Impact of Graft Quality and Fluid Overload on Postoperative Massive Ascites After Living Donor Liver Transplantation

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Mechanisms of the ascites volume differences between patients receiving a left or right hemi-liver graft liver transplantation: From biofluidic analysis

BACKGROUND AND OBJECTIVE

Post-transplant refractory ascites (RA) is common in patients receiving living donor liver transplantation (LDLT) using a left hemi-liver graft than in those using a right hemi-liver graft. However, there is currently no clear mechanism explaining the effect of grafts on ascites drainage. The purpose of this study is to analyze the values of blood flow parameters in the portal vein under different grafts using computational fluid dynamics (CFD) to interpret the relationship between portal pressure values with ascites drainage.

METHODS

In this work, ascites drainage was counted in 30 patients who underwent left-sided liver transplantation and 26 patients who underwent right-sided liver transplantation. The portal vein flow models of the transplanted liver under different flow rates were established based on computed tomography (CT) images and finite element theory. Ascites drainage and blood flow parameters were qualitatively compared.

RESULTS

The results show that the ascites drained from patients who received LDLT with a left hemi-liver is three times as that with a right hemi-liver. The simulation results show that the coefficient of the pressure-velocity curve of the left-liver is 1.7 times of the right-liver under the same hydrodynamic conditions, which qualitatively agrees with the clinical data. Moreover, the streamline of the transplanted left liver shows more vortexes compared with the right liver, which is a major reason for the left liver's higher pressure value.

CONCLUSION

This clinical phenomenon is reproduced and comprehensively explained by the hemodynamic parameters of the portal vein. This work establishes the relationship between portal pressure values and floating water drainage, and offers a new way for physicians to predict postoperative risks intuitively.

Early removal of drains and lines after liver transplantation to reduce the length of hospital stay and enhance recovery - A systematic review of the literature and expert panel recommendations

BACKGROUND

The timing of removing abdominal drains, central venous catheters (CVC), and urinary catheters (UC) on post liver transplantation (LT) outcomes is not well elucidated.

OBJECTIVES

To provide international expert panel recommendations and guidelines on time of drain and catheter removal as a part of an ERAS protocol to reduce the length of hospital stay and enhance recovery.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Papers considered were those reporting one or more outcomes of interest related to drainage and line removal in the setting of LT. POSPERO Protocol ID: CRD42021238349 RESULTS: On analyzing five relevant studies pertaining to drains in patients undergoing LT (four retrospectives and one prospective), the length of hospital and/or ICU stay was similar or shorter, and postoperative morbidity and mortality were lower in those without drains. No studies pertaining specifically to the time of removal of drains, CVC's, or UC's in LT were found. Studies in patients undergoing major abdominal surgery or hepatectomies recommend early removal of CVC and UC to reduce catheter-associated infections.

CONCLUSIONS

Based more on expert recommendation, we propose that abdominal drains, if placed during LT, should be removed by postoperative day 5 after LT, based on quantity and fluid characteristics (Quality of Evidence; Low to Moderate | Grade of Recommendation; Strong). Larger studies are needed to more reliably determine indications for early drain and line removal in an ERAS protocol setting.

Pulse oximetry-based capillary refilling evaluation predicts postoperative outcomes in liver transplantation: a prospective observational cohort study

Background

Capillary refill time (CRT) is a non-invasive technique to evaluate tissue perfusion, and quantitative CRT (Q-CRT) adapted to pulse oximetry was developed with patients with sepsis and compared to blood lactate and sepsis scores. In post liver transplantation, large amounts of fluid administration are necessary for maintaining tissue perfusion to grafted liver against intravascular hypovolemia. This study aimed to evaluate whether Q-CRT can predict poor outcomes by detecting peripheral tissue perfusion abnormality in patients with liver transplantations who were treated with massive fluid administration.

Methods

In this single-center prospective cohort study, we enrolled adult patients with liver transplantations between June 2018 and July 2019. Measurement of Q-CRT was conducted at intensive care units (ICU) admission and postoperative day 1 (POD1).

Results

A total of 33 patients with liver transplantations were enrolled. Significant correlations of Q-CRT and ΔA_b, a tissue oxygen delivery parameter calculated by pulse oximetry data, at ICU admission with the postoperative outcomes such as length of ICU and hospital stay and total amount of ascitic fluid discharge were observed. Quantitative CRT and ΔA_b at ICU admission were significantly associated with these postoperative outcomes, even after adjusting preoperative and operative factors (MELD score and bleeding volume, respectively). However, quantitative CRT and ΔA_b at POD1 and changes from ICU admission to POD1 failed to show significant associations.

Conclusions

Q-CRT values were significantly associated with postoperative outcomes in liver transplantation. Although the mechanisms of this association need to be clarified further, Q-CRT may enable identification of high-risk patients that need intensive postoperative managements.