TY - JOUR
T1 - Determination of cryothermal injury thresholds in tissues impacted by cardiac cryoablation
AU - Goff, Ryan P.
AU - Quallich, Stephen G.
AU - Buechler, Robert A.
AU - Bischof, John C.
AU - Iaizzo, Paul A.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Despite widespread clinical use of cryoablation, there remain questions regarding dosing and treatment times which may affect efficacy and collateral injury. Dosing and treatment times are directly related to the degree of cooling necessary for effective lesion formation. Human and swine atrial, ventricular, and lung tissues were ablated using two cryoablation systems with concurrent infrared thermography. Post freeze-thaw samples were cultured and stained to differentiate viable and non-viable tissue. Matlab code correlated viability staining to applied freeze-thaw thermal cycles, to determine injury thresholds. Tissue regions were classified as live, injured, or dead based upon staining intensity at the lesion margin. Injury begins at rates of ∼10 °C/min to 0 °C, with non-viable tissue requiring cooling rates close to 100 °C/min to ∼ −22 °C for swine and significantly greater cooling to −26 °C for human tissue (p = 0.041). At similar rates, lung tissue injury began at 0 °C, with human tissue requiring significantly less cooling, to ∼ −15 °C for complete necrosis and −26 °C for swine (p = 0.024). Data suggest that there are no significant differences between swine and human myocardial response, but there may be differences between swine and human lung cryothermal tolerance.
AB - Despite widespread clinical use of cryoablation, there remain questions regarding dosing and treatment times which may affect efficacy and collateral injury. Dosing and treatment times are directly related to the degree of cooling necessary for effective lesion formation. Human and swine atrial, ventricular, and lung tissues were ablated using two cryoablation systems with concurrent infrared thermography. Post freeze-thaw samples were cultured and stained to differentiate viable and non-viable tissue. Matlab code correlated viability staining to applied freeze-thaw thermal cycles, to determine injury thresholds. Tissue regions were classified as live, injured, or dead based upon staining intensity at the lesion margin. Injury begins at rates of ∼10 °C/min to 0 °C, with non-viable tissue requiring cooling rates close to 100 °C/min to ∼ −22 °C for swine and significantly greater cooling to −26 °C for human tissue (p = 0.041). At similar rates, lung tissue injury began at 0 °C, with human tissue requiring significantly less cooling, to ∼ −15 °C for complete necrosis and −26 °C for swine (p = 0.024). Data suggest that there are no significant differences between swine and human myocardial response, but there may be differences between swine and human lung cryothermal tolerance.
KW - Atrial fibrillation
KW - Cryoablation
KW - Cryothermal tolerance
KW - Phrenic nerve palsy
UR - http://www.scopus.com/inward/record.url?scp=85009289222&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85009289222&partnerID=8YFLogxK
U2 - 10.1016/j.cryobiol.2017.01.002
DO - 10.1016/j.cryobiol.2017.01.002
M3 - Article
C2 - 28062180
AN - SCOPUS:85009289222
SN - 0011-2240
VL - 75
SP - 125
EP - 133
JO - Cryobiology
JF - Cryobiology
ER -