The Choice of Priming Solution for Cardiopulmonary Bypass during Pulmonary Endarterectomy for CTEPH Patients Has Important Impact

Abstract

<h3>Purpose</h3> Pulmonary endarterectomy (PEA) is the treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH). In recent decades, refined surgical PEA technique using cardiopulmonary bypass (CPB) has achieved significant reduction in mortality. Hemodilution generated by crystalloid priming solution in heart surgery causes a number of disadvantages, and no standard for PEA is described. We aim to assess the outcome of CTEPH patients after protocol change for CPB with adding 5% albumin to priming solution during PEA. <h3>Methods</h3> Since changing the CPB protocol in 2018, 28 CTEPH patients were retrospectively compared to a historical control by 1:1 propensity score matching gender, age, PVR (pulmonary vascular resistance) before PEA surgery. The resulting two cohort groups were analysed for intraoperative fluid balance, vasoactive inotropic score (VIS), operative time and their influence on outcome. Regression models of hospitalization, ICU (intensive care unit) and intubation time considered the total blood volume balance as mediator of the effect of the new protocol. <h3>Results</h3> Lower CPB-balance (p<0.001), VIS score (p=0.04), shorter operative time (p=0.03) and hospitalization (p=0.008) were observed in the cohort operated with the new protocol. Postoperative 30 and 90 day mortality and morbidity were similar between groups. Shorter operative time (mean change (mc) 1.4, 95% CI [0.8. 2.0], p< 0.0001) and new protocol (mc -3.68, 95% CI [-5.22, -2.14], p< 0.0001) are independently associated with lower CPB balance, resulting in a beneficial effect on VIS score, ICU, intubation and hospitalization time (mean ratio (mr) 1.12, 1.11, 1.14, 1.05, p<0.0001, p=0.0011, 0.0013, 0.008, respectively). The protocol change shows positive trend with significant impact on hospitalization time (p=0.02). <h3>Conclusion</h3> Priming protocol for CPB with addition of 5% albumin had a beneficial effect on the CPB balance and improved postoperative outcome after PEA for CTEPH patients.