Immune cell dynamics deconvoluted by single-cell RNA sequencing in normothermic machine perfusion of the liver.

Normothermic machine perfusion (NMP) has emerged as an innovative organ preservation technique. Developing an understanding for the donor organ immune cell composition and its dynamic changes during NMP is essential. We aimed for a comprehensive characterization of immune cell (sub)populations, cell trafficking and cytokine release during liver NMP. Single-cell transcriptome profiling of human donor livers prior to, during NMP and after transplantation shows an abundance of CXC chemokine receptor 1+/2+ (CXCR1+/CXCR2+) neutrophils, which significantly decreased during NMP. This is paralleled by a large efflux of passenger leukocytes with neutrophil predominance in the perfusate. During NMP, neutrophils shift from a pro-inflammatory state towards an aged/chronically activated/exhausted phenotype, while anti-inflammatory/tolerogenic monocytes/macrophages are increased. We herein describe the dynamics of the immune cell repertoire, phenotypic immune cell shifts and a dominance of neutrophils during liver NMP, which potentially contribute to the inflammatory response. Our findings may serve as resource to initiate future immune-interventional studies.

Static cold storage compared with normothermic machine perfusion of the liver and effect on ischaemic-type biliary lesions after transplantation: a propensity score-matched study.

BACKGROUND: Given the susceptibility of organs to ischaemic injury, alternative preservation methods to static cold storage (SCS), such as normothermic machine perfusion (NMP) are emerging. The aim of this study was to perform a comparison between NMP and SCS in liver transplantation with particular attention to bile duct lesions. METHODS: The outcomes of 59 consecutive NMP-preserved donor livers were compared in a 1 : 1 propensity score-matched fashion to SCS control livers. Postoperative complications, patient survival, graft survival and bile duct lesions were analysed. RESULTS: While patients were matched for cold ischaemia time, the total preservation time was significantly longer in the NMP group (21 h versus 7 h, P < 0.001). Patient and graft survival rates at 1 year were 81 versus 82 per cent (P = 0.347) and 81 versus 79 per cent (P = 0.784) in the NMP and SCS groups, respectively. The postoperative complication rate was comparable (P = 0.086); 37 per cent NMP versus 34 per cent SCS patients had a Clavien-Dindo grade IIIb or above complication. There was no difference in early (30 days or less) (NMP 22 versus SCS 19 per cent, P = 0.647) and late (more than 30 days) (NMP 27 versus SCS 36 per cent, P = 0.321) biliary complications. However, NMP-preserved livers developed significantly fewer ischaemic-type bile duct lesions (NMP 3 versus SCS 14 per cent, P = 0.047). CONCLUSION: The use of NMP allowed for a significantly prolonged organ preservation with a lower rate of observed ischaemic-type bile duct lesions.

Assessment of the Clinical Impact of a Liver-Specific, BCAA-Enriched Diet in Major Liver Surgery.

BACKGROUND: The relationship between nutrition and liver disease is relevant for the outcome after surgery. Patients with liver cirrhosis characteristically show protein-energy malnutrition with decreased levels of branched-chain amino acids (BCAA) and increased levels of aromatic amino acids. MATERIALS AND METHODS: We conducted a prospective controlled clinical trial including 57 patients after liver transplantation or major liver resection surgery in order to test the effect of early postoperative nutrition on the outcome and nutrition profile of these patients. The test group received a dietetic program composed of ingredients naturally rich in BCAA (BCAA group), and the control group received standard hospital meals. Patient survival, liver function tests, subjective well-being, and a nutritional status including amino acid profiles were analyzed immediately and 14 days after major liver surgery (secondary end points). General health and well-being were assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (primary end point). RESULTS: In-depth analysis of amino acid profiles was performed for patients undergoing liver resection (n = 21) and liver transplantation (n = 36). Interestingly, amino acid profiles did not correlate with body mass index or the Model for End-Stage Liver Disease score. Patients scheduled for liver transplantation showed significantly lower levels of BCAA pretransplant compared to patients undergoing liver resection. Patients in the liver resection subgroup were more likely to benefit from the BCAA cuisine in terms of significantly higher food intake and subjective rating. The clinical liver function tests, however, did not show statistical difference between the BCAA group and the control group in the examination period of 14 days. CONCLUSION: Our specifically designed BCAA-enriched diet resulted in greater patient satisfaction and compliance with nutrition. A larger trial or longer-term follow-up may be required to identify an effect on survival, recovery, surgical complications, protein profiles, and amino acid profiles.

Early Post-Operative Pancreatitis and Systemic Inflammatory Response Assessed by Serum Lipase and IL-6 Predict Pancreatic Fistula.

BACKGROUND: Post-operative pancreatic fistula (POPF) remains a critical complication after pancreatic resection. This prospective pilot study evaluates perioperative markers of pancreatitis and systemic inflammation to predict clinically relevant grade B/C-POPF (CR-POPF). METHODS: All patients undergoing pancreatic resection from December 2017 to April 2019 were prospectively enrolled. Surgical procedures and outcomes were correlated with perioperative blood markers. ROC analysis was performed to assess their predictive value for CR-POPF. Cut-offs were calculated with the Youden index. RESULTS: In total, 70 patients were analysed (43 pancreatoduodenectomies and 27 distal pancreatectomies). In-hospital/90-d mortality and morbidity were 5.7/7.1% (n = 4/n = 5) and 75.7% (n = 53). Major complications (Clavien-Dindo ≥ 3a) occurred in 28 (40.0%) patients, CR-POPF in 20 (28.6%) patients. Serum lipase (cut-off > 51U/L) and IL-6 (> 56.5 ng/l) on POD3 were significant predictors for CR-POPF (AUC = 0.799, 95%-CI 0.686-0.912 and AUC = 0.784, 95%-CI 0.668-0.900; combined AUC = 0.858, 95%-CI 0.758-0.958; all p < 0.001). Patients with both or one factor(s) above cut-off more frequently developed CR-POPF than cases without (100 vs. 50% vs. 7.5%, p < 0.001). This also applied for overall and severe complications (p = 0.013 and p = 0.009). CONCLUSIONS: Post-operative pancreatitis and inflammatory response are major determinants for development of POPF. A combination of serum lipase and IL-6 on POD3 is a highly significant early predictor of CR-POPF and overall complications, potentially guiding patient management. CLINICAL TRIAL REGISTRATION: The study protocol was registered at clinicaltrials.gov (NCT04294797).

Laparoscopic fundoplication and new aspects of neural anatomy at the oesophagogastric junction.

BACKGROUND: In fundoplication, mobilization of the distal oesophagus and proximal stomach is essential to obtain a sufficient tension-free intra-abdominal oesophageal length for creation of an efficient antireflux barrier. Most surgical literature and anatomical illustrations do not describe nerve branches running from the diaphragm to the stomach. After observing small nerve branches at laparoscopic fundoplication, penetrating the left crus of the diaphragm lateral to the hiatus and apparently running into the stomach, an anatomical cadaver study was undertaken to identify the origin and target organ of these nerves. METHODS: Fifty-three human cadavers (23 men, 30 women; age range 35-103 years) were dissected with special attention to the nerves that penetrate the left crus of the diaphragm. The entire course of these nerves was documented with standardized drawings and photos. RESULTS: Small nerve branches penetrating the diaphragm lateral to the left crus of the hiatus were found in 17 (32 per cent) of the 53 cadavers. In 14 of these 17 cadavers, one or two splanchnic nerve branches were identified, and in ten of the 17 the nerve branches were found to be phrenic nerves. In seven of these 17 cadavers, two different nerve branches were found and assigned to both splanchnic and phrenic nerves. CONCLUSION: Nerves penetrating the left crus with splanchnic origin or phrenic origin have been identified. Their function remains unclear and their relationship to postfundoplication symptoms remains to be determined.

ANTECEDENTES: A la hora de realizar una fundoplicatura, la movilización del esófago distal y del estómago proximal es esencial para obtener una longitud de esófago intraabdominal suficiente y sin tensión para crear una barrera antirreflujo eficiente. La mayoría de la literatura quirúrgica y de las ilustraciones anatómicas no describen unas ramas nerviosas que discurren desde el diafragma al estómago. Tras observar pequeñas ramas nerviosas durante la realización de una fundoplicatura laparoscópica que penetran la crura izquierda del diafragma lateral al hiato y que aparentemente discurren hacia el estómago, se llevó a cabo un estudio anatómico en cadáver para identificar el origen y el órgano diana de estos nervios. MÉTODOS: Se diseccionaron 53 cadáveres humanos (23 varones, 30 mujeres, rango de edad: 35-103 años) con especial atención hacia los nervios que penetran la crura izquierda del diafragma. Se documentó el recorrido completo de estos nervios con fotos y dibujos de una forma estandarizada. RESULTADOS: En 17 (32%) de 53 cadáveres se hallaron pequeñas ramas nerviosas que penetraban el diafragma lateral a la crura izquierda del hiato. En 14 cadáveres (de los 17) se identificaron una o dos ramas nerviosas esplácnicas, y en 10 de los 17 cadáveres las ramas nerviosas que se hallaron resultaron ser nervios frénicos. En 7 de estos 17 cadáveres, se hallaron dos ramas nerviosas diferentes y se asignaron a ambos nervios, esplácnicos y frénicos. CONCLUSIÓN: Se han identificado los nervios que penetran la crura izquierda con un origen esplácnico y frénico. Sus funciones están por aclarar, así como su relación con los síntomas que aparecen tras la fundoplicatura.

Outcomes of pancreas retransplantation in patients with pancreas graft failure.

BACKGROUND: Pancreas retransplantation is still a controversial option after loss of a pancreatic graft. This article describes the experience of pancreas retransplantation at a high-volume centre. METHODS: This was a retrospective observational study of all pancreas retransplantations performed in a single centre between 1997 and 2013. Pancreatic graft loss was defined by the return to insulin dependence. Risk factors for graft loss as well as patient and graft survival were analysed using logistic and time-to-event regression models. RESULTS: Of 409 pancreas transplantations undertaken, 52 (12·7 per cent) were identified as pancreas retransplantations. After a median follow-up of 65·0 (range 0·8-174·3) months, 1- and 5-year graft survival rates were 79 and 69 per cent respectively, and 1- and 5-year patient survival rates were 96 and 89 per cent. During the entire follow-up, 22 grafts (42 per cent) were lost. Patient survival was not associated with any of the donor- or recipient-related factors investigated. Five-year graft survival was better after simultaneous kidney-pancreas retransplantation than pancreas retransplantation alone: 80 per cent (16 of 20) versus 63 per cent (20 of 32) (P = 0·226). Acute rejection (odds ratio 4·49, 95 per cent c.i. 1·59 to 12·68; P = 0·005) and early surgical complications (OR 3·29, 1·09 to 9·99, P = 0·035) were identified as factors with an independent negative effect on graft survival. CONCLUSION: Pancreas retransplantation may be considered for patients whose previous graft has failed.

Integrating interventional oncology in the treatment of liver tumors.

BACKGROUND: Percutaneous ablation techniques offer a vast armamentarium for local, minimally invasive treatment of liver tumors, nowadays representing an established therapeutic option, which is integrated in treatment algorithms, especially for non-resectable liver tumors. The results of ablative treatment compare very well to surgical treatment in liver lesions, and confirm that these techniques are a valuable option for bridging for transplantation. Different techniques have been established to perform tumor ablation, and the feasibility varies according to the procedure and technical skills of the operator, depending on the size and location of the liver lesion. In recent years, stereotactic multi-needle techniques using 3D trajectory planning, general anesthesia, and tube disconnection during needle placement have had a strong impact on the application range of ablation for liver tumors. CONCLUSION: It is well known that creating a sufficient ablation margin and overlapping ablation zones is one key issue to enable ablation of large liver lesions with tumor-free margins (A0 ablation in analogy to R0 resection). Image fusion during treatment and follow-up assure highly accurate staging procedures and interventional planning. NOVEL ASPECTS: Review on the standards in ablation techniques for the treatment of liver tumors. Update on different ablation techniques, indications, and contraindications for percutaneous liver tumor treatment. Summary of recently published reports on liver tumor ablation.

Donor pretreatment with tetrahydrobiopterin saves pancreatic isografts from ischemia reperfusion injury in a mouse model.

Depletion of the nitric oxide synthase cofactor tetrahydrobiopterin (H4B) during ischemia and reperfusion is associated with severe graft pancreatitis. Since clinically feasible approaches to prevent ischemia reperfusion injury (IRI) by H4B-substitution are missing we investigated its therapeutic potential in a murine pancreas transplantation model using different treatment regimens. Grafts were subjected to 16 h cold ischemia time (CIT) and different treatment regimens: no treatment, 160 µM H4B to perfusion solution, H4B 50 mg/kg prior to reperfusion and H4B 50 mg/kg before recovery of organs. Nontransplanted animals served as controls. Recipient survival and endocrine graft function were assessed. Graft microcirculation was analyzed 2 h after reperfusion by intravital fluorescence microscopy. Parenchymal damage was assessed by histology and nitrotyrosine immunohistochemistry, H4B tissue levels by high pressure liquid chromatography (HPLC). Compared to nontransplanted controls prolonged CIT resulted in significant microcirculatory deterioration. Different efficacy according to route and timing of administration could be observed. Only donor pretreatment with H4B resulted in almost completely abrogated IRI-related damage showing graft microcirculation comparable to nontransplanted controls and restored intragraft H4B levels, resulting in significant reduction of parenchymal damage (p < 0.002) and improved survival and endocrine function (p = 0.0002 each). H4B donor pretreatment abrogates ischemia-induced parenchymal damage and represents a promising strategy to prevent IRI following pancreas transplantation.