In Vivo Expression of Transplant Arteriosclerosis in Mice: The Non-invasive Assessment Strategies

Background: Transplant arteriosclerosis (TA) represents the hallmark of chronic rejection in solid organ transplants, leading to long-term graft failure. Traditionally, TA evaluation in murine models has relied heavily on histological analysis of vascular tissues. However, histology is invasive and terminal. Non-invasive methods, particularly high-resolution ultrasound, offer a promising alternative for real-time assessment of aortic dimensions, allowing longitudinal monitoring of TA progression without sacrificing the animal.

Methods: In this pilot study, we employed high-resolution ultrasound imaging to assess TA in a mouse model. TA was induced via orthotopic transplantation of the infrarenal aorta from six C57BL/6 mice. Ultrasound was used to non-invasively measure luminal obstruction and aortic wall thickening in the transplanted vessels. These measurements were compared with traditional histological analysis performed at 30 days post-transplantation.

Results: The ultrasound imaging revealed significant thickening of the aortic wall and reduction of the intimal diameter, consistent with the presence of TA. There was no major difference in diameters measured between these images for the aortic diameter (ultrasound: 1.67 ± 0.31 mm versus ex vivo: 1.65 ± 0.21 mm). The non-invasive ultrasound findings correlated strongly with histological observations (correlation coefficient > 0.99) confirming the validity of the ultrasound-based approach.

Conclusion: High-resolution ultrasound provides a reliable, reproducible, and non-invasive method for tracking the progression of TA, offering comparable results to histological assessment. This technique enables longitudinal studies and early detection of transplant arteriosclerosis.

Publication History

Article published online:
11 February 2025