Robich MP, Hagberg R, Schermerhorn ML, Pomposelli FB, Nilson MC, Gendron ML, Sellke FW, Rodriguez R. Hypothermia severely effects performance of nitinol-based endovascular grafts in vitro.
Ann Thorac Surg 2012;
93:1223-7. [PMID:
22385821 DOI:
10.1016/j.athoracsur.2011.12.058]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 12/18/2011] [Accepted: 12/21/2011] [Indexed: 12/20/2022]
Abstract
BACKGROUND
Nitinol is an alloy that serves as the base for numerous medical devices, including the GORE TAG Thoracic Endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ) thoracic aortic graft device. Given the increasing use of therapeutic hypothermia used during the placement these devices and in post-cardiac arrest situations, we sought to understand the impact of hypothermia on this device.
METHODS
Five 34-mm TAG devices were deployed in a temperature-controlled chamber at 20°C, 25°C, 30°C, 35°, and 37°C (25 total devices). A halographic measurement device was used to measure radial expansive force and normalized to the force at 37°C. Three 34-mm TAG devices were similarly deployed in a temperature-controlled water bath at each of the above temperatures. A laser micrometer was utilized to measure deployed diameter.
RESULTS
A statistically significant decrease in expansive force at 20°C, 25°C, and 30°C of 65%, 46%, and 6%, respectively, was noted. A statistically significant decrease in radial diameter at 20°C and 25°C of 17% and 11%, respectively, was noted. Although a 9% difference was noted at 30°C, it was not significant.
CONCLUSIONS
The nitinol-based TAG device shows marked decreases in radial expansive force and deployed diameter at temperatures at or below 30°C. Surgeons should be aware of the potential implications of placing nitinol-based endoprostheses in hypothermic conditions. In addition, all health care providers should be aware of the changes that occur in nitinol-based endoprostheses during therapeutic hypothermia.
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