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Ikiades A, Bassukas ID, Kourkoumelis N. A Fiber Optic Sensor for Monitoring the Spectral Alterations and Depth in Ex Vivo and In Vivo Cryosurgery. SENSORS (BASEL, SWITZERLAND) 2023; 23:2690. [PMID: 36904893 PMCID: PMC10007682 DOI: 10.3390/s23052690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/24/2023] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
This article discusses how to monitor the freezing depth during cryotherapy using a fiber optic array sensor. The sensor was used to measure the backscattered and transmitted light from frozen and unfrozen ex vivo porcine tissue and in vivo human skin tissue (finger). The technique exploited the variations in optical diffusion properties of the frozen and unfrozen tissues to determine the extent of freezing. Ex vivo and in vivo measurements yielded comparable results, despite spectral variations attributable to the hemoglobin absorption peak in the human frozen and unfrozen tissues. However, because the spectral fingerprints of the freeze-thaw process in the ex vivo and in vivo experiments were similar, we could extrapolate the maximum depth of freezing. Therefore, this sensor has the potential to be utilized for monitoring cryosurgery in real time.
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Affiliation(s)
- Aris Ikiades
- Department of Physics, University of Ioannina, 45110 Ioannina, Greece
| | - Ioannis D. Bassukas
- Department of Skin & Venereal Diseases, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Nikolaos Kourkoumelis
- Department of Medical Physics, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
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An In Vitro Investigation into Cryoablation and Adjunctive Cryoablation/Chemotherapy Combination Therapy for the Treatment of Pancreatic Cancer Using the PANC-1 Cell Line. Biomedicines 2022; 10:biomedicines10020450. [PMID: 35203660 PMCID: PMC8962332 DOI: 10.3390/biomedicines10020450] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 02/01/2023] Open
Abstract
As the incidence of pancreatic ductal adenocarcinoma (PDAC) continues to grow, so does the need for new strategies for treatment. One such area being evaluated is cryoablation. While promising, studies remain limited and questions surrounding basic dosing (minimal lethal temperature) coupled with technological issues associated with accessing PDAC tumors and tumor proximity to vasculature and bile ducts, among others, have limited the use of cryoablation. Additionally, as chemotherapy remains the first-line of attack for PDAC, there is limited information on the impact of combining freezing with chemotherapy. As such, this study investigated the in vitro response of a PDAC cell line to freezing, chemotherapy, and the combination of chemotherapy pre-treatment and freezing. PANC-1 cells and PANC-1 tumor models were exposed to cryoablation (freezing insult) and compared to non-frozen controls. Additionally, PANC-1 cells were exposed to varying sub-clinical doses of gemcitabine or oxaliplatin alone and in combination with freezing. The results show that freezing to −10 °C did not affect viability, whereas −15 °C and −20 °C resulted in a reduction in 1 day post-freeze viability to 85% and 20%, respectively, though both recovered to controls by day 7. A complete cell loss was found following a single freeze below −25 °C. The combination of 100 nM gemcitabine (1.1 mg/m2) pre-treatment and a single freeze at −15 °C resulted in near-complete cell death (<5% survival) over the 7-day assessment interval. The combination of 8.8 µM oxaliplatin (130 mg/m2) pre-treatment and a single −15 °C freeze resulted in a similar trend of increased PANC-1 cell death. In summary, these in vitro results suggest that freezing alone to temperatures in the range of −25 °C results in a high degree of PDAC destruction. Further, the data support a potential combinatorial chemo/cryo-therapeutic strategy for the treatment of PDAC. These results suggest that a reduction in chemotherapeutic dose may be possible when offered in combination with freezing for the treatment of PDAC.
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Fischer G, Handler M, Johnston PR, Baumgarten D. Impedance and conductivity of bovine myocardium during freezing and thawing at slow rates - implications for cardiac cryo-ablation. Med Eng Phys 2019; 74:89-98. [PMID: 31570217 DOI: 10.1016/j.medengphy.2019.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 01/19/2023]
Abstract
Increasing impedance during freezing might be a valuable marker for guiding cardiac cryo-ablation. We provide model based insights on how decreasing temperature below the freezing point of tissue relates to the percentage of frozen water. Furthermore, we provide experimental data for comparing this percentage with the increase in impedance. Measurements were performed on a bovine tissue sample at frequencies between 5 and 80 kHz. Slow cooling and heating rates were applied to minimize temperature gradients in the myocardial sample and to allow accurate assessment of the freezing point. Computer simulation was applied to link impedance with temperature dependent conductivities. The osmotic virial equation was used to estimate the percentage of frozen water. Measurements identified the freezing point at -0.6 ∘C. At -5 ∘C, impedance rose by more than a factor of ten compared to that at the freezing point and the percentage of frozen water was estimated as being 89%. At -49 ∘C impedance had increased by up to three orders of magnitude and ice formation was most pronounced in the extracellular space. Progressive ice formation in tissue is reflected by a large increase in impedance, and impedance increases monotonically with the percentage of frozen water. Its analysis allows for experimental assessment of factors relevant to cell death. Solid ice contributes to the rupture of the micro-vasculature, while phase shifts reflect concentration differences between extra- and intracellular space driving osmotic water transfer across cell membranes.
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Affiliation(s)
- G Fischer
- Institute of Electrical and Biomedical Engineering, UMIT - Private University for Health Sciences, Medical Informatics and Technology, Eduard-Wallnoefer-Zentrum 1, Hall in Tyrol 6060, Austria; AFreeze GmbH, Innsbruck, Austria.
| | - M Handler
- Institute of Electrical and Biomedical Engineering, UMIT - Private University for Health Sciences, Medical Informatics and Technology, Eduard-Wallnoefer-Zentrum 1, Hall in Tyrol 6060, Austria; School of Environment and Science, Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, Australia
| | - P R Johnston
- School of Environment and Science, Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, Australia
| | - D Baumgarten
- Institute of Electrical and Biomedical Engineering, UMIT - Private University for Health Sciences, Medical Informatics and Technology, Eduard-Wallnoefer-Zentrum 1, Hall in Tyrol 6060, Austria; Institute of Electrical and Biomedical Engineering, Technische Universität Ilmenau, Ilmenau, Germany
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Abstract
STUDY PURPOSE Effectiveness of cryotherapy on skin wart models. MATERIALS AND METHODS Two small cryotherapy devices, Wartner and Wortie, were administered for 10″-60″ on tomatoes and potatoes used as skin wart models. Frozen surface and depth were evaluated by standardized photography and computer analysis. Tissue temperature at depths of 0.1-10 mm was assessed by an electronic thermometer during treatment. RESULTS Cryotherapy induced a transient freezing of the tomato surface. The devices produced similar tomato tissue temperature reduction at all depths examined. At 5 mm, Wortie induced lower tissue temperatures than Wartner. Both devices induced potato tissue destruction to a depth of 0.5-1.2 mm at 40″ and 50″. Wartner induced a maximum destruction at 40″, Wortie led to a partially linear destruction depth with freezing time. The devices produced similar reduction of potato tissue temperature at all depths tested. Wartner induced more rapidly lower temperatures (1.5 mm, 10″, p = .001). Wortie induced lower tissue temperatures with time (0.1 mm, 50″, p = .025; 60″, p = .039; 5 mm, 60″, p = .05). None of the devices reached the lethal temperature of -22 °C. CONCLUSIONS Both cryotherapy devices produced sufficient tissue damage, at least in the potatoes, to a depth of 0.5-1.2 mm when applied for 40″ (commercially proposed time).
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Affiliation(s)
| | - Christos C Zouboulis
- b Departments of Dermatology, Venereology, Allergology and Immunology , Dessau Medical Center, Theodore Fontane Medical University of Brandenburg , Dessau , Germany
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Kolomeyets NL, Roshchevskaya IM. The electrical resistivity of a segment of the tail, lungs, liver, and intercostal muscles of the grass snake during in vivo cooling. Biophysics (Nagoya-shi) 2016. [DOI: 10.1134/s0006350916050110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Meir A, Rubinsky B. Electrical impedance tomographic imaging of a single cell electroporation. Biomed Microdevices 2014; 16:427-37. [PMID: 24573503 DOI: 10.1007/s10544-014-9845-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A living cell placed in a high strength electric field, can undergo a process known as electroporation. It is believed that during electroporation nano-scale defects (pores) occur in the membrane of the cell, causing dramatic changes to the permeability of its membrane. Electroporation is an important technique in biotechnology and medicine and numerous methods are being developed to improve the understanding and use of the technology. We propose to extend the toolbox available for studying electroporation by generating impedance distribution images of the cell as it undergoes electroporation using Electrical Impedance Tomography (EIT). To investigate the feasibility of this concept, we develop a mathematical model of the process of electroporation in a single cell and of EIT of the process and show simulation results of a computer-based finite element model (FEM). Our work is an attempt to develop a new imaging tool for visualizing electroporation in a single cell, offering a different temporal and spatial resolution compared to the state of the art, which includes bulk measurements of electrical properties during single cell electroporation, patch clamp and voltage clamp measurement in single cells and optical imaging with colorimetric dyes during single cell electroporation. This paper is a preliminary theoretic feasibility study.
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Affiliation(s)
- Arie Meir
- Graduate Program in Biophysics, UC Berkeley, 6124 Etcheverry Hall, Berkeley, CA, 94720, USA,
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Daniels CS, Rubinsky B. Cryosurgery with pulsed electric fields. PLoS One 2011; 6:e26219. [PMID: 22087224 PMCID: PMC3210118 DOI: 10.1371/journal.pone.0026219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 09/22/2011] [Indexed: 01/04/2023] Open
Abstract
This study explores the hypothesis that combining the minimally invasive surgical techniques of cryosurgery and pulsed electric fields will eliminate some of the major disadvantages of these techniques while retaining their advantages. Cryosurgery, tissue ablation by freezing, is a well-established minimally invasive surgical technique. One disadvantage of cryosurgery concerns the mechanism of cell death; cells at high subzero temperature on the outer rim of the frozen lesion can survive. Pulsed electric fields (PEF) are another minimally invasive surgical technique in which high strength and very rapid electric pulses are delivered across cells to permeabilize the cell membrane for applications such as gene delivery, electrochemotherapy and irreversible electroporation. The very short time scale of the electric pulses is disadvantageous because it does not facilitate real time control over the procedure. We hypothesize that applying the electric pulses during the cryosurgical procedure in such a way that the electric field vector is parallel to the heat flux vector will have the effect of confining the electric fields to the frozen/cold region of tissue, thereby ablating the cells that survive freezing while facilitating controlled use of the PEF in the cold confined region. A finite element analysis of the electric field and heat conduction equations during simultaneous tissue treatment with cryosurgery and PEF (cryosurgery/PEF) was used to study the effect of tissue freezing on electric fields. The study yielded motivating results. Because of decreased electrical conductivity in the frozen/cooled tissue, it experienced temperature induced magnified electric fields in comparison to PEF delivered to the unfrozen tissue control. This suggests that freezing/cooling confines and magnifies the electric fields to those regions; a targeting capability unattainable in traditional PEF. This analysis shows how temperature induced magnified and focused PEFs could be used to ablate cells in the high subzero freezing region of a cryosurgical lesion.
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Affiliation(s)
- Charlotte S Daniels
- Department of Mechanical Engineering, University of California, Berkeley, Berkeley, California, United States of America.
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Abstract
The increase in detection of small (≤ 4 cm) renal cortical neoplasms has made nephron-sparing surgery the new standard of care for T1a renal lesions. Advances in minimally invasive surgery have improved the surgical approach to these lesions to include laparoscopic partial nephrectomy and renal ablative therapies. In this review, we discuss the indications, outcomes, and potential complications of the commonly used ablative modalities in urologic practice. We will expand on renal cryoablation and review the mechanism of action, surgical approaches, and evidence based medicine using this modality.
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Affiliation(s)
- Adam C Mues
- Columbia University, Department of Urology, 161 Fort Washington Avenue, Herbert Irving Pavilion, 11th Floor, New York, NY 10032, USA
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Daniels CS, Rubinsky B. Temperature modulation of electric fields in biological matter. PLoS One 2011; 6:e20877. [PMID: 21695144 PMCID: PMC3113852 DOI: 10.1371/journal.pone.0020877] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 05/11/2011] [Indexed: 12/21/2022] Open
Abstract
Pulsed electric fields (PEF) have become an important minimally invasive surgical technology for various applications including genetic engineering, electrochemotherapy and tissue ablation. This study explores the hypothesis that temperature dependent electrical parameters of tissue can be used to modulate the outcome of PEF protocols, providing a new means for controlling and optimizing this minimally invasive surgical procedure. This study investigates two different applications of cooling temperatures applied during PEF. The first case utilizes an electrode which simultaneously delivers pulsed electric fields and cooling temperatures. The subsequent results demonstrate that changes in electrical properties due to temperature produced by this configuration can substantially magnify and confine the electric fields in the cooled regions while almost eliminating electric fields in surrounding regions. This method can be used to increase precision in the PEF procedure, and eliminate muscle contractions and damage to adjacent tissues. The second configuration considered introduces a third probe that is not electrically active and only applies cooling boundary conditions. This second study demonstrates that in this probe configuration the temperature induced changes in electrical properties of tissue substantially reduce the electric fields in the cooled regions. This novel treatment can potentially be used to protect sensitive tissues from the effect of the PEF. Perhaps the most important conclusion of this investigation is that temperature is a powerful and accessible mechanism to modulate and control electric fields in biological tissues and can therefore be used to optimize and control PEF treatments.
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Affiliation(s)
- Charlotte S Daniels
- Department of Mechanical Engineering, University of California, Berkeley, California, United States of America.
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Gage AA, Baust JM, Baust JG. Experimental cryosurgery investigations in vivo. Cryobiology 2009; 59:229-43. [PMID: 19833119 DOI: 10.1016/j.cryobiol.2009.10.001] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/30/2009] [Accepted: 10/01/2009] [Indexed: 12/16/2022]
Abstract
Cryosurgery is the use of freezing temperatures to elicit an ablative response in a targeted tissue. This review provides a global overview of experimentation in vivo which has been the basis of advancement of this widely applied therapeutic option. The cellular and tissue-related events that underlie the mechanisms of destruction, including direct cell injury (cryolysis), vascular stasis, apoptosis and necrosis, are described and are related to the optimal methods of technique of freezing to achieve efficacious therapy. In vivo experiments with major organs, including wound healing, the putative immunological response following thawing, and the use of cryoadjunctive strategies to enhance cancer cell sensitivity to freezing, are described.
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Affiliation(s)
- A A Gage
- Department of Surgery, SUNY Buffalo, Buffalo, NY, USA
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