Novel thermographic detection of regional malperfusion caused by a thrombosis during ex vivo lung perfusion.

OBJECTIVES

Although ex vivo lung perfusion (EVLP) has been clinically applied as a novel rig to evaluate marginal donor lungs, no parameters have been reported to objectively detect regional lung damage during EVLP. The aim of this study was to investigate whether regional donor lung malperfusion-related damage caused by a thrombus could be detected by thermography during EVLP.

METHODS

Lewis rats were divided into two groups: the Thrombosis group and the Control group (n = 6 in each group). All rats were heparinized and the lungs were flushed with 20 ml of Steen solution. In the Thrombosis group, a 30-mg artificial thrombus was inserted into the left main pulmonary artery. All the lungs were perfused and ventilated using the EVLP system. Perfusion flow was increased every 2 min up to 10 ml/min. The lungs were evaluated by collecting thermographical and physiological data during EVLP.

RESULTS

Pulmonary artery pressure was higher and lung compliance was lower in the Thrombosis group compared with those in the Control group (P = 0.0005 and <0.0001, respectively). Macroscopically, no differences were seen between the perfused area and the malperfused area, whereas significant differences were detected between them by thermography. The surface temperature of both lungs in the Control group and the right lungs in the Thrombosis group rose with increasing perfusion flow, whereas the surface temperature of the left lungs in the Thrombosis group did not rise (P < 0.0001).

CONCLUSIONS

Although physiological data could possibly imply the existence of thrombi in the Thrombosis group, it could not reveal which area was obstructed by thrombi; however, thermography could detect a malperfused region. Thermographical evaluation may become a promising strategy to detect regional damage in donor lungs.