2009/1

Y1 - 2009/1

N2 - OBJECTIVE: To determine if the starting voltage in a step-wise ramping protocol for extracorporeal shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS: To address this question, one kidney from 19 juvenile pigs (aged 7-8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3-4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS: Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS: The data suggest that initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the initial shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.

AB - OBJECTIVE: To determine if the starting voltage in a step-wise ramping protocol for extracorporeal shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs. MATERIALS AND METHODS: To address this question, one kidney from 19 juvenile pigs (aged 7-8 weeks) was treated in an unmodified Dornier HM-3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3-4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated. RESULTS: Kidneys that received the standard clinical treatment had a mean (sem) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group. CONCLUSIONS: The data suggest that initial voltage in a voltage-ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the initial shocks and the clinical dose of SWs, in our one-step ramping protocol, is important for protecting the kidney against injury.

KW - Animal models

KW - Renal protection

KW - Tissue injury

UR - http://www.scopus.com/inward/record.url?scp=57649198276&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=57649198276&partnerID=8YFLogxK

U2 - 10.1111/j.1464-410X.2008.07922.x

DO - 10.1111/j.1464-410X.2008.07922.x

M3 - Article

VL - 103

SP - 104

EP - 107

JO - BJU International

JF - BJU International

SN - 1464-4096

IS - 1

ER -