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Interstitial laser thermotherapy in pig liver : Effect of inflow occlusion on extent of necrosis and ultrasound image

Möller, Páll H. LU ; Hannesson, Pétur H. ; Ivarsson, Kjell LU ; Olsrud, Johan LU ; Stenram, Unne LU and Tranberg, Karl G. LU (1997) In Hepato-Gastroenterology 44(17). p.1302-1311
Abstract

Background/Aims: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. Methodology: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3 W or without inflow occlusion at 5 W (target temperature 43°C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. Results: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did... (More)

Background/Aims: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. Methodology: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3 W or without inflow occlusion at 5 W (target temperature 43°C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. Results: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did not occur, unoccluded blood flow was associated with hypoechoic lesions. Following inflow occlusion, maximum lesion width 2 and 6 days after thermotherapy averaged 21.9 ± 1.3 and 20.2 ± 0.8 (means ± SEM) mm, respectively. This was larger than the corresponding values of 10.8 ± 0.8 and 11.1 ± 2.0 observed after treatment without inflow occlusion at 3 W (p < 0.01). Increase in laser power from 3 to 5 W in experiments without inflow occlusion produced early carbonization and a slight increase in lesion size that did not match that produced by inflow occlusion. Ultrasound gave a correct prediction of necrosis size after treatment with inflow occlusion but overestimated the necrosis when inflow occlusion was not used. Ultrasound was furthermore unable to predict size of necrosis in individual experiments. Conclusion: Blood flow has a major influence on lesion size in interstitial laser thermotherapy of the liver and affects ultrasonographic images. Also, it appears that intraoperative ultrasonography cannot monitor lesion size with an accuracy that is sufficient for clinical use.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Feedback control, Interstitial therapy, Nd:YAG laser, Temperature distribution, Thermotherapy, Ultrasonography
in
Hepato-Gastroenterology
volume
44
issue
17
pages
10 pages
publisher
Georg Thieme Verlag KG
external identifiers
  • scopus:0030830120
  • pmid:9356843
ISSN
0172-6390
language
English
LU publication?
yes
id
f76b6eaa-3d9b-4ca2-a3c3-9b0dcf257a9a
date added to LUP
2019-06-15 17:00:34
date last changed
2020-06-10 06:10:02
@article{f76b6eaa-3d9b-4ca2-a3c3-9b0dcf257a9a,
  abstract     = {<p>Background/Aims: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. Methodology: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3 W or without inflow occlusion at 5 W (target temperature 43°C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. Results: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did not occur, unoccluded blood flow was associated with hypoechoic lesions. Following inflow occlusion, maximum lesion width 2 and 6 days after thermotherapy averaged 21.9 ± 1.3 and 20.2 ± 0.8 (means ± SEM) mm, respectively. This was larger than the corresponding values of 10.8 ± 0.8 and 11.1 ± 2.0 observed after treatment without inflow occlusion at 3 W (p &lt; 0.01). Increase in laser power from 3 to 5 W in experiments without inflow occlusion produced early carbonization and a slight increase in lesion size that did not match that produced by inflow occlusion. Ultrasound gave a correct prediction of necrosis size after treatment with inflow occlusion but overestimated the necrosis when inflow occlusion was not used. Ultrasound was furthermore unable to predict size of necrosis in individual experiments. Conclusion: Blood flow has a major influence on lesion size in interstitial laser thermotherapy of the liver and affects ultrasonographic images. Also, it appears that intraoperative ultrasonography cannot monitor lesion size with an accuracy that is sufficient for clinical use.</p>},
  author       = {Möller, Páll H. and Hannesson, Pétur H. and Ivarsson, Kjell and Olsrud, Johan and Stenram, Unne and Tranberg, Karl G.},
  issn         = {0172-6390},
  language     = {eng},
  month        = {10},
  number       = {17},
  pages        = {1302--1311},
  publisher    = {Georg Thieme Verlag KG},
  series       = {Hepato-Gastroenterology},
  title        = {Interstitial laser thermotherapy in pig liver : Effect of inflow occlusion on extent of necrosis and ultrasound image},
  volume       = {44},
  year         = {1997},
}