Development of the pulmonary circulation in ventricular septal defect: a quantitative structural study

Area of Science:

• Pediatric Cardiology
• Pulmonary Hypertension
• Vascular Biology

Background:

• Ventricular septal defects (VSDs) can lead to pulmonary hypertension, affecting lung development.
• Understanding the impact of VSDs on pulmonary circulation is crucial for timely intervention.

Purpose of the Study:

• To investigate the effects of pulmonary hypertension secondary to VSD on pulmonary artery morphometry in children.
• To determine the relationship between elevated pulmonary resistance and the development of the intraacinar pulmonary circulation.

Main Methods:

• Quantitative morphometric analysis of pulmonary arteries in nine children with VSD.
• Comparison of arterial size, number, and muscularity with normal controls.

Main Results:

• Pulmonary hypertension associated with VSDs hinders the growth and development of intraacinar pulmonary arteries.
• Reduced arterial size and number within the acinus were observed, resembling neonatal levels.
• Increased arterial and venous muscularity, with muscle extending to more peripheral vessels, was noted.

Conclusions:

• Pulmonary hypertension in VSD impairs normal pulmonary vascular development, characterized by reduced intraacinar circulation rather than obliterative disease.
• Early surgical closure of large VSDs (before age 2) is recommended due to the rapid progression of these vascular changes.