Challenges With the Implementation of Machine Perfusion in Clinical Liver Transplantation.

Dynamic organ preservation is a relatively old technique which has regained significant interest in the last decade. Machine perfusion (MP) techniques are applied in various fields of solid organ transplantation today. The first clinical series of ex situ MP in liver transplantation was presented in 2010. Since then, the number of research and clinical applications has substantially increased. Despite the notable beneficial effect on organ quality and recipient outcome, MP is still not routinely used in liver transplantation. Based on the enormous need to better preserve organs and the subsequent demand to continuously innovate and develop perfusion equipment further, this technology is also beneficial to test and deliver future therapeutic strategies to livers before implantation. This article summarizes the various challenges observed during the current shift from static to dynamic liver preservation in the clinical setting. The different organ perfusion strategies are discussed first, together with ongoing clinical trials and future study design. The current status of research and the impact of costs and regulations is highlighted next. Factors contributing to costs and other required resources for a worldwide successful implementation and reimbursement are presented third. The impact of research on cost-utility and effectivity to guide the tailored decision-making regarding the optimal perfusion strategy is discussed next. Finally, this article provides potential solutions to the challenging field of innovation in healthcare considering the various social and economic factors and the role of clinical, regulatory, and financial stakeholders worldwide.

Procalcitonin in early allograft dysfunction after orthotopic liver transplantation: a retrospective single centre study.

BACKGROUND: Ischemia-reperfusion injury (IRI) is the pathophysiological hallmark of hepatic dysfunction after orthotopic liver transplantation (OLT). Related to IRI, early allograft dysfunction (EAD) after OLT affects short- and long-term outcome. During inflammatory states, the liver seems to be the main source of procalcitonin (PCT), which has been shown to increase independently of bacterial infection. This study investigates the association of PCT, IRI and EAD as well as the predictive value of PCT during the first postoperative week in terms of short- and long-term outcome after OLT. METHODS: Patients ≥ 18 years undergoing OLT between January 2016 and April 2020 at the University Hospital of Zurich were eligible for this retrospective study. Patients with incomplete PCT data on postoperative days (POD) 1 + 2 or combined liver-kidney transplantation were excluded. The PCT course during the first postoperative week, its association with EAD, defined by the criteria of Olthoff, and IRI, defined as aminotransferase level > 2000 IU/L within 2 PODs, were analysed. Finally, 90-day as well as 12-month graft and patient survival were assessed. RESULTS: Of 234 patients undergoing OLT, 110 patients were included. Overall, EAD and IRI patients had significantly higher median PCT values on POD 2 [31.3 (9.7-53.8) mcg/l vs. 11.1 (5.3-25.0) mcg/l; p < 0.001 and 27.7 (9.7-51.9) mcg/l vs. 11.5 (5.5-25.2) mcg/l; p < 0.001] and impaired 90-day graft survival (79.2% vs. 95.2%; p = 0.01 and 80.4% vs. 93.8%; p = 0.033). IRI patients with PCT < 15 mcg/l on POD 2 had reduced 90-day graft and patient survival (57.9% vs. 93.8%; p = 0.001 and 68.4% vs. 93.8%; p = 0.008) as well as impaired 12-month graft and patient survival (57.9% vs. 96.3%; p = 0.001 and 68.4% vs. 96.3%; p = 0.008), while the outcome of IRI patients with PCT > 15 mcg/l on POD 2 was comparable to that of patients without IRI/EAD. CONCLUSION: Generally, PCT is increased in the early postoperative phase after OLT. Patients with EAD and IRI have a significantly increased PCT maximum on POD 2, and impaired 90-day graft survival. PCT measurement may have potential as an additional outcome predictor in the early phase after OLT, as in our subanalysis of IRI patients, PCT values < 15 mcg/l were associated with impaired outcome.

Proceedings of the 26th Annual Virtual Congress of the International Liver Transplantation Society.

After a 1-y absence due to the coronavirus disease 2019 pandemic, the 26th Annual Congress of the International Liver Transplantation Society was held from May 15 to 18, 2021, in a virtual format. Clinicians and researchers from all over the world came together to share their knowledge on all the aspects of liver transplantation (LT). Apart from a focus on LT in times of coronavirus disease 2019, featured topics of this year's conference included infectious diseases in LT, living donation, machine perfusion, oncology, predictive scoring systems and updates in anesthesia/critical care, immunology, radiology, pathology, and pediatrics. This report presents highlights from invited lectures and a review of the select abstracts. The aim of this report, generated by the Vanguard Committee of International Liver Transplantation Society, is to provide a summary of the most recent developments in clinical practice and research in LT.

The role of T-tubes and abdominal drains on short-term outcomes in liver transplantation - A systematic review of the literature and expert panel recommendations.

BACKGROUND: This systematic review and expert panel recommendation aims to answer the question regarding the routine use of T-tubes or abdominal drains to better manage complications and thereby improve outcomes after liver transplantation. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel to assess the potential risks and benefits of T-tubes and intra-abdominal drainage in liver transplantation (CRD42021243036). RESULTS: Of the 2996 screened records, 33 studies were included in the systematic review, of which 29 (six RCTs) assessed the use of T-tubes and four regarding surgical drains. Although some studies reported less strictures when using a T-tube, there was a trend toward more biliary complications with T-tubes, mainly related to biliary leakage. Due to the small number of studies, there was a paucity of evidence on the effect of abdominal drains with no clear benefit for or against the use of drainage. However, one study investigating the open vs. closed circuit drains found a significantly higher incidence of intra-abdominal infections when open-circuit drains were used. CONCLUSIONS: Due to the potential risk of biliary leakage and infections, the routine intraoperative insertion of T-tubes is not recommended (Level of Evidence moderate - very low; grade of recommendation strong). However, a T-tube can be considered in cases at risk for biliary stenosis. Due to the scant evidence on abdominal drainage, no change in clinical practice in individual centers is recommended. (Level of Evidence very low; weak recommendation).

Morbidity and mortality of iatrogenic hemothorax occurring in a cohort of liver transplantation recipients: a multicenter observational study.

Hemothorax (HT) is a life-threatening condition, mainly iatrogenic and poorly explored in Liver Transplantation (LT) recipients. The aim of this study is to report and analyze for the first time incidence and outcomes of HT in LT recipients, as well as to suggest a management strategy. Data concerning 7130 consecutive adult liver and liver-kidney transplant recipients were retrospectively collected from ten Transplantation Centers' institutional databases, over a 10-year period. Clinical parameters, management strategies and survival data about post-operative HT were analyzed and reported. Thirty patients developed HT during hospitalization (0.42%). Thoracentesis was found to be the most common cause of HT (16 patients). A non-surgical management was performed in 17 patients, while 13 patients underwent surgery. 19 patients developed thoracic complications after HT treatment, with an overall mortality rate of 50%. The median length of stay in Intensive Care Units was 22 days (IQR25-75 5-66.5). Postoperative hemothorax is mainly due to iatrogenic causes in LT recipients. Despite rare, it represents a serious complication with a high mortality rate and a challenging medical and surgical management. Its occurrence should always be prevented.

Donor Warm Ischemia Time in DCD Liver Transplantation-Working Group Report From the ILTS DCD, Liver Preservation, and Machine Perfusion Consensus Conference.

Donation after circulatory death (DCD) grafts are commonly used in liver transplantation. Attributable to the additional ischemic event during the donor warm ischemia time (DWIT), DCD grafts carry an increased risk for severe ischemia/reperfusion injury and postoperative complications, such as ischemic cholangiopathy. The actual ischemia during DWIT depends on the course of vital parameters after withdrawal of life support and varies widely between donors. The ischemic period (functional DWIT) starts when either Spo2 or blood pressure drop below a certain point and lasts until the start of cold perfusion during organ retrieval. Over the years, multiple definitions and thresholds of functional DWIT duration have been used. The International Liver Transplantation Society organized a Consensus Conference on DCD, Liver Preservation, and Machine Perfusion on January 31, 2020 in Venice, Italy. The aim of this conference was to reach consensus about various aspects of DCD liver transplantation in context of currently available evidence. Here we present the recommendations with regards to the definitions used for DWIT and functional DWIT, the importance of vital parameters after withdrawal of life support, and acceptable thresholds of duration of functional DWIT to proceed with liver transplantation.

Intention to treat outcomes among patients with pancreatic cancer treated using International Study Group on Pancreatic Surgery recommended pathways for resectable and borderline resectable disease.

BACKGROUND: The International Study Group on Pancreatic Surgery recommends upfront surgery for resectable pancreatic cancer or borderline resectable-venous (BR-V) disease and neoadjuvant therapy (NAT) among those with arterial involvement (BR-A or locally advanced, LA). Though neoadjuvant therapy (NAT) is a promising strategy, outcomes are rarely reported on intention-to-treat (ITT) basis. This study presents ITT outcomes where pathways to surgery were in line with International Study Group on Pancreatic Surgery guidelines. METHODS: Patients recommended for potentially curative treatment with PDAC between 2012 and 2017 (n = 345) were classified as resectable, BR-A/BR-V or LA, according to NCCN criteria. The primary outcome was overall survival. Secondary outcomes were resection rates, positive margins and toxicity among patients receiving NAT. RESULTS: At surgery, the resection rates were 78% (172/221), 65% (35/54) and 54% (21/39) for those with resectable, BR-V and BR-A/LA disease, respectively (P < 0.0001). The median survival of those resected in the BR-A/LA cohort was 31 months. However, on an ITT basis, there was no significant difference in survival between resectable, BR-V and BR-A/LA disease (median: 19 versus 15 versus 19 months; P = 0.585). On review, some 31 (44%) patients of the BR-A/LA cohort either did not receive or did not complete NAT. CONCLUSION: To realize benefits of NAT, more patients need to complete NAT and to undergo resection. Upfront resection for BR-V disease is associated with equivalent outcomes to upfront surgery for resectable disease or NAT for BR-A/LA disease. Strategies to increase the proportion of patients who complete NAT and undergo resection are needed.

Hypothermic Oxygenated Liver Perfusion (HOPE) Prevents Tumor Recurrence in Liver Transplantation From Donation After Circulatory Death.

OBJECTIVE: The aim of this study was to investigate tumor recurrence after liver transplantation for hepatocellular carcinoma (HCC), with and without hypothermic oxygenated liver perfusion (HOPE) before transplantation. PATIENTS AND METHODS: We analyzed all liver recipients with HCC, transplanted between January 2012 and September 2019 with donation after circulatory death (DCD) livers after previous end-ischemic HOPE-treatment (n = 70, Center A). Tumor parameters and key confounders were compared to consecutive recipients with HCC, transplanted during the same observation period with an unperfused DBD liver (n = 70). In a next step, we analyzed unperfused DCD (n = 70) and DBD liver recipients (n = 70), transplanted for HCC at an external center (Center B). RESULTS: Tumor parameters were not significantly different between HOPE-treated DCD and unperfused DBD liver recipients at Center A. One-third of patients were outside established tumor thresholds, for example, Milan criteria, in both groups. Despite no difference in tumor load, we found a 4-fold higher tumor recurrence rate in unperfused DBD livers (25.7%, 18/70), compared to only 5.7% (n = 4/70) recipients with tumor recurrence in the HOPE-treated DCD cohort (P = 0.002) in Center A. The tumor recurrence rate was also twice higher in unperfused DCD and DBD recipients at the external Center B, despite significant less cases outside Milan. HOPE-treatment of DCD livers resulted therefore in a 5-year tumor-free survival of 92% in HCC recipients, compared to 73%, 82.7%, and 81.2% in patients receiving unperfused DBD or DCD livers, from both centers. CONCLUSION: We suggest that a simple machine liver perfusion approach appears advantageous to protect from HCC recurrence after liver transplantation, despite extended tumor criteria.

Proceedings of the 25th Annual Congress of the International Liver Transplantation Society.

The 25th Annual Congress of the International Liver Transplantation Society was held in Toronto, Canada, from May 15 to 18, 2019. Surgeons, hepatologists, anesthesiologists, critical care intensivists, radiologists, pathologists, and research scientists from all over the world came together with the common aim of improving care and outcomes for liver transplant recipients and living donors. Some of the featured topics at this year's conference included multidisciplinary perioperative care in liver transplantation, worldwide approaches to organ allocation, donor steatosis, and updates in pediatrics, immunology, and radiology. This report presents excerpts and highlights from invited lectures and select abstracts, reviewed and compiled by the Vanguard Committee of International Liver Transplantation Society. This will hopefully contribute to further advances in clinical practice and research in liver transplantation.

Effect of time to surgery in resectable pancreatic cancer: a systematic review and meta-analysis.

PURPOSE: Achieving surgical resection is essential if patients with pancreatic ductal adenocarcinoma (PDAC) have a chance for cure. The objective of this study was to evaluate the effect of time to surgery on resection rates in patients with resectable PDAC. METHODS: A systematic literature search was performed to identify studies reporting times to surgery and resection rates. Meta-regression models were then produced to assess the relationship between time to surgery and resection rates, using both intra- and inter-study comparisons. RESULTS: A total of 21 studies were included, comprising n = 2171 patients, with a pooled resection rate of 76%. Intra-study meta-analysis of the five studies that reported comparisons between patients with vs. without preoperative biliary drainage (PBD) or with long vs. short delays to surgery found earlier surgery to be associated with a significantly higher rate of resection (pooled odds ratio 1.93, 95% CI: 1.25-2.97, P = 0.003). Inter-study meta-regression across all studies found a tendency for resection rates to decline with increasing time from CT or ERCP to surgery (gradient - 0.13 log-odds per week, 95% CI - 0.28, 0.03, P = 0.100), although this did not reach statistical significance, in part due to considerable heterogeneity between studies. CONCLUSION: Pathways to reduce the time to surgery, primarily by avoiding PBD, demonstrate significantly greater resection rates. Early surgery, including avoidance of PBD, not only provides patients with the benefit of avoiding harm associated with PBD but also with a greater chance of undergoing resection.

Recurrence patterns of pancreatic cancer after pancreatoduodenectomy: systematic review and a single-centre retrospective study.

BACKGROUND: Positive margins in pancreatoduodenectomy (PD) for pancreatic cancer, specifically the superior mesenteric artery (SMA) margin, are associated with worse outcomes. Local therapies targeting these margins could impact on recurrence. This study analysed recurrence-patterns to identify whether strategies to control local disease could have a meaningful impact. METHODS: (I) Systematic review to define recurrence patterns and resection margin status. (II) Additional retrospective study of PD performed at our centre. RESULTS: In the systematic review, 23/617 evaluated studies were included (n = 3815). Local recurrence was observed in 7-69%. SMA margin (6 studies) was positive in 15-35%. In the retrospective study (n = 204), local recurrence was more frequently observed with a positive SMA margin (66 vs.45%; p = 0.005). Furthermore, in a multivariate cox-proportional hazard model, only a positive SMA margin was associated with disease recurrence (HR 1.615; 95%CI 1.127-2.315; p = 0.009). Interestingly, median overall survival was 20 months and similar for patients who developed local only, metastases only or simultaneous recurrence (p = 0.124). CONCLUSION: Local recurrence of pancreatic cancer is common and associated with similar mortality rates as those who present with simultaneous or metastatic recurrence. Involvement of the SMA margin is an independent predictor for disease progression and should be the target of future adjuvant local therapies.

Future liver remnant portal or hepatic vein reconstruction at stage I of ALPPS-How far can we push the boundaries?

Preservation of the future liver remnant (FLR) vascular integrity has always been considered crucial to achieving successful liver growths after major hepatectomies. Most surgeons appeared therefore reluctant to combine stage I of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) with vascular reconstructions. Here we describe a case series, where we combine parenchymal transection and venous in- or outflow reconstruction of the FLR at stage I of ALPPS. In addition, the cold flush of the FLR or delayed portal vein embolization is applied in selected cases.

The UK-DCD-Risk-Score - practical and new guidance for allocation of a specific organ to a recipient?

Introduction: Multiple factors contribute to the overall outcome in donation after circulatory death liver transplantation. The majority is however inconsistently reported with various acceptance criteria and thresholds, when to decline a specific graft. Recent improvement in outcome was based on an increased awareness of the cumulative risk, combining donor and recipient parameters, which encouraged the community to accept livers with an overall higher risk. Areas covered: This review pictures the large number of risk factors in this field with a special focus on parameters, which contribute to available prediction models. Next, features of the recently developed UK-DCD-Risk-Score, which led to a significantly impaired graft survival, above a suggested threshold of >10 score points, are discussed. The clinical impact of this new model on the background of other prediction tools with their subsequent limitations is highlighted in a next chapter. Finally, we provide suggestions, how to further improve outcomes in this challenging field of transplantation. Expert opinion: Despite the recent development of new prediction models, including the UK-DCD-Risk-Score, which provides a sufficient prediction of graft loss after DCD liver transplantation, the consideration of other confounders is essential to better understand the overall risk and metabolic liver status to improve the comparability of clinical studies. More uniform definitions and thresholds of individual risk factors are required.

The AKI Prediction Score: a new prediction model for acute kidney injury after liver transplantation.

BACKGROUND: Acute kidney injury (AKI) is a frequent complication after liver transplantation. Although numerous risk factors for AKI have been identified, their cumulative impact remains unclear. Our aim was therefore to design a new model to predict post-transplant AKI. METHODS: Risk analysis was performed in patients undergoing liver transplantation in two centres (n = 1230). A model to predict severe AKI was calculated, based on weight of donor and recipient risk factors in a multivariable regression analysis according to the Framingham risk-scheme. RESULTS: Overall, 34% developed severe AKI, including 18% requiring postoperative renal replacement therapy (RRT). Five factors were identified as strongest predictors: donor and recipient BMI, DCD grafts, FFP requirements, and recipient warm ischemia time, leading to a range of 0-25 score points with an AUC of 0.70. Three risk classes were identified: low, intermediate and high-risk. Severe AKI was less frequently observed if recipients with an intermediate or high-risk were treated with a renal-sparing immunosuppression regimen (29 vs. 45%; p = 0.007). CONCLUSION: The AKI Prediction Score is a new instrument to identify recipients at risk for severe post-transplant AKI. This score is readily available at end of the transplant procedure, as a tool to timely decide on the use of kidney-sparing immunosuppression and early RRT.

Chronic Kidney Disease After Liver Transplantation: Impact of Extended Criteria Grafts.

The use of extended criteria donor (ECD) grafts has been associated with acute kidney injury (AKI) after liver transplantation. However, the relation between graft quality and development of chronic kidney disease (CKD) remains unknown. Therefore, the aim of this study was to analyze the impact of ECD grafts for CKD after liver transplantation. All patients (2007-2015) transplanted for end-stage liver disease at our center were assessed. Longterm kidney function was divided into 4 groups: no CKD (estimated glomerular filtration rate [eGFR], ≥60 mL/minute/1.73 m2 ), mild CKD (eGFR, 30-59 mL/minute/1.73 m2 ), severe CKD (eGFR, 15-29 mL/minute/1.73 m2 ), and end-stage renal disease (ESRD). Marginal donation after brain death (DBD) grafts (donor age, >70 years; body mass index, >35 kg/m2 ; cold storage, >12 hours) and donation after circulatory death (DCD) grafts were considered ECD grafts. Overall, 926 patients were included, and 43% received an ECD graft (15% marginal DBD; 28% DCD). After 5 years, 35% developed CKD; severe CKD and ESRD occurred in only 2% and 1%, respectively. CKD rates were comparable for all 3 graft groups (standard group, 36%; marginal DBD group, 29%; DCD group, 35%; standard versus marginal DBD groups, P = 0.16; standard versus DCD group, P = 0.80). None of the ECD criteria were identified as independent risk factors in a Cox regression model for CKD. Risk factors included recipient age, female sex, and preoperative kidney function. Furthermore, recipients who had severe acute kidney injury (AKI; Kidney Disease: Improving Global Outcomes stages 2 and 3) had a 1.8-fold increased risk for CKD. Longterm kidney function of recipients with severe AKI depended on the recovery of kidney function in the first postoperative week. In conclusion, there is no direct relation between the use of ECD grafts and CKD after liver transplantation. However, caution should be taken in recipients who experience severe AKI, regardless of graft type.

Benchmarks in Pancreatic Surgery: A Novel Tool for Unbiased Outcome Comparisons.

OBJECTIVE: To use the concept of benchmarking to establish robust and standardized outcome references after pancreatico-duodenectomy (PD). BACKGROUND: Best achievable results after PD are unknown. Consequently, outcome comparisons among different cohorts, centers or with novel surgical techniques remain speculative. METHODS: This multicenter study analyzes consecutive patients (2012-2015) undergoing PD in 23 international expert centers in pancreas surgery. Outcomes in patients without significant comorbidities and major vascular resection (benchmark cases) were analyzed to establish 20 outcome benchmarks for PD. These benchmarks were tested in a cohort with a poorer preoperative physical status (ASA class ≥3) and a cohort treated by minimally invasive approaches. RESULTS: Two thousand three hundred seventy-five (38%) low-risk cases out of a total of 6186 PDs were analyzed, disclosing low in-hospital mortality (≤1.6%) but high morbidity, with a 73% benchmark morbidity rate cumulated within 6 months following surgery. Benchmark cutoffs for pancreatic fistulas (B-C), severe complications (≥ grade 3), and failure-to-rescue rate were 19%, 30%, and 9%, respectively. The ASA ≥3 cohort showed comparable morbidity but a higher in hospital-mortality (3% vs 1.6%) and failure-to-rescue rate (16% vs 9%) than the benchmarks. The proportion of benchmark cases performed varied greatly across centers and continents for both open (9%-93%) and minimally invasive (11%-62%) PD. Centers operating mostly on complex PD cases disclosed better results than those with a majority of low-risk cases. CONCLUSION: The proposed outcome benchmarks for PD, established in a large-scale international patient cohort and tested in 2 different cohorts, may allow for meaningful comparisons between different patient cohorts, centers, countries, and surgical techniques.

Retrieval Practice or Overall Donor and Recipient Risk: What Impacts on Outcomes After Donation After Circulatory Death Liver Transplantation in the United Kingdom?

Parameters of retrieval surgery are meticulously documented in the United Kingdom, where up to 40% of livers are donation after circulatory death (DCD) donations. This retrospective analysis focuses on outcomes after transplantation of DCD livers, retrieved by different UK centers between 2011 and 2016. Donor and recipient risk factors and the donor retrieval technique were assessed. A total of 236 DCD livers from 9 retrieval centers with a median UK DCD risk score of 5 (low risk) to 7 points (high risk) were compared. The majority used University of Wisconsin solution for aortic flush with a median hepatectomy time of 27-44 minutes. The overall liver injury rate appeared relatively high (27.1%) with an observed tendency toward more retrieval injuries from centers performing a quicker hepatectomy. Among all included risk factors, the UK DCD risk score remained the best predictor for overall graft loss in the multivariate analysis (P < 0.001). In high-risk and futile donor-recipient combinations, the occurrence of liver retrieval injuries had negative impact on graft survival (P = 0.023). Expectedly, more ischemic cholangiopathies (P = 0.003) were found in livers transplanted with a higher cumulative donor-recipient risk. Although more biliary complications with subsequent graft loss were found in high-risk donor-recipient combinations, the impact of the standardized national retrieval practice on outcomes after DCD liver transplantation was minimal.

Report of the 24th Annual Congress of the International Liver Transplantation Society.

The 24th Joint Annual Congress of the International Liver Transplantation Society in association with European Liver and Intestine Transplant Association and Liver Intensive Care Group of Europe was held in Lisbon, Portugal from May 23 to 26, 2018. More than 1200 participants from over 60 countries including surgeons, hepatologists, anesthesiologists and critical care intensivists, radiologists, pathologists, organ procurement personnel, and research scientists came together with the common aim of improving care and outcomes for liver transplant recipients. Over 600 scientific abstracts were presented. The principal themes were living donation, use of marginal liver donors, machine preservation, disease-specific immunosuppressive regimen, malignancies, and advances in pediatric liver transplantation and liver transplant anesthesia. This report presents excerpts from invited lectures and select abstracts from scientific sessions, which add to current knowledge, and will drive clinical practice and future research.