Biliary complications after liver transplantation: old problems and new challenges

Optimal drainage of anastomosis stricture after living donor liver transplantation

BACKGROUND

Endoscopic biliary stenting (EBS) with a fully covered, self-expandable metallic stent (FC-SEMS) and plastic stent (PS) is safe and efficient for biliary anastomotic strictures (ASs) after a deceased donor liver transplantation. Limited studies have investigated the use of FC-SEMSs for biliary strictures post-living donor liver transplantation (LDLT). We compared the resolution rate of biliary ASs post-LDLT and the 12-month recurrence rates post-stent removal between EBS with an FC-SEMS, PS, and percutaneous transhepatic biliary drainage (PTBD).

METHODS

Patients with biliary ASs after an LDLT (mean age: 57.3 years, 76.1% men) hospitalized between 2014 and 2017 were enrolled. Endoscopic retrograde cholangiopancreatography (ERCP) was repeated every 3-4 months. Patients were followed-up for at least 1-year post-stent removal.

RESULTS

Of the 75 patients enrolled, 16, 20, and 39 underwent EBS with an FC-SEMS, PS, and PTBD, respectively. Median follow-up period was 39.2 months. Fewer ERCP procedures were needed in the FC-SEMS group than in the PS group (median, 2 vs. 3; P = 0.20). Median stent indwelling periods were 4.7, 9.3, and 5.4 months in the FC-SEMS, PS, and PTBD groups, respectively (P = 0.006). The functional resolution rate was lower in the PS group (16/20) than in the FC-SEMS (16/16) or PTBD (39/39) group (P = 0.005). The radiologic resolution rate was higher in the FC-SEMS group (16/16) than in the PS group (14/20) (P = 0.07). The 12-month recurrence rates showed no significant differences (FC-SEMS, 4/16; PS, 3/16; PTBD, 6/39; P = 0.66). The rates of complications during treatment differed significantly between the groups (P = 0.04). Stent migration occurred in 1 (6.3%) and 5 (25.0%) patients in the FC-SEMS and PS groups, respectively (P = 0.59).

CONCLUSIONS

EBS with an FC-SEMS is comparable with EBS with a PS or PTBD in terms of biliary stricture resolution and 12-month recurrence rates. The use of FC-SEMSs is potentially effective and safe for biliary AS resolution after LDLT.

Incidence of Cholangitis and Sepsis Associated with Percutaneous Transhepatic Cholangiography in Pediatric Liver Transplant Recipients

Background. Percutaneous transhepatic cholangiography (PTC) is an established treatment in the management of biliary strictures. The aim of our study was to determine the incidence of PTC-related infectious complications in transplanted children, and identify their precise aetiol-ogy. Methods. We retrospectively reviewed all PTC performed from January 2017 to October 2020 in our center. Before the procedure, all patients received antibiotic prophylaxis defined as first line, while second line was used in case of previously microbiological isolation. Cholangitis was defined as fever (>38.5°) and elevated inflammatory markers after PTC, while sepsis included hemodynamic instability in addition to cholangitis. Results. One hundred and fifty-seven PTCs from 50 pediatric recipients were included. The overall incidence of cholangitis and sepsis after PTC was 44.6% (70/157) and 3.2% (5/157), respectively, with no fatal events. Blood cultures yielded positive results in 15/70 cases (21.4%). Enterococcus faecium and Pseudomonas aeruginosa were the most common isolated pathogens. Multidrug-resistant (MDR) pathogens were found in 11/50 patients (22%). Conclusion. PTC is associated with a relatively high rate of post-procedural cholangitis, although with low rate of sepsis and no fatal events. Blood cultures allowed to find a precise aetiology in roughly a quarter of the cases, showing prevalence of Enterococcus faecium and Pseudomonas aeruginosa.

Bile duct reconstruction using scaffold-free tubular constructs created by Bio-3D printer

Introduction

Biliary strictures after bile duct injury or duct-to-duct biliary reconstruction are serious complications that markedly reduce patients’ quality of life because their treatment involves periodic stent replacements. This study aimed to create a scaffold-free tubular construct as an interposition graft to treat biliary complications.

Methods

Scaffold-free tubular constructs of allogeneic pig fibroblasts, that is, fibroblast tubes, were created using a Bio-3D Printer and implanted into pigs as interposition grafts for duct-to-duct biliary reconstruction.

Results

Although the fibroblast tube was weaker than the native bile duct, it was sufficiently strong to enable suturing. The pigs' serum hepatobiliary enzyme levels remained stable during the experimental period. Micro-computed tomography showed no biliary strictures, no biliary leakages, and no intrahepatic bile duct dilations. The tubular structure was retained in all resected specimens, and the fibroblasts persisted at the graft sites. Immunohistochemical analyses revealed angiogenesis in the fibroblast tube and absence of extensions of the biliary epithelium into the fibroblast tube's lumen.

Conclusions

This study's findings demonstrated successful reconstruction of the extrahepatic bile duct with a scaffold-free tubular construct created from pig fibroblasts using a novel Bio-3D Printer. This construct could provide a novel regenerative treatment for patients with hepatobiliary diseases.

Biliary complications after liver transplantation: current perspectives and future strategies

Importance

Liver transplantation (LT) is a life-saving therapy for patients with end-stage liver disease and with acute liver failure, and it is associated with excellent outcomes and survival rates at 1 and 5 years. The incidence of biliary complications (BCs) after LT is reported to range from 5% to 20%, most of them occurring in the first three months, although they can occur also several years after transplantation.

Objective

The aim of this review is to summarize the available evidences on pathophysiology, risk factors, diagnosis and therapeutic management of BCs after LT.

Evidence Review

a literature review was performed of papers on this topic focusing on risk factors, classifications, diagnosis and treatment.

Findings

Principal risk factors include surgical techniques and donor's characteristics for biliary leakage and anastomotic biliary strictures and vascular alterations for non- anastomotic biliary strictures. MRCP is the gold standard both for intra- and extrahepatic BCs, while invasive cholangiography should be restricted for therapeutic uses or when MRCP is equivocal. About treatment, endoscopic techniques are the first line of treatment with success rates of 70-100%. The combined success rate of ERCP and PTBD overcome 90% of cases. Biliary leaks often resolve spontaneously, or with the positioning of a stent in ERCP for major bile leaks.

Conclusions and Relevance

BCs influence morbidity and mortality after LT, therefore further evidences are needed to identify novel possible risk factors, to understand if an immunological status that could lead to their development exists and to compare the effectiveness of innovative surgical and machine perfusion techniques.

Diagnosis and management of benign biliary strictures post liver transplantation in adults

Benign biliary strictures after liver transplantation are common and can lead to graft dysfunction and decreased patient survival. Post-transplant strictures are classified as anastomotic or non-anastomotic which differ in response to therapy. Risk factors for biliary strictures following transplantation include impaired blood supply, surgical factors, and biliary anomalies. Patients can present with biliary obstruction but most will be asymptomatic, with only abnormal graft function. MRCP is the most sensitive noninvasive tool for diagnosing biliary complications. In most centres worldwide endoscopy is used first-line in the management of anastomotic strictures, although there is significant variation in endoscopic technique employed; including dilation, placing a single or multiple plastic stents, a fully covered metal stent and most recently using intra-ductal fully covered metal stents. With the introduction of fully covered metal stents the number of interventions patients require has reduced and overall the clinical success of the endoscopic approach has steadily improved. Percutaneous and surgical treatments are now reserved for patients in whom endoscopic management fails or who have had Roux-en-Y anastomoses. However even in these cases, combined procedures with interventional radiology, or implementation of enteroscopy and EUS-guided approaches now means very few patients ultimately require surgical revision.

Subclinical biliary strictures as a cause of long-term allograft dysfunction in children who underwent liver transplantation

We aimed to evaluate the role of liver biopsy to predict subclinical biliary strictures (BS) and assess the impact of BS on long-term allograft dysfunction following liver transplantation in children (LT). We reviewed all liver biopsies performed from 2012-2018. Percutaneous transhepatic cholangiography (PTC) was performed in patients presenting cholangiolar proliferation on cytokeratin-7 stained sections. We performed 271 biopsies in 161 children (86% with a left lateral segment); 44/161 (27%) presented with diffuse or multifocal cholangiolar proliferation. Among them, a tight BS was confirmed in 38/44 (86%, 24% of total) and it was managed by balloon dilatation. Cholangiolar proliferation showed a positive predictive value (PPV) for BS of 86.4%. Levels of alkaline phosphatase >325 IU/L predicted BS (P = .007). Dilatation of intrahepatic bile ducts on ultrasound was found only in 44% of patients with BS. Following a median follow-up of 9.2 years, only 15/38 (39%) patients resolved the BS. In conclusion subclinical BS is very common and probably underdiagnosed in these patients. Histological evidence of cholangiolar proliferation detectable by cytokeratin-7 immunostain should be preferred to liver function tests and ultrasound to suspect BS. BS in this setting should be regarded as a main cause of long-term allograft dysfunction.

Surgical Duct-to-Duct Reconstruction: an Alternative Approach to Late Biliary Anastomotic Stricture After Deceased Donor Liver Transplantation

BACKGROUND

Bilio-enteric diversion is the current surgical standard in patients after deceased donor liver transplantation (DDLT) with a biliary anastomotic stricture failing interventional treatment and requiring surgical repair. In contrast to this routine, the aim of this study was to show the feasibility and safety of a duct-to-duct biliary reconstruction.

PATIENTS

Between 2012 and 2019, we performed a total of 308 DDLT in 292 adult patients. The overall biliary complication rate was 20.5%. Patients with non-anastomotic or combined strictures were excluded from this analysis. Out of 273 patients after a primary duct-to-duct reconstruction, 20 (7.3%) developed late isolated AS. Seven of these patients failed interventional biliary treatment and required a surgical repair.

RESULTS

Duct-to-duct reconstruction was feasible and successful in all patients. Liver function tests fully normalized and no patient required any form of biliary intervention after surgery. One patient with intraoperative cholangiosepsis was ICU bound for 5 days, and another patient with a subhepatic abscess required percutaneous drainage. There was no perioperative death. The median length of hospital stay was 8 (5-17) days. The median time of follow-up after relaparotomy was 1593 (434-2495) days.

CONCLUSION

Duct-to-duct reconstruction is a feasible and safe option in selected patients requiring surgical repair for isolated AS after DDLT. This approach preserves the biliary anatomy and avoids the potential side effects of a bilio-enteric diversion.

The real incidence of biliary tract complications after adult liver transplantation: the role of the prospective routine use of cholangiography during post-transplant follow-up

Biliary tract complications (BTCs) still burden liver transplantation (LT). The wide reporting variability highlights the absence of systematic screening. From 2000 to 2009, simultaneous liver biopsy and direct biliary visualization were prospectively performed in 242 recipients at 3 and 6 months (n = 212, 87.6%) or earlier when indicated (n = 30, 12.4%). Median follow-up was 148 (107-182) months. Seven patients (2.9%) experienced postprocedural morbidity. BTCs were initially diagnosed in 76 (31.4%) patients; 32 (42.1%) had neither clinical nor biological abnormalities. Acute cellular rejection (ACR) was present in 27 (11.2%) patients and in 6 (22.2%) BTC patients. Nine (3.7%) patients with normal initial cholangiography developed BTCs after 60 (30-135) months post-LT. BTCs directly lead to 7 (2.9%) re-transplantations and 14 (5.8%) deaths resulting in 18 (7.4%) allograft losses. Bile duct proliferation at 12-month biopsy proved an independent risk factor for graft loss (P = 0.005). Systematic biliary tract and allograft evaluation allows the incidence and extent of biliary lesions to be documented more precisely and to avoid erroneous treatment of ACR. The combination 'abnormal biliary tract-canalicular proliferation' is an indicator of worse graft outcome. BTCs are responsible for important delayed allograft and patient losses. These results underline the importance of life-long follow-up and appropriate timing for re-transplantation.

Lebertransplantation in der Schweiz 2020

Die Lebertransplantation ist in den letzten beinahe 40 Jahren zu einer etablierten Therapie der fortgeschrittenen Leberzirrhose, des akuten Leberversagens sowie gewisser auf die Leber beschränkter Tumorerkrankungen geworden und stellt somit für viele unserer Patientinnen und Patienten eine lebensrettende Behandlungsmöglichkeit dar. Leider jedoch ist der Zugang zu einer Lebertransplantation dadurch limitiert, dass nicht für alle Patientinnen und Patienten ausreichend Spenderorgane zur Verfügung stehen. Der folgende Artikel fasst die wichtigsten Punkte zur Indikation, Abklärung vor Transplantation sowie zum Management nach der Transplantation zusammen.

Can ultrasonography differentiate anastomotic and non-anastomotic biliary strictures after orthotopic liver transplantation- a single-center experience

PURPOSE

To evaluate the role of ultrasonography (US) in differentiating anastomotic biliary strictures (AS) and non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT).

METHOD

This retrospective study included 1259 OLT recipients between 2005-2018. Seventy-six with anastomotic strictures (AS) and 103 with non-anastomotic strictures (NAS) were analyzed. The reference standard was cholangiography. The sensitivity, specificity, accuracy of US was evaluated.

RESULTS

There were significant differences between AS and NAS groups (p < 0.001) for skipped and irregular dilatation of intrahepatic bile duct and visualization of hilar biliary lumen. The better US imaging feature for NAS was poorly visualized and non- visible hilar bile duct luminal contour. The sensitivity, specificity and accuracy were 94.2 %, 84.2 % and 88.9 % respectively. Combined two predictors greatly increased the specificity to 93.4 % while diminished its sensitivity and accuracy.

CONCLUSION

US is useful and efficient to differentiate AS and NAS after OLT.

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

Biliary complications in donation after circulatory death liver transplantation: the Australian National Liver Transplantation Unit's experience

BACKGROUND

Biliary complications are the most common complications of donation after circulatory death (DCD) liver transplantation and the international experience with DCD transplants suggests increased rates of biliary complications compared to donation after brain death transplants. Therefore, it is important to understand factors that are associated with the development of biliary complications within the Australian DCD context in order to inform future practice. The aim of this study is to determine the incidence of biliary complications after DCD liver transplantation at the Australian National Liver Transplantation Unit and identify factors associated with this outcome.

METHODS

A retrospective analysis of all adult DCD liver transplants at the Australian National Liver Transplantation Unit from 2007 to 2015 was undertaken. The primary outcome measure was the incidence of biliary complications and was censored on 31 December 2016. Recipients were then stratified into groups based on the development of biliary complications and risk factor analysis was performed.

RESULTS

Biliary complications occurred in 35% of DCD transplants, including seven anastomotic strictures and 10 non-anastomotic strictures. Higher donor risk index scores (P = 0.03), post-transplant portal vein complications (P = 0.042) and peak gamma-glutamyl transferase levels within 7 days post-transplant (P = 0.047) were associated with biliary complications.

CONCLUSION

Findings from this study demonstrate that biliary complications remain common in DCD liver recipients. Recipients who developed a biliary complication tended to have higher donor risk index, elevated peak gamma-glutamyl transferase levels within 7 days post-transplant or a portal vein complication. The presence of any of these factors should prompt close monitoring for post-transplant biliary complications.

Efficacy and safety of device-assisted enteroscopy ERCP in liver transplantation: A systematic review and meta-analysis

BACKGROUND

Enterobiliary anastomoses are the main source of complications after liver transplantation. An endoscopic approach combining device-assisted enteroscopy and ERCP (DAE-ERCP) is technically feasible in postsurgical anatomy.

AIMS

This study aimed at assessing the efficacy, feasibility, and safety of DAE-ERCP in liver-transplanted patients (LT) and other subsets (non-LT).

METHODS

A systematic review and meta-analysis of studies involving DAE procedures in LT patients (between January 2000 and May 2017) was conducted. The main endpoints were as follows: endoscopic, diagnostic, therapeutic, and overall success rates, complications, and the need for surgery.

RESULTS

A total of 155 studies were retrieved, and 6 relevant trials were analyzed. Overall, 132 subjects (72 LT and 60 non-LT) undergoing 257 DAE-ERCP (135 and 122) were included. Complications were rare (4/257), and no deaths occurred. These are the pooled success rates among LT and non-LT patients: 80%-100% and 82%-95% (enteroscopic), 75%-100% and 89%-100% (diagnostic), 67%-100% and 92%-100% (therapeutic), and 60%-100% and 79%-83% (overall results). The requirement for surgery was similar in the two subgroups.

CONCLUSION

In managing biliary complications, the high diagnostic and therapeutic success rates of DAE-ERCP combined with its safety and feasibility encourage its application as a first-line approach to transplanted patients.

From in vitro evaluation to human postmortem pre-validation of a radiopaque and resorbable internal biliary stent for liver transplantation applications

The implantation of an internal biliary stent (IBS) during liver transplantation has recently been shown to reduce biliary complications. To avoid a potentially morbid ablation procedure, we developed a resorbable and radiopaque internal biliary stent (RIBS). We studied the mechanical and radiological properties of RIBS upon in vivo implantation in rats and we evaluated RIBS implantability in human anatomical specimens. For this purpose, a blend of PLA₅₀-PEG-PLA₅₀ triblock copolymer, used as a polymer matrix, and of X-ray-visible triiodobenzoate-poly(ε-caprolactone) copolymer (PCL-TIB), as a radiopaque additive, was used to design X-ray-visible RIBS. Samples were implanted in the peritoneal cavity of rats. The radiological, chemical, and biomechanical properties were evaluated during degradation. Further histological studies were carried out to evaluate the degradation and compatibility of the RIBS. A human cadaver implantability study was also performed. The in vivo results revealed a decline in the RIBS mechanical properties within 3 months, whereas clear and stable X-ray visualization of the RIBS was possible for up to 6 months. Histological analyses confirmed compatibility and resorption of the RIBS, with a limited inflammatory response. The RIBS could be successfully implanted in human anatomic specimens. The results reported in this study will allow the development of trackable and degradable IBS to reduce biliary complications after liver transplantation. STATEMENT OF SIGNIFICANCE: Biliary reconstruction during liver transplantation is an important source of postoperative morbidity and mortality although it is generally considered as an easy step of a difficult surgery. In this frame, internal biliary stent (IBS) implantation is beneficial to reduce biliary anastomosis complications (leakage, stricture). However, current IBS are made of non-degradable silicone elastomeric materials, which leads to an additional ablation procedure involving potential complications and additional costs. The present study provides in vitro and human postmortem implantation data related to the development and evaluation of a resorbable and radiopaque internal biliary stent (RIBS) that could tackle these drawbacks.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Impact of human-derived hemoglobin based oxygen vesicles as a machine perfusion solution for liver donation after cardiac death in a pig model

The recent clinical application of perfusion technology for the machine preservation of donation after cardiac death (DCD) grafts has some advantages. Oxygenation has been proposed for the preservation of DCD liver grafts. The aim of this study is to clarify whether the use of HbV-containing preservation solution during the subnormothermic machine perfusion (SNMP) of the liver graft improves the graft function of DCD porcine livers in an ex vivo reperfusion model. Pig livers were excised after 60 minutes of warm ischemic time and were preserved under one of three preservation conditions for 4 hours. The preservation conditions were as follows: 4°C cold storage (CS group; N = 5), Hypothermic machine preservation (HMP) with UW gluconate solution (HMP group; N = 5), SNMP (21°C) with UW gluconate solution (SNMP group; N = 5), SNMP (21°C) with HbVs (Hb; 1.8 mg/dl) perfusate (SNMP+HbV group; N = 5). Autologous blood perfusion was performed for 2 hours in an isolated liver reperfusion model (IRM). The oxygen consumption of the SNMP and SNMP+HbV group was higher than the HMP groups (p < 0.05). During the reperfusion, the AST level in the SNMP+HbV group was lower than that in the CS, HMP and SNMP groups. The changes in pH after reperfusion was significantly lower in SNMP+HbV group than CS and HMP groups. The ultrastructural findings indicated that the mitochondria of the SNMP+HbV group was well maintained in comparison to the CS, HMP and SNMP groups. The SNMP+HbVs preservation solution protected against metabolic acidosis and preserved the liver function after reperfusion injury in the DCD liver.

Paradigm shift in the management of bile duct strictures complicating living donor liver transplantation

AIM

Validation of new metrics to identify functionally significant obstruction (FSO), to better define biliary strictures complicating living donor liver transplantation (LDLT).

METHODS

All LDLT recipients who presented with cholestasis were studied. Novel metrics for FSO are as follows: (1) magnetic resonance cholangiopancreatography (MRCP) ductal ratio (MDR): The ratio between hepatic duct and recipient duct diameter on the MRCP taken at presentation; (2) endoscopic retrograde cholangiography (ERC) ductal ratio (EDR): The ratio between hepatic duct and recipient duct diameter on the first ERC done for suspected biliary strictures; (3) delayed contrast drainage (DCD): > 50% contrast retained above the anastomotic site, in more than three consecutive fluoroscopic images taken at least 15 min after contrast instillation. Association between these metrics and endotherapy response was analyzed along with patient demographics, intraoperative variables (cold ischemia time, blood transfusions, biliary anastomosis) and perioperative complications (hepatic artery thrombosis [HAT], bile leak). Favorable response to endotherapy was defined as symptomatic relief with ≥ 80% reduction in total bilirubin/alkaline phosphatase.

RESULTS

A total of 83 LDLT recipients presented with altered liver function tests. Favorable response was seen in 18/39 patients (46.2%). On univariate analysis, HAT, multiple biliary anastomoses, graft-to-recipient weight ratio (GRWR), MDR, EDR and DCD were significant (p value ≤ 0.05). On multivariate analysis, only MDR ≥ 1.15 was an independent predictor of favorable response to endotherapy (OR 48 [95% CI 7.096-324.71]).

CONCLUSION

A paradigm shift in the approach to management of biliary strictures complicating LDLT is proposed whereby a multidimensional definition of FSO can help in reliable patient selection for endotherapy and improve patient outcome as a whole.

Pediatric Hepatobiliary Interventions in the Setting of Intrahepatic Vascular Malformations, Portal Hypertension, and Liver Transplant

Within the broad spectrum of pediatric hepatobiliary disorders, hepatic vascular malformations, portal hypertension, and hepatic transplant interventions pose numerous challenges. The role of interventional radiology within each of these conditions is discussed herein, beginning with endovascular management of high flow hepatic vascular malformations. Next, while becoming less common in adult populations, surgical portoportal and portosystemic shunts remain prevalent in many pediatric centers. Shunt anatomy is reviewed along with endovascular management techniques for shunt dysfunction. Next, the growing experience with pediatric transjugular intrahepatic portosystemic shunt placement is reviewed along with tips for success in pediatric patients. Finally, pediatric hepatic transplant interventions are discussed with technical notes pertinent to split liver anatomy.

Transplantation of High-risk Donor Livers After Ex Situ Resuscitation and Assessment Using Combined Hypo- and Normothermic Machine Perfusion: A Prospective Clinical Trial

OBJECTIVE

The aim of this study was to evaluate sequential hypothermic and normothermic machine perfusion (NMP) as a tool to resuscitate and assess viability of initially declined donor livers to enable safe transplantation.

SUMMARY BACKGROUND DATA

Machine perfusion is increasingly used to resuscitate and test the function of donor livers. Although (dual) hypothermic oxygenated machine perfusion ([D]HOPE) resuscitates livers after cold storage, NMP enables assessment of hepatobiliary function.

METHODS

In a prospective clinical trial, nationwide declined livers were subjected to ex situ NMP (viability assessment phase), preceded by 1-hour DHOPE (resuscitation phase) and 1 hour of controlled oxygenated rewarming (COR), using a perfusion fluid containing an hemoglobin-based oxygen carrier. During the first 2.5 hours of NMP, hepatobiliary viability was assessed, using predefined criteria: perfusate lactate <1.7 mmol/L, pH 7.35 to 7.45, bile production >10 mL, and bile pH >7.45. Livers meeting all criteria were accepted for transplantation. Primary endpoint was 3-month graft survival.

RESULTS

Sixteen livers underwent DHOPE-COR-NMP. All livers were from donors after circulatory death, with median age of 63 (range 42-82) years and median Eurotransplant donor risk index of 2.82. During NMP, all livers cleared lactate and produced sufficient bile volume, but in 5 livers bile pH remained <7.45. The 11 (69%) livers that met all viability criteria were successfully transplanted, with 100% patient and graft survival at 3 and 6 months. Introduction of DHOPE-COR-NMP increased the number of deceased donor liver transplants by 20%.

CONCLUSIONS

Sequential DHOPE-COR-NMP enabled resuscitation and safe selection of initially declined high-risk donor livers, thereby increasing the number of transplantable livers by 20%.

TRIAL REGISTRATION

www.trialregister.nl; NTR5972.

Cholangiolithiasis postliver transplantation: Successful treatment utilizing percutaneous transhepatic cholangioscopy and laser lithotripsy

Liver transplant is a risk factor for the development of cholangiolithiasis and choledocholithiasis. While usually addressed by endoscopic techniques, percutaneous transhepatic cholangioscopy combined with laser lithotripsy can be considered a suitable alternative option in select patients.

A 29-year-old male with a 27-year history of liver transplant presented with new onset of persistent pain localized to the lower abdomen 9 days after a liver biopsy. Abdominal CT scan and MRCP showed large calculi expanding intra- and extrahepatic bile ducts. All intrahepatic ductal calculi were removed after 2 sessions of laser lithotripsy and basket retrieval, while common hepatic duct calculi were anterogradely swept into the jejunum after balloon cholangioplasty of the hepaticojejunal anastomosis. No major procedure-related complications were seen.

Percutaneous transhepatic cholangioscopy and choledochoscopy with laser lithotripsy is a minimally invasive and efficient technique for removal of intra- and extrahepatic bile duct stones postliver transplantation.

Use of Elderly Donors in Liver Transplantation: A Paired-match Analysis at a Single Center

OBJECTIVE

To evaluate the use of elderly donors in liver transplantation (LT) and identify risk factors associated with a worse outcome.

SUMMARY BACKGROUND DATA

Use of livers from very old donors could expand the donor pool but is not universally implemented.

METHODS

This is a retrospective, single-center medical record review. From January 2001 to December 2014, 1354 LTs were performed. After exclusion of donors <18 years, ABO-incompatible LT, re-LT and UNOS 1 status patients, LT recipients were stratified into 2 groups based on donor age: 18-69 (n=692) vs. ≥70 years (n=515) then matched using a propensity score approach. Two groups were finally matched (young group = 448 cases; old group = 515 cases).

RESULTS

The median (interquartile range [IQR]) follow-up was 5.0 (2.0-8.4) years. Comparing the 2 identified groups, no differences were observed regarding early retransplants (1.8 vs. 2.9; P = 0.3), HCV-related death (7.6 vs. 8.7%; P = 0.6), vascular (5.8 vs. 5.0%; P = 0.7), and biliary complications (16.5 vs. 18.6%; P = 0.4). On multivariate analysis, independent risk factors for graft loss were: HCV-positive recipient (HR = 2.1; 95% CI = 1.6-2.7; P < 0.001), donor age (HR = 1.0; 95% CI = 1.0-1.0; P < 0.001), cold ischemia time (HR = 1.0; 95% CI = 1.0-1.0; P = 0.042), and donor history of diabetes mellitus (HR = 1.48; 95% CI = 1.03-2.13; P = 0.036).

CONCLUSIONS

Use of elderly donors is not associated per se with an increased risk of vascular and biliary complications. In the presence of cold ischemia time and diabetes mellitus, appropriate donor-to-recipient matching is warranted.

Staged Biliary Reconstruction After Orthotopic Liver Transplantation: A Practical Surgical Strategy for High-Acuity Adult Recipients

Biliary complications (BC) following orthotopic liver transplantation (OLT) is strongly associated with inferior patient outcomes and increased healthcare cost. BC in high-acuity patients can be lethal. While the utility of staged biliary reconstruction after liver transplantation (SBRALT) has been reported in adult and pediatric OLT, biliary outcome data are scarce. We sought to evaluate the clinical utility and outcomes of SBRALT in high-acuity transplant recipients.

Methods

We conducted an analysis from our prospective database of 149 adult OLT between January 1, 2012, and September 30, 2017. Mean follow-up was 26 months. Variables were compared for Group I: one-stage OLT with biliary reconstruction (N = 58) versus Group II: SBRALT (N = 91).

Results

Compared with Group I, patients in Group II had higher acuity of illness: median model for end-stage liver disease scores (19 vs 35 P = 0.002), requirement for pretransplant intensive care unit (29.3% vs 54.9%, P = 0.022), pretransplant renal replacement therapy (15.5% vs 48.4%), estimated blood loss (2000 vs 4750 mL, P < 0.001), and intraoperative packed red blood cells transfusion (4 vs 10 units, P < 0.001). For Group II, biliary reconstruction was performed between 1 and 6 days after OLT. Hepaticojejunostomy was performed in 8.6% (Group I) and 26.4% (Group II), P = 0.010. For Groups I and II, BC rates (8.6% vs 7.7%, P = 0.955) and 1-year graft failure-free survival rates (89.7% vs 88.2%, P = 0.845) were comparable.

Conclusions

Graft failure-free survival and biliary outcomes of SBRALT in high-acuity recipients are excellent and comparable to one-stage OLT for low-risk patients. SBRALT is a practical surgical strategy in complex OLT.

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.

Hypothermic Oxygenated Machine Perfusion of Liver Grafts from Brain-Dead Donors

Hypothermic oxygenated machine perfusion (HOPE) was introduced in liver transplantation (LT) to mitigate ischemia-reperfusion injury. Available clinical data mainly concern LT with donors after circulatory-determined death, whereas data on brain-dead donors (DBD) are scarce. To assess the impact of end-ischemic HOPE in DBD LT, data on primary adult LTs performed between March 2016 and June 2018 were analyzed. HOPE was used in selected cases of donor age >80 years, apparent severe graft steatosis, or ischemia time ≥10 hours. Outcomes of HOPE-treated cases were compared with those after static cold storage. Propensity score matching (1:2) and Bayesian model averaging were used to overcome selection bias. During the study period, 25 (8.5%) out of 294 grafts were treated with HOPE. After matching, HOPE was associated with a lower severe post-reperfusion syndrome (PRS) rate (4% versus 20%, p = 0.13) and stage 2–3 acute kidney injury (AKI) (16% versus 42%, p = 0.046). Furthermore, Bayesian model averaging showed lower transaminases peak and a lower early allograft dysfunction (EAD) rate after HOPE. A steeper decline in arterial graft resistance throughout perfusion was associated with lower EAD rate. HOPE determines a significant reduction of ischemia reperfusion injury in DBD LT.

Hepatobiliary scintigraphy in the study of complications in adult patients after liver transplant. Description of the experience

OBJECTIVE

To show the experience of the use of hepatobiliary scintigraphy in patients with suspected complications after liver transplantation in a high complexity centre.

MATERIAL AND METHOD

Retrospective, observational and descriptive study. All consecutive adult patients with liver transplantation between January 2013 and February 2018 were included, with one or more hepatobiliary scintigraphy during the early or late postoperative period. A total of 58 studies were analyzed in 38 patients (22 men and 16 women). Mean age: 48 years. In 34/38: cadaverous donor (89%), and in 4 (11%): a living donor. Demographic data and relevant information regarding the transplant were obtained, and the result was related to the surgical findings to determine the correlation between them. The influence of the test on the final clinical decisions was evaluated.

RESULTS

Findings: 9 scans (14%) were normal, 36 studies were negative, and 21 were positive for biliary complications. Of the total of 58 studies, 50 (86%) had impact on the clinical behaviour of observation or intervention. All the patients with findings of biliary complications (21/21; 100%) had clinical repercussion since 18/21 patients were taken to invasive studies or treatments, and 3/21 patients continued in medical management for findings of non-surgical biliary complications. In 14/18 patients taken to studies or procedures, correlation was found with the scintigraphic study. In 24/36 (66%) of patients with negative scintigraphy, an impact on clinical behaviour was found.

CONCLUSION

Hepatobiliary scintigraphy is a simple, non-invasive, reliable, current and available form for the early study of biliary complications in patients with liver transplantation. Important hepatocellular dysfunction should be taken into account as a frequent cause of false negative studies.

Endoscopic Management of Biliary Issues in the Liver Transplant Patient

Biliary complications remain a common problem after liver transplantation (LT). The therapeutic endoscopist encounters a variety of situations in LT including strictures at the duct-to-duct biliary anastomosis, strictures elsewhere in the biliary tree caused by an ischemic injury, and bile leaks at the anastomosis or from the cut surface and stone disease. Biliary complications lead to significant morbidity and occasionally reduced graft and patient survival. Several factors increase the risk of strictures and leaks. Endoscopic intervention in experienced hands is successful in the management of biliary complications following LT and percutaneous or surgical correction should seldom be required.

Vascular and Biliary Complications Following Deceased Donor Liver Transplantation: A Meta-analysis

OBJECTIVE

To assess biliary and vascular complications after liver transplantations (LTs) sourced from deceased donors.

METHODS

This study reviewed potentially relevant English-language articles gathered from PubMed and Medline published from 2012 to 2017. One additional study was carried out using our institution's database for articles published from 2013 to 2017. Biliary and vascular complications from adult patients receiving their first deceased-donor LT were included. This meta-analysis was performed using Review Manager version 5.2 (Cochrane Collaboration, Copenhagen, Denmark) and the study quality was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Ten studies met our inclusion criteria. Heterogeneity in donation after cardiac death (DCD) and donation after brain death (DBD) recipients was observed and minimized after pooling a subgroup analysis. This latter analysis focused on biliary stricture, biliary leaks and stones, and vascular thrombosis and stenosis. Meta-analyses showed that patients receiving DCD organs have a greatly increased risk of biliary complications compared to those receiving DBD organs, particularly the following: biliary leaks and stones (odds ratio [OR] = 1.69, 95% confidence interval [CI] 1.22-2.34); and biliary stricture (OR = 1.58, 95% CI 1.21-2.06). DCD grafts tended to be but were not significantly associated with DBD regarding vascular thrombosis (OR = 1.62, 95% CI 1.05-2.50), and the risk of vascular stenosis in DCD grafts was not statistically significant (OR = 1.25, 95% CI, .70-2.25).

CONCLUSION

DCD was associated with an increased risk of biliary complications after LT, tended to indicate an increased risk of vascular thrombosis versus, and was not associated with an increased risk of vascular stenosis compared to DBD. There was no significant difference between the grafts.

Percutaneous Treatment of Biliary Strictures After Pediatric Liver Transplantation

Background

Biliary strictures (BS) are frequent after pediatric liver transplantation (LTx) and in spite of ongoing progress, they remain a significant cause of morbidity. In children, the majority of reconstruction is hepatico-jejunal anastomosis (HJA). The aim of this study was to analyze our experience in percutaneous transhepatic treatment of BS.

Material/Methods

Between 1998 and 2014, 589 (269 living donor) pediatric LTx were performed in our institution. We retrospectively reviewed clinical data of patients with HJA who developed BS and who underwent percutaneous transhepatic biliary drainage (PTBD).

Results

Out of 400 patients with HJA, 35 patients developed BS. There were 27 cases (77%) of anastomotic BS (ABS) and 8 cases (23%) of multilevel BS (MBS). Ninety-two PTBD sessions (2.5 per patient) were performed, with successful outcomes in 20 cases (57%). Fifteen patients, after failed PTBD, underwent surgery which was successful in 11 cases. Overall good outcomes were achieved in 31 cases (88.5%). The most common complication of PTBD was cholangitis which occurred in 5.4% of the cases. We did not find any risk factors for PTBD failure, except for treatment occurring before 2007.

Conclusions

Percutaneous treatment is effective and safe in BS and is recommended as a first-line approach. The majority of patients in our study required multiple interventions, however, the overall risk of complications was low. Surgery is essential in selected cases and always should be considered if PTBD fails.

Endoscopic treatment in biliary strictures after pediatric liver transplantation

BACKGROUND AND AIM

The aim of the study was to assess efficacy and safety of endoscopic treatment in BS after pediatric LTx.

METHODS

We retrospectively reviewed data of patients with DDA who developed BS and underwent ERCP.

RESULTS

Of 189 transplanted patients with DDA, strictures developed in 30 (16%). In this subgroup, the median age at LTx was 14.7 (1.5-17.6) and follow-up period was 3.9 (1.3-11.3). ABS were in 76% and NABS in combination with ABS in 24% of patients. Overall, 95 ERCP sessions (3.0 per patient) were performed with successful outcome in 22 (73%) cases. Duration of treatment was 9.1 (1.8-24.1) months. Five patients underwent surgical revision and three patients retransplantation (10%). Risk factors of endoscopy failure were HCV or HBV infection, prolonged CIT and treatment before 2007. The most common complications after ERCP were cholangitis (8.2%) and pancreatitis (4.2%). There were worse overall prognosis and higher risk of post-ERCP complications in NABS.

CONCLUSIONS

ERCP is safe and effective in the majority of patients with post-transplant duct-to-duct BS, and it is currently recommended as the first-line treatment.

Preliminary results from the use of intraoperative real-time biliary oxygen monitoring in liver transplantation

BACKGROUND AND AIMS

Biliary anastomosis is a frequent area of complications after liver transplantation (LT) and a potential area of "microangiopathy". The concept of a "marginal bile duct" is unexplored. The main aim was to make a preliminary evaluation of the utility of an innovative real-time oxygen microtension (pO2mt) testing device for the assessment of bile duct viability during LT and to correlate these pO2mt values with microvascular tissue quality by histopathology and outcomes.

PATIENTS AND METHODS

Observational prospective cohort study with 23 patients. Oxygen microtension measurements were made placing a micropO2 probe in different areas of recipient and donor's bile duct intraoperative.

RESULTS

Mean pO2mt in the graft bile duct at the level of the anastomosis 103.82 (31-157) mm Hg, being 121.52 (55-174) mm Hg 1.5 cm proximal to the hilar plate (P < 0.001). Mean pO2mt in the recipient's bile duct was 117.87 (62-185) mm Hg, while a value of 137.30 (81-198) mm Hg was observed 1.5 cm distal to the anastomosis (P < 0.001). Cystic duct resection (12 cases) was also related with higher pO2mt values at anastomosis [117.8 (93-157) vs 88.54 (31-124) mm Hg] and distal to anastomosis [135.6 (111-174) vs 106.2 (55-133) mm Hg; P < 0.001]. Patients with 1-, 3-, and 12-month biliary complications had significantly lower pO2mt in the intraoperative measurements.

CONCLUSION

Our preliminary results show that distal borders of donor and recipient bile ducts may be low-vascularized areas. Tissue pO2mt is significantly higher in areas close to the hilar plate and to the duodenum in donor and recipient's sides, respectively. Bile duct injury and biliary complications are associated with worse tissue pO2mt.

A retrospective analysis of re-exploration after living donor right lobe liver transplantation: incidence, causes, outcomes, and risk factors

Despite technical difficulties, right lobe liver grafting is preferred in living donor liver transplantation because of the graft size. Re-exploration after living donor right lobe liver transplantation (LRLT) has never been separately analyzed. We aimed to analyze the incidence, causes, outcomes, and risk factors of re-exploration after LRLT. We reviewed medical records of 1016 LRLT recipients from October 2003 to July 2017 and identified recipients who underwent re-exploration within hospital stay. Separate analyses were also performed according to cause of re-exploration. The overall incidence of re-exploration was 17.0% (173/1016). The most common cause of re-exploration was bleeding (50%). Overall re-exploration was associated with clinical outcome, but different results were shown on analyses according to cause of re-exploration. Risk factors of re-exploration were underlying hepatocellular carcinoma and operative duration [Odds ratio (OR), 1.49; 95% confidence interval (CI), 1.05-2.12; P = 0.03, and OR, 1.002; 95% CI, 1.001-1.004; P = 0.0023, respectively]. Re-exploration after LRLT is relatively common, and is strongly associated with mortality and graft failure.

Solid organ transplantation in the 21st century

Solid organ transplantation (SOT) has emerged from an experimental approach in the 20th century to now being an established and practical definitive treatment option for patients with end-organ dysfunction. The evolution of SOT has seen the field progress rapidly over the past few decades with incorporation of a variety of solid organs-liver, kidney, pancreas, heart, and lung-into the donor pool. New advancements in surgical technique have allowed for more efficient and refined multi-organ procurements with minimal complications and decreased ischemic injury events. Additionally, immunosuppression therapy has also seen advancements with the expansion of immunosuppressive protocols to dampen the host immune response and improve short and long-term graft survival. However, the field of SOT faces new barriers, most importantly the expanding demand for SOT that is outpacing the current supply. Allocation protocols have been developed in an attempt to address these concerns. Other avenues for SOT are also being explored to increase the donor pool, including split-liver donor transplants, islet cell implantation for pancreas transplants, and xenotransplantation. The future of SOT is bright with exciting new research being explored to overcome current obstacles.

A cost analysis of early biliary strictures following orthotopic liver transplantation in the United States

INTRODUCTION

To date, the financial burden of biliary strictures (BS) after orthotopic liver transplantation (OLT) has remained largely unassessed. This study sought to approximate perioperative costs associated with early BS and delineate where in the hospital these costs are incurred.

METHODS

The Premier Healthcare Database was queried for patients undergoing OLT between 2010 and 2016. Patients who did and did not develop early BS were compared with respect to perioperative costs and outcome variables. Multivariable regression models were used to estimate differences between groups.

RESULTS

Patients who developed early BS had a longer length of stay (LOS) (35.3 days vs 17.8 days, P < 0.001) and were less likely to be discharged home (odds ratio = 0.45, P = 0.003). Development of early BS was associated with an incremental cost increase of $81 881 (45.8%, P < 0.001). The greatest relative cost increases were in radiology (+163.5%) and respiratory therapy (+157.1%), while the greatest absolute increase was in room and board (+$27 589).

CONCLUSIONS

Early BS after OLT result in higher costs stemming from longer LOS and increased need for various diagnostic studies and therapies. In addition to incentivizing measures that may prevent early BS, hospitals should account for these factors when developing payment schemes for OLT with payors.

Hyaluronic Acid Is a Biomarker for Allograft Dysfunction and Predicts 1-Year Graft Loss After Liver Transplantation

BACKGROUND

Allograft dysfunction after liver transplantation has a profound impact on the risks of death and retransplantation within the first year. We tested whether elevated hyaluronic acid (HA; a glycosaminoglycan cleared by hepatic sinusoidal endothelium) levels may predict excess risk of graft loss.

METHODS

This was a retrospective single-center prognostic cohort study. Patients with either a plasma sample before transplantation, an early post-transplantation sample nearest day 30 (range 10-89 d, 80% within days 15-60), or both were included. Plasma HA was measured with the use of enzyme-linked immunosorbent assays. The primary end point was 1-year graft loss (all-cause mortality and retransplantation). A secondary end point was biliary stricture.

RESULTS

In this study, 169 of 196 patients who received a liver transplant in the study period were included. Pre-transplantation HA (n = 152) did not predict graft loss. Post-transplantation HA (n = 124) was higher among patients with graft loss (median, 177 μg/L [interquartile range (IQR), 89-465] vs 54 μg/L [IQR 37-93]) and was a strong predictor of this outcome (hazard ratio per 50 μg/L, 1.24 [95% confidence interval [CI], 1.14-1.34]). The discriminatory ability of HA was high (area under the receiver operating characteristic curve, 0.86 [95% CI, 0.77-0.94]) and noninferior to other liver function tests. When adjusted for known risk factors of graft loss, HA remained an independent predictor of graft loss.

CONCLUSIONS

High post-transplantation plasma HA level was a strong predictor of 1-year all-cause mortality and retransplantation, whereas pre-transplantation levels were not, despite variety in the time span of blood sampling. Prospective studies are warranted to assess the utility of HA in liver transplantation.

Metallic vs plastic stents to treat biliary stricture after liver transplantation: a systematic review and meta-analysis based on randomized trials

Background and study aims  The first-line approach to anastomotic biliary stricture after orthotopic liver transplantation (OLTX) involves endoscopic retrograde cholangiopancreatography (ERCP). The most widely used technique is placement of multiple plastic stents, but discussions are ongoing on the benefits of fully-covered self-expandable metallic stents (FCEMS) in this situation. This study aimed to compare results from use of plastic and metal stents to treat biliary stricture after transplantation. Patients and methods  Searches were performed in the Medline, EMBASE, SciELO/LILACS, and Cochrane databases, and only randomized studies comparing the two techniques were included in the meta-analysis. Results  Our study included four randomized clinical trials totaling 205 patients. No difference was observed between the stricture resolution rate (RD: 0.01; 95 %CI [-0.08 - 0.10]), stricture recurrence (RD: 0.13; 95 %CI [-0.03 - 0.28]), and adverse events (RD: -0.10; 95 %CI [-0.65 - 0.44]) between the plastic and metallic stent groups. The metallic stent group demonstrated benefits in relation to the number of ERCPs performed (MD: -1.86; 95 %CI [-3.12 to -0.6]), duration of treatment (MD: -105.07; 95 %CI [-202.38 to -7.76 days]), number of stents used (MD: -10.633; 95 %CI [-20.82 to -0.44]), and cost (average $ 8,288.50 versus $ 18,580.00, P  < 0.001). Conclusions  Rates of resolution and recurrence of stricture are similar, whereas the number of ERCPs performed, number of stents used, duration of treatment, and costs were lower in patients treated with FCEMS, which shows that this device is a valid option for initial treatment of post-OLTX biliary stricture.

Onset of Donor Warm Ischemia Time in Donation After Circulatory Death Liver Transplantation: Hypotension or Hypoxia?

The aim of this study was to investigate the impact of hypoxia and hypotension during the agonal phase of donor warm ischemia time (DWIT) on hepatic ischemia/reperfusion injury (IRI) and complications in donation after circulatory death (DCD) liver transplantation. A retrospective single-center study of 93 DCD liver transplants (Maastricht type III) was performed. DWIT was divided into 2 periods: the agonal phase (from withdrawal of treatment [WoT] until circulatory arrest) and the asystolic phase (circulatory arrest until cold perfusion). A drop to <80% in peripheral oxygenation (SpO₂ ) was considered as hypoxia in the agonal phase (SpO₂ -agonal) and a drop to <50 mm Hg as hypotension in the agonal phase (SBP-agonal). Peak postoperative aspartate transaminase level >3000 U/L was considered as severe hepatic IRI. SpO₂ dropped within 2 minutes after WoT <80%, whereas the systolic blood pressure dropped to <50 mm Hg after 9 minutes, resulting in a longer SpO₂ -agonal (13 minutes) than SBP-agonal (6 minutes). In multiple logistic regression analysis, only duration of SpO₂ -agonal was associated with severe hepatic IRI (P = 0.006) and not SBP-agonal (P = 0.32). Also, recipients with long SpO₂ -agonal (>13 minutes) had more complications with a higher Comprehensive Complication Index during hospital admission (43.0 versus 32.0; P = 0.002) and 90-day graft loss (26% versus 6%; P = 0.01), compared with recipients with a short SpO₂ -agonal (≤13 minutes). Furthermore, Cox proportional hazard modeling identified a long SpO₂ -agonal as a risk factor for longterm graft loss (hazard ratio, 3.30; 95% confidence interval, 1.15-9.48; P = 0.03). In conclusion, the onset of hypoxia during the agonal phase is related to the severity of hepatic IRI and postoperative complications. Therefore, SpO₂ <80% should be considered as the start of functional DWIT in DCD liver transplantation.