Retrograde autologous priming method reduces plasma free hemoglobin level in aortic surgery

Although conventional cardiopulmonary bypass (cCPB) is still the most widely used method in open heart surgery, methods such as retrograde autologous priming (RAP) are increasingly popular in terms of limiting hemodilution. Our hypothesis is that the use of the RAP method in aortic surgery may result in a limitation of hemodilution and a decrease in fHb levels. For this purpose, plasma free hemoglobin (fHb) levels were investigated in adult open aortic arch repair with axillary artery cannulation patients using cCPB and rRAP methods.

In this study, a total of 36 patients undergoing aortic surgery using rRAP and standard cCPB were investigated. Measurements were performed at five time points: After induction of anesthesia, 5^th minute of CPB, 10^th minute of antegrade cerebral perfusion, 30^th minute after declamping of aorta, and at sternum closure. Besides hemodynamic variables, arterial blood gas analysis and postoperative variables, patients were assessed for fHb levels.

The rRAP group had a significantly lower increase in fHb levels in T3, T4, and T5 time points, when compared to the cCPB group (p = 0.002, 0.047, 0.009, respectively). There was no significant difference between the rRAP and cCPB groups in other intraoperative, and postoperative variables. Also, it was observed that rRAP did not make a difference in terms of blood and blood product transfusion.

In this study, in patients undergoing aortic surgery, a reduction in the increase of fHb was observed with the rRAP method which is a simple procedure that does not require high cost or advanced technology.