Experimental Investigation on the Ice Formation and Growth in Ex Vivo Bovine Liver
The paper presents a set of experiments to characterize the ice front propagation in ex vivo bovine liver samples. Based on previous successful experiments using water and agar-gel as tested materials, the methodology infers the ice evolution in the sample from temperature measures obtained at the cooling device only, with a technique known as mirror image. No analytical or numerical solutions are proposed for the phase change propagation inside the tested material, such as for instance the Stefan approach as a classical free boundary problem for a parabolic partial differential equation. Thermal events inside the tested material, such as the heat flux released during the phase transition, have been deduced by the measured temperatures and the numerical solution of the thermal field inside the cooling device, conceived to mimic some thermal features of an actual cryogenic probe. The application domain for these experiments is in the cryoablative therapy, and the aim is to help providing an increased knowledge on the thermal effects to better deduce the effectiveness of the treatment and reduce recurrences, while at the same time avoid damages in the proximal anatomical structures. Results show that it is possible to detect the triggering of ice formation at the interface between the liver samples and the cooling device and predict the ice front propagation according to a law linear on the heat subtracted per unit of area. In a few tens of seconds, the maximum ice penetration distance is about 2 mm inside the liver tissue, with a penetration rate that goes from 0.2 mm/s to 0.02 mm/s. Moreover, adopting a special sample configured as an agar-gel coating superimposed to an ex vivo liver layer, the arrival time of the ice penetrating the liver and the temperature at the interface between these materials were detected, in order to estimate the part of the heat flux useful to the ice formation with respect to that spent for cooling the surrounding medium. Based on this preliminary result, to improve the cryoablation effectiveness it could be useful to increase the heat flux per unit of surface at the beginning, instead of the ablation duration.
Experimental Investigation on the Ice Formation and Growth in Ex Vivo Bovine Liver, American Journal of BioScience.
Vol. 6, No. 3,
2018, pp. 35-44.
Mazur, P. (1984). Freezing of living cells: Mechanisms and implications. American Journal of Physiology - Cell Physiology, 16, C125–C142.
Choi, J., & Bischof, J. C. (2011). Cooling rate dependent biophysical and viability response shift with attachment state in human dermal fibroblast cells. Cryobiology, 63, 285 – 291.
Toner, M., Cravalho, E., Stachecki, J., Fitzgerald, T., Tompkins, R., Yarmush, M., & Armant, D. (1993). Nonequilibrium freezing of one-cell mouse embryos. Membrane integrity and developmental potential. Biophysical Journal, 64, 1908–1921.
Pegg, D. E., & Diaper, M. P. (1988). On the mechanism of injury to slowly frozen erythrocytes. Biophysical Journal, 54, 471 – 488.
Muldrew, K., & McGann, L. (1990). Mechanisms of intracellular ice formation. Biophysical Journal, 57, 525 – 532.
Muldrew, K., & McGann, L. (1994). The osmotic rupture hypothesis of intracellular freezing injury. Biophysical Journal, 66, 532 – 541.
Han, B., & Bischof, J. C. (2004). Direct cell injury associated with eutectic crystallization during freezing. Cryobiology, 48, 8–21.
Acker, J. P., Elliott, J. A., & McGann, L. E. (2001). Intercellular ice propagation: Experimental evidence for ice growth through membrane pores. Biophysical Journal, 81, 1389 – 1397.
Balasubramanian, S., Bischof, J., & Hubel, A. (2006). Water transport and iif parameters for a connective tissue equivalent. Cryobiology, 52, 62–73.
Weng, L., Tessier, S. N., Swei, A., Stott, S. L., & Toner, M. (2017). Controlled ice nucleation using freeze-dried pseudomonas syringae encapsulated in alginate beads. Cryobiology, 75, 1 – 6.
Gaita, F., Riccardi, R., Caponi, D., Shah, D., Garberoglio, L., Vivalda, L., Dulio, A., Chiecchio, A., Manasse, E., & Gallotti, R. (2005). Linear cryoablation of the left atrium versus pulmonary vein cryoisolation in patients with permanent atrial fibrillation and valvular heart disease. Circulation, 111, 136–142.
Gaita, F., Caponi, D., Scaglione, M., Montefusco, A., Corleto, A., Di Monte, F., Coin, D., Di Donna, P., & Giustetto, C. (2008). Long-term clinical results of 2 different ablation strategies in patients with paroxysmal and persistent atrial fibrillation. Circulation: Arrhythmia and Electrophysiology, 1, 269–275.
Giaretto, V., & Passerone, C. (2017). Mirror image technique for the thermal analysis in cryoablation: Experimental setup and validation. Cryobiology, 79, 56 – 64.
Fürnkranz, A., Köster, I., Chun, K. J., Metzner, A., Mathew, S., Konstantinidou, M., Ouyang, F., & Kuck, K. H. (2011). Cryoballoon temperature predicts acute pulmonary vein isolation. Heart Rhythm, 8, 821 – 825.
Gonzalez, R. C., & Woods, R. E. (2006). Digital Image Processing (3rd Edition). Upper Saddle River, NJ, USA: Prentice-Hall, Inc.
Kim, C., O’Rourke, A. P., Will, J. A., Mahvi, D. M., & Webster, J. G. (2008). Finite-element analysis of hepatic cryoablation around a large blood vessel. IEEE Transactions on Biomedical Engineering, 55, 2087–2093.
Chan, J. Y., & Ooi, E. H. (2016). Sensitivity of thermophysiological models of cryoablation to the thermal and biophysical properties of tissues. Cryobiology, 73, 304 – 315.
Matta, M., Anselmino, M., Ferraris, F., Scaglione, M., Gaita, F. (2018). Cryoballoon vs. radiofrequency contact force ablation for paroxysmal atrial fibrillation: a propensity score analysis. J Cardiovasc Med, 19(4), 141 – 147.
Matta, M., Anselmino, M., Scaglione, M., Vitolo, M., Ferraris, F., Di Donna, P., Caponi, D., Castagno, D., Gaita, F. (2017). Cooling dynamics: a new predictor of long-term efficacy of atrioventricular nodal reentrant tachycardia cryoablation. J Interv Card Electrophysio, 48(3), 333 – 341.
Ting-Yung, C., Li-Wei, L., Abigail, L., Yenn-Jiang, L., Shih-Lin, C., Yu-Feng, H., Fa-Po, C., Tze-Fan, C., Nan, L., Ta-Chuan, T., Chin-Yu, L. (2018). The importance of Extra-Pulmonary Vein Triggers and Atypical Atrial Flutter in Atrial Fibrillation Recurrence After Cryoablation: Insights from Repeat Ablation Procedures. J Cardiovasc Electrophysiol. doi: 10.1111/jce. 13741.
Larnier, L., Badenco, N., Thuillot, M., Bravetti, M., Gandjbakhch, E., Duthoit, G. (2018). Comparison of incidences of pulmonary vein stenosis between radiofrequency and cryoablation in atrial fibrillation ablation. Rhythmology and stimulation, 10(1), 89 – 90.
Marrouche, N. F., Brachmann, J., Andresen, D., Siebels, J., Boersma, L., Jordaens, L., Merkely, B., Pokushalov, E., Sanders, P., Proff, J., Schunkert, H., Christ, H., Vogt, J., Bänsch, D. (2018). CASTLE-AF Investigators. Catheter Ablation for Atrial Fibrillation with Heart Failure. N Engl J Med., 378(5), 417 – 427.
de Asmundis, C., Chierchia, G. B., La Meir, M. (2018). Extracardiac ice formation during CoolLoop cryoablation of atrial fibrillation. Pacing Clin Electrophysiol. 41, 1264 – 1265.