Cross Sectional Representation of the Pulmonary Trunk Interleaflet Triangles

Description

Seen from an anterosuperior angle, the pulmonary trunk is opened in cross section to expose the semilunar valve cusps and the interleaflet triangles (intercuspal trigones) that extend between adjacent commissures. Each triangle occupies the interval between the thin valve leaflets, rising superiorly toward the sinotubular junction and descending inferiorly toward the annular hinge line, with its fibrous tissue forming a small but distinct wedge between cusp insertions. The cusps sit centrally within the luminal circumference, while the triangular spaces lie peripherally, oriented radially between the leaflet attachments. Small structures. Big implications. Interleaflet triangles matter because they define the geometry of semilunar valve coaptation and the continuity between the arterial wall and the fibrous skeleton, a relationship surgeons must respect when repairing or replacing the right ventricular outflow tract (RVOT) or reconstructing the pulmonary root. Congenital variants and postoperative states, including pulmonary valve stenosis, repaired tetralogy of Fallot, or Ross procedure autograft implantation, often alter commissural position and leaflet symmetry, and the interleaflet triangles become key landmarks for restoring effective cusp apposition without inducing regurgitation. When you need to teach why a seemingly minor fibrous region can destabilize valve competence, this is the view that makes it concrete. Ideal for cardiothoracic surgery atlases, congenital heart disease teaching files, and valve morphology lectures in anatomy, pathology, and echocardiography or CT correlation sessions focused on the semilunar valves and great vessels. It also supports figure panels discussing leaflet repair, commissuroplasty, or root reconstruction where precise terminology around cusps, trigones, and fibrous continuity matters. Anatomical accuracy verified by SciePro's Medical Advisory Board.