Behavior and clinical impact of ascites after living donor liver transplantation: risk factors associated with massive ascites

Risk factors and crucial prognostic indicators of mortality in liver transplant recipients with bloodstream infections: A comprehensives study of 1049 consecutive liver transplants over an 11-year period

BACKGROUND

Liver transplantation (LT) is a pivotal treatment for end-stage liver disease. However, bloodstream infections (BSI) in the post-operative period present a significant threat to patient survival. This study aims to identify risk factors for post-LT BSI and crucial prognostic indicators for mortality among affected patients.

METHODS

We conducted a retrospective study of adults diagnosed with end-stage liver disease who underwent their initial LT between 2010 and 2021. Those who developed BSI post-LT during the same hospital admission were classified into the BSI group.

RESULTS

In this cohort of 1049 patients, 89 (8.4%) developed BSI post-LT, while 960 (91.5%) did not contract any infection. Among the BSI cases, 17 (19.1%) patients died. The average time to BSI onset was 48 days, with 46% occurring within the first month post-LT. Of the 123 isolated microorganisms, 97 (78.8%) were gram-negative bacteria. BSI patients had significantly longer stays in the intensive care unit and hospital compared to non-infected patients. The 90-day and in-hospital mortality rates for recipients with BSI were significantly higher than those without infections. Multivariate analysis indicated heightened BSI risk in patients with blood loss >3000 mL during LT (odds ratio [OR] 2.128), re-operation within 30 days (OR 2.341), post-LT bile leakage (OR 3.536), and graft rejection (OR 2.194). Additionally, chronic kidney disease (OR 6.288), each 1000 mL increase in intraoperative blood loss (OR 1.147) significantly raised mortality risk in BSI patients, whereas each 0.1 mg/dL increase in albumin levels correlated with a lower risk of death from BSI (OR 0.810).

CONCLUSIONS

This study underscores the need for careful monitoring and management in the post-LT period, especially for patients at higher risk of BSI. It also suggests that serum albumin levels could serve as a valuable prognostic indicator for outcomes in LT recipients experiencing BSI.

Comparison of postoperative ascites replacement strategies on time to first flatus after living donor liver transplantation: Albumin vs. lactated Ringer's solution

INTRODUCTION

There is insufficient evidence regarding the optimal regimen for ascites replacement after living donor liver transplantation (LT) and its effectiveness. The aim of this study is to evaluate the impact of replacing postoperative ascites after LT with albumin on time to first flatus during recovery with early ambulation and incidence of acute kidney injury (AKI).

METHODS

Adult patients who underwent elective living donor LT at Seoul National University Hospital from 2019 to 2021 were randomly assigned to either the albumin group or lactated Ringer's group, based on the ascites replacement regimen. Replacement of postoperative ascites was performed for all patients every 4 h after LT until the patient was transferred to the general ward. Seventy percent of ascites drained during the previous 4 h was replaced over the next 4 h with continuous infusion of fluids with a prescribed regimen according to the assigned group. In the albumin group, 30% of a total of 70% of drained ascites was replaced with 5% albumin solution, and remnant 40% was replaced with lactated Ringer's solution. In the lactated Ringer's group, 70% of drained ascites was replaced with only lactated Ringer's solution. The primary outcome was the time to first flatus from the end of the LT and the secondary outcome was the incidence of AKI for up to postoperative day 7.

RESULTS

Among the 157 patients who were screened for eligibility, 72 patients were enrolled. The mean age was 63 ± 8.2 years, and 73.0 % (46/63) were male. Time to first flatus was similar between the two groups (66.7 ± 24.1 h vs. 68.5 ± 25.6 h, p = .778). The albumin group showed a higher glomerular filtration rate and lower incidence of AKI until postoperative day 7, compared to the lactated Ringer's group.

CONCLUSIONS

Using lactated Ringer's solution alone for replacement of ascites after living donor LT did not reduce the time to first flatus and was associated with an increased risk of AKI. Further research on the optimal ascites replacement regimen and the target serum albumin level which should be corrected after LT is required.

Post Living Donor Liver Transplantation Small-for-size Syndrome: Definitions, Timelines, Biochemical, and Clinical Factors for Diagnosis: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes.

METHODS

A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference.

RESULTS

The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed.

CONCLUSIONS

The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

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.

Effect of the response to preoperative treatment for hepatorenal syndrome on the outcome of recipients of living-donor liver transplantation

BACKGROUND

The effect of pretransplant hepatorenal syndrome (HRS) on the outcomes of living-donor liver transplantation (LDLT) recipients with special reference to the recovery of HRS before LDLT was investigated.

METHODS

The rate of HRS was 43.9% (125/285) among the cohort, and the subjects were divided into 3 groups: those without HRS (No-HRS group, n=160), those with HRS but recovered following pretransplant renal function restoration treatment (Responders group, n=55), and those with persistent HRS (Non-responders group, n=70).

RESULTS

While the 1-, 3-, and 5-year patient survival rates were comparable between those with and without HRS (89.6%, 84.7%, and 84.7% vs. 95.6%, 92.2%, and 87.5%), the cumulative incidence of the development of posttransplant chronic kidney disease (CKD) was significantly higher in those with HRS (p<0.001). In addition, there was a significant difference between Responders and Non-responders in the development of CKD (p=0.01). In the Cox regression model, Non-responders (p=0.032, HR 1.79 [95% C.I. 1.05-3.03]) and recipient age (p=0.014, HR 1.62 [95% C.I. 1.10-2.37]) were independent predictors for the development of CKD after LDLT.

CONCLUSION

LDLT is safe and effective for patients with HRS, and CKD progression could be reduced among those with HRS who responded to renal restoration treatment.

Importance of reconstruction of middle hepatic vein tributaries of right-lobe grafts in living donor liver transplantation: demonstration of the reconstruction technique

PURPOSE

The aim of the present study on living donor liver transplantation (LDLT) using a right-lobe graft without the middle hepatic vein (MHV) was to investigate the clinical impact of MHV tributary reconstruction using our criteria and techniques.

METHODS

The medical records of 40 patients who underwent adult LDLT using a right-lobe graft without the MHV between April 2008 and December 2020 were retrospectively reviewed. In this cohort, the criterion for MHV tributary reconstruction was estimated drainage volume of each MHV tributary greater than 100 mL. The drainage vein of segment 8 (V8) was reconstructed as the common orifice of the right hepatic vein and V8 using a venous patch graft, and that of segment 5 was reconstructed using artificial vascular grafts. The outcomes were compared between the groups with and without MHV tributary reconstruction. Factors associated with postoperative massive ascites were also investigated.

RESULTS

Twenty patients underwent MHV tributary reconstruction. There were no significant differences in the amount of postoperative ascites, Clavien-Dindo classification ≥ III postoperative complications, and 90-day in-hospital mortality between the groups (P = 0.678, P = 1.000, and P = 0.244, respectively). On multivariate analyses, a low-estimated functional graft-to-recipient weight ratio, which was calculated using estimated graft volume minus the territory of MHV tributaries that was not reconstructed, was identified as an independent predictor of postoperative massive ascites (odds ratio, 40.479; 95% confidence interval, 3.823-428.622).

CONCLUSION

The present study suggests that selective MHV tributary reconstruction might be useful for achieving successful graft function.

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.

Postoperative Course of Serum Albumin Levels and Organ Dysfunction After Liver Transplantation

BACKGROUND AND AIMS

Postoperative hypoalbuminemia, especially following liver transplantation, can lead to adverse multisystem effects and even death. We investigated the relationship between postoperative albumin levels and organ failure (assessed using Sequential Organ Failure Assessment [SOFA] scores).

METHODS

Sixty liver transplant recipients admitted to the intensive care unit (ICU) from 2012 to 2015 were retrospectively divided into 2 groups: lower albumin (LA) (n=28) and higher albumin (HA) (n=32), using whether serum albumin level fell below 3.0 g/dL during the first postoperative week as the stratifying factor. The SOFA scores (primary endpoint) and associated complications (ascites amount, rejection, re-intubation, abdominal re-operation, thrombosis), additional treatment (dialysis, pleural effusion drainage), and duration of ICU stay (secondary endpoints) of the 2 groups were compared.

RESULTS

Average serum albumin levels were significantly different between HA and LA groups (3.6 [3.4-3.8] vs 3.1 [2.9-3.3], respectively, P<.05), although the amounts of albumin infused in the 2 groups during the first postoperative week were not different (HA vs LA: 42 [30-71] vs 40 [30-58], respectively, P=.37). Mean daily SOFA scores were not significantly different between the HA and LA groups (8.3 [6.6-9.0] vs 7.2 [6.3-8.6], P=.73), although the HA group had lower mean cardiovascular SOFA sub-scores than the LA group (0.1 [0-0.4] vs 0.4 [0-1.3], P=.032). There were no significant differences between the groups with regard to complication rates and duration of ICU and hospital stays.

CONCLUSIONS

Serum albumin level might not influence cumulative organ function, but it decreases the amount of hemodynamic support required in liver transplant recipients.

Naturally-Derived Biomaterials for Tissue Engineering Applications

Naturally-derived biomaterials have been used for decades in multiple regenerative medicine applications. From the simplest cell microcarriers made of collagen or alginate, to highly complex decellularized whole-organ scaffolds, these biomaterials represent a class of substances that is usually first in choice at the time of electing a functional and useful biomaterial. Hence, in this chapter we describe the several naturally-derived biomaterials used in tissue engineering applications and their classification, based on composition. We will also describe some of the present uses of the generated tissues like drug discovery, developmental biology, bioprinting and transplantation.

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

After living donor liver transplantation, we encounter cases with massive ascites, which is difficult to manage. We analyzed the risk factors for massive ascites after living donor liver transplantation. The subjects were 100 adult recipients who underwent living donor liver transplantation at Kyoto University Hospital from 2013 to 2017. We retrospectively assessed patient, graft, operative factors, and percent fluid overload, which were defined as [(weight on the day - preoperative weight)/preoperative weight] × 100%. We defined the massive ascites group as having a14-day average ascites ≥ 2500 mL and the mild ascites group as having a 14-day average ascites < 2500 mL. Forty-seven patients were included in the massive group, and 53 patients were included in the mild group. There was no difference in short- and long-term survival. In multivariate analysis, the presence of preoperative ascites (P = .0008), 14-day average percent fluid overload ≥ 14.5% (P = .0095), graft-to-recipient weight ratio < 0.86 (P = .0253), and donors' age ≥ 47 years (P = .0466) were identified as independent risk factors for massive ascites after living donor liver transplantation. A liver graft with a small graft-to-recipient weight ratio or from an elderly donor, which may indicate poor graft quality, presence of preoperative ascites, and postoperative fluid overload were associated with massive ascites after living donor liver transplantation.

Predictive Value of Hepatic Venous Pressure Gradient for Graft Hemodynamics in Living Donor Liver Transplantation

The hepatic venous pressure gradient (HVPG) measurement is known to correlate with the severity of portal hypertension in patients with liver cirrhosis. This retrospective study investigated the clinical value of preoperative measurement of HVPG in patients who underwent adult-to-adult living donor liver transplantation (LDLT) and its predictive value for hepatic hemodynamics after graft reperfusion. For this study, 75 patients who underwent adult-to-adult LDLT were divided into 2 groups (HVPG <16 mm Hg or HVPG ≥16 mm Hg) to investigate the correlation between preoperative HVPG and characteristics and surgical outcomes of the patients, including portal vein flow (PVF) and hepatic artery flow (HAF) after graft reperfusion. In total, 35 (46.7%) patients had an HVPG ≥16 mm Hg. These patients had significantly higher international normalized ratio values, serum creatinine levels, and Model for End-Stage Liver Disease scores compared with the 40 patients with HVPG <16 mm Hg. They also had higher rates of variceal bleeding, encephalopathy, and intractable ascites as well as lower serum albumin levels and platelet counts compared with those patients with HVPG <16 mm Hg. Portal inflow modulation (PIM) was frequently performed in the patients with HVPG ≥16 mm Hg compared with those with HVPG <16 mm Hg. No significant differences in surgical outcomes after LDLT were found between these 2 groups except for postoperative ascites. Preoperative HVPG showed a positive correlation with PVF and a negative correlation with HAF after graft reperfusion (false discovery rate [FDR] P = 0.08 and FDR P = 0.08, respectively). In linear regression analyses, preoperative HVPG was independently associated with PVF after graft reperfusion. In conclusion, our findings indicate that preoperative HVPG is associated with hepatic hemodynamics after graft implantation in LDLT. HVPG as a routine preoperative evaluation may be helpful for surgical planning of PIM.

Risk Factors for Refractory Ascites After Living Donor Liver Transplant

OBJECTIVES

Refractory ascites after liver transplant commonly occurs in living donor liver transplant (LDLT). Refractory ascites is associated with postoperative complications and poor prognosis. This study sought to determine the risk factors of refractory ascites and discuss their perioperative management.

METHODS

A retrospective study of 122 living donor liver transplant recipients between 2008 and 2017 was performed to analyze the risk factors, incidence, and characteristics of refractory ascites. Refractory ascites post LDLT was defined as the production of ascites fluid >1000 mL/d on postoperative day 14 or required repeated drainage.

RESULTS

A total of 24 patients (19.6%) developed refractory ascites. The 1-year survival rate was significantly worse in the refractory ascites group compared with the nonrefractory ascites group (P < .001). In a univariate analysis, patients with refractory ascites had a higher Model for End-Stage Liver Disease (MELD) score, donor age, presence of left lobe graft, ascites at laparotomy, portal venous pressure just after surgery, cold ischemia time, and absence of hepatocellular carcinoma compared with patients without refractory ascites. Multivariate proportional regression analyses revealed that MELD score ≥20, left lobe graft, donor age 50 years or older, and ascites at laparotomy ≥350 mL were independently associated with refractory ascites. Postoperative complications, such as bleeding (P < .001), sepsis (P < .001), and bloodstream infection within 30 days after LDLT (P < .00), were significantly higher in the refractory ascites group.

CONCLUSION

Refractory ascites is associated with reduced 1-year survival and increased postoperative complications. Four factors including MELD score ≥20, donor age 50 years or older, presence of left graft, and ascites at laparotomy ≥350 mL were independent predictors for refractory ascites.

Postoperative complications as a predictor for survival after liver transplantation - proposition of a prognostic score

BACKGROUND

Liver transplantation is major surgery with a high risk of complications. Existing scoring systems for evaluating complications after surgery are not specific for liver transplantation. Nor are they designed to evaluate the relation to recipient survival or graft loss. We wished to uncover the relation between postoperative complications and one-year risk of death or retransplantation, and to develop a prognostic score for complications based on our findings.

METHOD

The study was a retrospective cohort study including 253 adult liver recipients. Thirty-days postoperative complications were registered using the Clavien-Dindo classification. A prognostic score was developed based on types, severity, and quantity of complications.

RESULTS

A total of 1113 complications occurred in 233 (92.1%) of the patients. One-year mortality or graft loss was associated with graft, biliary, surgical, systemic, pulmonary, cardiovascular, renal, and infectious complication but not with neurologic or gastrointestinal complications. The developed score was more accurate in predicting the outcome than both the modified Clavien-Dindo score and the Comprehensive Complication Index.

CONCLUSION

Types, severity, and quantity of different postoperative complications after liver transplantation are not equally important. The proposed score may focus attention on treating or preventing complications with strong relation to recipient mortality or graft loss.

Double-blind randomized controlled trial of the routine perioperative use of terlipressin in adult living donor liver transplantation

Perioperative terlipressin (Tp) during living donor liver transplantation (LDLT) has been shown to reduce intraoperative portal pressures and improve renal function. Its role and safety profile have never been evaluated in a double-blind randomized controlled trial (RCT). The aim was to evaluate the hemodynamic effects, clinical benefits, and safety of perioperative Tp infusion in adult LDLT. This was a single-center double-blind RCT. Consenting adults with chronic liver disease and low risk of posttransplant renal dysfunction undergoing their first LDLT were randomized. The study group (terlipressin group [TpG]) received an initial bolus of Tp during surgery followed by a Tp infusion for 72 hours in the postoperative period. The placebo group (PbG) received a saline infusion. The primary endpoint was portal pressure after arterial reperfusion. Multiple intraoperative and postoperative variables served as secondary endpoints. A total of 41 patients were enrolled in the trial (TpG, 21; PbG, 20). There were no significant differences in intraoperative portal pressures, blood loss, fluid requirement, vasopressor requirement, or urine output. Peak intraoperative and end of surgery lactate levels were significantly higher in the Tp group. There was no difference in postoperative liver function tests. Incidence of acute kidney injury as assessed by Risk, Injury, Failure, Loss, and End-Stage Kidney Disease criteria was lower in the Tp group (27% versus 60%; P = 0.04). The TpG had less postoperative ascites, a lower need for percutaneous interventions, and a shorter hospital stay. Incidence of bradycardia requiring pharmacological intervention and withdrawal from study was significantly higher in the TpG. In conclusion, this study has not demonstrated a reduction in postreperfusion portal pressure with Tp. However, Tp infusion reduced postoperative ascitic drain output resulting in less frequent percutaneous interventions and reduced hospital stay. Intraoperative hyperlactatemia and symptomatic bradycardia are major concerns. Its use should be restricted to patients with high-volume ascites, and it needs close monitoring during drug infusion. Liver Transplantation 23 1007-1014 2017 AASLD.