When Is Surgical Intervention Necessary for Isolated Ventricular Septal Defects?

Discovering a ventricular septal defect (VSD) during an echocardiogram can raise concerns, especially among parents of newborns. Many wonder whether immediate surgical treatment is always necessary. In this article, we will explore the types of VSDs that typically require surgical intervention, helping to clarify common uncertainties surrounding this condition.

1. Large VSDs Accompanied by Pulmonary Hypertension

Large ventricular septal defects associated with pulmonary hypertension often require early surgical correction. However, in the first three months of life, infants naturally experience a period of elevated pulmonary vascular resistance, which may mimic pulmonary hypertension. Therefore, a diagnosis of pulmonary hypertension before three months of age may not necessarily be caused by the VSD. For example, a one-month-old baby with a 4mm perimembranous VSD and pulmonary hypertension may show resolution of the elevated pressure after three months as the pulmonary resistance naturally decreases.

If, after three months, the VSD remains small (less than 5mm), especially if a pseudoaneurysm formation is observed, there may be potential for spontaneous closure. In such cases, and especially if there are no symptoms like recurrent respiratory infections or growth delays, surgery can often be postponed with regular echocardiographic follow-ups.

However, if pulmonary hypertension persists beyond three months, it may indicate a significant left-to-right shunt, leading to pulmonary overcirculation, poor growth, and cardiac dysfunction. In such cases, early surgical closure is strongly recommended. Additionally, if severe symptoms such as tachypnea, frequent lung infections, or feeding difficulties appear before three months, delaying surgery could be life-threatening. Early intervention is crucial to prevent heart failure, respiratory failure, or severe pulmonary infections.

In rare, extreme cases, long-standing pulmonary hypertension can lead to irreversible pulmonary vascular resistance and Eisenmenger syndrome, where right-to-left shunting causes cyanosis even at rest. At this stage, surgical closure is no longer an option. This highlights the importance of timely intervention before irreversible changes occur.

2. Subarterial or Supracristal VSDs

Ventricular septal defects located beneath the pulmonary artery, known as subarterial or supracristal VSDs, typically do not close on their own. These defects are often in close proximity to the right coronary cusp of the aortic valve and can lead to aortic valve prolapse and regurgitation. Early surgical intervention is recommended to prevent complications such as aortic regurgitation, which can significantly increase surgical complexity if left untreated.

Similarly, if echocardiography shows aortic valve override over the VSD, spontaneous closure is unlikely, and surgical correction is necessary. It is important to note that transcatheter closure is generally not advised for these types of defects due to the increased risk of inducing aortic valve regurgitation.

3. Perimembranous VSDs with Associated Complications

Some perimembranous VSDs are associated with high-velocity left ventricular to right atrial shunting, diffuse flow patterns, or proximity to the non-coronary cusp of the aorta. These characteristics increase the risk of aortic valve prolapse and regurgitation. In such cases, surgical correction is usually required, as spontaneous closure is unlikely and the risk of valve complications is significant.

4. VSDs Coexisting with Other Cardiac or Vascular Anomalies

Ventricular septal defects can also occur alongside other cardiac abnormalities. When associated with moderate to severe valvular regurgitation or coarctation of the aorta, early surgical intervention becomes essential. In complex congenital heart disease, VSDs are often part of broader anatomical anomalies, requiring a tailored treatment approach based on the specific combination of defects.

5. Management of Muscular VSDs

Single Small Muscular VSDs

Muscular VSDs may occur in isolation or in combination with perimembranous defects. Small muscular VSDs (less than 3mm) with minimal shunting may be observed conservatively, especially if surgical closure is technically challenging. Some of these defects may decrease in size or close completely as the child grows and the muscular septum develops further.

Multiple or Large Muscular VSDs

Large or multiple muscular VSDs are more complex to manage. In some cases, surgical closure may not be immediately feasible, and a palliative procedure such as pulmonary artery banding may be performed to reduce pulmonary overcirculation and protect heart function. Delaying intervention until heart failure develops significantly increases surgical risk, making early management critical.

In conclusion, not all ventricular septal defects require surgical treatment. However, certain types—especially those associated with pulmonary hypertension, aortic valve complications, or other cardiac anomalies—necessitate early intervention. Each case should be evaluated individually, ideally with the guidance of a pediatric cardiologist or congenital heart disease specialist. Regular follow-up and timely decision-making are key to ensuring the best outcomes for patients with VSDs.