Plastic bronchitis is a rare life-threatening complication of Fontan operation. When medical treatment is ineffective in the setting of high systemic venous pressures, Fontan fenestration may be considered to decompress venous pressures and improve cardiac output by creation of the right-to-left shunting. However, transcatheter approach can be difficult in patients with complex venous anatomy. We report a 4-year-old girl born with hypoplastic left ventricle and heterotaxy syndrome, who developed plastic bronchitis following extracardiac Fontan procedure. Her venous anatomy was complex with dextrocardia and interrupted inferior vena cava with azygos continuation. Stent fenestration was successfully performed via transhepatic approach, which was selected based on the anatomical relationship (between extracardiac conduit, left atrium, and hepatic veins) delineated by pre-catheterization cardiac MRI. Simultaneous transesophageal echocardiography guided the intervention. Her plastic bronchitis improved significantly in 3 months but slowly progressed after the stent fenestration. At her 8-month follow-up, stent fenestration remains open and she is currently under heart transplantation evaluation due to persistent plastic bronchitis. Treatment of plastic bronchitis can be undertaken with Fontan fenestration, with pre-procedural MRI playing an essential role in patients with complex venous anatomy.