scholarly journals Influence of the heat irrigating effect of radiofrequency ablation on regional liver tissue in Bama miniature pigs

2021 ◽  
Vol 13 (2) ◽  
pp. 109-118
Author(s):  
Jian Feng ◽  
Song Wang ◽  
Kai Jiang
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhihui Jiao ◽  
Yajun Ma ◽  
Qianzhen Zhang ◽  
Yue Wang ◽  
Tao Liu ◽  
...  

Abstract Background Hepatic ischaemia-reperfusion injury (HIRI) is inevitable in complicated liver surgery and is a major factor leading to postoperative complications and liver dysfunction. Studies have shown that the paracrine mechanisms of stem cell may be essential to tissue repair and functional improvement after transplantation. However, the role of the adipose-derived mesenchymal stem cell secretome (ASC-secretome) in liver regeneration in large animals remains to be determined. Methods Twenty-four miniature pigs were subjected to laparoscopic liver ischaemia-reperfusion combined with partial hepatectomy and divided into the following four groups: the saline group, the DMEM group, the ASC group and the ASC-secretome group. Serum and liver tissue samples were collected before the operation and at 1, 3 and 7 days after the operation, and changes in tissue pathology, serum inflammation, liver function, angiogenesis-related factors and liver tissue regeneration-related genes and proteins were evaluated. Results Detailed histological analysis showed that ASCs and the ASC-secretome changed pathological damage to liver tissue after liver ischaemia-reperfusion combined with partial hepatectomy (1 and 3 days: p < 0.01). Compared with the saline and DMEM control groups, the ASC-secretome group had significantly reduced expression levels of ALP (1 and 3 days: p < 0.05), ALT (1 day: p < 0.01; 3 days: p < 0.05) and AST (1 and 3 days: p < 0.01), which promoted the recovery of liver function. Moreover, detection of the expression levels of TNF-α and IL-1β (1 day: p < 0.01; 3 days: p < 0.05), IL-6 (1 and 3 days: p < 0.05) and IL-10 (1 and 3 days: p < 0.01) in serum confirmed that the ASC-secretome had obvious anti-inflammatory effects. In addition, the ASC-secretome increased the expression levels of ANG-1 (3 days: p < 0.01), ANG-2 (3 and 7 days: p < 0.01) and VEGF (1 and 7 days: p < 0.05; 3 days: p < 0.01) and promoted angiogenesis during liver regeneration. Moreover, it promoted the mRNA expression of HGF and Cyclin D1 (1 and 3 days: p < 0.01); increased the levels of p-STAT3 (1 and 3 days: p < 0.01), PCNA and Ki67 (1 and 3 days: p < 0.01; 7 days: p < 0.05); inhibited the negative feedback of SOCS3 (1 and 3 days: p < 0.01); and decreased the mRNA expression of TGF-β (3 days: p < 0.01). The cytokines and growth factors detected in the ASC-secretome included TNF-α, IL-6, IL-1β, ANG-1, ANG-2, VEGF and b-FGF. Conclusion The ASC-secretome alleviates the inflammatory response induced by ischaemia-reperfusion combined with partial hepatectomy in miniature pigs and promotes liver regeneration.


2016 ◽  
Vol 58 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Urte Zurbuchen ◽  
Franz Poch ◽  
Ole Gemeinhardt ◽  
Martin E Kreis ◽  
Stefan M Niehues ◽  
...  

Background Radiofrequency ablation is used to induce thermal necrosis in the treatment of liver metastases. The specific electrical conductivity of a liver metastasis has a distinct influence on the heat formation and resulting tumor ablation within the tissue. Purpose To examine the electrical conductivity σ of human colorectal liver metastases and of tumor-free liver tissue in surgical specimens. Material and Methods Surgical specimens from patients with resectable colorectal liver metastases were used for measurements (size of metastases <30 mm). A four-needle measuring probe was used to determine the electrical conductivity σ of human colorectal liver metastasis (n = 8) and tumor-free liver tissue (n = 5) in a total of five patients. All measurements were performed at 470 kHz, which is the relevant frequency for radiofrequency ablation. The tissue temperature was also measured. Hepatic resections were performed in accordance with common surgical standards. Measurements were performed in the operating theater immediately after resection. Results The median electrical conductivity σ was 0.57 S/m in human colorectal liver metastases at a median temperature of 35.1℃ and 0.35 S/m in tumor-free liver tissue at a median temperature of 34.9℃. The electrical conductivity was significantly higher in tumor tissue than in tumor-free liver tissue ( P = 0.005). There were no differences in tissue temperature between the two groups ( P = 0.883). Conclusion The electrical conductivity is significantly higher in human colorectal liver metastases than in tumor-free liver tissue at a frequency of 470 kHz.


2021 ◽  
Author(s):  
Elmira Ghahramani Z. ◽  
Peter D. Grimm ◽  
Bahar Saremi ◽  
Jiang Wang ◽  
Syed A. Ahmad ◽  
...  

2008 ◽  
Vol 38 (6) ◽  
pp. 694-708 ◽  
Author(s):  
Rimantas Barauskas ◽  
Antanas Gulbinas ◽  
Tomas Vanagas ◽  
Giedrius Barauskas

Medicina ◽  
2007 ◽  
Vol 43 (4) ◽  
pp. 310 ◽  
Author(s):  
Rimantas Barauskas ◽  
Antanas Gulbinas ◽  
Giedrius Barauskas

Background. The character of ablation processes with high-frequency electrical current is similar in most biological tissues; however, quantitative characteristics are very different. Consequently, mathematical models of the process have a lot of specific aspects. In this study, we developed mathematical model of radiofrequency ablation in liver tissues with experimental validation of model in ex vivo porcine liver. Methods. The finite element nonlinear computational model for the simulation of the radiofrequency ablation processes and taking into account coupled electrical and thermal phenomena has been developed. The radiofrequency electric current processes are dominated by the active electric conductivity. The heat generation in biological tissues is determined by the electric current density. Simultaneously, the conductivity of the tissue is nonlinearly dependent upon the temperature of the tissue. The model has been implemented in COMSOL Multiphysics computational environment. Tests on physical characteristics of the thermal effect in ex vivo liver tissue have been performed and results compared. Results. Two oval-shaped zones of total and relative tissue destruction were highlighted. The principal distribution of the thermal effect is congruous with the theoretical model; however, the discrepancy of temperatures in experimental and theoretical models increases distally from active perfusion electrode. Conclusions. Distribution of the thermal effect is congruous in the theoretical and experimental model; however, discrepancies of temperatures imply certain inadequacies of the mathematical models. Differences of computed and actual temperatures should be regarded predicting tissue ablation in clinical setting.


2001 ◽  
Vol 12 (10) ◽  
pp. 1193-1201 ◽  
Author(s):  
Jonathan B. Kruskal ◽  
Brian Oliver ◽  
Juan-Carlos Huertas ◽  
S. Nahum Goldberg

2000 ◽  
Vol 118 (4) ◽  
pp. A912
Author(s):  
Ryoko Kuromatsu ◽  
Masatoshi Tanaka ◽  
Yoshihiro Shimauchi ◽  
Riko Ogata ◽  
Satoshi Itano ◽  
...  

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