Gross features of normal tracheal vascular anatomy. (A) Anterior and lateral lumenal surface of casted but uncorroded trachea (opened posteriorly and flattened). Longitudinal vessels (LV) give off circumferential branches (CB) that are connected by vertical branches (VB). (B) Corroded specimen showing thyroid cartilage, trachea and esophagus with sutures delineating important anatomical areas. (C) Closer view of casted specimen showing circumferential branches (CB) and vertical branches (VB).