CA-39
Emergent bidirectional Glenn in an infant following innominate artery injury and considerations for early Glenn conversion
Scott J, Hoffman G, Niebler R, Hraska V
Children's Hospital of Wisconsin, Medical College of Wisconsin, Milwaukee, WI, USA
Introduction
We describe a case of emergent conversion to bidirectional Glenn (BDG) circulation in a 35-d/o infant s/p Norwood BT Shunt.
Case Report
35-d/o male with HLHS s/p Norwood BT shunt who required cardiac catheterization on DOL 34 for progressive hypoxia. He underwent left pulmonary artery stenting with improved oxygenation. However, the next day he became acutely hypoxic due to inadequate pulmonary blood flow and presumed stent thrombosis. He was emergently taken for BT shunt revision, but was found to have an innominate artery injury limiting viable positions for alternate BT shunt placement. From our database of early BDG in HLHS, we projected manageable oxygenation and pulmonary hemodynamics at his postnatal age, and therefore conversion to BDG circulation was performed.
Following BDG conversion the transpulmonary gradient was 5-8 mmHg and atrial pressure was 8-10 mmHg. Pharmacologic support consisted of milrinone, norepinephrine and epinephrine infusions. Diuretics were administered to minimize interstitial alveolar edema and inhaled nitric oxide (iNO) to reduce pulmonary vascular resistance. Permissive hypercapnea was maintained with PaCO2 50-60 mmHg and hematocrit maintained greater than 45%. Immediate postoperative Sp02 was 80-85%. He was extubated on POD 3 and supplemental oxygen was gradually weaned. He was discharge on DOL 67 with SpO2 75-80 % on room air.
Discussion
Optimal timing of BDG remains controversial. The interstage period between the Norwood and BDG represents the time of greatest risk of mortality for the infant with HLHS. Factors affecting decisions regarding timing of BDG conversion include oxygen saturation, ventricular function, presence of AV valve regurgitation, and pulmonary vascular resistance. Early BDG has been linked to lower oxygen saturation, prolonged pleural drainage and hospital length of stay without increased mortality. Recent work from the SVR trial revealed that transplant free survival was optimized when BDG palliation was performed between 3 and 6 months of age. However, there are instances when BDG conversion must be performed earlier due to elevated risk of interstage mortality.
Studies describing early BDG have generally described a lower age limit of approximately 2 months of age. In this case we elected to perform BDG in an infant just beyond the neonatal period due to inadequate systemic to pulmonary artery shunt options. We were able to successfully incorporate strategies to improve cerebral and pulmonary blood flow to reduce post-BDG hypoxia including permissive hypercapnea, iNO, and high hematocrit. This case highlights the potential for selective BDG conversion in infants as early as 1month of age when continued Stage 1 physiology represents a elevated risk of mortality.
Sources
1. Jacquiss RD et al. Ann Thorac Surg 2006;82:1260–6.
2. Petrucci J et al. Thorac Cardiovasc Surg 2010;139:562-8.
3. Meza JM et al. Circulation. 2017 Oct 31;136(18):1737-1748.
Top
