The impact of early perioperative heparin-free anticoagulation for extracorporeal membrane oxygenation on bleeding and thrombotic events in lung transplantation: a retrospective cohort study

Abstract

Background: Perioperative heparin-free anticoagulation extracorporeal membrane oxygenation (ECMO) for lung transplantation is rarely reported.

Objective: To evaluate the impact of a heparin-free strategy on bleeding and thrombotic events, blood transfusion, and coagulation function during the early perioperative period and on prognosis, and to observe its effect on different ECMO types.

Design: A retrospective cohort study.

Methods: Data were collected from 324 lung transplantation patients undergoing early perioperative heparin-free ECMO between August 2017 and July 2022. Clinical data including perioperative bleeding and thrombotic events, blood product transfusion, coagulation indicators and 1-year survival were analysed.

Results: Patients were divided in venovenous (VV; n = 251), venoarterial (VA; n = 40) and venovenous-arterial (VV-A; n = 33) groups. The VV group had the lowest intraoperative bleeding and thoracic drainage within 24 h postoperatively. Vein thrombosis occurred in 30.2% of patients within 10 days postoperatively or 1 week after ECMO withdrawal, and no significant difference was found among the three groups. Double lung transplantation, increased intraoperative bleeding, and increased postoperative drainage were associated with vein thrombosis. Except for acute myocardial infarction in one patient, no other serious thrombotic events occurred. The VV-ECMO group had the lowest demand for blood transfusion. The highest prothrombin time and the lowest fibrinogen levels were observed in the VA group during ECMO run, while the highest platelet counts were found in the VV group. Both intraoperative bleeding and thoracic drainage within 24 h postoperatively were independent predictors for 1-year survival, and no thrombosis-related deaths occurred.

Conclusion: Short-term heparin-free anticoagulation, particularly VV-ECMO, did not result in serious thrombotic events or thrombosis-related deaths, indicating that it is a safe and feasible strategy for perioperative ECMO in lung transplantation.

Keywords: bleeding and thrombotic events; coagulation function; extracorporeal membrane oxygenation; heparin-free anticoagulation; lung transplantation.

Figure 1.

Flow chart of the Cohort. ECMO, extracorporeal membrane oxygenation; LT, lung transplantation.

Figure 2.

The impact of heparin-free anticoagulation strategy on the coagulation system. (a)–(e): The dynamic changes of prothrombin time, APTT, fibrinogen, D-Dimer and platelet counts from ECMO run to day 2 after ECMO withdrawal. (f) The dynamic changes in haemoglobin levels. APTT, Activated partial thromboplastin time; ECMO, Extracorporeal membrane oxygenation; T0, Pre-ECMO; T1, During ECMO; T2, Day 1 after ECMO withdrawal; T3, Day 2 after ECMO withdrawal. &p < 0.05 VA versus VV group; #p < 0.05 VV-A versus VV group.

Figure 3.

Kaplan–Meier curves for 1-year survival after lung transplantation based on different prognostic factors. (a) and (b) According to optimal thresholds of intraoperative bleeding and thoracic drainage within postoperative 24 h determined by receiver operating characteristic curves based on 1-year survival, Kaplan–Meier survival curves showed statistically different outcomes. (c) ECMO types; (d) Platelet transfusion.