Minimal invasive extracorporeal circulation in comorbid patients

Background: As the severity of comorbid diseases increases, risks of cardiopulmonary bypass (CPB) complications significantly increase. A complex of the procedure's damaging factors provokes a systemic inflammatory response that in some cases is accompanied by the damage to target organs, transitioning from chronic organ dysfunctions into acute ones. Some studies on the use of minimal invasive extracorporeal circulation (MiECC) systems show their advantage over conventional extracorporeal circulation (CECC); however, the diversity of MiECC systems, patients, and outcomes precludes us from confidently extrapolating these data to older comorbid patients. Objective: To compare the severity of systemic inflammation and treatment outcomes in comorbid patients who underwent cardiac surgery with CECC and MiECC. Methods: We conducted a retrospective cohort study of 760 patients who consecutively underwent elective cardiac operations in 2019-2022. Inclusion criteria: comorbid status (age-adjusted Charlson Comorbidity Index score of ≥6); CPB time ≥90 min. Exclusion criteria: emergency surgery, refusal to participate in the study. A total of 68 patients met the inclusion criteria. We formed 2 study groups based on the extracorporeal circulation method: CECC group (n = 51) and MiECC group (n = 17). Control points: before CPB and 24 hours after the surgery (lactate; creatinine; oxygenation index, hemolysis level). For systemic inflammatory response markers: 1 hour after the CPB start and 24 hours after the CPB end (interleukin 6; interleukin 10; procalcitonin; C-reactive protein; soluble Triggering Receptor Expressed on Myeloid Cells-1 [sTREM-1]). We evaluated respiratory and renal complications, drainage-related hemorrhages, hemostatic disorders, the need for sympathomimetic drugs, and the length of stay in an intensive care unit and inpatient hospital. Results: Between the groups there were no statistically significant differences in gender and anthropometric characteristics, surgery types, and main perfusion parameters. In the CECC group, we observed significantly higher doses of vasoconstrictors (norepinephrine) as well as a decrease in urine output and lung injury and an increase in lactate and hemolysis. The systemic inflammatory response markers were also significantly higher. Conclusion: Compared with CECC, MiECC does not significantly affect the frequency of organ dysfunctions; however, it reduces the severity of the systemic inflammatory response and immune suppression that are trigger mechanisms for multiple organ dysfunction syndrome. It is particularly important for patients with chronic organ dysfunctions. A range of indications for MiECC systems should be defined given its high cost and off-target effect on pleiotropic factors of systemic inflammatory response development.