ObjectiveTo evaluate clinical outcomes of de-airing technique in minimally invasive cardiac surgery (MICS). MethodsFifty-six patients undergoing MICS in Zhongshan Hospital of Fudan University between June 2011 and June 2013 were recruited as a MICS group, including 31 male and 25 female patients with their age of 33-71 (57.3±7.2)years. Fifty-six patients who underwent mitral valvuloplasty via routine median sternotomy during the same period were recruited as the control group, including 27 male and 29 female patients with their age of 51-69 (53.7±6.8)years. Postoperative residual air in the heart, abnormal ECG findings, time to recovery of consciousness, cognitive function and neurological complications were compared between the 2 groups. ResultsThere were 69.6% patients with mild residual air and 30.4% patients with moderate residual air in the heart of MICS group, and 73.2% patients with mild residual air and 26.8% patients with moderate residual air in the heart of the control group (P > 0.05). There was no statistical difference in the incidence of abnormal ECG findings between the 2 groups (32.1% vs. 26.8%, P > 0.05). Patients with better, good and bad postoperative cognitive function accounted for 85.7%, 12.5% and 1.8% in MICS group respectively, and 78.6%, 19.6% and 1.8% in the control group respectively (P > 0.05). There was no statistical difference in the incidence of neurological complications between the 2 groups (1.8% vs. 1.8%, P > 0.05). ConclusionWith appropriate de-airing techniques, postoperative incidence of air embolism of MICS is comparable with that of conventional cardiac surgery via median sternotomy, and the risk of air embolism of MICS is not higher.