INTACT RIGHT VENTRICLE-PULMONARY ARTERY SHUNT AFTER STAGE II PALLIATION IN HYPOPLASTIC LEFT HEART SYNDROME IMPROVES PULMONARY ARTERY GROWTH

Abstract

For patients with hypoplastic left heart syndrome who have undergone the Norwood procedure with a right ventricle–pulmonary artery (RV-PA) shunt, the shunt can either be removed or left intact at the time of the stage 2 procedure. This study aimed to determine the effects of an intact shunt on pulmonary artery growth and clinical outcomes after the stage 2 procedure. A retrospective review of patients who underwent Norwood with an RV-PA shunt from 2005 to 2010 was performed. Catheterization data, echocardiographic data, postoperative outcome variables, and mortality data were collected. Pulmonary artery size was measured at pre-stage 2 and pre-Fontan catheterizations using the Nakata Index and the McGoon Ratio. Of the 68 patients included in the study, 48 had the shunt removed at the time of stage 2 (group 1), and 20 had the shunt left intact (group 2). The two groups did not differ in terms of pre-stage 2 hemodynamics or pulmonary artery size. After stage 2, group 2 had higher oxygen saturations. The two groups did not differ regarding duration of chest tube drainage, length of hospital stay, need for unplanned interventions, or mortality. Before Fontan, the group 2 patients had higher superior vena cava (SVC) pressures and more venovenous collaterals closed. There was increased pulmonary artery growth between the pre-stage 2 and pre-Fontan catheterizations in group 2 using both the Nakata Index (+148.5 vs −52.4 mm2/m2; p = 0.01) and the McGoon Ratio (+0.36 vs +0.01; p = 0.01). These findings indicate that patients with an intact RV-PA shunt after stage 2 have greater pulmonary artery growth than patients with the shunt removed, with no increased risk of complications.