Interatrial shunting after major thoracic surgery: a rare but clinically significant event

Interatrial shunting after thoracic surgery through a patent foramen ovale or previously asymptomatic atrial septal defect has been reported as a rare, clinically significant and potentially treatable condition. The incidence, presentation, management, and outcome after thoracic surgery have yet to be defined.

We performed a retrospective cohort study of all patients undergoing major thoracic surgery (pneumonectomy, extrapleural pneumonectomy, pleurectomy) at our institution between January 2005 and December 2009. Perioperative records were reviewed up to 1 year postoperatively. The presenting clinical symptoms, and complications were identified, and data from the cardiac investigations (right-side heart catheterization, echocardiogram) were extracted into our database.

In all, 581 patients underwent major thoracic surgery during the period of study. We identified 8 cases of postoperative interatrial shunting, of which 7 occurred after right-sided surgery. The most common presentations were dyspnea, increase in oxygen requirements, and platypnea-orthodeoxia. Two patients presented with neurologic complications secondary to paradoxic embolism. The median time to presentation was 14 days after the operation. Five patients had increased pulmonary pressures postoperatively. Two patients required intervention, and the symptoms of the rest resolved with conservative management.

Interatrial shunting is a rare but clinically significant complication after thoracic surgery. The presentation is myriad, and can occur immediately postoperatively or more than a month later. Some cases may require interventions, although most resolve with conservative management.