Porto-Pulmonary Hypertension in Children: Insights From a National Registry.

Porto-pulmonary hypertension (PoPH) represents a rare but significant form of pulmonary arterial hypertension (PAH) in children. Despite its clinical importance, systematic analyses of paediatric presentations and outcomes remain limited. We analysed the United Kingdom National Registry for Paediatric Pulmonary Hypertension (2001-2022) identifying children with PoPH through standardised diagnostic criteria including cardiac catheterisation and cross-sectional imaging. In our cohort of 12 patients (58% female, median age 4 years, range: 3 months-12 years), congenital porto-systemic shunts (CPSS) were the predominant pathology (58%). We found a high prevalence of genetic abnormalities (50%) and congenital heart disease (50%). Haemodynamic assessment revealed evidence of pulmonary vascular disease (mean pulmonary artery pressure 38 mmHg, range 20-52 mmHg; mean pulmonary vascular resistance index 6.1 WU·m², range 4.2-9.0 WU·m²) without vaso-reactivity. Over a median follow-up of 8.2 years, three patients achieved resolution of pulmonary hypertension after definitive treatment of underlying liver pathology. Four deaths occurred during follow-up: three from progressive PAH and one unrelated death that occurred 2 years following PAH resolution. Our analysis reveals distinctive features of paediatric PoPH, including predominant CPSS aetiology, and earlier age of onset than previously reported. Multi-modality imaging proved essential for diagnosis, as initial ultrasound missed CPSS in 5/7 cases. The variable treatment outcomes emphasise the importance of individualised therapeutic approaches and sustained clinical surveillance.