<p>Aneurysm and pseudoaneurysm development is a known, albeit uncommon, complication after right ventricular outflow tract surgical reconstruction. Large right ventricular outflow tract aneurysms and pseudoaneurysms have not been extensively described in recent literature and we report our experience with this unusual complication in five patients at our institution over the last 8 years. Although uncommon, this complication has potentially important clinical implications. Thus, clinicians should be aware of its potential, particularly in certain anatomic conditions.</p>

<p><strong>OBJECTIVES: </strong>To evaluate short- and middle-term outcomes after transcatheter patent ductus arteriosus (TC-PDA) closure in small infants, specifically device-related left pulmonary artery (LPA) stenosis and aortic coarctation, risk factors, and changes over time.</p>

<p><strong>BACKGROUND: </strong>Recent studies have demonstrated successful transcatheter PDA (TC-PDA) closure in small infants. LPA stenosis and aortic coarctation have been seen after TC-PDA, but it is not clear whether device-related LPA/aortic obstruction persists.</p>

<p><strong>METHODS: </strong>A single-center retrospective study of infants ≤4 kg who underwent TC-PDA closure from February 1, 2007 to September 1, 2018 was performed, evaluating the incidence and risk factors for LPA stenosis and coarctation.</p>

<p><strong>RESULTS: </strong>Forty-four patients underwent successful TC-PDA with Amplatzer Vascular Plug II (AVPII; n = 30), Amplatzer Duct Occluder II-Additional Sizes (n = 10), Amplatzer Duct Occluder I (n = 3), and coil-filled AVPI (n = 1) devices, all via an antegrade approach. Median birthweight and procedural weight were 890 g (range: 490-3,250) and 2.8 kg (range: 1.2-4.0), respectively. Median follow-up was 0.7 years (range: 2 days-7 years). Thirty-eight patients had post-procedure echocardiograms assessing LPA/aortic obstruction. Of those, 17 had LPA flow acceleration/stenosis (≥1.5 m/s), which improved or resolved in all patients with available follow-up; 3 developed mild coarctation (&gt;2 m/s), which improved in the two with more than short-term follow-up; 4 developed mild flow acceleration (1.5-2 m/s) in the descending aorta, which resolved in three and increased in one (2.4 m/s). Flow acceleration in the LPA was associated with younger procedural age, larger PDA minimal diameter, and placement of a device other than the AVPII. There was no device-related mortality or need for reintervention.</p>

<p><strong>CONCLUSION: </strong>TC-PDA in small infants is effective, without significant complications. Device-related LPA/aortic obstruction can improve with time/growth.</p>