New application of heparin-bonded extracorporeal membrane oxygenation in difficult neurosurgery

We wished to evaluate the safety and the advantages of using heparin-bonded extracorporeal membrane oxygenation (ECMO) to replace conventional cardiopulmonary bypass (CPB) in deep hypothermic circulation for complex cerebral aneurysm surgery. Heparin-bonded ECMO without the bridging tube and the cardiotomy reservoir was set up through the femoral vessels. Limited heparin was infused. In deep hypothermia, the ECMO blood flow was temporarily decreased as low as the neurosurgeons' request. It was applied to 4 patients with difficult intracranial aneurysms who were selected for the procedure. Clipping, wrapping, or vascular bypass was implemented to manage the aneurysms under deep hypothermia. The total heparin dosage used in the whole procedure was 9,875 ± 1,625 U, and the mean ECMO time was 270 ± 105 min. The blood consumption was packed red blood cell 3.0 ± 0.5 U and fresh frozen plasma 3.8 ± 2.3 U. Compared with our previous experiences using conventional CPB, ECMO did need less heparin and blood transfusions. Clipping was applied in 2 patients, wrapping in 1, and venous graft interposition was performed in 1. Mortality occurred in 1 patient (25%) due to brain herniation. This preliminary study suggested that the heparin-bonded ECMO without reservoir in deep hypothermia could be safe in cerebral aneurysm surgery under a low flow circuit.