Viability assessment of livers donated after circulatory determination of death during normothermic regional perfusion.

BACKGROUND: Abdominal normothermic regional perfusion (A-NRP) allows in-situ reperfusion and recovery of abdominal organs metabolism in donors after circulatory death (DCD). Besides improving liver transplantation outcomes, liver injury and function can be assessed during A-NRP. METHODS: To refine liver viability assessment during A-NRP, prospectively collected data of controlled DCD donors managed at our Institution between October 2019 and May 2022 were retrospectively analyzed. Baseline characteristics, procedural variables and A-NRP parameters of donors whose liver was successfully transplanted were compared to those of donors whose liver was discarded. RESULTS: Twenty-seven donors were included and in 20 (74%) the liver was accepted (positive outcome). No differences between study groups were observed concerning baseline characteristics and warm ischemia times (WIT). Initial lactate levels were positively correlated with functional WIT (r2 = 0.4, p = 0.04), whereas transaminase levels were not. Blood flow during A-NRP was comparable, whereas oxygen consumption (VO2 ) was significantly higher in the positive outcome group after 1 h. Time courses of lactate, AST and ALT were significantly different between study groups (p < 0.001). Donors whose liver was accepted showed faster lactate clearance, a difference which was amplified by normalizing lactate clearance to oxygen delivery (DO2 ) and VO2 . Lactate clearance was correlated to transaminase levels and DO2 -normalized lactate clearance was the parameter best discriminating between study groups. CONCLUSIONS: DO2 -normalized lactate clearance may represent an element of liver viability assessment during A-NRP.

Outcome of liver transplantation with grafts from brain-dead donors treated with dual hypothermic oxygenated machine perfusion, with particular reference to elderly donors.

Prompted by the utilization of extended criteria donors, dual hypothermic oxygenated machine perfusion (D-HOPE) was introduced in liver transplantation to improve preservation. When donors after neurological determination of death (DBD) are used, D-HOPE effect on graft outcomes is unclear. To assess D-HOPE value in this setting and to identify ideal scenarios for its use, data on primary adult liver transplant recipients from January 2014 to April 2021 were analyzed using inverse probability of treatment weighting, comparing outcomes of D-HOPE-treated grafts (n = 121) with those preserved by static cold storage (n = 723). End-ischemic D-HOPE was systematically applied since November 2017 based on donor and recipient characteristics and transplant logistics. D-HOPE use was associated with a significant reduction of early allograft failure (OR: 0.24; 0.83; p = .024), grade ≥3 complications (OR: 0.57; p = .046), comprehensive complication index (-7.20 points; p = .003), and improved patient and graft survival. These results were confirmed in the subset of elderly donors (>75-year-old). Although D-HOPE did not reduce the incidence of biliary complications, its use was associated with a reduced severity of ischemic cholangiopathy. In conclusion, D-HOPE improves postoperative outcomes and reduces early allograft loss in extended criteria DBD grafts.

Clinical assessment of liver metabolism during hypothermic oxygenated machine perfusion using microdialysis.

BACKGROUND: While growing evidence supports the use of hypothermic oxygenated machine perfusion (HOPE) in liver transplantation, its effects on liver metabolism are still incompletely understood. METHODS: To assess liver metabolism during HOPE using microdialysis (MD), we conducted an open-label, observational pilot study on 10 consecutive grafts treated with dual-HOPE (D-HOPE). Microdialysate and perfusate levels of glucose, lactate, pyruvate, glutamate, and flavin mononucleotide (FMN) were measured during back table preparation and D-HOPE and correlated to graft function and patient outcome. RESULTS: Median (IQR) MD and D-HOPE time was 228 (210, 245) and 116 (103, 143) min. Three grafts developed early allograft dysfunction (EAD), with one requiring retransplantation. During D-HOPE, MD glucose and lactate levels increased (ANOVA = 9.88 [p = 0.01] and 3.71 [p = 0.08]). Their 2nd-hour levels were higher in EAD group and positively correlated with L-GrAFT score. 2nd-hour MD glucose and lactate were also positively correlated with cold ischemia time, macrovesicular steatosis, weight gain during D-HOPE, and perfusate FMN. These correlations were not apparent when perfusate levels were considered. In contrast, MD FMN levels invariably dropped steeply after D-HOPE start, whereas perfusate FMN was higher in dysfunctioning grafts. CONCLUSION: MD glucose and lactate during D-HOPE are markers of hepatocellular injury and could represent additional elements of the viability assessment.

Endo-therapies for biliary duct-to-duct anastomotic stricture after liver transplantation: Outcomes of a nationwide survey.

BACKGROUND: The most appropriate endo-therapeutic approach to biliary anastomotic strictures is yet to be defined. AIM: To retrospectively report on the endo-therapy of duct-to-duct anastomotic strictures during 2013 in Italy. METHODS: Data were collected from 16 Endoscopy Units at the Italian Liver Transplantation Centers (BASALT study group). RESULTS: Complete endo-therapy and follow-up data are available for 181 patients: 101 treated with plastic multistenting, 26 with fully covered self-expandable metal stenting and 54 with single stenting. Radiological success was achieved for 145 patients (80%), that is, 88% of plastic multistenting, 88% of self-expandable metal stenting and 61% of single stenting (P < 0.001 vs plastic multistenting; P < 0.05 vs self-expandable metal stenting). After first-line endo-therapy failure, the patients underwent a second-line endo-therapy with plastic multistenting for 25%, fully covered self-expandable metal stenting for 53% and single stenting for 22% of cases, and radiological success was achieved for 84%, that is, 100%, 85% and 63% with plastic multistenting, self-expandable metal stenting and single stenting (P < 0.05 vs plastic multistenting or self-expandable metal stenting) respectively. Procedure-related complications occurred in 7.8% of endoscopic retrograde cholangiopancreatographies. Overall, clinical success was achieved in 87% of patients after a median follow-up of 25 months. CONCLUSION: Plastic multistenting is confirmed as the preferred first-line treatment, while fully covered self-expandable metal stenting as rescue option for biliary anastomotic strictures. Single stenting has sub-optimal results and should be abandoned.

Liver transplantation with an uncommon full right hemiliver graft after hydatid cysts resection: Case report and review of the literature.

Because of widespread organ shortage, the transplant community has been exploiting more and more so-called "extended criteria" donors. In this scenario, liver grafts harboring benign tumors or large cysts represent an infrequent but potentially valuable source of viable grafts. We depict a challenging case of liver transplantation performed using a graft harboring two large Echinococcus granulosus hydatid cysts in close proximity with the hilar plate and complicated by cystobiliary communication. Although liver transplantation using grafts with hydatid cyst has been rarely reported (three published cases), our case was peculiar as one of the cysts was located close to the hilum and was ruptured into the left hepatic duct. The graft was finally accepted taking into account the low risk profile of the recipient, the good quality and size of the remnant liver parenchyma, and only after complete resection of the cysts was achieved. Although the recipient had a complication due to biliary confluence necrosis, at 10-months follow-up he is in good health with normal hepatic function, and a graft that could have been otherwise discarded was successfully used. The decision process along with technical and management issues are discussed.

Cost analysis of laparoendoscopic rendezvous versus preoperative ERCP and laparoscopic cholecystectomy in the management of cholecystocholedocholithiasis.

BACKGROUND: Evidence from controlled trials and meta-analyses suggests that laparoendoscopic rendezvous (LERV) is preferable to sequential treatment in the management of common bile duct stones. MATERIALS AND METHODS: With this retrospective analysis of a prospective database that included consecutive patients treated for cholecystocholedocholithiasis at our institution between January 2007 and July 2015, we compared LERV with sequential treatment. The primary endpoint was global cost, defined as the cost/patient/hospital stay, and the secondary end points were efficacy and morbidity. Fisher's exact test or Mann-Whitney test was used. RESULTS: Of a total of 249 consecutive patients, 143 underwent LERV (group A) and 106 a two-stage procedure (group B). Based on an average cost of €613 for 1 day of hospital stay in the General Surgery Department, the overall median cost of treatment was €6403 for group A and €8194 for group B (p < 0.001). Operative time was significantly shorter (p < 0.001), and length of hospital stay was significantly longer for group B (p < 0.001). No mortality in either group was observed. The postoperative complications rate was significantly higher in group B than in group A (24.5 vs. 10.5%; p = 0.003). No significant difference in the postoperative pancreatitis rate or the number of patients with increased serum amylase at 24 h was observed in either group. CONCLUSION: Our study suggests that LERV is preferable to sequential treatment not only in terms of less morbidity, but also of lower costs accrued by a shorter hospital stay. However, the longer operative time raises multiple organizational issues in the coordination of surgery and endoscopy services.

How to Preserve Steatotic Liver Grafts for Transplantation.

Liver allograft steatosis is a significant risk factor for postoperative graft dysfunction and has been associated with inferior patient and graft survival, particularly in the case of moderate or severe macrovesicular steatosis. In recent years, the increasing incidence of obesity and fatty liver disease in the population has led to a higher proportion of steatotic liver grafts being used for transplantation, making the optimization of their preservation an urgent necessity. This review discusses the mechanisms behind the increased susceptibility of fatty livers to ischemia-reperfusion injury and provides an overview of the available strategies to improve their utilization for transplantation, with a focus on preclinical and clinical evidence supporting donor interventions, novel preservation solutions, and machine perfusion techniques.

The Presence of Metastatic Thoracic Duct Lymph Nodes in Western Esophageal Cancer Patients: A Multinational Observational Study.

BACKGROUND: The thoracic lymphadenectomy during an esophagectomy for esophageal cancer includes resection of the thoracic duct (TD) compartment containing the TD lymph nodes (TDLNs). The role of TD compartment resection is still a topic of debate since metastatic TDLNs have only been demonstrated in squamous cell carcinomas in Eastern esophageal cancer patients. Therefore, the aim of this study was to assess the presence and metastatic involvement of TDLNs in a Western population, in which adenocarcinoma is the predominant type of esophageal cancer. METHODS: From July 2017 to May 2020, all consecutive patients undergoing an open or robot-assisted transthoracic esophagectomy with concurrent lymphadenectomy and resection of the TD compartment in the University Medical Center Utrecht in Utrecht, the Netherlands, and the Città della Salute e della Scienza University Hospital in Turin, Italy, were included. The TD compartment was resected en bloc and was separated in the operation room by the operating surgeon after which it was macroscopically and microscopically assessed for (metastatic) TDLNs by the pathologist. RESULTS: A total of 117 patients with an adenocarcinoma (73%) or squamous cell carcinoma (27%) of the esophagus were included. In 61 (52%) patients, TDLNs were found, containing metastasis in 9 (15%) patients. No major complications related to TD compartment resection were observed. CONCLUSIONS: This study demonstrates the presence of metastatic TDLNs in adenocarcinomas of the esophagus. This result provides a valid argument to routinely extend the thoracic lymphadenectomy with resection of the TD compartment during an esophagectomy for esophageal cancer.

Semimechanical anastomosis during oesophagectomy reduces leaks and stenosis: a propensity score matched analysis.

OBJECTIVES: Several techniques for oesophageal anastomosis during oesophagectomy have been described, all of which are associated with variable leakage and stricture rates. Given the notable morbidity of oesophageal fistula, reducing its incidence is of paramount importance. We report our single-centre experience with the semimechanical (SM) technique as compared to a totally manual (TM) technique. METHODS: Three hundred and twelve partial and subtotal oesophagectomies performed between January 1998 and April 2018 were analysed. The series was split into a training period (January 1998-September 2015), when both TM and SM techniques were used, and a validation period (October 2015-April 2018), during which SM technique became standard practice. Propensity score matching was used to reduce confounding. RESULTS: The training period included 212 oesophagectomies (90 TM, 122 SM); SM technique was initially used in the neck and afterwards also in the thorax, mainly with gastric conduits (92%), whereas the TM group contained a prevalence of jejunal loops (48%). SM anastomosis was associated with a significant reduction in both leak (0.8% vs 12%; P < 0.001) and stricture rate (0% vs 7%; P = 0.005). After propensity score matching, the difference in leak (0% vs 14%; P = 0.013) and stricture rate (0% vs 10%; P = 0.022) was confirmed. During the validation period, which included 100 oesophagectomies performed with SM anastomosis, 1 leak (1%) and 1 stricture (1%) were observed. CONCLUSIONS: SM technique for oesophageal anastomosis outperforms TM technique and allows achieving very low complication rates.

Perfusate Analysis During Dual Hypothermic Oxygenated Machine Perfusion of Liver Grafts: Correlations With Donor Factors and Early Outcomes.

BACKGROUND: Liver graft viability assessment has long been considered a limit of hypothermic oxygenated machine perfusion (HOPE). Aim of this study was assessing correlations of easily available perfusate parameters (PP) (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, glucose, lactate, and pH) with graft features and outcome. METHODS: In the period October 2018-February 2020, perfusate samples were obtained every 30 minutes during 50 dual-HOPE (D-HOPE) procedures. Correlations of PP with graft factors, 90-day graft loss, early allograft dysfunction (EAD), L-GrAFT score, acute kidney injury, and comprehensive complication index were analyzed using Pearson coefficient, receiver-operating characteristics analysis and by univariable and multivariable regression. RESULTS: Median D-HOPE time was 122 minutes. All parameters were normalized to liver weight. Only macrovesicular steatosis (MaS) significantly impacted PP levels and slope. Grafts with ≥30% MaS exhibited significantly different PP values and slope. Graft loss and EAD rate were 2% (n = 1) and 26% (n = 13). All PP except lactate correlated with EAD, 90-minute alanine aminotransferase showing the highest area under the receiver-operating characteristics curve (0.84). However, at multivariable analysis, the only factor independently associated with EAD was MaS (odds ratio, 5.44; confidence interval, 1.05-28.21; P = 0.04). Ninety minutes lactate dehydrogenase had the strongest correlation with L-GrAFT (R = 0.70; P < 0.001). PP correlated poorly with comprehensive complication index and grades 2-3 acute kidney injury rate. CONCLUSIONS: PP were predictive of graft function after transplant, but their association with graft survival and clinical outcomes requires further evaluation. MaS influenced levels of PP and was the only independent predictor of EAD.

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.

Hypothermic Oxygenated Machine Perfusion for Liver Transplantation: An Initial Experience.

OBJECTIVES: Due to widespread exploitation of extended criteria donors, machine perfusion is emerging as an alternative to static cold storage for organ preservation. Hypothermic oxygenated machine perfusion has been associated with improved outcomes after liver transplant, both in laboratory and clinical settings. Here, we present our initial experience with hypothermic oxygenated machine perfusion, evaluating incidence of postreperfusion syndrome, early allograft dysfunction, and long-term biliary complications. MATERIALS AND METHODS: End-ischemic dual (hepatic artery and portal vein) hypothermic oxygenated machine perfusion was carried out for 150 to 200 minutes before organ implantation in 4 liver transplants considered at increased risk due to donor, recipient, or matching issues. RESULTS: No device malfunction occurred. Theatre logistics were minimally affected. Incidences of post-reperfusion syndrome and early allograft dysfunction were 25% and 50%. At 6-month follow-up, all patients were alive with normal hepatic function and no evidence of ischemic cholangiopathy. CONCLUSIONS: In our experience, hypothermic oxygenated machine perfusion appeared safe and logistically simple. Further studies are needed to assess the real value of this technique and to identify which subset of patients would benefit from its implementation.

Volumetric modulated arc therapy (VMAT) in the treatment of esophageal cancer patients.

The aim of the study is to evaluate feasibility, safety, toxicity profile, and dosimetric results of volumetric modulated arc therapy (VMAT) to deliver definitive or pre-operative radiation in locally advanced esophageal cancer patients. A total of 68 patients were treated with VMAT between March 2014 and March 2018 (44% vs 56% for definitive and neoadjuvant settings, respectively). Dose prescription differed depending on the clinical scenario (54-60 Gy in 30 fractions for definitive treatments; 41.4/45 Gy in 23-25 fractions in the pre-operative setting). Most of the patients were given concurrent chemotherapy. Two coplanar and one non-coplanar arcs were employed for VMAT delivery. Treatment was generally well tolerated. Acute toxicity was generally mild. In patients treated with definitive intent, ≥ G3 toxicities were observed for esophagitis (30%), anorexia (26.7%), fatigue (26.7%), nausea (6.7%), and vomiting (3.3%). In patients treated within a neoadjuvant approach, ≥ G3 anorexia (21%), esophagitis (15.8%), fatigue (13.3%), nausea (5.3%), and vomiting (2.6%) were observed. Dosimetric results were consistent in term of both target coverage and normal tissue sparing. In conclusion, VMAT proved to be a feasible, safe, and effective strategy to deliver definitive or pre-operative radiation in locally advanced esophageal cancer patients.

Extracellular Vesicles from Human Liver Stem Cells Reduce Injury in an Ex Vivo Normothermic Hypoxic Rat Liver Perfusion Model.

BACKGROUND: The gold standard for organ preservation before transplantation is static cold storage, which is unable to fully protect suboptimal livers from ischemia/reperfusion injury. An emerging alternative is normothermic machine perfusion (NMP), which permits organ reconditioning. Here, we aimed to explore the feasibility of a pharmacological intervention on isolated rat livers by using a combination of NMP and human liver stem cells-derived extracellular vesicles (HLSC-EV). METHODS: We established an ex vivo murine model of NMP capable to maintain liver function despite an ongoing hypoxic injury induced by hemodilution. Livers were perfused for 4 hours without (control group, n = 10) or with HLSC-EV (treated group, n = 9). Bile production was quantified; perfusate samples were collected hourly to measure metabolic (pH, pO2, pCO2) and cytolysis parameters (AST, alanine aminotransferase, lactate dehydrogenase). At the end of perfusion, we assessed HLSC-EV engraftment by immunofluorescence, tissue injury by histology, apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, tissue hypoxia-inducible factor 1-α, and transforming growth factor-beta 1 RNA expression by quantitative reverse transcription-polymerase chain reaction. RESULTS: During hypoxic NMP, livers were able to maintain homeostasis and produce bile. In the treated group, AST (P = 0.018) and lactate dehydrogenase (P = 0.032) levels were significantly lower than those of the control group at 3 hours of perfusion, and AST levels persisted lower at 4 hours (P = 0.003). By the end of NMP, HLSC-EV had been uptaken by hepatocytes, and EV treatment significantly reduced histological damage (P = 0.030), apoptosis (P = 0.049), and RNA overexpression of hypoxia-inducible factor 1-α (P < 0.0001) and transforming growth factor-beta 1 (P = 0.014). CONCLUSIONS: HLSC-EV treatment, even in a short-duration model, was feasible and effectively reduced liver injury during hypoxic NMP.

Liver graft preconditioning, preservation and reconditioning.

Liver transplantation is the successful treatment of end-stage liver disease; however, the ischaemia-reperfusion injury still jeopardizes early and long-term post-transplant outcomes. In fact, ischaemia-reperfusion is associated with increased morbidity and graft dysfunction, especially when suboptimal donors are utilized. Strategies to reduce the severity of ischaemia-reperfusion can be applied at different steps of the transplantation process: organ procurement, preservation phase or before revascularization. During the donor procedure, preconditioning consists of pre-treating the graft prior to a sustained ischaemia either by a transient period of ischaemia-reperfusion or administration of anti-ischaemic medication, although a multi-pharmacological approach seems more promising. Different preservation solutions were developed to maintain graft viability during static cold storage, achieving substantial results in terms of liver function and survival in good quality organs but not in suboptimal ones. Indeed, preservation solutions do not prevent dysfunction of poor quality organs and are burdened with inadequate preservation of the biliary epithelium. Advantages derived from either hypo- or normothermic machine perfusion are currently investigated in experimental and clinical settings, suggesting a reconditioning effect possibly improving hepatocyte and biliary preservation and resuscitating graft function prior to transplantation. In this review, we highlight acquired knowledge and recent advances in liver graft preconditioning, preservation and reconditioning.