Commonly used extracorporeal membrane oxygenation (ECMO) systems for cardiac support are limited by bleeding complications, especially after surgery in the adult patient. Recently, we have switched from the use of a conventional ECMO system to a miniature-circuit including a centrifugal pump and the Novalung membrane ventilator (iLA). This system allows us to administer less heparin compared to the conventional system. Between January and August 2007, 1469 patients underwent cardiac surgery at our center, of which 18 patients (1.2%) required temporary postoperative ECMO system support. Surgical procedures in these patients included coronary artery bypass grafting (CABG) surgery (n=5), valvular replacement (n=2), aortic surgery (n=2), cardiac transplantation (n=5), and other procedures (n=3). The mean age of the 18 patients was 50+/-15 years (n=13 male) with a mean duration of ECMO system support of 4.3 days (range: <1 to 14 days). Twelve patients (67%) were successfully weaned from ECMO system. The 30-day survival was 44% with a hospital mortality of 61%. Re-thoracotomy for bleeding was necessary in six patients (33%) under ECMO system support. In summary, the miniature ECMO system circuit seems to be suitable for middle-term cardiac support and is associated with a low rate of bleeding complications.