Background: Traditional palliation for biventricular cyanotic congenital heart lesions often involves staging with systemic-to-pulmonary arterial shunts to secure pulmonary blood flow (PBF) in the newborn period prior to complete repair. However, shunts may lead to life-threatening events secondary to shunt occlusion or acute coronary steal. They may be associated with morbidity secondary to diastolic runoff, systemic steal and volume loading, and do not provide pulsatile flow which has the potential to promote pulmonary artery (PA) growth. We have alternatively performed modified right ventricular outflow (mRVO) procedures by establishing antegrade right ventricle-to-PA flow.
Methods: Retrospective review of data on all patients who underwent the mRVO procedure from 2013 to 2016, including anatomy, number of interstage catheterizations, reoperations, intensive care unit admissions, hypercyanotic episodes, interval to complete repair, and mortality.
Results: Seventeen nonconsecutive patients included tetralogy of Fallot (n = 14), pulmonary valve stenosis (n = 2), and 1 with pulmonary atresia-intact septum; 14 had significant branch PA stenosis. Median age of first mRVO procedure was 14 days (range 5-193), and median duration of follow-up was 15.3 months (range 4-47 months). No patients had post-palliation acute hypercyanotic episodes. Nine were admitted to the ICU for persistent interstage hypoxemia, 7 of whom required reintervention prior to complete repair, which was achieved in 11 patients. Two late deaths unrelated to mRVO occurred.
Conclusions: The mRVO procedure is a potential option with satisfactory results. It avoids potential shunt-related sudden death. The physiology of the mRVO palliation may provide unique benefits by providing antegrade pulsatile PBF, facilitates catheter interventions, and avoids branch PA distortion and stenosis.
Keywords: CHD; cyanosis; pulmonary arteries; tetralogy.