Branch pulmonary artery stent angioplasty in infants less than 10 kg

Background: Branch pulmonary artery (PA) Stenting is an established strategy for PA stenosis in older children and adults. Its use in infants is less well established. We describe our experience of branch PA Stenting in infants <10 kg. Method: Retrospective chart review of infants <10 kg who underwent PA Stenting at The Children's Hospital, Westmead between 2010 and 2020. Pre and post-procedural angiograms were reviewed to determine PA size. Technical procedural success was defined as >50% increase in PA diameter. Procedural complications and need for PA re-intervention were ascertained. Results: Forty-one children (age 7.6 months, IQR 2.4–9.8 months, weight 5.9 ± 2.2 kg) had 43 primary Stent implantations (10/43 intraoperative versus 33/43 transcatheter; left pulmonary artery [LPA] 25/43, right pulmonary artery [RPA] 8/43 and bilateral 10/43). Diagnoses were tetralogy of Fallot (27%), hypoplastic left heart syndrome (24%), truncus arteriosus (12%), transposition of the great arteries (7%), other single ventricle (10%) and other biventricular (20%). 40/41 (98%) had undergone a cardiac intervention in the preceding 31 days, [IQR 1–181], with 17/41 having prior branch PA intervention. 14/41 patients had urgent Stenting. There were 2 minor and 1 major complications with no procedural mortality. LPA (LPApre 2.3 ± 1.0 × 2.2 ± 1.2 mm versus LPApost 5.2 ± 1.3 × 5.0 ± 1.7 mm, p < 0.01) and RPA (RPApre 2.5 ± 0.8 × 1.9 ± 0.8 mm versus RPApost 4.9 ± 1.0 × 4.1 ± 1.0 mm, p < 0.01) calibre increased post Stenting. 20/41 required branch PA reintervention (time to reintervention 13.6 months [IQR 8.2–29.3]. Conclusions: Branch PA Stenting is effective and safe in infants <10 kg with expected high rates of reintervention. Urgent PA Stenting provides relief of early post-operative haemodynamic compromise.