Incidental finding of PFO during cardiac surgery and implications - A dilemma in decision making

Abstract

Introduction Patent foramen ovale (PFO) is common finding during coronary artery bypass graft (CABG) surgery. There is lack of data to help guide treatment decisions regarding incidental findings of PFO during CABG surgery. Certainly, the benefit versus risk equation seems to be a reasonable approach on individualized basis. Methods 67 years old female with history of unstable angina, no other comorbidities and normal preoperative Echocardiogram underwent elective CABG. Intraoperative TOE showed good biventricular function, no significant valvular abnormality and moderate size PFO with left-right shunt. The PFO was not treated as the patient was asymptomatic preoperatively. Immediately in postoperative period the patient was hypoxic. CTPA showed basal atelectasis, TOE demonstrated pericardial collection and reversal of the flow across the PFO. Percutaneous closure of PFO was considered but deemed inappropriate due to lack of evidence. Following discharge patient was readmitted with shortness of breath. She underwent a complicated redo-sternotomy for surgical removal of pericardial collection and PFO closure. Injury to the RV due to adhesion required femoral cannulation and led to compartment syndrome. Peri-operative TOE demonstrated moderate PFO with significant right-left shunt. Failure of mechanical ventilation wean mandated another review by cardiology and decision to percutaneously close the PFO was agreed. PFO closure was followed by immediate drop in oxygen requirement and facilitated immediate extubation and wean from ventilation. Discussion There is no evidence to suggest incidental PFO in patients undergoing cardiac surgery is linked to morbidity or mortality, and no evidence to support closure. One study showed that change from a planned procedure to include PFO closure increased risk of postoperative stroke with no long-term survival benefit. PFOs in patients with history of cryptogenic stroke are known to be larger (>4 mm) with longer tunnels (>1 cm) and that size and history of paradoxical embolism are major factor behind the surgeon's decision to close PFO. Conclusion Lack of strong evidence has led to our patient's unanticipated complication and longer hospital stay. Closure of PFO in asymptomatic patient should be decided on individual basis. Stronger evidence and recommendations are necessary to prevent complications.