J . Blanco-Morillo et al .: J Extra Corpor Technol 2023 , 55 , 30 – 38 31
Figure 1 . Graphical abstract . This figure summarizes the preliminary assessment of HAR ’ s potential benefits , to enhance postoperative recovery after cardiopulmonary bypass , considering a sample composed of high-risk patients and a propensity score matching methodology for the estimation of the effects . Abbreviations : MiECC – minimized extracorporeal circuit ; VAVD – vacuum-assisted venous drainage ; < 10 h – lower than ten hours ; < 2 d – lower than two days .
Thus , with these concerns in mind , in 2014 our team developed the concept of Haematic Antegrade Repriming ( HAR ) as a standardized methodology , combining the benefits of MiECC and a new antegrade repriming method , improved with the application of vacuum-assisted venous drainage and the initiation of CPB with an empty venous line , to minimize the haemodilutional impact to 300 mL [ 12 ].
Once proven the biosafety of the procedure in terms of gaseous microemboli ( GME ), and the beneficial effect of reducing the total embolic load delivered during CPB , seems mandatory to evaluate the potential benefit of HAR as a perfusion tool for ERACS ( Figure 1 ).
Material and methods Study design
Two retrospective cohorts of high-risk patients were compared by applying a propensity score matching ( PSM ), to estimate the effect of HAR , after the approval of the institutional ethics committee ( IRB / EC Nr . 2019-10-3-HCUVA ). Because of the retrospective nature of the research , no reported consent was required .
One thousand eight hundred and ninety-six patients undergoing elective cardiac surgery under CPB for four consecutive years in our institution were considered . After the application of exclusion criteria , 425 patients were assessed in a PSM model . The treatment group ( HG ) was recruited since the HAR procedure was standardized for every patient in our hospital , while the control group ( CG ) was composed , considering patients
from a historical cohort , presenting similar preoperative conditions and treated under the same predefined clinical criteria to reduce the influence of biases ( Figure 2 ).
For election , patients required a preoperative logistic EUROSCORE index 5 [ 13 ] to be included and none of the exclusion criteria : preoperative anemia ( Hgb < 8 g / dL ), emergent / urgent surgery , heart transplantation , endocarditis , preoperative renal failure , redo surgery within the first 48 h or multiple CPB initiations in a surgical process . Each case with controversial registers about clinical treatment , transfusion threshold , or postoperative management was also excluded from the study ( Figure 2 ).
CPB was conducted with a Stöckert S5
Ò ( Livanova™ PLC , London ) heart-lung machine and the support of an AutoLog
Ò cell saver ( Medtronic™ PLC , Minneapolis , Minnesota ). Both groups received a biocompatible circuits including a Revolution
Ò centrifugal pump ( Livanova™ PLC , London ). Patients with a body surface area 1,8 m
2 were oxygenated with a Capiox FX25
Ò , included in a circuit treated with XCoating
Ò ( Terumo Corp ., Tokyo , Japan ), while in smaller patients (< 1,8 m
2 ), a circuit with P . H . I . S . I . O .
Ò coating and the Inspire 6F
Ò oxygenator ( Livanova™ PLC , London ) was used .
Procedure
CG patients underwent CPB , being connected to a conventional open circuit with ø inch return line , ( 1350 mL of dynamic priming ).