The size of a ventricular septal defect (VSD) plays a role in determining whether surgery is required. VSDs range in size from small to large, with small VSDs (3 mm in diameter or less) being the most common and usually closing on their own by the time a child is 6 years old. Surgery for small VSDs is rare. Moderate VSDs (3-5 mm in diameter) dont usually cause symptoms and delaying surgery is usually advised if they arent causing problems elsewhere in the heart and lungs. Large VSDs (6-10 mm in diameter) often require surgery, and repair before age 2 can prevent permanent damage to the heart and lungs. Without repair before age 2, the damage becomes permanent and gets worse over time.
Infants with unrestrictive, large VSDs who are growing should be observed for signs that the VSD is becoming pressure restrictive and decreasing. If the VSD remains large and unrestrictive, most infants should undergo surgical closure at age 4-6 months. However, this is somewhat controversial, and although a repair later in the first year of life is acceptable, a progressive risk of pulmonary vascular disease after age 6 months is observed.
In summary, the size of a VSD determines whether surgery is required. Small VSDs usually close on their own, moderate VSDs dont usually cause symptoms, and large VSDs often require surgery. Infants with unrestrictive, large VSDs who are growing should be observed for signs that the VSD is becoming pressure restrictive and decreasing, and most infants should undergo surgical closure at age 4-6 months if the VSD remains large and unrestrictive.
