How does descending aorta geometry change when it dissects?

Abstract

Type B aortic dissection increases the diameter, length and volume of the descending thoracic aorta. The predissection aortic diameter most closely resembles the post-dissection maximum diameter of the true lumen.

Equations for Estimating the Predissected Diameter of the Descending Aorta From Computed Tomographic Images at the Onset of Aortic Dissection

“…Okuno et al15 reported an increase in the descending aorta from 10.9±2.9 to 12.9±3.8 mm after induced dissection in an experimental study using the swine model. Rylski et al11 reported a geometrical change in the descending aorta in 25 patients with acute type B aortic dissection compared with enhanced CT scans within 2 years before dissection, which is similar to the present study. They found that the mean total diameter changed from 28.2 to 34.6 mm (+23% increase), and the predissection diameter showed a significant difference from the postdissection TL maximum diameter (30.5 versus 28.5 mm, P <0.0001).…”

“…The cross‐sectional area and CL of the TL are affected by the shape of the decompressed TL. In Rylski et al's11 study, the severity of TL decompression was not addressed, and we thus could not compare our results with their results.…”

“…Second, information on the predissected aortic diameter just before dissection is not usually available in the clinical setting. Few reports have addressed the morphological relation between the predissected and postdissected descending aorta 11. Additionally, to the best of our knowledge, no reports have addressed the method of measuring the exact size of dissected aorta.…”

“…Unfortunately, we could not find any previous data that might support our equations. Rylski et al11 reported that the predissection diameter and postdissection TL at the first descending thoracic aortic quartile (calculated from the cross‐sectional area) were 30.5 and 23.8 mm (−23% decrease), respectively. In our study the mean predissected aortic diameter and postdissected TL diameter (measured by tracing the borderline) were 27.3 and 23.9 mm (−13.1% decrease), respectively.…”

Certain aortic geometries and hemodynamics are associated with FID development and impact the evolution of uncomplicated type B intramural hematoma during the acute phase

“…However, compared with healthy elderly individuals in Asian populations, uncomplicated patients with IMHB showed clear changes in the diameters of the ascending aorta (39.4 ± 6.7 mm) and descending aorta (34.5 ± 7.9 mm) and the arch angle (103.8 ± 25 degrees) . Rylski et al reported similar geometric changes before and after the onset of acute aortic syndromes, including aortic dilatation and increased aortic tortuosity. Schäfer also demonstrated in patients with elevated aortic stiffness that the wall shear stress and time‐averaged wall shear stress were significantly reduced from zones 1 to 4 and the oscillatory shear index was significantly elevated in zones 0, 1, and 4, which predicted the development of severe aortopathy.…”