Background: 

Cardiac surgery can lead to dysregulation with a pro-inflammatory state, resulting in adverse outcomes. Hemadsorption using the AN69 membrane (Oxiris membrane) has the properties to chelate inflammatory cytokines. We hypothesized that in patients at high risk of inflammation, the use of the Oxiris membrane could decrease inflammation, preserve endothelial function, and improve postoperative outcomes.

Methods: 

We conducted a randomized single-center study at Amiens University Hospital. The study population consisted of adult patients admitted for scheduled cardiac surgery with an expected cardiopulmonary bypass (CPB) time over 90 minutes. The patients were allocated to either the standard group or the Oxiris group. The intervention consisted of using the Oxiris membrane on a Prismaflex device at a blood flow rate of 450 ml/min during CPB. The primary outcome was the assessment of microcirculation on day 1 after surgery by measuring sublingual microcirculation using the microvascular flow index (MFI). MFI reflects the microcirculation flow type and is graded from 0 to 3 as follows: 0: no flow; 1: intermittent flow; 2: sluggish flow; 3: continuous flow. The secondary outcome was a composite adverse outcome within 30 days after surgery. Cytokines and endothelial biomarkers were measured in all patients at different time points. An intention-to-treat analysis was performed.

Results: 

From October 2019 to November 2022, we included 70 patients. Two patients were excluded from the Oxiris group: one patient did not undergo surgery and one procedure was performed under deep hypothermia. The MFI did not differ between groups on day 1 from baseline: difference Oxiris-standard at -0.17 [-0.44; 0.10]; P=0.2. The occurrence of a composite adverse outcome did not significantly differ between groups (14 [42%] for the Oxiris group vs 12 [35%] for the standard group; P=0.7). The overall variation in cytokines and angiopoietins did not significantly differ between groups.

Conclusions: 

In patients scheduled for a cardiac surgery with prolonged CPB, we could not demonstrate the benefit on microcirculation and major cardiovascular events.