Ventricular Septal Defects Treatment & Management

Children with small ventricular septal defects (VSDs) are asymptomatic and have an excellent long-term prognosis. Neither medical therapy nor surgical therapy is indicated. Prophylactic antibiotic therapy against endocarditis is no longer indicated in most cases. For more information, see the American Heart Association recommendations for Antibiotic Prophylaxis for Infective Endocarditis. Maintenance of good oral hygiene is of paramount importance in reducing the risk of endocarditis.

In children with moderate or large VSDs, medical therapy is indicated to manage symptomatic congestive heart failure (CHF) because some VSDs may become smaller with time.

Uncontrolled CHF with growth failure and recurrent respiratory infection is an indication for immediate surgical repair. Neither the age nor the size of the patient is prohibitive in considering surgery.

Large, asymptomatic defects associated with elevated pulmonary artery (PA) pressure are often repaired when infants are younger than age 6-12 months. Surgical repair is indicated in older asymptomatic children with a normal pulmonary pressure if the pulmonary-to-systemic flow ratio (Qp:Qs) is large enough to result in left ventricular dilatation on echocardiography.

Prolapse of an aortic valve cusp is an indication for surgery even if the VSD is small. Early repair may prevent progression of the aortic valve insufficiency.

Early surgical repair (younger than age 1 year) of VSD appears to lead to a significant postsurgical acceleration of growth within 3-6 months in term and preterm infants and, thus, a favorable growth pattern. ^[15] However, patients who undergo a rapid postsurgery catch-up growth after a period of failure to thrive may have an increased risk of insulin resistance, metabolic syndrome, obesity, and cardiovascular disease. ^[15]

Elevated pulmonary vascular resistance may be maintained in some patients despite VSD closure and may, in fact, represent a primary disease of the pulmonary vessels.

Therapies used to manage symptomatic congestive heart failure (CHF) in children with moderate or large ventricular septal defects (VSDs) may include the following:

• Increased caloric density of feedings to ensure adequate weight gain - Occasionally, oral feeds must be supplemented with nasogastric tube feedings, because a baby in CHF may be unable to consume adequate calories for appropriate weight gain

• Diuretics (eg, furosemide) to relieve pulmonary congestion - Furosemide is usually given in a dosage of 1-3 mg/kg/d divided in 2 or 3 doses; long-term furosemide treatment results in hypercalciuria, renal damage, and electrolyte disturbances

• Angiotensin-converting enzyme (ACE) inhibitors (eg, captopril and enalapril) - These medications reduce both the systemic and pulmonary pressures (the former to a greater degree), thereby reducing the left-to-right shunt

• Digoxin (5-10 µg/kg/d) - This may be indicated if diuresis and afterload reduction do not relieve adequately symptoms, although the data regarding efficacy of this drug in this particular situation are controversial.  

The first operation described for the treatment of a VSD was a palliative one and involved placing a restrictive band across the main PA. ^[16] This approach was proposed because pulmonary vascular disease as a result of unimpeded flow to the lungs was recognized as a dreaded complication of a VSD. The procedure was popular for about 2 decades because it was associated with low mortality and morbidity.

The first intracardiac repair of a VSD was performed in 1954 by Lillehei et al, who used a parent as an oxygenator and a pump in controlled cross-circulation. ^[17] The current techniques of hypothermia and cardiopulmonary bypass were first reported in the 1970s. ^{[18, 19, 20]}

Surgical closure

At present, direct surgical repair using cardiopulmonary bypass is the preferred surgical therapy in most centers. PA banding, part of a 2-stage procedure, is largely reserved for critically ill infants with multiple VSDs or for those with associated anomalies.

Most perimembranous and inlet VSDs are repaired via a transatrial surgical approach. Defects in the outlet septum are approached through the pulmonary valve. Multiple muscular defects, especially near the apex, pose a difficult problem. Initial pulmonary banding or left ventricular (LV) approach through an apical left ventriculotomy and closing the defect with a single patch are the standard techniques.

Transcatheter therapy (see below) remains an experimental approach. A hybrid operation is a joint procedure involving the interventional cardiologist and the cardiac surgeon. This approach may be used for multiple VSDs where the perimembranous VSD is repaired surgically and the muscular VSDs are closed with a transcatheter device.

Transcatheter closure

Muscular VSDs have been closed with transcatheter devices for the past 15 years. Perimembranous VSDs, though relatively common, can be difficult to close percutaneously. With previous devices (eg, Rashkind or button devices), attempts to close this type of VSD have been unsuccessful, because of the proximity of the defects to the aortic valve resulting in potential aortic valve damage.

The Amplatzer membranous VSD occluder (AGA Medical Corporation; Golden Valley, Minnesota), has undergone phase I trials in the United States. This device is an asymmetric, self-expandable, double-disk unit. Current recommendations are to use this device in older patients who weigh more than 8 kg and who have a subaortic rim of more than 2 mm.

Most procedures are performed with the patient under general anesthesia and with transesophageal echocardiographic guidance. Reported complications have included aortic and tricuspid regurgitation, device embolization, complete heart block, transient left bundle-branch block (LBBB), hemolysis, small residual shunts, and perforation.

In a phase I study, Fu et al reported 3 adverse events of complete heart block, perihepatic bleeding, and rupture of tricuspid valve chordae tendineae. ^[21] In a previous article, they reported 2 cases of transient heart block that responded to high-dose steroids. ^[22] Subsequent studies found that the Amplatzer membranous VSD occluder resulted in excellent closure rates but had an unacceptably high rate of complete heart block. ^{[23, 24]}

Complications

A murmur of a residual VSD is not infrequent. Selective use of intraoperative transesophageal echocardiography (TEE) to assess closure may be useful. Decisions regarding reoperation are based on symptoms, left heart size, pulmonary pressure, and degree of shunting.

Right bundle branch block (RBBB) is common and may be caused by ventriculotomy or direct injury to the right bundle itself when suturing the VSD closed on the right ventricular aspect of the interventricular septum. Complete heart block can rarely occur and is associated with late mortality. LV dysfunction may occur after left ventriculotomy to close a muscular VSD. Ventricular arrhythmia can be a late problem.

Schmitt et al caution that use of hypothermic cardiopulmonary bypass in infants and children should be approached with care, as pediatric patients perfused with moderate hypothermia (32ºC) appear to require significantly higher and longer inotropic support compared those perfused with normothermia (36ºC). ^[25] However, perfusion temperature does not appear to affect cytokine release, organ injury, or coagulation. ^[25]

Pregnancy and prenatal care

The presence or lack of early care is not a factor in congenital cardiovascular malformations (CCVMs).

VSD associated with pulmonary vascular disease is one of the 2 major maternal cardiac risks; the other is pulmonary edema. A major objective of medical management is to minimize the factors that interfere with the limited circulatory reserve of pregnant women with VSDs. Diuretics can be used judiciously to manage edema of cardiac failure, but they should not be used to treat edema of normal pregnancy.

Pregnant women with heart disease should limit themselves to moderate isotonic exercise. Maternal mortality in pregnant women with heart disease has been associated with the functional class.

Because anxiety is a special concern in a primigravida, the expectant mother should be prepared mentally for pregnancy, labor, delivery, and puerperium.

Labor and delivery

In women with functionally mild unoperated lesions and in patients after successful surgical repair, management of labor and delivery is the same as for pregnant women without a VSD.

The recommendations of the American Heart Association state that no antibiotic prophylaxis is required for a normal vaginal delivery.

For pregnant women with functionally important congenital cardiac disease (unoperated or operated), the management of labor, delivery, and the puerperium is crucial to minimize risk.

Induced vaginal delivery is preferred over cesarean delivery. Cesarean delivery results in twice the blood loss of vaginal delivery. In addition, it is associated with risks of wound infection, uterine infection, thrombophlebitis, and potential postoperative complications.

Lifestyle changes (ie, exercise before and after surgery or catheterization) may not be required.

A restrictive VSD with a functional normal heart imposes no exercise limitation. Although patients can safely participate in competitive sports without restriction, adults in this category are uncommon. An important exception is the adult whose moderately restrictive perimembranous VSD decreased in size or closed spontaneously in infancy. However, 2-dimensional (2D) echocardiography with Doppler interrogation and color flow imaging should be performed to determine whether the defect closed by means of formation of a septal aneurysm.

Unrestricted exercise after surgical closure of a moderate-to-large VSD is permitted if the following criteria are met:

• Acceptable postoperative PA pressure

• Absence of clinically significant disturbances in ventricular rhythm during maximal exercise stress testing and during 24-hour ambulatory electrocardiography

• 2D echocardiographic evidence of an intact ventricular septum with normalization of LV and left atrial (LA) size and LV function

• 12-lead scalar electrocardiogram (ECG) revealing little or no evidence of LV volume overload or right ventricular (RV) pressure overload

After intracardiac repair of a VSD, long-term infrequent follow-up is necessary. Patients with small VSDs do not require indefinite follow-up although subacute bacterial endocarditis remains a theoretical risk. 

Patients with perimembranous VSDs who have undergone aneurysmal closure have a high incidence of LV-to-right atrium (RA) shunting and a 6% incidence of subaortic ridge, as shown in a large Chinese study. ^[6]

With increasing age, the incidence of aortic leaflet prolapse and aortic insufficiency increases in children with the doubly committed and perimembranous type of VSD.