Smaller right pulmonary artery is associated with longer survival time without scimitar vein repair.

Introduction: The optimal management of scimitar syndrome remains incompletely defined. We (1) evaluated the impact of aortopulmonary collateral (APC) occlusion, (2) compared outcomes according to surgical approach for patients who underwent surgery, and (3) identified anatomic factors associated with longer survival time without scimitar vein repair.

Methods: We conducted a single center, retrospective study of 61 patients diagnosed with scimitar syndrome between 1995 and 2019. Right pulmonary artery to total pulmonary artery cross-sectional area (RPA:PA CSA) quantitatively assessed right pulmonary artery size. Anatomical features were analyzed for association with longer survival time without scimitar vein repair.

Results: Median follow-up time was 6 years (Q1-Q3, 2-12), with 96% 5-year survival. Twenty-three patients underwent APC occlusion, which significantly decreased symptoms of overcirculation (100%-46%; p = .001) and systolic pulmonary artery pressure (median, 34-29 mmHg; p = .004). Twenty-three patients underwent scimitar vein repair; 5-year freedom from scimitar vein stenosis was 90% among patients who underwent a reimplantation compared with 42% in patients with baffle repair (p = .1). Three patients underwent surgery before the first year of age, with lower 5-year freedom from scimitar vein stenosis (0% vs. 84%; p < .001). On multivariate analysis, a lower RPA:PA CSA was associated with longer survival time without scimitar vein repair (p = .003).

Conclusions: APC occlusion improves the clinical status of young and hemodynamically unstable patients. Repair at an early age is associated with an increased risk of scimitar vein stenosis. Scimitar vein repair might be avoided in patients with a smaller right pulmonary artery.