International Hepato-Pancreato-Billiary Association (IHPBA) registry study on COVID-19 infections in HPB surgery patients.

BACKGROUND: In response to the pandemic, the International Hepato-Pancreato-Biliary Association (IHPBA) developed the IHPBA-COVID Registry to capture data on HPB surgery outcomes in COVID-positive patients prior to mass vaccination programs. The aim was to provide a tool to help members gain a better understanding of the impact of COVID-19 on patient outcomes following HPB surgery worldwide. METHODS: An online registry updated in real time was disseminated to all IHPBA, E-AHPBA, A-HPBA and A-PHPBA members to assess the effects of the pandemic on the outcomes of HPB procedures, perioperative COVID-19 management and other aspects of surgical care. RESULTS: One hundred twenty-five patients from 35 centres in 18 countries were included. Seventy-three (58%) patients were diagnosed with COVID-19 preoperatively. Operative mortality after pancreaticoduodenectomy and major hepatectomy was 28% and 15%, respectively, and 2.5% after cholecystectomy. Postoperative complication rates of pancreatic procedures, hepatic interventions and biliary interventions were respectively 80%, 50% and 37%. Respiratory complication rates were 37%, 31% and 10%, respectively. CONCLUSION: This study reveals a high risk of mortality and complication after HPB surgeries in patient infected with COVID-19. The more extensive the procedure, the higher the risk. Nonetheless, an increased risk was observed across all types of interventions, suggesting that elective HPB surgery should be avoided in COVID positive patients, delaying it at distance from the viral infection.

IL-17A-producing CD8+ T cells promote PDAC via induction of inflammatory cancer-associated fibroblasts.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is characterised by an abundant desmoplastic stroma composed of cancer-associated fibroblasts (CAF) and interspersed immune cells. A non-canonical CD8+ T-cell subpopulation producing IL-17A (Tc17) promotes autoimmunity and has been identified in tumours. Here, we evaluated the Tc17 role in PDAC. DESIGN: Infiltration of Tc17 cells in PDAC tissue was correlated with patient overall survival and tumour stage. Wild-type (WT) or Il17ra-/- quiescent pancreatic stellate cells (qPSC) were exposed to conditional media obtained from Tc17 cells (Tc17-CM); moreover, co-culture of Tc17-CM-induced inflammatory (i)CAF (Tc17-iCAF) with tumour cells was performed. IL-17A/F-, IL-17RA-, RAG1-deficient and Foxn1nu/nu mice were used to study the Tc17 role in subcutaneous and orthotopic PDAC mouse models. RESULTS: Increased abundance of Tc17 cells highly correlated with reduced survival and advanced tumour stage in PDAC. Tc17-CM induced iCAF differentiation as assessed by the expression of iCAF-associated genes via synergism of IL-17A and TNF. Accordingly, IL-17RA controlled the responsiveness of qPSC to Tc17-CM. Pancreatic tumour cells co-cultured with Tc17-iCAF displayed enhanced proliferation and increased expression of genes implicated in proliferation, metabolism and protection from apoptosis. Tc17-iCAF accelerated growth of mouse and human tumours in Rag1-/- and Foxn1nu/nu mice, respectively. Finally, Il17ra-expressed by fibroblasts was required for Tc17-driven tumour growth in vivo. CONCLUSIONS: We identified Tc17 as a novel protumourigenic CD8+ T-cell subtype in PDAC, which accelerated tumour growth via IL-17RA-dependent stroma modification. We described a crosstalk between three cell types, Tc17, fibroblasts and tumour cells, promoting PDAC progression, which resulted in poor prognosis for patients.

[Robotics in Liver Surgery - Tips and Tricks]. / Robotik in der Leberchirurgie ­ Tipps und Tricks.

Since minimally invasive liver surgery has proven benefits over open surgery, this technique should also be implemented more broadly in Germany. With the dramatic development in minimally invasive and robotic liver surgery, this approach has been established in recent years. Most recent analyses suggest lower complication rates, blood loss and hospital stay compared to open and laparoscopic liver surgery. In contrast to laparoscopic surgery, the technical setting of robotic liver surgery is widely independent of the type of resection. The laparoscopic and robotic technologies should be considered to be equal at the moment, although most recent analyses even suggest additional advantages of robotic over laparoscopic liver surgery. Moreover, robotics has a greater potential for technical refinements, including the inclusion of artificial intelligence and machine learning. Most steps can be transferred from open and laparoscopic liver surgery, but a dissection device such as the CUSA has not yet been developed. Consequently, different techniques have been reported for parenchymal transsection. Due to the special technical features of robotic surgery, intensive training programs should be used prior to the establishment of a robotic liver surgery program.

[Liver Resections Can Be Safely Performed in Cirrhotic Patients after Careful Patient Selection]. / Leberresektionen können bei vorsichtiger Patientenselektion auch in Zirrhose sicher durchgeführt werden.

BACKGROUND: Hepatocellular Carcinoma (HCC) is the most frequent malignant primary liver tumour in a cirrhotic liver. Liver transplantation and resection are the only curative treatment options in compensated liver cirrhosis, but liver resections are associated with increased perioperative morbidity and mortality. PATIENTS: We identified 108 cirrhotic patients, who underwent liver resections at the University Hospital of Mainz between January 2008 and December 2019. During the same period, 185 liver resections were performed for HCC in non-cirrhotic livers. Furthermore, 167 liver resections served as control group, which were performed for colorectal liver metastases (CRLM) with comparable extent of resection to HCC in cirrhotic livers. Preoperatively, we assessed the Charlson Comorbidity Index (CCI), MELD and Child scores in addition to the general patient characteristics. Perioperative morbidity was graded according to the Clavien-Dindo classification. Resections of HCC in cirrhosis and liver metastases were additionally compared by a matched-pair analysis. RESULTS: The three groups were comparable in age. Preoperative liver function was best in patients with CRLM (p < 0.001). Resections for HCC in non-cirrhotic livers were more extended than in cirrhotic livers (p < 0.001). The overall morbidity (Clavien/Dindo stage III - IV) was higher after resections in cirrhotic livers than in CRLM resections (p = 0.026). Postoperative mortality was comparably low in all three groups (2.2%). Neither MELD nor Child score was predictive for postoperative morbidity or mortality (area under the curve: AUC < 0.6, each). Preoperative CCI was predictive for postoperative mortality (AUC = 0.78). CONCLUSIONS: Liver resections in cirrhotic livers are feasible after adequate patient selection and limitation of the extent of surgery. Comorbidities additionally increase the postoperative mortality in addition to impaired liver function and should therefore always be included into the preoperative assessment of patients undergoing liver surgery.

Histone H3K27 demethylase KDM6A is an epigenetic gatekeeper of mTORC1 signalling in cancer.

OBJECTIVE: Large-scale genome sequencing efforts of human tumours identified epigenetic modifiers as one of the most frequently mutated gene class in human cancer. However, how these mutations drive tumour development and tumour progression are largely unknown. Here, we investigated the function of the histone demethylase KDM6A in gastrointestinal cancers, such as liver cancer and pancreatic cancer. DESIGN: Genetic alterations as well as expression analyses of KDM6A were performed in patients with liver cancer. Genetic mouse models of liver and pancreatic cancer coupled with Kdm6a-deficiency were investigated, transcriptomic and epigenetic profiling was performed, and in vivo and in vitro drug treatments were conducted. RESULTS: KDM6A expression was lost in 30% of patients with liver cancer. Kdm6a deletion significantly accelerated tumour development in murine liver and pancreatic cancer models. Kdm6a-deficient tumours showed hyperactivation of mTORC1 signalling, whereas endogenous Kdm6a re-expression by inducible RNA-interference in established Kdm6a-deficient tumours diminished mTORC1 activity resulting in attenuated tumour progression. Genome-wide transcriptional and epigenetic profiling revealed direct binding of Kdm6a to crucial negative regulators of mTORC1, such as Deptor, and subsequent transcriptional activation by epigenetic remodelling. Moreover, in vitro and in vivo genetic epistasis experiments illustrated a crucial function of Deptor and mTORC1 in Kdm6a-dependent tumour suppression. Importantly, KDM6A expression in human tumours correlates with mTORC1 activity and KDM6A-deficient tumours exhibit increased sensitivity to mTORC1 inhibition. CONCLUSION: KDM6A is an important tumour suppressor in gastrointestinal cancers and acts as an epigenetic toggle for mTORC1 signalling. Patients with KDM6A-deficient tumours could benefit of targeted therapy focusing on mTORC1 inhibition.

DEM-Based Approach for the Modeling of Gelation and Its Application to Alginate.

The gelation of biopolymers is of great interest in the material science community and has gained increasing relevance in the past few decades, especially in the context of aerogels─lightweight open nanoporous materials. Understanding the underlying gel structure and influence of process parameters is of great importance to predict material properties such as mechanical strength. In order to improve understanding of the gelation mechanism in aqueous solution, this work presents a novel approach based on the discrete element method for the mesoscale for modeling gelation of hydrogels, similarly to an extremely coarse-grained molecular dynamics (MD) approach. For this, polymer chains are abstracted as dimer units connected by flexible bonds and interactions between units and with the environment, that is, diffusion in implicit water, are described. The model is based on Langevin dynamics and includes an implicit probabilistic ion model to capture the effects of ion availability during ion-mediated gelation. The model components are fully derived and parameterized using literature data and theoretical considerations based on a simplified representation of atomistic processes. The presented model enables investigations of the higher-scale network formation during gelation on the micrometer and millisecond scale, which are beyond classical modeling approaches such as MD. As a model system, calcium-mediated alginate gelation is investigated including the influence of ion concentration, polymer composition, polymer concentration, and molecular weight. The model is verified against numerous literature data as well as own experimental results for the corresponding Ca-alginate hydrogels using nitrogen porosimetry, NMR cryoporometry, and small-angle neutron scattering. The model reproduces both bundle size and pore size distribution in a reasonable agreement with the experiments. Overall, the modeling approach paves the way to physically motivated design of alginate gels.

Hierarchical Coarse-Grained Strategy for Macromolecular Self-Assembly: Application to Hepatitis B Virus-Like Particles.

Macromolecular self-assembly is at the basis of many phenomena in material and life sciences that find diverse applications in technology. One example is the formation of virus-like particles (VLPs) that act as stable empty capsids used for drug delivery or vaccine fabrication. Similarly to the capsid of a virus, VLPs are protein assemblies, but their structural formation, stability, and properties are not fully understood, especially as a function of the protein modifications. In this work, we present a data-driven modeling approach for capturing macromolecular self-assembly on scales beyond traditional molecular dynamics (MD), while preserving the chemical specificity. Each macromolecule is abstracted as an anisotropic object and high-dimensional models are formulated to describe interactions between molecules and with the solvent. For this, data-driven protein-protein interaction potentials are derived using a Kriging-based strategy, built on high-throughput MD simulations. Semi-automatic supervised learning is employed in a high performance computing environment and the resulting specialized force-fields enable a significant speed-up to the micrometer and millisecond scale, while maintaining high intermolecular detail. The reported generic framework is applied for the first time to capture the formation of hepatitis B VLPs from the smallest building unit, i.e., the dimer of the core protein HBcAg. Assembly pathways and kinetics are analyzed and compared to the available experimental observations. We demonstrate that VLP self-assembly phenomena and dependencies are now possible to be simulated. The method developed can be used for the parameterization of other macromolecules, enabling a molecular understanding of processes impossible to be attained with other theoretical models.

[Extended Liver Resection with Complex Vascular Reconstruction in Locally Advanced Alveolar Echinococcosis]. / Erweiterte Leberresektion mit komplexer Gefäßrekonstruktion bei fortgeschrittener alveolärer Echinokokkose der Leber.

BACKGROUND: Hepatic echinococcosis is rare in Germany. Liver resection is a potentially curative treatment, if a complete resection according to oncological standards can be achieved. Due to the infiltrating growth of E. multilocularis, liver resections can be challenging. CASE: We present a case of hepatic echinococcosis with complete infiltration of left and middle hepatic vein and a partial infiltration of the right hepatic vein (RHV) and the vena cava (VCI). To better evaluate resectability, we performed a three-dimensional reconstruction based on the preoperative CT scan. Complete resection was achieved with an extended left hemihepatectomy (removal of segment 1-5 and partially segment 8) and tangential resection of the VCI and partial resection of the RHV. VCI was reconstructed with a bovine pericardial patch and the RHV was reconstructed end-to-end. CONCLUSION: Liver resection may require complex vascular resections and reconstructions to achieve an R0 situation in the therapy of E. multilocularis. Three dimensional planning of the resection facilitated curative resection in the current case.

[Liver Surgery 4.0 - Planning, Volumetry, Navigation and Virtual Reality]. / Leberchirurgie 4.0 - OP-Planung, Volumetrie, Navigation und Virtuelle Realität.

Due to the optimisation of conservative treatment, the improvement of imaging methods and the continuous development of surgical techniques, the borders of resectability in liver surgery have changed significantly in recent decades.Thanks to numerous technical developments, in particular three-dimensional segmentation, preoperative planning and orientation during the operation itself, can now be facilitated, especially in complex procedures.New technologies such as 3D printing as well as virtual and augmented reality offer additional display options for the patients' individual anatomy. Various intraoperative navigation options are intended to make preoperative planning available in the operating room in order to increase patient safety.This review article is intended to provide an overview of the current state of available technologies and an outlook into the operating theatre of the future.

Neoadjuvant Therapy for Resectable Pancreatic Cancer: A New Standard of Care. Pooled Data From 3 Randomized Controlled Trials.

OBJECTIVE: The aim of this study was to pool data from randomized controlled trials (RCT) limited to resectable pancreatic ductal adenocarcinoma (PDAC) to determine whether a neoadjuvant therapy impacts on disease-free survival (DFS) and surgical outcome. SUMMARY BACKGROUND DATA: Few underpowered studies have suggested benefits from neoadjuvant chemo (± radiation) for strictly resectable PDAC without offering conclusive recommendations. METHODS: Three RCTs were identified comparing neoadjuvant chemo (± radio) therapy vs. upfront surgery followed by adjuvant therapy in all cases. Data were pooled targeting DFS as primary endpoint, whereas overall survival (OS), postoperative morbidity, and mortality were investigated as secondary endpoints. Survival endpoints DFS and OS were compared using Cox proportional hazards regression with study-specific baseline hazards. RESULTS: A total of 130 patients were randomized (56 in the neoadjuvant and 74 in the control group). DFS was significantly longer in the neoadjuvant treatment group compared to surgery only [hazard ratio (HR) 0.6, 95% confidence interval (CI) 0.4-0.9] (P = 0.01). Furthermore, DFS for the subgroup of R0 resections was similarly longer in the neoadjuvant treated group (HR 0.6, 95% CI 0.35-0.9, P = 0.045). Although postoperative complications (Comprehensive Complication Index, CCI®) occurred less frequently (P = 0.008), patients after neoadjuvant therapy experienced a higher toxicity, but without negative impact on oncological or surgical outcome parameters. CONCLUSION: Neoadjuvant therapy can be offered as an acceptable standard of care for patients with purely resectable PDAC. Future research with the advances of precision oncology should now focus on the definition of the optimal regimen.

Intrahepatic cholangiocarcinoma - influence of resection margin and tumor distance to the liver capsule on survival.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is often diagnosed in advanced stage. Aim of this study was to analyse the influence of resection margins and tumor distance to the liver capsule on survival and recurrence in a single center with a high number of extended resections. METHODS: From January 2008 to June 2018 data of all patients with ICC were collected and further analysed with Kaplan Meier Model, Cox regression or Chi2 test for categorical data. RESULTS: Out of 210 included patients 150 underwent curative intended resection (71.4%). Most patients required extended resections (n = 77; 51.3%). R0-resection was achieved in 131 patients (87.3%) with minimal distances to the resection margin > 1 cm in 22, 0.5-1 cm in 11, 0.1-0.5 cm in 49 patients, and <  0.1 cm in 49 patients. Overall survival (OS) for margins > 0.5 cm compared to 0.5-0.1 cm or R1 was better, but without reaching significance. All three groups had significantly better OS compared to the irresectable group. Recurrence-free survival (RFS) was also better in patients with a margin > 0.5 cm than in the < 0.5-0.1 cm or the R1-group, but even without reaching significance. Different distance to the liver capsule significantly affected OS, but not RFS. CONCLUSIONS: Wide resection margins (> 0.5 cm) should be targeted but did not show significantly better OS or RFS in a cohort with a high percentage of extended resections (> 50%). Wide margins, narrow margins and even R1 resections showed a significant benefit over the irresectable group. Therefore, extended resections should be performed, even if only narrow margins can be achieved.

Delivery of hepato-pancreato-biliary surgery during the COVID-19 pandemic: an European-African Hepato-Pancreato-Biliary Association (E-AHPBA) cross-sectional survey.

BACKGROUND: The extent of the COVID-19 pandemic and the resulting response has varied globally. The European and African Hepato-Pancreato-Biliary Association (E-AHPBA), the premier representative body for practicing HPB surgeons in Europe and Africa, conducted this survey to assess the impact of COVID-19 on HPB surgery. METHODS: An online survey was disseminated to all E-AHPBA members to assess the effects of the pandemic on unit capacity, management of HPB cancers, use of COVID-19 screening and other aspects of service delivery. RESULTS: Overall, 145 (25%) members responded. Most units, particularly in COVID-high countries (>100,000 cases) reported insufficient critical care capacity and reduced HPB operating sessions compared to COVID-low countries. Delayed access to cancer surgery necessitated alternatives including increased neoadjuvant chemotherapy for pancreatic cancer and colorectal liver metastases, and locoregional treatments for hepatocellular carcinoma. Other aspects of service delivery including COVID-19 screening and personal protective equipment varied between units and countries. CONCLUSION: This study demonstrates that the COVID-19 pandemic has had a profound adverse impact on the delivery of HPB cancer care across the continents of Europe and Africa. The findings illustrate the need for safe resumption of cancer surgery in a "new" normal world with screening of patients and staff for COVID-19.

Application of patient-derived liver cancer cells for phenotypic characterization and therapeutic target identification.

Primary liver cancer (PLC) ranks among the most lethal solid cancers worldwide due to lack of effective biomarkers for early detection and limited treatment options in advanced stages. Development of primary culture models that closely recapitulate phenotypic and molecular diversities of PLC is urgently needed to improve the patient outcome. Long-term cultures of 7 primary liver cancer cell lines of hepatocellular and cholangiocellular origin were established using defined culture conditions. Morphological and histological characteristics of obtained cell lines and xenograft tumors were analyzed and compared to original tumors. Time course analyses of transcriptomic and genomic changes were performed using next-generation sequencing (NGS). Key oncogenic alterations were identified by targeted NGS and cell lines carrying potentially actionable mutations were treated with corresponding specific inhibitors. PDCL fully resembled morphological features of the primary cancers in vitro and in vivo over extended period in culture. Genomic alterations as well as transcriptome profiles showed high similarity with primary tumors and remained stable during long-term culturing. Targeted-NGS confirmed that key oncogenic mutations such as TP53, KRAS, CTNNB1 as well as actionable mutations (e.g. MET, cKIT, KDR) were highly conserved in PDCL and amenable for individualized therapeutic approaches. Integrative genomic and transcriptomic approaches further demonstrated that PDCL more closely resemble molecular and prognostic features of PLC than established cell lines and are valuable tool for direct target evaluation. Our integrative analysis demonstrates that PDCL represents refined model for discovery of relevant molecular subgroups and exploration of precision medicine approaches for the treatment of this deadly disease.

Extended Molecular Profiling Improves Stratification and Prediction of Survival After Resection of Colorectal Liver Metastases.

OBJECTIVE: The aim of this study was to assess the effect of cancer-related genes and their mutations analyzed by next-generation sequencing (NGS) on the oncological outcome after resection of colorectal liver metastases (CRLM). BACKGROUND: Traditional prognostic scores include clinical and pathological parameters of primary tumor and metastases. The modified clinical risk score (m-CS), based on size of metastases, primary tumor nodal status, and RAS mutation status outperformed traditional scores. We hypothesized to further improve the scoring system based on the results of NGS. METHODS: Cancer tissues of 139 patients with CRLM were used for NGS. The work-up included the analysis of recurrent somatic mutations and copy number changes of 720 genes. Clinical data were extracted from a prospectively collected institutional liver database. RESULTS: Depending on significance, the following cancer-related genes and their alterations (%) were further investigated: APC (86%), TP53 (78%), KRAS (29%), SMAD4 (15%), PIK3CA (14%), BRAF (8%), ERBB2 (6%), SMAD3 (5%), SMAD2 (4%), and NRAS (4%). The most predictive parameters for poor oncological outcome were alterations in the SMAD family (P = 0.0186) and RAS-RAF pathway (P = 0.032). Refining the m-CS by replacing RAS with RAS-RAF pathway and adding SMAD family resulted in an extended clinical risk score which is highly predictive for oncological outcome (P < 0.0001). CONCLUSION: In conclusion, mutations of the SMAD family revealed a strong prognostic effect after surgery for CRLM. Integration of alterations of the SMAD family as well as the RAS/RAF pathway resulted in a new, still simple but highly prognostic score.

10th Anniversary of ALPPS-Lessons Learned and quo Vadis.

OBJECTIVE: Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has been tested in various indications and clinical scenarios, leading to steady improvements in safety. This report presents the current status of ALPPS. SUMMARY BACKGROUND DATA: ALPPS offers improved resectability, but drawbacks are regularly pointed out regarding safety and oncologic benefits. METHODS: During the 12th biennial congress of the European African-Hepato-Pancreato-Biliary Association (Mainz, Germany, May 23-26, 2017) an expert meeting "10th anniversary of ALPP" was held to discuss indications, management, mechanisms of regeneration, as well as pitfalls of this novel technique. The aim of the meeting was to make an inventory of what has been achieved and what remains unclear in ALPPS. RESULTS: Precise knowledge of liver anatomy and its variations is paramount for success in ALPPS. Technical modifications, mainly less invasive approaches like partial, mini- or laparoscopic ALPPS, mostly aiming at minimizing the extensiveness of the first-stage procedure, are associated with improved safety. In fibrotic/cirrhotic livers the degree of future liver remnant hypertrophy after ALPPS appears some less than that in noncirrhotic. Recent data from the only prospective randomized controlled trial confirmed significant higher resection rates in ALPPS with similar peri-operative morbidity and mortality rates compared with conventional 2-stage hepatectomy including portal vein embolization. ALPPS is effective reliably even after failure of portal vein embolization. CONCLUSIONS: Although ALPPS is now an established 2-stage hepatectomy additional data are warranted to further refine indication and technical aspects. Long-term oncological outcome results are needed to establish the place of ALPPS in patients with initially nonresectable liver tumors.

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.

Opinions and use of neoadjuvant therapy for resectable, borderline resectable, and locally advanced pancreatic cancer: international survey and case-vignette study.

BACKGROUND: Several new treatment options have become available for pancreatic ductal adenocarcinoma (PDAC), but the support for their use for resectable, borderline resectable and locally advanced PDAC is unclear. METHODS: A survey was distributed to the members of the European-African Hepato-Pancreato Biliary Association (E-AHPBA) and the pancreas group of the European Organization for Research and Treatment of Cancer (EORTC) regarding 1) definitions of local resectability, 2) indications for neoadjuvant therapy and 3) case-vignettes regarding the resectability and treatment of PDAC. RESULTS: In total, 114 participants from 37 countries were registered. About 35% of respondents, each, were of the opinion that borderline resectability is defined by any venous tumor contact and venous involvement < 180° or > 180°, respectively. The majority (75.4%) of participants believed that borderline resectable PDAC has a high risk for R1 resection and that neoadjuvant therapy might increase the R0-resection rate (79.8%) and improve oncological patient selection (84.2%). Chemotherapy was regarded useful to convert locally advanced to resectable PDAC by 55.7% of respondents. In the cases with resectable, borderline resectable, and locally advanced PDAC, 10 (8.8%), 78 (68.4%), 55 (48.2%) of participants would start with chemotherapy, respectively. CONCLUSIONS: Although definitions for borderline resectability differ among European surgeons, there seems to be a rather strong support for preoperative chemotherapy in PDAC aiming at minimizing R1 resections while increasing resection rates.

Toward Multiscale Modeling of Proteins and Bioagglomerates: An Orientation-Sensitive Diffusion Model for the Integration of Molecular Dynamics and the Discrete Element Method.

Most processes involved in biological and biotechnological systems spread over many scales in space and time. For example, the interaction of multiple enzymes in heterogeneous enzymatic agglomerates or clusters, necessary for efficient enzymatic conversion, is of high interest for research and enzyme engineering. In order to understand and predict their overall behavior and performance, it is important to describe these scales as completely as possible, known as multiscale modeling. While many different approaches have been presented in recent years, knowledge about protein formation and bioagglomeration at the micro scale is still very limited. In an attempt to address such systems, we propose a bottom- up multiscale modeling methodology, bridging the gaps between molecular dynamics (MD) with an explicit solvent and the larger scale discrete element method (DEM) using an implicit solvent and abstracting macromolecules (e.g., proteins) as objects with anisotropic properties. We term this approach the molecular discrete element method (MDEM). For this, we present an orientation-sensitive diffusion model for DEM, which describes the dynamics of anisotropic translational and rotational diffusion, while implicitly considering solvent molecules and enforcing a canonical ensemble. A general-purpose model and parametrization approach is presented, which can be used to simulate any process involving diffusion of discrete particles. Effects of temperature and viscosity changes can be considered, and guidance is provided concerning time step selection. This model is generally applicable and serves as a precondition to enforce the proper dynamics (i.e., diffusion characteristics and canonical ensemble, similar to a thermostat in MD) for the proposed multiscale modeling methodology with anisotropic properties. Thereby, it presents a first step toward modeling at the micro scale and is integral to enforcing dynamics of such systems and therefore extensively validated. As a next step, interaction models are to be defined and added to the presented model. In comparison to atomistic and coarse-grained (CG) MD, a speedup of 5-7 orders of magnitude can be achieved. The approach is demonstrated on multiple components of the pyruvate dehydrogenase enzyme complex, a multienzymatic machinery that involves very different types of enzymes and is of high value to further elucidate the mechanisms of bioagglomeration and metabolic channeling.

Surgical Resection for Recurrent Intrahepatic Cholangiocarcinoma.

BACKGROUND: Although after R0 resection of intrahepatic cholangiocarcinoma (ICC) recurrence is frequent, most guidelines do not address strategies for this. The aim of this study was to analyze the outcome of repeated resection and to determine criteria when repeated resection is reasonable. METHODS: Between 2008 and 2016, we consecutively collected all cases of ICC (n = 176) in a prospective database and further analyzed them with a focus on tumor recurrence, its surgical treatment, overall survival and recurrence-free survival. RESULTS: Overall, a total of 22 explorations were performed for recurrent ICC in 17 patients. Resection rate was 18 repeated resections in 13 patients. Three patients underwent repeated resection twice and one patient three times. Recurrence was solitary in 7 patients and multifocal in 11 re-resected cases. Median overall survival (OS) of patients who underwent repeated resection was 65.2 months (interquartile range 37-126.5) with a 5-year OS rate of 62%, calculated from primary resection. Patients who underwent repeated resections had a significant better OS compared to those receiving chemotherapy, transarterial chemoembolization, selective internal radiotherapy, radiofrequency ablation or best supportive care (p < 0.001). CONCLUSION: Repeated resection of recurrent ICC is reasonable and associated with an improved survival. Re-exploration should be considered as long as resection is technically possible.

[Hepatocellular carcinoma in an inflammatory adenoma with ß-catenin mutation in a patient with hepatocellular adenomatosis due to germline mutation in HNF1α]. / Entstehung eines hepatozellulären Karzinoms in einem inflammatorischen Adenom mit ß-Catenin-Mutation bei einem Patienten mit hepatozellulärer Adenomatose und HNF1α-Keimbahnmutation.

Hepatocyte nuclear factor 1 α (HNF1α) mutations cause maturity-onset diabetes of the young (MODY) type 3 and are associated with hepatocellular adenomatosis. Malignant transformation of HNF1α-mutated hepatocellular adenomas is rare. We report a case of a 28-year-old man with HNF1α-inactivated adenomatosis who developed an inflammatory adenoma with ß catenin mutation with malignant transformation into a well-differentiated hepatocellular carcinoma (HCC).