Commissures of the Pulmonary Valve Semilunar Leaflet Transverse Section

Description

Cut through the right ventricular outflow tract in transverse section, the pulmonic (pulmonary) valve sits centrally at the junction of the infundibulum and the pulmonary trunk. Three semilunar cusps form a triradiate pattern, and their free margins meet at the commissures along the valve’s annulus, just inferior to the pulmonary sinuses. The anterior cusp lies most anterior, while the right and left cusps sit anterolateral to their respective sides, with the thin leaflet tissue spanning between commissural posts. Commissural anatomy matters when you are explaining why a seemingly small change in cusp coaptation can produce a clinically meaningful pressure gradient across the pulmonary valve. Congenital pulmonary valve stenosis often presents with commissural fusion and thickened cusps, and this transverse view is the clearest way to localize where balloon valvuloplasty splits fused commissures and where it can leave residual obstruction. A short step away sits the right ventricular outflow tract, so the illustration also supports teaching on postoperative or catheter-related pulmonary regurgitation when commissural integrity and leaflet edge apposition are altered. Cardiology and cardiothoracic surgery texts can pair this section with echocardiographic short-axis concepts, helping learners translate 2D planes into the actual geometry of cusp commissures in the pulmonic position. It also fits congenital heart disease modules, cath lab procedural briefs, and valve morphology figures in journal articles discussing stenosis severity, commissurotomy, and leaflet remodeling. Anatomical accuracy verified by SciePro's Medical Advisory Board.