Table 3.

Aneurysmal structural wall score (adapted from Kataoka et al. [41])

Score	Histological observations
1	Dense wall with smooth muscle cells and regular layers of type IV collagen
2	Dense wall with smooth muscle cells and irregular layers of type IV collagen or scattered smooth muscle cells and relatively regular layers of type IV collagen
3	Scattered smooth muscle cells and irregular layers of type IV collagen
4	Presence of hyaline-like structures. Smooth muscle cells and collagen are still present
5	Hyaline-like structures in the entire aneurysmal wall. Smooth muscle cells and collagen are absent