ObjectiveTo evaluate the safety of modified blood-sparing approach in cardiac surgery with cardiopulmonary bypass (CPB) in low-weight infants (≤15 kg) with congenital heart disease. MethodsA total of 283 infants were applied a new blood-sparing approach, known as without homologous blood priming, during the cardiac surgery with CPB between August 2012 and October 2013. There were 154 males and 129 females with a median (interquartile range) age of 13 (9, 20) months. The infants were assigned to an intraoperative transfusion (IT) group once having transfusion during operation. And the infants without transfusion during operation were assigned to a postoperative transfusion (PT) group or a transfusion-free (TF) group according to post-operative transfusion. All infants experienced routine heart surgery with CPB. Blood samples were collected at following time points, ie. pre-CPB, 10 minutes after CPB, before termination of CPB, and after modified ultrafiltration. Clinical data and transfusion requirements were collected and compared between three groups. ResultsA total of 106 infants (53 males and 53 females) completed bloodless surgery. The median (interquartile range) age was 14 (9, 22) months. A total of 121 infants (71 males and 50 females) received red blood cell (RBC) transfusion intraoperatively. The median (interquartile range) age was 10 (8, 12) months. A total of 56 infants (30 males and 26 females) at age of 15 (7, 20) months received RBC transfusion postoperatively. The intraoperative transfusion (IT) group had lower body weight (9 (7,10) kg vs. 12.6 (9,14) kg) and size (72 (68, 80) cm vs. 86 (78, 97) cm), younger age (10 (8, 12) months vs. 14 (9, 22) months), and higher 24-hour chest tube drainage volume (89 (40, 122) ml vs. 58 (30, 106) ml, P<0.05) than those in the transfusion free (TF) group. Pre-operative hematocrit was also lower in the IT group than that in the PT group and the TF group (32% (29%, 37%) vs. 39% (34%, 41%) vs. 36% (33%, 38%), P<0.05). The hospital stay in the PT group and the IT group was longer than that in the TF group, respectively (13 (8, 23) d vs. 14 (11, 22) d vs. 11(8, 20) d, P<0.05). ConclusionAlthough applied with blood-sparing approach, perioperative transfusion is required in some infants. Infants who are free from transfusion have shorter hospital stay and less 24-hour chest tube drainage volume. Consideration of risk factors of transfusion in this population may benefit further reduction in blood transfusion in the future.