Viscoelastic Monitoring in Liver Transplantation

Abstract

Cirrhosis and liver transplantation (LT) surgery are associated with substantial alterations to the patient's coagulation status. Accurate monitoring of these changes during LT can help manage bleeding proactively and potentially reduce transfusion requirements. Unlike conventional coagulation tests (CCTs), viscoelastic monitoring (VEM) can provide an accurate, realtime, point-of-care assessment of coagulation status during LT and hence has become an invaluable tool for anesthetists and intensive care physicians. However, it remains an enigmatic subject for transplantation surgeons who are more conversant with CCTs. This review discusses the principles of VEM, provides a primer to understanding and interpreting its output, and explains how it can be used to make real-world clinical decisions during LT.

Viscoelastic versus conventional coagulation tests to reduce blood product transfusion in patients undergoing liver transplantation

“…This systematic review and meta-analysis, based on 17 studies including 5345 liver transplantation patients, studied the role of VETs in reducing blood product transfusion during liver transplantations. Compared with previous findings 15–19 that highlighted an overall reduction in the use of allogeneic blood products with implementation of VETs, our results suggest that the use of VETs, compared with CCTs, is associated with reduced transfusions of RBCs and FFP; PLT consumption was not affected by VET use, and cryoprecipitate transfusion was increased.…”

“…This systematic review and meta-analysis, based on 17 studies including 5345 liver transplantation patients, studied the role of VETs in reducing blood product transfusion during liver transplantations. Compared with previous findings [15][16][17][18][19] that highlighted an overall Certainty of evidence assessment for observational (a) and randomised controlled trials (b) Analysing all 15 observational studies, 28,[30][31][32][33][34][35][36][38][39][40][41][42][43][44] a significantly lower number of RBC units transfused was found when coagulation management was guided by VETs, with a rather moderate heterogeneity (I 2 ¼ 61%) between studies. In this regard, sensitivity analyses showed a low heterogeneity (I 2 ¼ 1%) for the reduction in RBC transfusion in the studies including only patients with MELD score 25 or less while there was no heterogeneity in those studies with specified deceased donors.…”

“…Despite recent narrative reviews 15,16,18,19 and one systematic 17 review showing an overall reduced need for allogenic blood products during liver transplantation using VETs, current evidence is impaired both by a lack of quantitative analyses on single blood products and a focus on exploring reasons for heterogeneous results found among the previous studies.…”

“…14 However, recent literature on liver transplantation patients, suggests VET-guided transfusion management may be associated with reduced blood product administration. [15][16][17][18][19] Limiting unnecessary allogeneic blood products helps reduce transfusion-associated risks and may be particularly beneficial for patients during liver transplantation to avoid worsening portal hypertension and exacerbating bleeding from the surgical field. 15,16 Despite recent narrative reviews 15,16,18,19 and one systematic 17 review showing an overall reduced need for allogenic blood products during liver transplantation using VETs, current evidence is impaired both by a lack of quantitative analyses on single blood products and a focus on exploring reasons for heterogeneous results found among the previous studies.…”

“…However, recent literature on liver transplantation patients, suggests VET-guided transfusion management may be associated with reduced blood product administration 15–19 . Limiting unnecessary allogeneic blood products helps reduce transfusion-associated risks and may be particularly beneficial for patients during liver transplantation to avoid worsening portal hypertension and exacerbating bleeding from the surgical field 15,16 …”