Bile acid predicts congenital portosystemic venous shunt in patients with pulmonary arterial hypertension

The etiology of pulmonary arterial hypertension (PAH) is complex, especially the investigation of rare pathogeny is difficult. Congenital portosystemic venous shunt (CPSS) is a rare congenital anomaly in which the portal blood completely or partially bypasses the liver through a congenital portosystemic shunt, and drains directly into the inferior vena cava (IVC) (Howard and Davenport in J Pediatr Surg 32:494–497, 1997).CPSS is an uncommon cause of PAH (Christiane et al. in J Pediatr Gastroenterol Nutr 56:675–681, 2013), and often covered by other pathogenic factors. The clinical manifestations of CPSS-associated PAH are not specific, thus making it difficult to distinguish from PAH caused by other pathogenetic factors based on clinical presentations alone. This is a retrospective analysis of data from six patients with CPSS at a single center. Of these, five were diagnosed as PAH: four were also associated with other predisposing factors of pulmonary hypertension (PH). All patients had high serum bile concentration and high cardiac output. The aim of this retrospective study was to investigate the clinical recognition of PAH secondary to CPSS. The concentration of serum bile acid and cardiac output can be used as two important non-invasive indicators in clinical practice. Thus far, few studies have reported the clinical outcomes of CPSS-associated PAH specifically (Anna et al. in Hepatology 71:658–669, 2020;Franchi-Abella et al. in J Pediatr Gastroenterol Nutr 51:322–330, 2010;Uike et al. in Pediatr Pulmonol 53:505–511, 2018;). In the current study, such patients carried a poor prognosis if left untreated, or treated with pulmonary vasodilators alone.