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Analysis on Secondary Flow Characteristics inside Bronchia of NonHeart Beating Donor Lung |
1 Institute of Biothermal Science and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China
2 Institute of Refrigeration and Cryogenic Engineering, University of Shanghai for Science and Technology, Shanghai 200093,China
3 Shanghai Pulmonary Hospital, Shanghai 200433,China |
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Abstract Nonheart beating donor (NHBD) lung is expected to be the most potential donor source for clinical lung transplantation, and low temperature ventilation was normally thought to effectively protect the donor lung in vivo. A 3D asymmetric bronchial model with four levels was reconstructed, and computational fluid dynamics (CFD) technique was adopted here for investigating the sencond flow structures inside NHBD lung bronchia under three kind respiratory frequencies, i.e. 0.125 Hz,0.25 Hz and 0.5 Hz. The results show that no second flow structures exist inside main bronchia during inspiration process, and the maximum difference of dimensionless velocity across the main section is 0.67@0.125 Hz, 0.5@0.25 Hz and 0.3 @0.5 Hz, respectively. However, there are obvious differences for the expiration process, and the maximum difference of dimensionless velocity across the main section is 1.25, 1.1 and 1.06, respectively. Due to the asymmetric structure of bronchial and bifurcation rotation angles, the second flow structures always present for further daughter bronchias but the maximum difference of dimensionless velocity of them do not change significantly with increasing breathing rates (about 1.0). Generally, the flow structures inside left side are more complicated than the right side. The current work indicates that the second flow structures always exist when low temperature ventilation is utilized to pretect NHBD lung, which may be beneficial to develop the optimization method for preserving NHBD lung in situ.
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[1]Gomez A, David, Varela U, et al. Present state of nonheartbeating lung donation [J]. Current Opinion in Organ Transplantation, 2008, 13(6): 659-663.
[2]Masaru K, Isao M. Effective 6\|hour preservation in nonheartbeating donor canine lungs with topical cooling: assessment from histopathological aspects [J]. Surgery Today, 2005, 35: 389-395.
[3]Van WC, Neyrinck AP, Geudens N, et al. Retrograde flush following topical cooling is superior to preserve the nonheartbeating donor lung [J]. European Journal of CardioThoracic Surgery, 2007, 31: 1125-1132.
[4]Kutschka I, Sommer SP, Hohlfeld JM, et al. Insitu topical cooling of lung grafts: early graft function and surfactant analysis in a porcine single lung transplant model [J]. European Journal of CardioThoracic Surgery, 2003, 24: 411-419.
[5]丁嘉安, 姜格宁. 肺移植 [M]. 上海:上海科学技术出版社, 2008.
[6]Han JQ, Zhang K, Cui J, et al. Acceptable Warm Ischemia Time of Tracheal Grafts From Non-|heartbeating Donors in Rats [J]. Transplantation Proceedings, 2011, 43(10): 3638-3642.
[7]Van Raemdonck DE, Jannis NC, Rega FR, et al. External cooling of warm ischemic rabbit lungs after death [J]. Ann Thoracic Surgery, 1996, 62: 331-337.
[8]Egan TM. Nonheartbeating donors in thoracic transplantation [J]. Journal of Heart Lung Transplant, 2004, 23: 3-10.
[9]Takahiro O, Alicia C, Salvatore P, et al. Highflow endobronchial cooled humidified air protects nonheartbeating donor rat lungs against warm ischemia [J]. Journal of Thoracic and Cardiovascular Surgery, 2006, 132: 413-419.
[10]彭富裕, 胥义, 赵晓刚,等. 无心跳供体肺原位降温保护系统的研究 [J]. 制冷学报, 2012, 33(4): 74-78.
[11]Werner H, Modeling inhaled particle deposition in the human lung—a review [J]. Journal of Aerosol Science, 2011, 42: 693-724.
[12]刘晶,胥义,刘道平, 等. 无心跳供体肺支气管内气体三维流动的数值模拟研究[J]. 中国生物医学工程学报, 2014,33(3):320-328.
[13]Nadim N, Chandratilleke TT. Secondary flow structure and thermal behaviour of immiscible twophase fluid flow in curved channels[J]. International Journal of Thermal Sciences, 2014, 82: 9-22.
[14]Horsfield K, Dart G, Olson DE. Models of the human bronchial tree [J]. Journal of Applied physiology, 1971, 31(2): 207-217.
[15]Lateb M, Masson C, Stathopoulos T, et al. Comparison of various types of k\|εmodels for pollutant emissions around a twobuilding conguration[J]. Wind Eng Ind Aerodyn, 2013, 115:9-21.
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