We report a patient with hypoxia secondary to a right-to-left shunt through a patent foramen ovale, following aortic root, valve, and arch replacement due to an aortic dissection in the setting of the Marfan syndrome. Following the operation, he failed extubation twice due to hypoxia. An extensive workup revealed a right-to-left shunt previously not seen. The patent foramen ovale was closed using a percutaneous closure device. Following closure, our patient was extubated without difficulty and has done well postoperatively.A pproximately 25% of the general population is estimated to have a patent foramen ovale (PFO). Th ese small atrial septal defects, present from birth, are usually asymptomatic and found incidentally by echocardiogram or at autopsy (1). We describe the benefi t of closure of a PFO for postoperative hypoxia.
CASE DESCRIPTIONA 23-year-old Hispanic man with the Marfan syndrome presented with acute chest pain that radiated to his back. Th e diagnosis of a dilated aortic root and a type B aortic dissection was made quickly by computed tomography scan with contrast. He underwent surgical repair using a two-staged "elephant trunk" procedure. Th e initial stage of the procedure consists of an aortic valve, root, and arch replacement, including leaving an elephant trunk portion of the graft that hangs down into the descending aorta. Finally the descending thoracic aorta is wrapped at that level of the diaphragm. Th e second stage of the procedure uses a stent graft, via an endovascular approach, to connect the elephant trunk with the wrapped portion of the aorta. Following the fi rst stage, his postoperative course was complicated by recurrent hypoxia. He underwent two attempted extubations on postoperative days 1 and 7, but the hypoxia persisted. A PFO with a signifi cant right-to-left shunt was found on transesophageal echocardiogram with bubble study (Figure 1).On postoperative day 9, a percutaneous closure procedure was performed via the right femoral vein. A #25 Amplatzer Cribriform Septal Occluder (AGA Medical Corp., Plymouth, MN) was deployed in the PFO, and placement was confi rmed with intracardiac echocardiography and fl uoroscopy (Figure 2). A negative echocardiographic bubble study at the conclusion of the procedure confi rmed resolution of the right-to-left shunt. On day 10, extubation was successful and normal oxygen saturation was maintained. Th e patient was discharged from the hospital on postoperative day 22. Five weeks later, he underwent stage 2 of the "elephant trunk" procedure without postoperative respiratory complications. He continues to do well 5 months following the second stage of the procedure.
DISCUSSIONDespite the severity of potential consequences of a PFO, hypothesized benefi ts of closing PFOs, specifi cally for migraine headaches and strokes, have not resulted in clinical benefi t over standard medical management. Th ree large randomized controlled trials, RESPECT (2), CLOSURE I (3), and PC Trial (4), failed to show a benefi t of PFO closure over medical management fo...