Biventricular Repair in Hypoplastic Left Heart Syndrome
The patient was a 23-month-old, 11.7 kg girl with an antenatal diagnosis of hypoplastic left heart syndrome (mitral stenosis/aortic stenosis).
Transthoracic echocardiogram demonstrated a hypoplastic, non-apex forming left ventricle with moderate dysfunction and evidence of extensive endocardial fibroelastosis (EFE). Initial left ventricular volume was measured at 17 ml/m^2. The mitral valve was hypoplastic and stenotic. Further, the mitral valve demonstrated poor leaflet excursion with a small effective orifice (0.66cm: Z-score -2.59). Echobright papillary muscles also suggested EFE. The aortic valve was unicuspid and severely hypoplastic (0.32cm: Z-score -4.83). The aortic valve was severely stenotic with mild insufficiency.
Due to the borderline left ventricle size, dysfunction, and extensive EFE at day of life 0, it was decided to take the patient down the single ventricle pathway. She then underwent a Norwood/Sano procedure within the first week of life. The patient had a relatively uneventful postoperative course and represented for bidirectional Glenn at four months of age. The postoperative course was relatively uncomplicated, although she developed severe tricuspid regurgitation that necessitated valvuloplasty at seven months of age.
At slightly under two years of age, the patient represented for pre-Fontan assessment. Catheterization and cardiac magnetic resonance imaging (MRI) demonstrated improved left ventricular size and function as evidenced by an LV EDVi of 40 ml, an LVEF of 55%, and a LVEDP of 11 mm Hg. The MRI did demonstrate extensive, circumferential left ventricular EFE as evidenced by late gadolinium enhancement. The patient was discussed at a case management conference and determined to be a suitable candidate for Norwood/BDG takedown and biventricular repair.
The patient then underwent successful Norwood/BDG takedown and biventricular repair. Of note, the aortic valve was of adequate size and only mildly insufficient at the time of surgery, thus no attempt at aortic valvuloplasty was made. Also, due to the distance between the superior vena cava and right atrium, a 10 mm Gore-Tex tube graft was utilized as an interposition graft. This graft was also augmented anteriorly at the SVC/RA junction with a pulmonary homograft patch. Postoperative transesophageal echocardiogram demonstrated normal biventricular function, no tricuspid regurgitation, no mitral regurgitation or stenosis, and only mild aortic stenosis with a peak gradient of 20 mm Hg. Left atrial pressures were measured at 13 mm Hg with systolic blood pressures of 70-80 mm Hg.
The patient had a relatively uncomplicated postoperative course and was discharged on postoperative day 17. The patient is currently doing well at home.