The impact of newly diagnosed patent foramen ovale in patients undergoing off-pump coronary artery bypass grafting: Case series of eleven patients

The increased use of transesophageal echocardiography (TEE) by anesthesiologists may lead to an increase in the intraoperative detection of previously undiagnosed patent foramen ovale (PFO). The impact of heart manipulation on interatrial shunting through a PFO during off-pump coronary artery bypass graft (CABG) has not been studied. We retrospectively studied 11 patients with PFOs who underwent off-pump CABG. TEE contrast studies and blood gas analyses were performed at baseline, during heart elevation for distal coronary arteries anastomoses, and at the end of the surgery. At baseline, 5 of 11 patients had left-to-right shunting and 2 of 11 had right-to-left shunting. Heart elevation did not result in oxygen desaturation in any patient; however, it caused the disappearance of a right-to-left shunt (n = 1), persistence of this shunt (n = 1), and the development of a new right-to-left shunt (n = 2). Return of the heart to its original position resulted in a return of TEE findings to the baseline state in all patients. This series suggests that off-pump CABG can be performed safely in the majority of patients with PFOs; however, additional investigation is needed to assure that adverse effects do not occur in a subset of patients undergoing off -pump CABG in the presence of a PFO.