Clinical characteristics and therapeutic outcomes of pulmonary arterial hypertension secondary to congenital portosystemic shunts

The aim of this retrospective study was to investigate the clinical characteristics and therapeutic outcomes of pulmonary arterial hypertension (PAH) secondary to congenital portosystemic shunts (CPSS). Thirty-three pediatric patients diagnosed in our institution with CPSS between 2012 and 2019 were enrolled in this study. The patients were divided into PAH and non-PAH groups. The PAH group included 15 patients who presented with unexplained PAH when CPSS was diagnosed. Two patients with microangiopathic hemolytic anemia died of right heart failure shortly after diagnosis. One patient received a liver transplant at the age of 4.3 years and showed a mild decrease in pulmonary artery pressure (PAP) 4 years after the operation. Seven patients underwent one-stage shunt closure at a median age of 2.8 years (1.4–13 years). Follow-up examinations, from 1.6 to 4.1 years after intervention, showed marked reduction of PAP in one patient and stabilization of PAH in six others. However, in one patient who underwent two-stage shunt closure, a marked increase in PAP was noted after partial ligation of the shunt. The remaining four patients received only pulmonary vasodilator therapy, and one of them died of right heart failure 12 years after the PAH diagnosis. The non-PAH group included 18 patients without evidence of PAH upon CPSS diagnosis. Shunt closure was carried out in eight of these patients, but one patient subsequently developed PAH after the resolution of hepatopulmonary syndrome. Conclusion : CPSS may be a more likely cause of unexplained PAH in pediatric patients than previously thought. Shunt closure or liver transplantation may prevent the progression of PAH, or even improve it for the majority of CPSS patients. What is Known: • Congenital portosystemic shunts (CPSS) are increasingly recognized as a cause of pulmonary arterial hypertension (PAH) in children, but the prevalence of CPSS in pediatric PAH patients is largely unknown, and the therapeutic outcomes of these conditions are not well described. What is New: • This is the largest cohort of CPSS-associated PAH ever published. CPSS may be a not uncommon cause of unexplained PAH in pediatric patients. • Shunt closure or liver transplantation may prevent the progression of PAH, or even improve it for the majority of CPSS patients. • Shunt closure might cause unique pulmonary hemodynamic changes in CPSS patients associated with hepatopulmonary syndrome (HPS), even leading to the transition from HPS to PAH.