Quantifying Thoracic Aortic Remodeling

The well-fixed thoracic aortic ring specimens were subjected to conventional tissue processing and embedded in paraffin wax. Thin sections (5 µm) were produced and stained with hematoxylin and eosin (H&E) to visualize the tissue morphology. Nikon Eclipse Ti2 microscope was used to capture the microscopic images of the thoracic aortic rings (4× and 40×). The thickness of the aorta was measured with Nikon NIS-Element AR software (Version 5.1). The media thickness was determined by measuring the distance from the internal elastic lamina to the external lamina. For each slide, measurements from 4 points (12, 3, 6, and 9 o’clock positions) were averaged. The lumen inner diameter was determined from the average of 12 and 6, and 9 and 3 o’clock positions. The media-to-lumen ratio, an index of aortic vascular remodelling, was calculated based on the measured lumen inner diameter and media data [28 (link)].