Deep Learning-Adjusted Monitoring of In-Hospital Mortality after Liver Transplantation.

Background: Surgeries represent a mainstay of medical care globally. Patterns of complications are frequently recognized late and place a considerable burden on health care systems. The aim was to develop and test the first deep learning-adjusted CUSUM program (DL-CUSUM) to predict and monitor in-hospital mortality in real time after liver transplantation. Methods: Data from 1066 individuals with 66,092 preoperatively available data point variables from 2004 to 2019 were included. DL-CUSUM is an application to predict in-hospital mortality. The area under the curve for risk adjustment with Model of End-stage Liver Disease (D-MELD), Balance of Risk (BAR) score, and deep learning (DL), as well as the ARL (average run length) and control limit (CL) for an in-control process over 5 years, were calculated. Results: D-MELD AUC was 0.618, BAR AUC was 0.648 and DL model AUC was 0.857. CL with BAR adjustment was 2.3 with an ARL of 326.31. D-MELD reached an ARL of 303.29 with a CL of 2.4. DL prediction resulted in a CL of 1.8 to reach an ARL of 332.67. Conclusions: This work introduces the first use of an automated DL-CUSUM system to monitor postoperative in-hospital mortality after liver transplantation. It allows for the real-time risk-adjusted monitoring of process quality.

Changes of long-term survival of resection and liver transplantation in hepatocellular carcinoma throughout the years: A meta-analysis.

BACKGROUND: Hepatocellular Carcinoma (HCC) still is one of the most detrimental malignant diseases in the world. As two curative surgical therapies exist, the discussion whether to opt for liver resection (LR) or transplantation (LT) is ongoing, especially as novel techniques to improve outcome have emerged for both. The aim of the study was to investigate how the utilization and outcome of the respective modalities changed through time. METHODS: We searched Medline and PubMed for relevant publications comparing LT and LR in HCC patients during the time period from 1990 to 2022, prior to March 31, 2023. A total of 63 studies involving 19,804 patients - of whom 8178 patients received a liver graft and 11,626 underwent partial hepatectomy - were included in this meta-analysis. RESULTS: LT is associated with significantly better 5-year overall survival (OS) (64.83%) and recurrence-free survival (RFS) (70.20%) than LR (OS: 50.83%, OR: 1.79, p < 0.001; RFS: 34.46%, OR: 5.32, p < 0.001). However, these differences are not as evident in short-term intervals. Older cohorts showed comparable disparities between the outcome of the respective modalities, as did newer cohorts after 2005. This might be due to the similar improvement in survival rates that were observed for both, LT (15-23%) and LR (12-20%) during the last 30 years. CONCLUSION: LT still outperforms LR in the therapy of HCC in terms of long-term survival rates. Yet, LR outcome has remarkably improved which is of major importance in reference to the well-known limitations that occur in LT.

Imaging-Derived Biomarkers Integrated with Clinical and Laboratory Values Predict Recurrence of Hepatocellular Carcinoma After Liver Transplantation.

Purpose: To investigate the prognostic value of computed tomography (CT) derived imaging biomarkers in hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) and develop a predictive nomogram model. Patients and Methods: This retrospective study included 178 patients with histopathologically confirmed HCC who underwent liver transplantation between 2007 and 2021 at the two academic liver centers. We evaluated dedicated imaging features from baseline multiphase contrast-enhanced CT supplemented by several clinical findings and laboratory parameters. Time-to-recurrence was estimated by Kaplan-Meier analysis. Univariable Cox proportional hazard regression and multivariable Least Absolute Shrinkage and Selection Operator (LASSO) regression were used to assess independent prognostic factors for recurrence. A nomogram model was then built based on the independent factors selected through LASSO regression, to predict the probabilities of HCC recurrence at one, three, and five years. Results: The rate of HCC recurrence after LT was 17.4% (31 of 178). The LASSO analysis revealed six independent predictors associated with an elevated risk of tumor recurrence. These predictors included the presence of peritumoral enhancement, the presence of over three tumor lesions, the largest tumor diameter greater than 3 cm, serum alpha-fetoprotein (AFP) levels exceeding 400 ng/mL, and the presence of a tumor capsule. Conversely, a history of bridging therapies was found to be correlated with a reduced risk of HCC recurrence. In addition, Kaplan-Meier curves showed patients with irregular margin, satellite nodules, or small lesions displayed shorter time-to-recurrence. Our nomogram demonstrated good performance, yielding a C-index of 0.835 and AUC values of 0.86, 0.88, and 0.85 for the predictions of 1-year, 3-year, and 5-year TTR, respectively. Conclusion: Imaging parameters derived from baseline contrast-enhanced CT showing malignant behavior and aggressive growth patterns, along with serum AFP and history of bridging therapies, show potential as biomarkers for predicting HCC recurrence after transplantation.

Regional transplant rates depend more on physician-dependent variables than on proximity to transplant center.

PURPOSE: The objective of this work was to uncover inequalities in access to liver transplantation in Bavaria, Germany. METHODS: For this purpose, the annual transplantation rate per 1 million inhabitants for the respective districts was determined from the aggregated postal codes of the place of residence of transplanted patients. The variables examined were proximity and travel time to the nearest transplant center, as well as the care category of the regional hospital. In addition, we assessed whether the head of gastroenterology at the regional hospital through which liver transplant candidates are referred was trained at a liver transplant center. RESULTS: We could not demonstrate a direct relationship between proximity or travel time to the nearest transplant center and access to liver transplantation. Multivariate regression analysis shows that liver transplant training (p < 0.0001) of the chief physician (gastroenterologist) of the regional hospital was the most decisive independent factor for access to liver transplantation within a district. CONCLUSION: We show that the transplant training experience of the head of gastroenterology at a regional hospital is an independent factor for the regional transplantation rate. Therefore, it appears important to maintain some liver transplant expertise outside the transplant centers in order to properly identify and assign potential transplant candidates for transplantation.

[Project: zero emission surgery]. / Projekt: "zero emission surgery".

BACKGROUND: Climate neutrality is the major aim of our generation. In order to be able to achieve this a net zero emission should be strived for in operating theaters. OBJECTIVE: What does zero emission implicate for the operative sector? Which structural approaches already exist? Can zero emission surgery be achieved? MATERIAL AND METHODS: Evaluation of published studies, discussion of fundamental research and expert recommendations. RESULTS: Studies in England and Germany show that by structural alterations and strict sustainability structures net zero emission surgery seems to be feasible. In Germany the attention and awareness of the topic are greatly increasing and the first projects and studies have been launched. CONCLUSION: To achieve the aim of net zero emission by 2050 we must rapidly and significantly increase our efforts.

Dynamics of Peripheral Blood Immune Cells during the Perioperative Period after Digestive System Resections: A Systematic Analysis of the Literature.

An operation in itself is a kind of trauma and may lead to immunosuppression followed by a bounce back. Not many studies exist that describe dynamics of the distribution of peripheral blood (PB) immune cells during the perioperative period. Considering this scarcity, we aggregated the data on the dynamics of immune cells in patients with digestive system resections during the perioperative period and the relationship with short- and long-term prognoses. By the systematic retrieval of documents, we collected perioperative period data on white blood cells (WBC), lymphocytes, neutrophil-lymphocyte ratio (NLR), CD4+ T cells, CD8+ T cells, helper T cells (Th), B cells, natural killer cells (NK), dendritic cells (DCs), regulatory T cells (Tregs), regulatory B cells (Bregs), and Myeloid derived suppressor cells (MDSC). The frequency and distribution of these immune cells and the relationship with the patient's prognosis were summarized. A total of 1916 patients' data were included. Compared with before surgery, WBC, lymphocytes, CD4+ cells, CD8+ T cells, MDSC, and NK cells decreased after surgery, and then returned to preoperative levels. After operation DCs increased, then gradually recovered to the preoperative level. No significant changes were found in B cell levels during the perioperative period. Compared with the preoperative time-point, Tregs and Bregs both increased postoperatively. Only high levels of the preoperative and/or postoperative NLR were found to be related to the patient's prognosis. In summary, the surgery itself can cause changes in peripheral blood immune cells, which might change the immunogenicity. Therefore, the immunosuppression caused by the surgical trauma should be minimized. In oncological patients this might even influence long-term results.

Kynurenine serves as useful biomarker in acute, Long- and Post-COVID-19 diagnostics.

Introduction: In patients with SARS-CoV-2, innate immunity is playing a central role, depicted by hyperinflammation and longer lasting inflammatory response. Reliable inflammatory markers that cover both acute and long-lasting COVID-19 monitoring are still lacking. Thus, we investigated one specific inflammatory marker involved as one key player of the immune system, kynurenine (Kyn), and its use for diagnosis/detection of the Long-/Post-COVID syndrome in comparison to currently used markers in both serum and saliva samples. Material and methods: The study compromised in total 151 inpatients with a SARS-CoV-2 infection hospitalized between 03/2020 and 09/2021. The group NC (normal controls) included blood bank donors (n=302, 144f/158m, mean age 47.1 ± 18.3 years (range 18-75)). Two further groups were generated based on Group A (n=85, 27f/58m, mean age 63.1 ± 18.3 years (range 19-90), acute admission to the hospital) and Group B (n=66, 22f/44m, mean age 66.6 ± 17.6 years (range 17-90), admitted either for weaning or for rehabilitation period due to Long-COVID symptoms/syndrome). Plasma concentrations of Kyn, C-Reactive Protein (CRP) and interleukin-6 (IL-6) were measured on admission. In Group B we determined Kyn 4 weeks after the negative PCR-test. In a subset of patients (n=11) concentrations of Kyn and CRP were measured in sera and saliva two, three and four months after dismission. We identified 12 patients with Post-COVID symptoms >20 weeks with still significant elevated Kyn-levels. Results: Mean values for NC used as reference were 2.79 ± 0.61 µM, range 1.2-4.1 µM. On admission, patients showed significantly higher concentrations of Kyn compared to NC (p-values < 0.001). Kyn significantly correlated with IL-6 peak-values (r=0.411; p-values <0.001) and CRP (r=0.488, p-values<0.001). Kyn values in Group B (Long-/Post-COVID) showed still significant higher values (8.77 ± 1.72 µM, range 5.5-16.6 µM), whereas CRP values in Group B were in the normal range. Conclusion: Serum and saliva Kyn are reflecting the acute and long-term pathophysiology of the SARS-CoV-2 disease concerning the innate immune response and thus may serve a useful biomarker for diagnosis and monitoring both Long- and Post-COVID syndrome and its therapy.

The interactions between major immune effector cells and Hepatocellular Carcinoma: A systematic review.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common liver neoplasm with high morbidity and mortality. Tumor immunotherapy might be promising adjuvant therapy for HCC after surgery. To better develop HCC immunotherapy, comprehensive understanding of cell-cell interactions between immune effector cells and HCC cells remains crucial. AIM: To review the existing studies to summarize the cell-cell interactions between major immune effector cells and HCC cells providing new data for HCC immunotherapy. METHODS: A systematic review was conducted by searching PubMed database covering all papers published in recent five years up to January 2020. The guidelines of the preferred reporting items for systematic reviews were firmly followed. RESULTS: There are 9 studies researching the interactions between CD8+ T lymphocytes and HCC cells and 22 studies researching that between natural killer (NK) cells and HCC cells. Among the 9 studies, 6 studies reported that CD8+ T lymphocytes showed cytotoxicity towards HCC cells while 3 studies found CD8+ T lymphocytes were impaired by HCC cells. Among the 22 studies, 20 studies presented that NK cells could inhibit HCC cells. Two studies were found to report NK cell dysfunction in HCC. CONCLUSION: Based on the systematic analysis, we concluded that CD8+ T lymphocytes and NK cells can inhibit HCC cells. While in turn, HCC cells can also result in the dysfunction of those effector cells through various mechanisms. Organoids and direct contact cell co-culture with primary HCC cells and TILs should be the most innovative way to investigate the interactions and develop novel immunotherapy.

Patient expectations shape convalescence after major liver surgery - A prospective, randomized study.

BACKGROUND: Several studies suggest an important influence of patient expectations on outcomes. We hypothesized that patient expectations with regard to length of postoperative stay influence convalescence after liver resections. METHOD: This prospective, randomized study compared patients who were preoperatively either informed to be expected to stay 7-10 days (short arm) or 12-16 days (long arm) after major liver resections (≥4 segments). Additionally, psychological traits were assessed using questionnaires and the time to fulfillment of objective discharge criteria [oral analgesics only, first bowel movement, ability to tolerate solid food, full mobilization, no complications which need general anesthesia (>CD IIIa)] was defined as the primary endpoint. RESULTS: Patients in the short arm reached the objective discharge criteria after 8.39 days (SD 3.60), while patients in the long arm needed 12.73 days (SD 3.43) (p = 0.001). The actual length of stay in the short arm was 12.00 (IQR 8-16) and 19.3 days in the long arm (IQR 14-26) (p = 0.008). A more pronounced self-efficacy correlated with earlier fulfillment of the objective discharge criteria (p = 0.048), whereas patients placing a high value on their health needed more time (p = 0.049). CONCLUSION: The expectation of a shorter length of stay results in a quicker objective, physical patient convalescence after major liver resections.

The predictive value of tumor infiltrating leukocytes in Hepatocellular Carcinoma: A systematic review and meta-analysis.

BACKGROUND: For Hepatocellular carcinoma (HCC) surgery either through resection or transplantation often provides the only chance for cure. Since hepatocarcinogenesis and postsurgical prognosis is not only dependent on cirrhosis but also on immune activation and exhaustion, many studies have investigated tumor infiltrating leukocyte (TIL) subsets. This systematic review and meta-analysis aims at describing the cell groups and their predictive power regarding overall (OS), disease free (DFS) and recurrence free survival (RFS). MATERIAL AND METHODS: A systematic search of the PubMed database was conducted (PROSPERO 172324). Data on CD3+, CD8+, Treg, B cells, macrophages, neutrophil and NK-cells were collected from Pubmed and related references up to December 2018. Overall (OS), disease-free (DFS) and recurrence free survival (RFS) in dependence of high vs. low infiltration rates were compared using a random effects meta-analysis. RESULTS: Altogether data from 3541 patients enrolled in 20 publications were included. Except for Tregs and Neutrophils, heterogeneity analysis was found to be moderate to high across the studies. High CD3+, CD8+, NK-cell infiltration predicted better survival (OS, DFS and RFS; p < 0.05). Higher Treg and Neutrophil infiltration predicted lower OS and DFS. For Macrophages and B cells no difference in survival could be found. DISCUSSION: As with other solid tumors immune infiltration has a great influence on survival after resection. However, a considerable publication bias cannot be ruled out in mostly retrospective analyses. Nevertheless, in light of novel immune modulatory treatments this opens a new avenue towards effective and well-tolerated adjuvant treatment.

Liver transplantation versus watchful waiting in hepatocellular carcinoma patients with complete response to bridging therapy - a retrospective observational study.

Bridging therapy to prevent progression on the waiting list can result in a sustained complete response (sCR). In some patients, the liver transplantation (LT) risk might exceed those of tumor recurrence. We thus evaluated whether a watchful waiting (CR-WW) strategy could be a feasible alternative to transplantation (CR-LT). We performed a retrospective analysis of overall survival (OS) and recurrence-free survival (RFS) of patients with a sCR (CR > 6 months). Permitted bridging included thermoablation, resection, and combinations of either with transarterial chemoembolization. Patients were divided into the intended treatment strategies CR-WW and CR-LT. 39 (18.40%) sCR patients from 212 were investigated. 22 patients were treated with a CR-LT and 17 patients a CR-WW strategy. Five-year RFS was lower in the CR-WW than in the CR-LT group [53.3% (22.1%; 77.0%) and 84.0% (57.6%; 94.7%)]. 29.4% (5/17) CR-WW patients received salvage transplantation because of recurrence. OS (5-year) was 83.9% [56.8%; 94.7%] after LT and 75.4% [39.8%; 91.7%] after WW. Our analysis shows that the intuitive decision made by our patients in agreement with their treating physicians for a watchful waiting strategy in sCR can be justified. Applied on a larger scale, this strategy could help to reduce the pressure on the donor pool.

Specific Management of Patients with Acute Abdomen during the COVID-19 Pandemic: A Surgical Perspective from Germany.

During the current COVID-19 pandemic, the triage, assessment, and management of patients presenting to the emergency department with critical conditions has become -challenging. The clinical features of COVID-19 are heterogeneous and subtle in many cases. They may easily be overlooked in the case of other acute diseases. Gastrointestinal symptoms are common in patients with COVID-19 as SARS-CoV-2 is able to enter gastrointestinal epithelial cells. However, these complaints can also be caused by a COVID-19-independent concomitant abdominal pathology. Therefore, patients with acute abdominal pain and fever need to be assessed very thoroughly. Based on a clinical case, we present our approach of managing emergency patients with acute abdomen and concomitant suspicion of -COVID-19.

A novel machine learning algorithm to predict disease free survival after resection of hepatocellular carcinoma.

BACKGROUND: Due to organ shortage, liver transplantation (LT) in hepatocellular carcinoma (HCC) patients can only be offered subsidiary to other curative treatments, including liver resection (LR). We aimed at developing and validating a machine-learning algorithm (ML) to predict which patients are sufficiently treated by LR. METHODS: Twenty-six preoperatively available routine laboratory values along with standard clinical-pathological parameters [including the modified Glascow Prognostic Score (mGPS), the Kings Score (KS) and the Model of Endstage Liver Disease (MELD)] were retrieved from 181 patients who underwent partial LR due to HCC in non-cirrhosis or compensated cirrhosis from January 2007 through March 2018 at our institution. These data were processed using a Random Forest (RF)-based workflow, which included preprocessing, recursive feature elimination (RFE), resampling, training and cross-validation of the RF model. A subset of untouched patient data was used as a test cohort. Basing on the RF prediction, test data could be stratified according to high (HR) or low risk (LR) profile characteristics. RESULTS: RFE analysis provided 6 relevant outcome predictors: mGPS, aPTT, CRP, largest tumor size, number of lesions and age at time of operation. After down-sampling, the predictive value of our model was 0.788 (0.658-0.919) for early DFS. 16.7% of HR and 74.2% of LR patients survived 2 years of follow-up (P<0.001). CONCLUSIONS: Our RF model, based solely on clinical parameters, proved to be a powerful predictor of DFS. These results warrant a prospective study to improve the model for selection of suitable candidates for LR as alternative to transplantation. The predictive model is available online: tiny.cc/hcc_model.