Percutaneous Left Atrial Venting for Prevention of Pulmonary Edema under Extracorporeal Membrane Oxygenation Therapy

Background: ECMO therapy as a short-term mechanical circulatory support increased in the last recent years. Besides ischemia of distal limbs and infections main complications include pulmonary edema. This results from a closed aortic valve and a low ejection fraction making weaning or bridging to a durable left ventricular assist device difficult. Pneumonia and pneumonic sepsis following pulmonary edema are associated with high mortality.

Case Report: A 55-year-old man with a history of dilative cardiomyopathy suffered from dyspnea and fatigue for 2 weeks. He was admitted in cardiogenic shock in a secondary care hospital with two episodes of cardio-pulmonary resuscitation. A miniaturized venous-arterial extracorporeal membrane oxygenation (ECMO) system was implanted into the femoral vessels on-site and the patient transported to our center. Echocardiography showed a left ventricular (LV) ejection fraction of 5%, a large LV thrombus and a closed aortic valve despite positive inotropic therapy. Implant Technique: To prevent pulmonary edema we implanted a TandemHeart Protekt Solo Transseptal cannula into the left atrium (LA) using a trans-septal approach via femoral vein. The cannula was connected to the venous line of the ECMO circulation. A flow probe and clamp to reduce flow if necessary were attached to the LA line. LA flow was adjusted under TEE control. After seven days the ECMO and TandemHeart cannula have been weaned and explanted. The patient is back to work without neurological sequelae. The LV function is still moderately impaired and the LV thrombus of same size.

Discussion: Different treatment options to prevent or treat pulmonary edema associated with ECMO therapy have been described. Percutaneous techniques include intra-aortic balloon pump insertion or axial flow pump insertion through the aortic valve. But, in case of LV thrombus, this treatment is contraindicated. As far as we know, this is the first report of a percutaneous LA Vent for prevention of pulmonary edema and successful weaning. After successful weaning neither the LV thrombus increased in size nor remained a septal defect after septal puncture. Therefore, percutaneous implantation of a trans-septal cannula is a feasible and safe and can be performed in selected cases with LV thrombus formation and pulmonary edema in patients in need of ECMO therapy.