**8. Treatment**

#### **8.1 Medical management**

Most small VSDs do not require intervention unless complications occur. In moderate to large defects, medical therapy is initiated if signs of pulmonary overcirculation and congestive heart failure develop. Standard medical therapy consists of diuretics, commonly furosemide. This helps to decrease preload and relieves symptoms such as tachypnea and tachycardia. Spironolactone is usually added to counter the hypokalemia related to the loop diuretic use. One other approach is afterload reduction, mostly with the use angiotensin converting enzyme (ACE) inhibitors such as captopril or enalapril to reduce the SVR which in turn decreases pulmonary blood flow and increases systemic flow. Digoxin, still preferred by some cardiologists, is not very commonly used anymore since the theoretical effect in the presence of normal systolic function is not well known. Medical therapy for congestive heart failure should be continued either until the defect size decreases, closes spontaneously, or until surgery as the case may be.

Medical management of patients with ES with anti – PAH drug therapy remains the main stay for treatment of Eisenmenger's syndrome. Three groups of pulmonary vasodilators have emerged since 1995. These include, prostacyclins such as epoprostenol, treprostinil, iloprost; endothelin receptor antagonists (bosentan, ambrisentan, macitentan); and phosphodiesterase-5 inhibitors, namely tadalafil and sildenafil [30]. One of the newer FDA approved therapy is a soluble guanylate cyclase stimulator, Riociguat. They are often used as mono, dual or triple therapy, as per the clinical scenario. Detailed discussion of the pulmonary vasodilators is beyond the scope of this chapter. Optimizing hemoglobin and iron levels is important, usually with oral and occasionally intravenous iron supplementation may become necessary. Phlebotomies and routine anticoagulation are not recommended. When polycythemia is found to be problematic (hematocrit >70%), erythropheresis instead phlebotomy is recommended. Oxygen supplementation is not shown to provide symptomatic relief or survival benefits in patients with ES. Definitive treatment is lung transplantation with VSD closure or heart–lung transplantation.

## **8.2 Surgical intervention**

Hemodynamically significant VSDs are those with congestive heart failure and pulmonary artery hypertension, and those causing failure to thrive or repeated respiratory infections [24]. VSDs producing cardiomegaly beyond a year of age are also considered hemodynamically significant [24].

Surgical closure of VSD remains the mainstay of treatment for most VSDs. Indications for surgical closure include hemodynamically significant shunts causing left ventricular volume overload and failure of medical therapy. A Qp:Qs >2:1 although difficult to calculate by non-invasive imaging modalities, is an indication for surgery in older and adult patients if there is normal or reversible pulmonary vascular resistance. Other indications include aortic valve prolapse with regurgitation, double chambered right ventricle with significant obstruction, left ventricular systolic dysfunction, or patients with previous history of bacterial endocarditis.

Majority of perimembranous VSDs are closed using a Dacron patch via right atriotomy with or without detachment of the tricuspid valve leaflets. Tricuspid valve detachment adds to the cardiopulmonary bypass and cross clamp time but there is no significant difference in postoperative residual shunts or degree of tricuspid regurgitation [31]. A transpulmonary approach is used in sub arterial, doubly committed VSDs. Although not widespread, some surgeons have reported use of the right axillary approach for closure of selected VSDs. Use of such methods are limited to certain centers and in mostly older adolescents and adults. Most muscular defects are difficult to close by surgical approach.

Surgery is relatively safe and the surgical mortality is low. Long term prognosis after surgical closure is excellent. After closure, catch up growth may take ~6–12 months and the left ventricular volume and mass eventually return to normal. Complications, although rare, include residual lesions, sinus node dysfunction, pulmonary hypertension, and modest progression of aortic insufficiency [32]. The incidence of complete heart block after closure of perimembranous defects is between 0.7 and 1% [33].

Although commonly used few decades ago, main pulmonary artery banding is rarely used in the management of most isolated VSDs. In rare situations such as in a child with other comorbidities where a complete repair is not feasible or where the VSD is difficult to close by standard techniques such as muscular "swiss-cheese" type defects, a main pulmonary artery banding procedure may be considered. Later, the band is removed with repair of main pulmonary artery and patch closure of VSD. In some cases, the muscular defects close spontaneously or at least become hemodynamically insignificant to require closure [32].
