Tetralogy of Fallot Repair

We present the case of a pediatric male at 3 months of age with tetralogy of Fallot with conoseptal hypoplasia and severe valvular and supravalvular stenosis. The patient presented with a 3/6 high pitched systolic ejection murmur loudest at the left upper sternal border and audible throughout the precordium and back. Standard surgical approach is through midline sternotomy using cardiopulmonary bypass with circulatory arrest. An incision is made into the right ventricular outflow tract (RVOT) with special care to avoid significant conal branch coronary arteries. The dysplastic valve is resected and a non-autologous CorMatrix patch is sewn into the ventricular septal defect in a running fashion. The anastomoses for the RVOT augmentation is begun at the distal main pulmonary artery and a second CorMatrix patch is sized and sewn into the RVOT in a running fashion. The patient was weaned from cardiopulmonary bypass and the chest tube and pacing wire were removed on post-operative day 1.

ECG and echocardiographic findings of right atrial enlargement and right ventricular hypertrophy.

Anterior descending coronary artery arising from the right coronary artery or associated congenital pulmonary atresia (discontinuity of the right ventricle and pulmonary artery).

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ECG (12/1/21): Sinus rhythm. Right atrial enlargement. Right ventricular hypertrophy. ECHO (10/19/21): Tetralogy of Fallot with conal septal hypoplasia. No muscular right ventricular outflow tract obstruction. Moderately hypoplastic pulmonary valve annulus (4.2 mm, z = -3.2) with thickened valve leaflets. Supravalvular pulmonary stenosis to 3.1 mm, with mildly hypoplastic distal MPA and confluent, low-normal size branch pulmonary arteries. Overall peak valvular and supravalvular pulmonary stenosis gradient is 83 mmHg. Large anterior malalignment ventricular septal defect with right-to-left systolic shunt and bidirectional diastolic shunt. Small secundum atrial septal defect vs patent foramen ovale with left to right shunt. Mildly dilated right atrium. Moderately dilated and hypertrophied right ventricle with normal systolic function. Normal left ventricular cavity size and systolic function. Trivial aortic valve insufficiency.

Tetralogy of fallot (TOF) is the most common cyanotic congenital heart disease and should be treated within the first year of life in order to prevent developmental delays, seizures, and correct heart rhythms. (1,2) The standard procedure is a transatrial-transpulmonary approach, however, in patients with small pulmonary valve annulus a transannular patch (TAP) is still necessary for right ventricular outflow tract obstruction (RVOTO) relief. (1) The patient is placed on cardiopulmonary bypass in the standard fashion. A conal branch coronary artery can be visualized next to the incision site, and care must be taken to preserve this vessel. A right ventricular to pulmonary artery conduit is performed in order to expose the septal defect. Upon exposure a non-autologous CorMatrix patch is sewn in a running fashion with 5-0 prolene. This patch is constructed from a multi-laminate sheet of decellularized, non-crosslinked, lyophilized extracellular matrix derived from porcine small intestine submucosa (SIS).(3) Similarly, the RVOT anastomoses was patched with a non-autologous CorMatrix patch and 5-0 prolene in a continuous running fashion. Overall survival following TOF repair has improved significantly in recent years, and perioperative mortality has fallen below 3%. (1) Patients who receive TAP have a higher perioperative mortality, although this may be due to the increased severity of diagnoses associated with this technique.

The transatrial correction of TOF was demonstrated by Prifti et al in 2003 [4]. This approach utilized a one-patch technique and reported a 10% in-hospital mortality rate, demonstrating a decrease in mortality, morbidity, and reoperation rates. [4] Consequently, the approach we used is better suited for patients with pulmonary valve annulus. [1] The TAP technique effectively relieves RVOTO but it leads to pulmonary valve regurgitation that must be corrected later. [5]

Complications of this procedure may include: -Leaking pulmonary valve (chronic pulmonary regurgitation), in which blood leaks through the valve back into the pumping chamber (right ventricle) -Leaking tricuspid valve -Holes in the wall between the ventricles (ventricular septal defects) that may continue to leak after repair or may need re-repair -Enlarged right ventricle or left ventricle that isn't working properly -Irregular heartbeats (arrhythmias) -Coronary artery disease -Enlargement of the ascending aorta (aortic root dilation) -Sudden cardiac death

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Van der Ven JPG, Van den Bosch E, et al. Current outcomes and treatment of tetralogy of Fallot. National Library of Medicine. 2019;8(1): Faculty Rev-1530. doi: 10.12688/f1000research.17174.1 Khan SM, Drury NE, et al. Tetralogy of Fallot: morphological variations and implications for surgical repair. Eur J Cardiothorac Surg. 2019 Jul 01;56(1):101-109. doi: 10.1093/ejcts/ezy474 Vasanthan V, Bigliogi M, et al. The CorMatrix PATCH for epicardial infarct repair. Future Cardiol. 2021;17(8):1297-1305. DOI: 10.2217/fca-2021-0017 Karl TR, Sano S, et al. Tetralogy of Fallot: favorable outcome of nonneonatal transatrial, transpulmonary repair. Ann Thorac Surg. 1992;54(5):903-907. oi: 10.1016/0003-4975(92)90646-l Blais S, Marielli A, et al. Comparison of long-term outcomes of valve-sparing and transannular patch procedures for correction of tetralogy of Fallot. JAMA Netw Open. 2021;4(7):e2118141. doi:10.1001/jamanetworkopen.2021.18141