Comparing outcomes of donation after cardiac death versus donation after brain death in liver transplant recipients with hepatitis C: a systematic review and meta-analysis

Donation After Circulatory Death Liver Transplantation: Impact of Normothermic Machine Perfusion on Key Variables

BACKGROUND

During orthotopic liver transplantation, allograft reperfusion is a dynamic point in the operation and often requires vasoactive medications and blood transfusions. Normothermic machine perfusion (NMP) of liver allografts has emerged to increase the number of transplantable organs and may have utility during donation after circulatory death (DCD) liver transplantation in reducing transfusion burden and vasoactive medication requirements.

METHODS

This is a single-center retrospective study involving 226 DCD liver transplant recipients who received an allograft transported with NMP (DCD-NMP group) or with static cold storage (DCD-SCS group). Veno-venous bypass was not used in any patients. Infusion doses of norepinephrine, epinephrine, and vasopressin as well as bolus doses of vasoactive medications during reperfusion were recorded. Blood component therapy was recorded according to phase of liver transplantation and during the first 24 hours postprocedure.

RESULTS

A total of 103 recipients in the DCD-NMP group and 123 patients in the DCD-SCS group were included. Post-reperfusion syndrome (PRS) incidence was reduced in the DCD-NMP group compared to the DCD-SCS group (10.7% [95% confidence interval, CI, 5.5%-18.3%] vs 42.3% [95% CI, 33.4%-51.5%]; P < .001). During the reperfusion period, patients in the DCD-SCS group required increased bolus doses of epinephrine and vasopressin compared to the DCD-NMP group (24.6 vs 7.5 µg; P < .001) and (5.4 vs 2.4 units; P < .001), respectively. The DCD-SCS group received a higher infusion dose of epinephrine during anhepatic phase, at reperfusion, and up to 90 minutes after reperfusion. In the postreperfusion period, there were significant increases in the transfusion of red blood cells (RBCs; 5.3 vs 3.7 units; P = .006), fresh frozen plasma (FFP; 3.4 vs 1.9 units; P < .001), cryoprecipitate (2.7 vs 1.8 pooled units; P = .015) and platelets (0.9 vs 0.4 units; P = .008) in the DCD-SCS group compared to the DCD-NMP group. During the first 24 hours postprocedure, transfusion of RBCs, FFP, and cryoprecipitate in the DCD-SCS group was increased compared to the DCD-NMP group ([2.6 vs 1.7 units; P = .028], [1.6 vs 0.8 units; P < .001], [1.5 vs 0.9 pooled units; P = .031]) respectively. Administration of tranexamic acid was more frequent in the DCD-SCS group during the post-reperfusion period compared to the DCD-NMP group (13% [95% CI, 5.7%-17.4%] vs 3.9% [95% CI, 1.1%-9.6% 95%]; P = .018).

CONCLUSIONS

In DCD liver transplantation, use of NMP was associated with reduced incidence of PRS and decreased vasopressor and inotrope requirements at the time of allograft reperfusion compared to using SCS. Additionally, NMP was associated with reduced transfusion of all blood product components as well as antifibrinolytic agent administration in the post-reperfusion period. Reduced transfusion burden in the DCD-NMP group also occurred during the first 24 hours posttransplant.

Days alive and out of hospital after liver transplant: comparing a patient-centered outcome between recipients of grafts from donation after circulatory and brain deaths

We retrospectively compared outcomes between recipients of donation after circulatory death (DCD) and donation after brain death (DBD) liver allografts using days alive and out of hospital (DAOH), a composite outcome of mortality, morbidity, and burden of care from patient perspective. The initial length of stay and duration of any subsequent readmission for the first year after liver transplantation were recorded. Donor category and perioperative and intraoperative characteristics pertinent to liver transplantation were included. The primary outcome was DAOH₃₆₅. Secondary outcomes included early allograft dysfunction and hepatic arterial and biliary complications. Although the incidence of both early allograft dysfunction (P < .001) and ischemic cholangiopathy (P < .001) was significantly greater in the recipients of DCD, there were no significant differences in the length of stay and DAOH₃₆₅. The median DAOH₃₆₅ was 355 days for recipients of DBD allografts and 353 days for recipients of DCD allografts (P = .34). Increased transfusion burden, longer cold ischemic time, and non-White recipients were associated with decreased DAOH. There were no significant differences in graft failure (P = .67), retransplantation (P = .67), or 1-year mortality (P = .96) between the 2 groups. DAOH is a practical and attainable measure of outcome after liver transplantation. This metric should be considered for quality measurement and reporting in liver transplantation.

Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation

This study investigated the effect of low-dose aspirin in primary adult liver transplantation (LT) on acute cellular rejection (ACR) as well as arterial patency rates. The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis (HAT), although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after LT has a protective effect against ACR. This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. In this cohort of 2365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1436 recipients (61%). The 1-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.63-0.94; p = 0.01). The 1-year primary arterial patency rates were 99% in the aspirin group and 96% in the no-aspirin group with an HR of 0.23 (95% CI, 0.13-0.40; p < 0.001). Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency.

Changes in the Deceased-Donor Trend in Korea: Establishment of Regional Trauma Centers and KODA

South Korea utilizes living-donor liver transplantation to overcome a shortage of deceased donors. After the Korea Organ Donation Agency (KODA) was established, many hospitals were selected to be donor-managing hospital. A nationwide regional trauma center project was carried out separately in 2015. This study aims to analyze how the trend of deceased-donor recruitment and donation has changed based on policy factors such as independent organ-procurement organization (IOPO) activities and establishing regional trauma centers. KONOS data from 2010-2019 were used to analyze the impacts of these policy changes. The results showed that 62 centers had 4395 deceased donors, and 3863 recipients underwent deceased-donor liver transplantation. The two most common causes of donor death are cerebrovascular events and head trauma. When the rate of deceased donors was analyzed by the early period (2010-2014) and the late period (2015-2019), 53 non-trauma centers went from an average of 29.3 cases to 31.0 cases (6.2% increase) annually. Nine regional trauma centers showed a statistically significant increase from an average of 39.8 cases to 70.3 cases (75.9% increase) annually. Based on these policies, he locations where deceased donors are identified are changing. It is necessary to communicate with regional trauma center staff to recruit more deceased donors.

Primary Nonfunction and Early Allograft Dysfunction after Liver Transplantation

BACKGROUND

Despite continuous progress in the field of liver transplantation, considerable proportion of patients still suffer from the postoperative graft dysfunction. Clinically, it presents as early allograft dysfunction (EAD), and its more severe form defined as primary nonfunction (PNF). Posttransplant liver dysfunction translates into significantly worse treatment outcomes.

SUMMARY

Both entities are multifactorial, with donor (graft), recipient, and procedure-related factors playing the key roles. Ischemia-reperfusion injury is a major driver of their development. So far, various noninvasive (pharmacological) and invasive strategies have been tested to mitigate its negative effects. This article pre-sents the current approach to diagnosis, prediction, and management of EAD and PNF.

KEY MESSAGES

Different pharmacological interventions may be considered to improve graft function after liver transplantation. Machine perfusion seems to be the most effective method at the moment.

Liver transplant after donation from controlled circulatory death versus brain death: A UNOS database analysis and publication bias adjusted meta-analysis

BACKGROUND

Donation after circulatory death (DCD) is an increasingly utilized alternative to donation after brain death (DBD) to expand the liver donor pool. We compared the outcomes of liver transplant (LT) after DCD versus DBD.

METHODS

A PRISMA-compliant systematic literature review was performed using the PubMed, Cochrane Library, and Embase databases (end-of-search-date: July 2, 2020). US outcomes were analyzed using the UNOS database (February, 2002-September, 2020). Pooled hazard ratios (HR) for patient and graft survival were obtained through random effect meta-analyses and adjusted for publication bias.

RESULTS

Thirteen studies reporting on 1426 DCD and 5385 DBD LT recipients were included. 5620 DCD and 87561 DBD LT recipients were analyzed from the UNOS database. Meta-analysis showed increased risk of patient mortality for DCD (HR = 1.36; 95%CI, 1.09-1.70; P = .01; I²  = 53.6%). When adjusted for publication bias, meta-analysis showed no difference in patient survival between DCD and DBD (HR = 1.15; 95%CI, .91-1.45; P = .25; I²  = 61.5%). Meta-analysis showed increased risk of graft loss for DCD (HR = 1.50; 95%CI, 1.20-1.88; P < .001; I²  = 67.8%). When adjusted for publication bias, meta-analysis showed a reduction in effect size (HR = 1.36; 95%CI, 1.06-1.74; P = .02; I²  = 73.5%).

CONCLUSION

When adjusted for publication bias, no difference was identified between DCD and DBD regarding patient survival, while DCD was associated with an increased risk of graft loss.

Clinical use of donation after circulatory death pancreas for islet transplantation

Due to a shortage of donation after brain death (DBD) organs, donation after circulatory death (DCD) is increasingly performed. In the field of islet transplantation, there is uncertainty regarding the suitability of DCD pancreas in terms of islet yield and function after islet isolation. The aim of this study was to investigate the potential use of DCD pancreas for islet transplantation. Islet isolation procedures from 126 category 3 DCD and 258 DBD pancreas were performed in a 9-year period. Islet yield after isolation was significantly lower for DCD compared to DBD pancreas (395 515 islet equivalents [IEQ] and 480 017 IEQ, respectively; p = .003). The decrease in IEQ during 2 days of culture was not different between the two groups. Warm ischemia time was not related to DCD islet yield. In vitro insulin secretion after a glucose challenge was similar between DCD and DBD islets. After islet transplantation, DCD islet graft recipients had similar graft function (AUC C-peptide) during mixed meal tolerance tests and Igls score compared to DBD graft recipients. In conclusion, DCD islets can be considered for clinical islet transplantation.

Improving Liver Graft Function Using CD47 Blockade in the Setting of Normothermic Machine Perfusion

BACKGROUND

Towards the goal of utilizing more livers for transplantation, transplant centers are looking to increase the use of organs from "marginal" donors. Livers from these donors, however, have been shown to be more susceptible to preservation and reperfusion injury.

METHODS

Using a porcine model of donation after circulatory death (DCD), we studied the use of antibody-mediated CD47 blockade to further improve liver graft function undergoing normothermic machine perfusion. Livers from 20 pigs (5 per group) were brought under either 30 or 60 minutes of warm ischemia time (WIT) followed by the administration of CD47mAb treatment or IgG control antibodies and 6 hours of normothermic extracorporeal liver perfusion (NELP).

RESULTS

After 6 hours of NELP, CD47mAb-treated livers with 30 or 60 minutes WIT had significantly lower ALT levels and higher bile production compared to their respective control groups. Blockade of the CD47 signaling pathway resulted in significantly lower TSP-1 protein levels, lower expression of Caspase-3, and higher expression of pERK.

CONCLUSIONS

These findings suggested that CD47mAb treatment decreases ischemia/reperfusion injury through CD47/TSP-1 signaling downregulation and the presence of necrosis/apoptosis after reperfusion, and could increase liver regeneration during normothermic perfusion of the liver.Supplemental Visual Abstract; http://links.lww.com/TP/C146.

Predictors of Biliary Strictures After Liver Transplantation Among Recipients of DCD (Donation After Cardiac Death) Grafts

INTRODUCTION

Biliary strictures are a common complication among donation after cardiac death (DCD) liver transplantation (LT) recipients and may require multiple endoscopic retrograde cholangiopancreatography (ERCP) procedures. We evaluated the risk factors associated with development of biliary strictures in DCD LT recipients.

METHODS

DCD LT recipients who underwent transplantation from 2012 to 2017 were divided into 2 groups: (a) those with anastomotic or non-anastomotic biliary strictures who required ERCP ("stricture group") and (b) those who did not require ERCP or had cholangiograms without evidence of biliary strictures ("non-stricture group"). Clinical data, cholangiograms and laboratory values at day 0 and day 7 after LT were compared between the two groups.

RESULTS

Forty-nine of the 100 DCD LT recipients underwent ERCP. Thirty-four of these 49 LT recipients had evidence of anastomotic or non-anastomotic biliary strictures (stricture group), while the remaining 66 LT recipients comprised the non-stricture group. Donor age was significantly higher in stricture group compared to non-stricture group (49.2 ± 1.8 vs 42.8 ± 1.57 years, respectively; p = 0.01). The stricture group had a significantly higher total bilirubin at day 0 (3.5 ± 0.37 vs 2.6 ± 0.21 mg/dL; p = 0.02) and INR at day 7 (1.24 ± 0.06 vs 1.13 ± 0.01; p = 0.048) compared to the non-stricture group. Multi-variate analysis demonstrated significant association between biliary strictures and total bilirubin at day 0 of LT and age of donor.

CONCLUSION

Biliary strictures occur frequently in DCD LT recipients and may be associated with older age of donor. Hyperbilirubinemia immediately after transplant and higher INR in the first 7 days after transplant may predict subsequent development of biliary strictures.

Hepatitis C Virus Recurrence Occurs Earlier in Patients Receiving Donation After Circulatory Death Liver Transplant Grafts Compared With Those Receiving Donation After Brainstem Death Grafts

INTRODUCTION

Hepatitis C virus (HCV)-related cirrhosis remains the commonest indication for liver transplantation worldwide, yet few studies have investigated the impact of donation after circulatory death (DCD) graft use on HCV recurrence and patient outcomes. DCD grafts have augmented the limited donor organ pool and reduced wait-list mortality, although concerns regarding graft longevity and patient outcome persist.

METHODS

This was a single-center study of all HCV + adults who underwent DCD liver transplantation between 2004 and 2014. 44 HCV+ patients received DCD grafts, and were matched with 44 HCV+ recipients of donation after brainstem death (DBD) grafts, and their outcomes examined.

RESULTS

The groups were matched for age, sex, and presence of hepatocellular carcinoma; no significant differences were found between the group's donor or recipient characteristics. Paired and unpaired analysis demonstrated that HCV recurrence was more rapid in recipients of DCD organs compared with DBD grafts (408 vs 657 days; P = .006). There were no significant differences in graft survival, patient survival, or rates of biliary complications between the cohorts despite DCD donors being 10 years older on average than those used in other published experience.

CONCLUSIONS

In an era of highly effective direct acting antiviral therapy, rapid HCV recrudescence in grafts from DCD donors should not compromise long-term morbidity or mortality. In the context of rising wait-list mortality, it is prudent to use all available sources to expand the pool of donor organs, and our data support the practice of using extended-criteria DCD grafts based on donor age. Notwithstanding that, clinicians should be aware that HCV recrudescence is more rapid in DCD recipients, and early post-transplant anti-viral therapy is indicated to prevent graft injury.

Extended criteria donors in liver transplantation Part I: reviewing the impact of determining factors

The definition and factors of extended criteria donors have already been set; however, details of the various opinions still differ in many respects. In this review, we summarize the impact of these factors and their clinical relevance. Elderly livers must not be allocated for hepatitis C virus (HCV) positives, or patients with acute liver failure. In cases of markedly increased serum transaminases, donor hemodynamics is an essential consideration. A prolonged hypotension of the donor does not always lead to an increase in post-transplantation graft loss if post-OLT care is proper. Hypernatremia of less than 160 mEq/L is not an absolute contraindication to accept a liver graft per se. The presence of steatosis is an independent and determinant risk factor for the outcome. The gold standard of the diagnosis is the biopsy. This is recommended in all doubtful cases. The use of HCV+ grafts for HCV+ recipients is comparable in outcome. The leading risk factor for HCV recurrence is the actual RNA positivity of the donor. The presence of a proper anti-HBs level seems to protect from de novo HBV infection. A favourable outcome can be expected if a donation after cardiac death liver is transplanted in a favourable condition, meaning, a warm ischemia time < 30 minutes, cold ischemia time < 8-10 hours, and donor age 50-60 years. The pathway of organ quality assessment is to obtain the most relevant information (e.g. biopsy), consider the co-existing donor risk factors and the reserve capacity of the recipient, and avoid further technical issues.

Computed Tomography Measurement of Hepatic Steatosis: Prevalence of Hepatic Steatosis in a Canadian Population

Background/Aims. Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that can progress to cirrhosis and hepatocellular carcinoma. This retrospective chart review investigated the incidence of hepatic steatosis in London, Ontario, Canada. Methods. A retrospective chart review was performed on emergency room (ER) patients undergoing nonscheduled computed tomography (CT) imaging over a six-month period in London, Ontario. CT images and reports were examined to determine presence of steatosis. Analyses of the electronic chart for a period of six months following the CT and communication with the patients' family doctors were used to determine if there was follow-up. Waist circumference, subcutaneous fat depth, and abdominal fat volumes were calculated. Results. 48/450 patients meeting inclusion criteria were identified by radiology as having steatosis, with 34/40 (85%) family physicians unaware of the finding. 24.7% (100/405) of patients met standard CT criteria for steatosis, 40 of which were reported by the radiologist. Waist circumference, subcutaneous adipose tissue depth, subcutaneous adipose tissue volume, and visceral adipose tissue volume were significantly associated with steatosis. Conclusions. The hepatic steatosis prevalence we report is the first reported in a Canadian population. Early identification of steatosis will become more important as new pharmacologic therapies arise.