Grade 1:
(1) Structure of valve: The structural integrity of the valve is retained. Mild fibrous thickening may be seen on the side of the sinus of Valsalva.
(2) Fibrosa and elastic tissue: intact
(3) Calcifications: none
Grade 2:
(1) Structure of valve: There is obvious thickening of the valve cusp.
(2) Fibrosa and elastic tissue: The fibrosa is slightly distorted but the elastic tissue is intact.
(3) Calcifications: There is early development of calcified nodules at the site of connective tissue degeneration, initially on the sinus of Valsalva side of the cusp.
Grade 3:
(1) Structure of valve: The valve cusp is grossly thickened and distorted.
(2) Fibrosa and elastic tissue: The fibrosa is distorted and the elastic tissue is stretched.
(3) Calcifications: Many calcified nodules present.
(4) Other findings: Cartilagenous and osseous metaplasia; cholesterol crystal deposits; neovascularization.
Grade 4A: Ulceration absent on the surface of the cusp.
(1) Structure of valve: The valve cusp is grossly distorted with most of the ordinary structural components altered, degenerated or destroyed.
(2) Fibrosa and elastic tissue: The fibrosa and elastic fibers are disrupted.
(3) Calcifications: Many calcified nodules present.
(4) Other findings: Cartilagenous and osseous metaplasia; cholesterol crystal deposits; neovascularization.
Grade 4B: Ulceration present on the surface of the cusp.
(1) Structure of valve: The valve cusp is grossly distorted with most of the ordinary structural components altered, degenerated or destroyed.
(2) Fibrosa and elastic tissue: The fibrosa and elastic fibers are disrupted.
(3) Calcifications: Many calcified nodules present.
(4) Other findings: Cartilagenous and osseous metaplasia; cholesterol crystal deposits; neovascularization.
