Fibrous obstruction within the left ventricular outflow tract associated with ventricular septal defect: a pathologic...

Area of Science:

• Cardiovascular Pathology
• Pediatric Cardiology
• Echocardiography

Background:

• Echocardiography effectively visualizes small ridges in the heart.
• Surgical removal of these ridges during VSD closure is clinically recommended.

Purpose of the Study:

• To characterize ridges in the left ventricular outflow tract associated with ventricular septal defects (VSDs).
• To correlate ridge morphology with patient age and VSD type.
• To inform echocardiographic diagnosis and prognosis of VSD-related ridges.

Main Methods:

• Examination of 37 human heart specimens with VSDs and associated ridges.
• Classification of ridges based on morphology, location, and tissue type.
• Histologic confirmation of ridge composition.
• Exclusion of complex congenital heart lesions causing outflow tract obstruction.

Main Results:

• Three distinct ridge patterns were identified: endocardial folds (n=18), fibrous/keloidal ridges (n=12), and circumferential lesions (n=7).
• Endocardial folds were associated with the membranous septum and younger patients, while fibrous/keloidal ridges were more common in older patients.
• Histology confirmed endocardial folds as endothelial tissue and fibrous/keloidal ridges as fibrous tissue.

Conclusions:

• Endocardial folds and circumferential lesions appear benign, originating from the membranous septum and found in younger individuals.
• Protuberant fibrous ridges, associated with the outlet septum, may represent a continuum and require careful echocardiographic assessment.
• Distinguishing these ridge types aids in echocardiographic diagnosis and predicting patient outcomes.