Reversal of Glenn-associated diffuse pulmonary arteriovenous malformations after total cavopulmonary connection: a case report

Background: Diffuse pulmonary arteriovenous malformations (PAVMs) are a rare but serious complication after the Glenn procedure. Clinically, they typically present with progressive hypoxemia, which can lead to worsening cyanosis, reduced exercise tolerance, and may even progress to heart failure. Case summary: We report an 8-year-old boy with complex congenital heart disease, including double outlet right ventricle, ventricular septal defect, atrial septal defect, and pulmonary stenosis. He underwent a bidirectional Glenn procedure at 6 months of age and subsequently developed progressive cyanosis. At 5 years old, he presented to our center, where comprehensive evaluation confirmed extensive PAVMs. Consequently, an extracardiac total cavopulmonary connection (TCPC) was performed. During the 3-year postoperative follow-up, the PAVMs completely resolved, oxygen saturation normalized, and clinical symptoms improved markedly. Conclusion: In patients with a history of Glenn procedure who present with unexplained hypoxemia, the possibility of postoperative PAVMs should be carefully considered. Early diagnosis and timely intervention can significantly improve outcomes. This case highlights the therapeutic value of TCPC in managing this complication.