Validation of the IWATE Criteria in Robotic-Assisted Liver Resections.

Background/Objectives: The IWATE criteria are well-established as a helpful tool to preoperatively estimate the difficulty and perioperative outcome of laparoscopic liver resections. We evaluated the relationship between the IWATE criteria and the perioperative outcomes in robotic-assisted liver resections (RARLs). Methods: We retrospectively analyzed the data of 58 patients who underwent robotic-assisted liver surgery at our center between July 2019 and April 2023. The operative difficulty of every patient was graded according to the IWATE criteria and compared to the perioperative outcome. Results: The median operation time was 236.5 min (range 37-671 min), and the median length of stay was 6 days (range 3-37 min). The majority had no complications (65.5%; n = 38), 18 (31.0%) patients suffered from mild complications (CD ≤ 3A) and 2 patients (3.4%) suffered from relevant complications (CD ≥ 3B). We observed no deaths within 30 postoperative days. The surgery time, postoperative ICU stay and perioperative blood transfusions increased significantly with a higher difficulty level (p = < 0.001; p < 0.001; p = 0.016). The length of stay, conversion to open surgery (n = 2) and complication rate were not significantly linked to the resulting IWATE group. Conclusions: The IWATE criteria can be implemented in robotic-assisted liver surgery and can be helpful in preoperatively estimating the difficulty of robotic liver resections. Whether there is a "robotic effect" in minimally invasive liver resections has to be further clarified. The IWATE criteria can help to develop curricula for robotic training.

The Influence of Apremilast-Induced Macrophage Polarization on Intestinal Wound Healing.

There is compelling evidence suggesting a pivotal role played by macrophages in orchestrating intestinal wound healing. Since macrophages display significant plasticity and heterogeneity, exhibiting an either classically activated (M1-like) or alternatively activated (M2-like) phenotype, they can aggravate or attenuate intestinal wound healing. Growing evidence also demonstrates a causal link between impaired mucosal healing in inflammatory bowel disease (IBD) and defects in the polarization of pro-resolving macrophages. By targeting the switch from M1 to M2 macrophages, the phosphodiesterase-4 inhibitor Apremilast has gained recent attention as a potential IBD drug. However, there is a gap in our current knowledge regarding the impact of Apremilast-induced macrophages' polarization on intestinal wound healing. The THP-1 cells were differentiated and polarized into M1 and M2 macrophages, and subsequently treated with Apremilast. Gene expression analysis was performed to characterize macrophage M1 and M2 phenotypes, and to identify possible target genes of Apremilast and the involved pathways. Next, intestinal fibroblast (CCD-18) and epithelial (CaCo-2) cell lines were scratch-wounded and exposed to a conditioned medium of Apremilast-treated macrophages. Apremilast had a clear effect on macrophage polarization, inducing an M1 to M2 phenotype switch, which was associated with NF-κB signaling. In addition, the wound-healing assays revealed an indirect influence of Apremilast on fibroblast migration. Our results support the hypothesis of Apremilast acting through the NF-κB-pathway and provide new insights into the interaction with fibroblast during intestinal wound healing.

The Impact of Phase-Specific Macrophage Depletion on Intestinal Anastomotic Healing.

Intestinal anastomotic healing (AH) is critical in colorectal surgery, since disruptive AH leads to anastomotic leakage, a feared postoperative complication. Macrophages are innate immune cells and are instrumental in orchestrating intestinal wound healing, displaying a functional dichotomy as effectors of both tissue injury and repair. The aim of this study was to investigate the phase-specific function and plasticity of macrophages during intestinal AH. Transgenic CD11b diphtheria toxin receptor (CD11b-DTR) mice were used to deplete intestinal macrophages in a temporally controlled manner. Distal colonic end-to-end anastomoses were created in CD11b-DTR, and wild-type mice and macrophages were selectively depleted during either the inflammatory (day 0-3), proliferative (day 4-10), or reparative (day 11-20) phase of intestinal AH, respectively. For each time point, histological and functional analysis as well as gene set enrichment analysis (GSEA) of RNA-sequencing data were performed. Macrophage depletion during the inflammatory phase significantly reduced the associated inflammatory state without compromising microscopic AH. When intestinal macrophages were depleted during the proliferative phase, AH was improved, despite significantly reduced perianastomotic neoangiogenesis. Lastly, macrophages were depleted during the reparative phase and GSEA revealed macrophage-dependent pathways involved in collagen remodeling, cell proliferation, and extracellular matrix composition. However, AH remained comparable at this late timepoint. These results demonstrate that during intestinal AH, macrophages elicit phase-specific effects, and that therapeutic interventions must critically balance their dual and timely defined role.

Resection margin status at the portomesenteric axis may not determine oncologic outcome after pancreaticoduodenectomy for lymph node-positive pancreatic ductal adenocarcinoma.

BACKGROUND: Lymph node and resection margin status are associated with oncologic outcomes after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. However, surgical radicality at the portomesenteric axis in case of suspected infiltration remains controversial. METHODS: Clinicopathological data of patients who underwent a partial or total pancreaticoduodenectomy for PDAC between 2012 to 2019 in 2 major hepato-pancreato-biliary centers in Germany and Switzerland were assessed. We evaluated the impact of positive resection margins at the vascular, parenchymal, and retropancreatic surfaces on overall survival in patients with and without lymph node involvement. Margin-positive vascular resection included both patients with positive margins at the vascular groove and the resected venous wall. RESULTS: During the study period, 217 patients underwent partial/total pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. After excluding 7 patients suffering postoperative complications resulting in mortality within 90 days after surgery (3%), 169 patients had lymph node involvement (80%). In the entire study cohort, margin-positive resection (33%) was significantly associated with worse overall survival (3-year overall survival: margin-positive resection: 27% vs margin-negative resection: 43%, P = .014). Among patients with positive lymph nodes, margin-positive vascular resection (n = 48, 28%) was not significantly associated with impaired overall survival (3-year overall survival: margin-positive vascular resection: 28% vs margin-negative vascular resection: 36%, P = .065). On the contrary, margin-positive parenchymal resection (n = 7, 4%) (3-year overall survival: margin-positive parenchymal resection: 0% vs margin-negative parenchymal resection: 35%, P < .0001) and margin-positive retropancreatic resection (n = 21, 12%) (3-year overall survival: margin-positive retropancreatic resection: 6% vs margin-negative retropancreatic resection: 39%, P < .0001) significantly diminished overall survival in univariate and multivariate analysis in all patients. Among patients without lymph node involvement (n = 41, 20%), there were no margin-positive parenchymal or margin-positive retropancreatic resections. In contrast, only 5 patients had margin-positive vascular resection (12%), with overall survival compared to those with margin-negative vascular resection. CONCLUSIONS: In patients with pancreatic ductal adenocarcinoma and lymph nodal positivity, resection status at the parenchymal and retropancreatic surface but probably not at the portal and/or superior mesenteric vein is a determinant of survival. Therefore, margin-negative resection should be pursued during pancreaticoduodenectomy. However, radical venous resection and/or reconstruction for suspected tumor infiltration may not be necessary for patients with intraoperatively detected lymph node metastases.

Struggle in the bubble - a prospective study on the effect of remote learning and distance education on confidence in practical surgical skills acquired during COVID-19.

BACKGROUND: The coronavirus disease (COVID-19) has significantly changed healthcare systems and medical education. Universities were required to develop innovative curricula based on remote and distance education to continue medical education. This prospective questionnaire-based study aimed to investigate the impact of COVID-19-associated remote learning on the surgical training of medical students. METHODS: A 16-item questionnaire-based survey was distributed to medical students at the University Hospital of Münster before and after a surgical skills laboratory (SSL). Two cohorts were included: summer semester 2021 (COV-19), with rigorous social-distancing restrictions requiered SSL to be remotely, and winter semester 2021 (postCOV-19), in which the SSL was provided as a face-to-face, hands-on course. RESULTS: Both, cohorts showed a significant improvement in self-assessment of pre- and post-course confidence. While no significant difference in the average gain in self-confidence for sterile working was observed between the two cohorts, improvement in self-confidence was significantly higher in the COV-19 cohort regarding skin suturing and knot tying (p < 0.0001). However the average improvement regarding history and physical was significantly higher in the postCOV-19 cohort (p < 0.0001). In subgroup analysis, gender-associated differences varied in the two cohorts and were not related to specific subtasks, while age-stratified analysis revealed superior results for younger students. CONCLUSION: The results of our study underline the usability, feasibility, and adequacy of remote learning for the surgical training of medical students. The on-site distance education version, presented in the study, allows the continuing of hands-on experience in a safe environment in compliance with governmental social-distancing restrictions.

Beyond Kolbe and Hofer-Moest: Electrochemical Synthesis of Carboxylic Anhydrides from Carboxylic Acids.

Herein we report a conceptually new non-decarboxylative electrolysis of carboxylic acids to obtain their corresponding anhydrides as highly valuable reagents in organic synthesis. All carbon atoms of the starting material are preserved in the product in an overall redox-neutral reaction. In a broad substrate scope of carboxylic acids the anhydrides are generated with high selectivity, which demonstrates the versatility of the developed method. Beneficially, no dehydrating reagents are required in comparison to conventional methods and the synthesis is based on uncritical starting materials using graphite and stainless steel as very inexpensive and eco-friendly electrode materials.

Bryostatin-1 Attenuates Ischemia-Elicited Neutrophil Transmigration and Ameliorates Graft Injury after Kidney Transplantation.

Ischemia reperfusion injury (IRI) is a form of sterile inflammation whose severity determines short- and long-term graft fates in kidney transplantation. Neutrophils are now recognized as a key cell type mediating early graft injury, which activates further innate immune responses and intensifies acquired immunity and alloimmunity. Since the macrolide Bryostatin-1 has been shown to block neutrophil transmigration, we aimed to determine whether these findings could be translated to the field of kidney transplantation. To study the effects of Bryostatin-1 on ischemia-elicited neutrophil transmigration, an in vitro model of hypoxia and normoxia was equipped with human endothelial cells and neutrophils. To translate these findings, a porcine renal autotransplantation model with eight hours of reperfusion was used to study neutrophil infiltration in vivo. Graft-specific treatment using Bryostatin-1 (100 nM) was applied during static cold storage. Bryostatin-1 dose-dependently blocked neutrophil activation and transmigration over ischemically challenged endothelial cell monolayers. When applied to porcine renal autografts, Bryostatin-1 reduced neutrophil graft infiltration, attenuated histological and ultrastructural damage, and improved renal function. Our novel findings demonstrate that Bryostatin-1 is a promising pharmacological candidate for graft-specific treatment in kidney transplantation, as it provides protection by blocking neutrophil infiltration and attenuating functional graft injury.

Surface modification of decellularized bovine carotid arteries with human vascular cells significantly reduces their thrombogenicity.

BACKGROUND: Since autologous veins are unavailable when needed in more than 20% of cases in vascular surgery, the production of personalized biological vascular grafts for implantation has become crucial. Surface modification of decellularized xenogeneic grafts with vascular cells to achieve physiological luminal coverage and eventually thromboresistance is an important prerequisite for implantation. However, ex vivo thrombogenicity testing remains a neglected area in the field of tissue engineering of vascular grafts due to a multifold of reasons. METHODS: After seeding decellularized bovine carotid arteries with human endothelial progenitor cells and umbilical cord-derived mesenchymal stem cells, luminal endothelial cell coverage (LECC) was correlated with glucose and lactate levels on the cell supernatant. Then a closed loop whole blood perfusion system was designed. Recellularized grafts with a LECC > 50% and decellularized vascular grafts were perfused with human whole blood for 2 h. Hemolysis and complete blood count evaluation was performed on an hourly basis, followed by histological and immunohistochemical analysis. RESULTS: While whole blood perfusion of decellularized grafts significantly reduced platelet counts, platelet depletion from blood resulting from binding to re-endothelialized grafts was insignificant (p = 0.7284). Moreover, macroscopic evaluation revealed thrombus formation only in the lumen of unseeded grafts and histological characterization revealed lack of CD41 positive platelets in recellularized grafts, thus confirming their thromboresistance. CONCLUSION: In the present study we were able to demonstrate the effect of surface modification of vascular grafts in their thromboresistance in an ex vivo whole blood perfusion system. To our knowledge, this is the first study to expose engineered vascular grafts to human whole blood, recirculating at high flow rates, immediately after seeding.

Early dynamic changes in circulating tumor cells and prognostic relevance following interventional radiological treatments in patients with hepatocellular carcinoma.

The aim of this study was to investigate the dynamic changes of circulating tumor cells (CTCs) in patients with hepatocellular carcinoma (HCC) before and immediately after conducting a microwave ablation (MWA) and conventional transarterial chemoembolization (C-TACE). Additionally, the CTCs short-term dynamics were compared with the clinical course of the HCC-patients. Blood samples from 17 patients with HCC who underwent MWA (n = 10) or C-TACE (n = 7) were analyzed. Venous blood was taken before and immediately after the radiological interventions to isolate and quantify CTCs using flow cytometry. CTCs were identified as CD45- and positive for the markers ASGPR, CD146 and CD274 (PD-L1). Patients were followed of up to 2.2 years after the radiological intervention. CTCs were detected in 13 HCC patients (76%) prior to the radiological interventions. The rate of CTCs was significantly decreased after the intervention in patients treated with MWA (0.4 CTCs/mL of blood, p = 0.031). However, no significant differences were observed in patients who received C-TACE (0.3 CTCs/mL of blood, p = 0.300). Overall, no correlation was found between the CTCs rate before and after the radiological intervention and recurrence rate of HCC. This preliminary data could confirm the tumoricidal effects of MWA in patients with HCC by significantly decreasing CTCs rate. In our study, we were able to detect CTCs in HCC patients using 3 different tumor markers. This preliminary data shows significant lower CTCs detected in response to MWA. However, large-scale randomized clinical trials are needed to determine the future role and the prognostic relevance of CTCs following this treatment.

Repeated resection for recurrent intrahepatic cholangiocarcinoma: A retrospective German multicentre study.

BACKGROUND: Tumour recurrence is common after resection of intrahepatic cholangiocarcinoma (ICC). Repeated resection is a potential curative treatment, but outcomes are not well-defined thus far. The aim of this retrospective multicentre cohort study was to show the feasibility and survival of repeated resection of ICC recurrence. METHODS: Data were collected from 18 German hepato-pancreatico-biliary centres for patients who underwent repeated exploration of recurrent ICC between January 2008 and December 2017. Primary end points were overall (OS) and recurrence-free survival from the day of primary and repeated resection. RESULTS: Of 156 patients who underwent repeated exploration for recurrent ICC, 113 underwent re-resection. CA19-9 prior to primary resection, R status of first liver resection and median time to recurrence were significant determinants of repeated resectability. Median OS in the repeated resection group was 65.2 months, with consecutive 1-, 3- and 5-year OS of 98%, 78% and 57% respectively. After re-exploration, median OS from primary resection was 46.7 months, with a consecutive 1-, 3- and 5-year OS of 95%, 55% and 22% respectively. From the day of repeated resection, the median OS was 36.8 months, with a consecutive 1-, 3- and 5-year OS of 86%, 51% and 34% respectively. Minor morbidity (grade I+II) was present in 27%, grade IIIa-IVb morbidity in 20% and mortality in 3.5% of patients. CONCLUSION: Repeated resection of ICC has acceptable morbidity and mortality and seems to be associated with improved long-term survival. Structured follow-up after resection of ICC is necessary for early identification of these patients.

Engineering an endothelialized, endocrine Neo-Pancreas: Evaluation of islet functionality in an ex vivo model.

Islet-based recellularization of decellularized, repurposed rat livers may form a transplantable Neo-Pancreas. The aim of this study is the establishment of the necessary protocols, the evaluation of the organ structure and the analysis of the islet functionality ex vivo. After perfusion-based decellularization of rat livers, matrices were repopulated with endothelial cells and mesenchymal stromal cells, incubated for 8 days in a perfusion chamber, and finally repopulated on day 9 with intact rodent islets. Integrity and quality of re-endothelialization was assessed by histology and FITC-dextran perfusion assay. Functionality of the islets of Langerhans was determined on day 10 and day 12 via glucose stimulated insulin secretion. Blood gas analysis variables confirmed the stability of the perfusion cultivation. Histological staining showed that cells formed a monolayer inside the intact vascular structure. These findings were confirmed by electron microscopy. Islets infused via the bile duct could histologically be found in the parenchymal space. Adequate insulin secretion after glucose stimulation after 1-day and 3-day cultivation verified islet viability and functionality after the repopulation process. We provide the first proof-of-concept for the functionality of islets of Langerhans engrafted in a decellularized rat liver. Furthermore, a re-endothelialization step was implemented to provide implantability. This technique can serve as a bioengineered platform to generate implantable and functional endocrine Neo-Pancreases.

The human liver matrisome - Proteomic analysis of native and fibrotic human liver extracellular matrices for organ engineering approaches.

The production of biomaterials that endow significant morphogenic and microenvironmental cues for the constitution of cell integration and regeneration remains a key challenge in the successful implementation of functional organ replacements. Despite the vast development in the production of biological and architecturally native matrices, the complex compositions and pivotal figures by which the human matrisome mediates many of its essential functions are yet to be defined. Here we present a thorough analysis of the native human liver proteomic landscape using decellularization and defatting protocols to create extracellular matrix scaffolds of natural origin that can further be used in both bottom-up and top-down approaches in tissue engineering based organ replacements. Furthermore, by analyzing human liver extracellular matrices in different stages of fibrosis and cirrhosis, we have identified distinct attributes of these tissues that could potentially be exploited therapeutically and thus require further investigation. The general experimental pipeline presented in this study is applicable to any type of tissue and can be widely used for different approaches in regenerative medicine and in the construction of novel biomaterials for organ engineering approaches.

Health-related quality of life after laparoscopic liver resection.

BACKGROUND: Potential benefits of laparoscopic liver resections (LLRs) over open liver resections (OLRs) such as the clinical outcome and health-related quality of life (HRQoL) have not convincingly been investigated, yet. PATIENTS AND METHODS: All patients who had undergone LLR and OLR at our department between 1 June 2014 and 10 October 2016 were identified. HRQoL was assessed using the short form 36 (SF-36). All patients who returned the surveys were then retrospectively analysed with regards to the perioperative outcome. RESULTS: We received 66 eligible questionnaires (50%). The number of major liver resections did not significantly differ between both groups (LLR: 11 [33%], OLR: 16 [48%], P = 0.211).The proportion of patients with two or more co-morbidities (P = 0.044) and liver cirrhosis (P = 0.016), respectively, was significantly higher in the LLR group, when compared to the OLR group (LLR: 11 [33%] vs. 3 of 33 patients [9%], P = 0.016). HRQoL scores were good with no significant differences between both groups. Among these patients, there were significantly more pulmonary complications in the OLR group, and length of hospital stay was longer when compared to the LLR group. CONCLUSIONS: Laparoscopic liver surgery can be performed safely even in multimorbid elderly patients resulting in high HRQoL scores.

The impact of directly acting antivirals on the enzymatic liver function of liver transplant recipients with recurrent hepatitis C.

BACKGROUND: The new directly acting antivirals (DAAs) enable all-oral interferon-free treatment of chronic hepatitis C virus (HCV) infection. We here investigated the effect of DAAs on the enzymatic liver function of liver transplant recipients with recurrent hepatitis C. METHODS: Twenty-one patients with elevated liver enzymes or advanced fibrosis/compensated cirrhosis caused by recurrent HCV were treated with sofosbuvir either in combination with simeprevir, or in combination with ribavirin or daclatasvir with or without ribavirin for 12 weeks. Biochemical parameters, tacrolimus trough levels, and the maximal liver function capacity (LiMAx) were measured monthly during the treatment and 12 weeks after the end of treatment. RESULTS: All patients achieved sustained virological response 12 weeks after the end of the treatment. The transaminases and cholestasis parameters normalized until week 8 of treatment. The mean LiMAx (normal ranges >315 µg/kg/h) increased from 344±142 µg/kg/h before treatment to 458±170 µg/kg/h (P<.0001) at the 12-week follow-up. In parallel, the tacrolimus trough level to dose ratio decreased from 4.68 down to 2.72 (P=.0004). CONCLUSION: Antiviral treatment with DAAs enabled sustained elimination of recurrent HCV in liver transplant recipients and was associated with a significant improvement of the enzymatic liver function.

Patient and tumour biology predict survival beyond the Milan criteria in liver transplantation for hepatocellular carcinoma.

BACKGROUND: Patients with hepatocellular carcinoma (HCC) beyond the Milan criteria are not considered for liver transplantation (LT) in many centres; however, LT may be the only treatment able to achieve long-term survival in patients with unresectable HCC. The aim of this study was to assess the role of recipient age and tumour biology expressed by the DNA index in the selection of HCC patients for LT. PATIENTS: Clinicopathological data of 364 patients with HCC who underwent LT between 1989 and 2010 were evaluated. Overall survival (OS) was analysed by patient age, tumour burden based on Milan criteria and the DNA index. RESULTS: After a median follow-up time of 78 months, the median survival was 100 months. Factors associated with OS on univariate analysis included Milan criteria, patient age, hepatitis C infection, alpha-fetoprotein (AFP) level, the DNA index, number of HCC, diameter of HCC, bilobar HCC, microvascular tumour invasion and tumour grading. On multivariate analysis, HCC beyond Milan criteria and the DNA index >1.5 independently predicted a worse OS. When stratifying patients by both age and Milan criteria, patients ≤ 60 years with HCC beyond Milan criteria had an OS comparable to that of patients >60 years within Milan criteria (10-year OS: 33% versus 37%, P = 0.08). Patients ≤ 60 years with HCC beyond Milan criteria but a favourable DNA index ≤ 1.5 achieved excellent long-term outcomes, comparable with those of patients within Milan criteria. CONCLUSIONS: Patients ≤ 60 years may undergo LT for HCC with favourable outcomes independently of their tumour burden. Additional assessment of tumour biology, e.g. using the DNA index, especially in this subgroup of patients can support the selection of LT candidates who may derive the most long-term survival benefit, even if Milan criteria are not fulfilled.