Time dependent changes in aortic tissue during cold storage in physiological solution

Stored vascular tissues are employed in biomedical research for studies in imaging, in biomechanics, and/or in assessing vessel diseases. In the present study, the stability of aortic tissue in phosphate buffer saline (PBS) at 4°C was monitored over a course of 10 days as determined by the rate of glucose permeation measured by optical coherence tomography (OCT) and validated by histology.

The initial mean permeability through fresh porcine aorta was (2.32 ± 0.46)× 10(-5)cm/s (n=5); after maintaining the tissue at 4°C for 10 days, the mean rate was (7.37 ± 0.41)× 10(-5)cm/s (n=4), an increase of nearly 300%. A z-test verified that a significant change in the permeability rate (p<0.05) had occurred after 4 days of 4°C storage. Histology was used to quantify changes in tissue pore area. The increase in average pore area paralleled the increase in permeability rate over 10 days.

These results suggest that (1) the structural integrity of aortic tissue at 4°C is retained for at least the first three days after resection and (2) OCT is a powerful technology well suited for evaluating tissue structural integrity over time.

Functional OCT imaging provides for a noninvasive and quantitative technique in determining the structural integrity of aortic tissue stored at 4°C. This modality may be used for assessing the efficacy of other preservation techniques.