Pattern of thermal damage and tissue carbonisation from endovenous radiofrequency ablation catheter – Using an in vitro porcine liver model

Background Successful endovenous thermoablation relies on transmural vein wall ablation. We investigated the pattern of thermal spread and tissue carbonisation from RadioFrequency-induced ThermoTherapy (RFiTT) at different powers and pull back methods, using a porcine liver model. Methods We used a previously validated in-vitro porcine liver model. Different powers from 5–25 W were used to administer 150 J. We compared continuous and pulsed energy delivery. Length, lateral spread, and total area of thermal damage, together with any tissue carbonisation, was measured using digital analysis software. Results All experiments used 150 J total energy. Total thermal damage area was smaller with lower power and pulsed energy. Continuous energy caused more tissue carbonisation than pulsed except at 25 W. Conclusion Reduced thermal damage with lower power or pulsed energy results from cooling due to increased time of treatment. Increasing the power increases tissue carbonisation. Optimal treatment is determined by the highest power used continuously that does not cause tissue carbonisation.

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An in vitro study to optimise treatment of varicose veins with radiofrequency-induced thermo therapy

Phlebology The Journal of Venous Disease ◽

10.1177/0268355514552005 ◽

2014 ◽

Vol 30 (1) ◽

pp. 17-23 ◽

Cited By ~ 14

Author(s):

George E Badham ◽

Sophie M Strong ◽

Mark S Whiteley

Keyword(s):

Thermal Ablation ◽

Varicose Veins ◽

Video Recording ◽

In Vitro Study ◽

Porcine Liver ◽

Vein Wall ◽

High Impedance ◽

Liver Model ◽

Thermal Spread

Objective To develop a reproducible method of using radiofrequency-induced thermotherapy with adequate thermal spread to ablate the whole vein wall in a truncal vein but avoiding carbonisation, device sticking and high impedance “cut outs” reducing interruptions during endovenous treatments. Methods Porcine liver was treated with radiofrequency-induced thermotherapy under glass to allow measurements, observation and video recording. Powers of 6–20 W were used at varying pullback speeds to achieve linear endovenous energy densities of 18–100 J/cm. Thermal spread, carbonisation of treated tissue and high-impedance cut outs were recorded. Results The currently recommended power settings of 18 and 20 W produced sub-optimal results. If pulled back at 3 s/cm to achieve linear endovenous energy densities around 60 J/cm, tissue carbonisation and high impedance cut outs occurred. When high powers and fast pullbacks of 1 s/cm were used, no carbonisation or cut outs occurred but thermal ablation of the liver model was below target due to reduced time for thermal conduction. Low powers (6–12 W) with slow pullbacks (6–12 s/cm) achieved target thermal ablation with minimal carbonisation and high impedance cut outs. Conclusions Using low power (6 W) and a slow discontinuous pullback (6 s every 0.5 cm, in steps), we were able to achieve our target thermal ablation in the porcine liver model without carbonisation and high impedance cut outs. This suggests the currently recommended power levels could be reduced, reducing the need to remove the device to clean the electrodes during treatment while achieving target thermoablation of the treated tissue.

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Electro-physiological parameters of hepatic radiofrequency ablation—a comparison of an in vitro versus an in vivo porcine liver model

Langenbeck s Archives of Surgery ◽

10.1007/s00423-009-0475-y ◽

2009 ◽

Vol 394 (3) ◽

pp. 503-509 ◽

Cited By ~ 5

Author(s):

R. Wahba ◽

C. Bangard ◽

R. Kleinert ◽

S. Rösgen ◽

J.-H. Fischer ◽

...

Keyword(s):

Radiofrequency Ablation ◽

Physiological Parameters ◽

Porcine Liver ◽

Liver Model

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A new hemostatic device utilizing a novel transmission structure for delivery of adrenaline and microwave energy at 5.8 GHz

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078717000496 ◽

2017 ◽

Vol 9 (8) ◽

pp. 1575-1582 ◽

Cited By ~ 2

Author(s):

Shaun C. Preston ◽

Malcolm White ◽

Brian Saunders ◽

Zacharias Tsiamoulos ◽

Christoper P. Hancock

Keyword(s):

Transmission Line ◽

Microwave Energy ◽

The Novel ◽

Good Match ◽

Porcine Liver ◽

Microwave Source ◽

Energy Delivery ◽

Liver Model ◽

Transmission Structure ◽

Coagulation Zone

A novel transmission line structure has been developed to facilitate the delivery of both adrenaline and microwave energy to achieve hemostasis. A proximal end impedance transformer and radiative tip have been designed and manufactured to provide good match between the novel hollow transmission line and the microwave source and tissue, respectively. Further consideration of the challenges and problems encountered along with evidence of successful microwave energy delivery at 5.8 GHz into porcine liver model providing a controlled and focused coagulation zone of approximately 5 mm.

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Electro-physiological parameters of hepatic radiofrequency ablation — a comparison of in vitro vs. in vivo porcine liver model

Deutsche Gesellschaft für Chirurgie - Chirurgisches Forum und DGAV Forum 2009 ◽

10.1007/978-3-642-00625-8_34 ◽

2009 ◽

pp. 85-87

Author(s):

R. Wahba ◽

C. Bangard ◽

R. Kleinert ◽

S. Rösgen ◽

K. -J. Lackner ◽

...

Keyword(s):

Radiofrequency Ablation ◽

Physiological Parameters ◽

Porcine Liver ◽

Liver Model

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In vitro recapitulation of the urea cycle using murine embryonic stem cell-derived in vitro liver model

Amino Acids ◽

10.1007/s00726-013-1594-x ◽

2013 ◽

Vol 45 (6) ◽

pp. 1343-1351 ◽

Cited By ~ 2

Author(s):

Miho Tamai ◽

Mami Aoki ◽

Akihito Nishimura ◽

Koji Morishita ◽

Yoh-ichi Tagawa

Keyword(s):

Stem Cell ◽

Embryonic Stem Cell ◽

Urea Cycle ◽

Embryonic Stem ◽

Murine Embryonic Stem Cell ◽

Liver Model

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Robotically Assisted Sonic Therapy as a Noninvasive Nonthermal Ablation Modality: Proof of Concept in a Porcine Liver Model

Radiology ◽

10.1148/radiol.2018171544 ◽

2018 ◽

Vol 287 (2) ◽

pp. 485-493 ◽

Cited By ~ 12

Author(s):

Amanda R. Smolock ◽

Mircea M. Cristescu ◽

Eli Vlaisavljevich ◽

Annette Gendron-Fitzpatrick ◽

Chelsey Green ◽

...

Keyword(s):

Proof Of Concept ◽

Porcine Liver ◽

Liver Model

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Toxicological Implications of Platinum Nanoparticle Exposure: Stimulation of Intracellular Stress, Inflammatory Response, and Akt Signaling In Vitro

Journal of Toxicology ◽

10.1155/2018/1367801 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Claudia J. Labrador-Rached ◽

Rebecca T. Browning ◽

Laura K. Braydich-Stolle ◽

Kristen K. Comfort

Keyword(s):

Stress Responses ◽

Health And Safety ◽

Cellular Responses ◽

Cellular Interactions ◽

Platinum Nanoparticle ◽

Liver Model ◽

Dependent Signal ◽

Cell Functionality

Due to their distinctive physicochemical properties, platinum nanoparticles (PtNPs) have emerged as a material of interest for a number of biomedical therapeutics. However, in some instances NP exposure has been correlated to health and safety concerns, including cytotoxicity, activation of cellular stress, and modification to normal cell functionality. As PtNPs have induced differential cellular responses in vitro, the goal of this study was to further characterize the behavior and toxicological potential of PtNPs within a HepG2 liver model. This study identified that a high PtNP dosage induced HepG2 cytotoxicity. However, lower, subtoxic PtNP concentrations were able to elicit multiple stress responses, secretion of proinflammatory cytokines, and modulation of insulin-like growth factor-1 dependent signal transduction. Taken together, this work suggests that PtNPs would not be overtly toxic for acute exposures, but sustained cellular interactions might produce long term health consequences.

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