Biventricular surgical repair of “Swiss Cheese” ventricular septal defects with two-patch and right ventricle apex excluding technique: preliminary experience and clinical results

Since May 2014, 10 consecutive infants were referred to our institution for “Swiss cheese” VSDs and 3 of them had major combined cardiac lesions. One patients had previously undergone a palliative procedure of main pulmonary artery banding in his neonatal period due to uncontrollable heart failure. The patients’ general characteristics are listed in Table 1. This study was approved by the institutional review board of the ethics committee in our hospital (QFELL-KY-2020-07).

The operation was performed through a median sternotomy with mild hypothermic (32–34 °C) cardiopulmonary bypass (CPB) established by standard aortic and bicavalcannulation. Myocardial protection was achieved by using one single dose of antegrade cold (4 °C–8 °C) HTK cardioplegic solution after aortic cross-clamping. A longitudinal right atriotomy was done and stay sutures were placed on the inner wall of the right atrium to evert the tricuspid valve.

The interventricular septum was exposed through the tricuspid valve orifice and a right angle clamp was passed through the atrial septum defect (ASD) or surgically created ASD, mitral valve orifice, left ventricular cavity and then one big “hole” of the “Swiss Cheese” VSDs to the right ventricular cavity. A 10 French size silicone Foley catheter was caught and withdrew to pass through the big “hole”, mitral valve orifice and ASD to meet the other end of the catheter by the right angle clamp. With gently pulling tension of the Foley catheter, the whole rim of the “Swiss Cheese” VSDs can be clearly visualized (Fig. 1). The “Swiss Cheese” VSDs involving interventricular septum could be always divided into two portions, the outflow tract area defects and the apex trabecular area defects, in the surgeon’s mind by the moderator band. The sizes of the two areas were measured and two fresh autologous pericardium patches of corresponding size were harvested and sutured along the edge of the portion with 6–0 or 5–0 polypropylene running suture respectively (Fig. 2). Sometimes, the upper patch would be sutured at the edge of the moderator band to make sure there was no leakage underneath. The lower patch was always sutured between the moderator band and the anterior wall of the right ventricular to exclude the apical portion of the right ventricle and obliterate all the left to right ventricular shunts. During suturing the lower patch, 3 to 5 6–0 or 5–0 polypropylene interrupted pledgetted sutures were evenly placed between the patch and the trabecular muscles to avoid septal bulging and prevent diminution of the right ventricular cavity or inflow occlusion across the inlet septum (Fig. 2). Combined cardiac lesions were corrected during the procedure. The tricuspid valve was tested for functional competence by infusion of saline into the right ventricle. Pacing wires were placed in all the cases and transesophageal echocardiography (TEE) was routinely done to evaluate the surgical results during the rewarming period (Fig. 3). Patient was wean off the CPB after TEE test. A mediastinal drainage tube was set and sternum was closed. Delayed chest closure was carried out to prevent cardiac tamponade in some cases.

Postoperative pulmonary hypertension was managed with phosphodiesterase inhibitor (Milrinone) in all the patients and treprostinil (Remodulin) in 3 cases with severe pulmonary hypertension. Chest radiography, electrocardiography (ECG), and TTE were performed before discharge. Outpatient follow-up was with clinical examination, ECG and TTE at 1 month, 3 months, 6 months, 1 year, and then yearly.