Detection of early allograft dysfunction at 30 min of reperfusion in liver transplantation: An intraoperative diagnostic tool with real time assessment of graft function

Abstract

Introduction: During the anhepatic phase of liver transplantation (LT), fibrinolytic activity increases, since the liver clears tissue plasminogen activator (tPA). We hypothesize that patients who fail to reduce fibrinolytic activity following graft reperfusion will have an increased rate of early allograft dysfunction (EAD).

Methods: Assessment of fibrinolysis in liver transplant recipients was quantified with thrombelastography (TEG) LY30. Changes in LY30 were assessed after graft reperfusion. The 30-min post-reperfusion LY30 was subtracted from the anhepatic LY30 quantifying fibrinolytic changes (delta-LY30).

Results: Seventy-three primary LT patients were included in the analysis. Receiver operating characteristic curve (ROC) analysis identified an inflection point of delta-LY30-5.3% as a risk factor for EAD. EAD occurred in 44% of these patients compared to 5% in high delta-LY30 (p = 0.002).

Conclusion: LT recipients that develop hyperfibrinolysis who fail to reduce fibrinolytic activity 30 min after graft reperfusion had an EAD rate 8-fold higher than patients who had a large reduction in LY30 following reperfusion.

Keywords: Early allograft dysfunction; Fibrinolysis; Liver transplantation; Tissue plasminogen activator.

Figure 1:

Strengthening the Reporting of Observational studies in Epidemiology (STROBE) Diagram

Figure 2:. Temporal Changes in Fibrinolysis During Surgery Between Patient Cohorts

e-SD = Early Shutdown, d-SD= Delayed Shutdown, Base = Baseline Blood Draw, R = reperfusion, Min = Minutes, POD = Post-Operative Day, LY30 = Lysis at 30 Minutes P Value represents Kruskal Wallis test across three groups Y-axis represents the median LY30 and X axis represents time. The no hyperfibrinolysis group (purple) did not generate a fibrinolytic response to surgery and represent hypofibrinolysis. Conversely, the large negative delta LY30 and low negative delta LY30 generated a fibrinolytic response to surgery that was subsequently inhibited and more appropriately termed fibrinolysis shutdown. The Large negative delta LY30 group suppressed fibrinolysis during early reperfusion and were termed early shutdown (e-SD), whereas the low negative LY30 group had increasing fibrinolysis during early reperfusion and were not inhibited until 120 minutes reperfusion and were termed delayed fibrinolysis shutdown (d-SD).

Figure 3:. Rates of Early Allograft Dysfunction Between Recipient Cohorts

e-SD = Early Shutdown, d-SD= Delayed Shutdown, EAD= Early Allograft Dysfunction, P Values represent Fisher’s Exact test between e-SD and d-SD or Hypofibrinolysis. Y-axis represents the percent of patients with EAD within the three cohorts along the x-axis

Figure 4:. Red Blood Cell Transfusions During Surgery

e-SD = Early Shutdown, d-SD= Delayed Shutdown, Baseline = Baseline Blood Draw, R = reperfusion, Min = Minutes, POD = Post-Operative Day, RBC = Red Blood Cells, P Value represents Kruskal Wallis test across three groups. The Y axis represents the median number of red blood cells transfused from TEG lab draw to subsequent TEG lab draw. The X Axis represents the different blood draw times. The e-SD (green) group had a significant increase in blood product utilization during the anhepatic phase of surgery with a rapid decrease in blood product utilization for the duration of the blood draws. The other phenotypes did not have significantly different blood product utilization but the total red blood cell transfusions between all three phenotypes was the similar.