A tale of two cases of pulmonary arteriovenous malformation: How they fared after cardiac transplantation

Background In single ventricle patients, aortopulmonary collaterals ( APC s) and pulmonary arteriovenous malformations ( PAVM s) following superior cavopulmonary shunt ( CPS ) can complicate orthotopic heart transplant ( OHT ) by cyanosis and hemoptysis. Although PAVM s can regress with the restoration of hepatic venous flow to the pulmonary circulation, the effects of hypoxemia on the “unconditioned” allograft are not known. Cases Two patients with significant PAVM s after CPS were cyanotic following OHT . One patient with predominantly unilateral left PAVM s had arterial saturation levels less than 70% despite pulmonary vasodilators and ventilation. A custom flow restrictor‐covered stent was deployed in the pulmonary artery of the affected side, redirecting the blood flow to the contralateral lung, immediately improving cyanosis. When the PAVM s regressed, the flow restrictor stent was dilated to eliminate the constriction. The second patient with PAVM s had cyanosis and severe hemoptysis from APC s post‐ OHT . The APC s required an extensive coil embolization, while the cyanosis responded to oxygen and pulmonary vasodilators. Both recipients did well with gradual resolution of PAVM s within 8 months. Conclusions Despite cyanosis from right‐to‐left intrapulmonary shunting, allograft function recovered. Novel transcatheter interventions can play a role in patients with significant APC s or PAVM following cardiac transplantation.