The objective of this study was to evaluate the impact of minimally invasive extracorporeal circulation on blood transfusion and asymptomatic brain injury in comparison to conventional extracorporeal circulation in the context of minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.

This was a retrospective observational study. Patients who underwent isolated aortic valve replacement through right lateral mini-thoracotomy surgery were divided into two groups: the minimally invasive extracorporeal circulation group and the conventional extracorporeal circulation group. Propensity matching was employed for further analysis.

Of 242 patients, the minimally invasive group and conventional group comprised 166 patients and 76 patients, respectively. In the matched cohort of 71 pairs, the two groups had similar preoperative characteristics. Extracorporeal circulation time was similar between the minimally invasive and conventional groups: 113 and 115 min, respectively, as was aortic clamp time: 86 and 82 min, respectively. Estimated amount of haemodilution was lower in the minimally invasive group (16.8 vs. 18.8%, P = 0.006). Blood transfusion frequency during surgery was less than half of conventional in the minimally invasive group (12.7 vs. 31.0%, P = 0.01). There were no deaths or stroke in either group during the hospital stay. Asymptomatic brain injury rate was the same for the two groups (35.2 vs. 35.2%, P = 1.00).

Minimally invasive extracorporeal circulation was associated with fewer patients requiring transfusion than conventional extracorporeal circulation without an increase of asymptomatic brain injury in minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.