Perioperative clinical practice in liver transplantation: a cross-sectional survey

Risk evaluation and recipient selection in adult liver transplantation: A mixed-methods survey

Background:

Liver transplant (LT) is the definitive treatment for end-stage liver disease. Limited resources and important post-operative implications for recipients compel judicious risk stratification and patient selection. However, little is known about the factors influencing physicians’ assessment regarding patient selection for LT and risk evaluation.

Methods:

We conducted a mixed-methods, cross-sectional survey involving Canadian hepatologists, anesthesiologists, LT surgeons, and French anesthesiologists. The survey contained quantitative questions and a vignette-based qualitative substudy about risk assessment and patient selection for LT. Descriptive statistics and qualitative content analyses were used.

Results:

We obtained answers from 129 physicians, and 63 participated in the qualitative substudy. We observed considerable variability in risk assessment prior to LT and identified many factors perceived to increase the risk of complications. Clinicians reported that the acceptable incidence of at least 1 severe post-operative complication for a LT program was 20% (95% CI: 20-30%). They identified the presence of any comorbidity as increasing the risk of different post-operative complications, especially acute kidney injury and cardiovascular complications. Frailty and functional disorders, severity of the liver disease, renal failure and cardiovascular comorbidities prior to LT emerged as important risk factors for post-operative morbidity. Most respondents were willing to pursue LT in patients with grade III acute-on-chronic liver failure but were less often willing to do so when faced with the uncertainty of a clinical example.

Conclusions:

Clinicians had a heterogeneous appraisal of the post-operative risk of complications following LT, as well as factors considered in risk assessment.

2023 Clinical Update in Liver Transplantation

Liver transplantation continues to provide life-saving treatment for patients with end-stage liver disease. Advances in the field of transplant anesthesia continue to support the care of more complex patients. The use of extracorporeal membrane oxygenation has been described in critical care settings and cardiac surgery but may be a valuable option for specific conditions for patients undergoing liver transplantation. Changes to the allocation process for liver grafts now focus on acuity circles to reduce regional disparities. As the number of life-saving transplant surgeries increases, so does the need for specialty knowledge in the anesthetic considerations of these procedures. The specialty of transplant anesthesia continues to grow and develop to meet the demands of complex patients and the increased number of transplants performed. Liver transplantation can be a resource-demanding procedure, and predicting the need for massive transfusion can aid in planning and preparing for significant blood loss.

Intraoperative Vasoactive Medications and Perioperative Outcomes in Liver Transplantation: A Systematic Review and Network Meta-analyses

We conducted a systematic review and network meta-analyses evaluating the effects of different intraoperative vasoactive drugs on acute kidney injury (AKI) and other perioperative outcomes in adult liver transplant recipients. We searched multiple electronic databases using words from the "liver transplantation" and "vasoactive drug" domains. We included all randomized controlled trials conducted in adult liver transplant recipients comparing 2 different intravenous vasoactive drugs or 1 against a standard of care that reported AKI, intraoperative blood loss, or any other postoperative outcome. We conducted 4 frequentist network meta-analyses using random effect models, based on the interventions' mechanism of action, and evaluated the quality of evidence (QoE) using Grading of Recommendations, Assessment, Development, and Evaluations recommendations. We included 9 randomized controlled trials comparing different vasopressor drugs (vasoconstrictor or inotrope), 3 comparing a somatostatin infusion (or its analogues) to a standard of care, 11 comparing different vasodilator infusions together or against a standard of care, and 2 comparing vasoconstrictor boluses at graft reperfusion. Intravenous clonidine was associated with shorter duration of mechanical ventilation, intensive care unit, and hospital length of stay (very low QoE), and some vasodilators were associated with lower creatinine level 24 h after surgery (low to very low QoE). Phenylephrine and terlipressin were associated with less intraoperative blood loss when compared with norepinephrine (low and moderate QoE). None of the vasoactive drugs improve any other postoperative outcomes, including AKI. There is still important equipoise regarding the best vasoactive drug to use in liver transplantation for most outcomes. Further studies are required to better inform clinical practice.

Preoperative fibrinogen level and blood transfusions in liver transplantation: A systematic review

BACKGROUND

Orthotopic liver transplantation (OLT) is a major surgery often associated with significant bleeding. We conducted a systematic review to explore the association between preoperative fibrinogen level and intraoperative blood products transfusion, blood loss and clinical outcomes in patients undergoing OLT.

METHODS

We included observational studies conducted in patients undergoing an OLT mostly for end-stage liver disease that reported an association between the preoperative fibrinogen level and our outcomes of interest. Our primary outcome was the intraoperative red blood cell (RBC) transfusion requirements. Our secondary outcomes were intraoperative blood loss, intraoperative transfusion of any blood product, postoperative RBC transfusion, postoperative thrombotic or hemorrhagic complications, and mortality. We used a standardized search strategy. We reported our results mostly descriptively but conducted meta-analyses using random-effect models when judged feasible.

RESULTS

We selected 24 cohort studies reporting at least one of our outcomes. We found that a high preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, and lower blood loss. We also found a lower overall survival in patients with a higher fibrinogen level (pooled hazard ratio [95% CI] of 1.50 [1.23 to 1.84]; 5 studies, n = 1012, I2 = 48%). Only one study formally explored a fibrinogen level threshold effect. Overall, reporting was heterogeneous, and risk of bias was variable mostly because of uncontrolled confounding.

CONCLUSION

A higher preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, lower blood loss, and higher mortality. Further studies may help clarify observed associations and inform guidelines.