Background. Several viability tests, including lactate clearance and bile production, are used to evaluate livers during normothermic machine perfusion (NMP). However, specific cutoff values and therapeutic consequences vary significantly. The noninvasive 13C-methacetin liver function breath test (LiMAx) was developed to measure the actual liver function capacity. This might also provide useful insights into graft function during NMP. Methods. Therefore, we used an established porcine model of prolonged static cold storage (pSCS) and subsequent NMP for additional functional monitoring with the LiMAx test. Livers obtained from 9 pigs underwent NMP for 6 h directly after procurement (control group) or after 20 h of SCS (pSCS). After 6 h of NMP, the LiMAx test was performed using a liver weight-adjusted dose of 13C-methacetin. Results. After pSCS, transaminase and cholestasis parameters were found to be elevated in the perfusate and reduced lactate clearance was measured. Bile analyses further revealed reduced bile production and elevated glucose concentrations. In line with these results, the LiMAx test also showed significantly reduced values compared with the control group, with a mean value of 57.0 µg/kg/h compared with 182.0 µg/kg/h in the control group (P = 0.032). Conclusions. Therefore, we suggest the LiMAx test as a novel diagnostic tool for evaluating donor organs during NMP.

Zusammenfassung Hintergrund Analog zu anderen Fachdisziplinen hat auch die digitale HNO-Heilkunde-Lehre deutliche Fortschritte während der Pandemiezeit verzeichnen können. So waren die HNO-Kliniken bundesweit vergleichsweise zeitig in der Lage, ein komplettes virtuelles Lehrangebot, auch unter Einsatz von innovativen Formaten, aufzubieten. Dies wurde entsprechend in studentischen Lehrevaluationen gewürdigt. Durch den zwischenzeitlich vermehrten Einsatz der virtuellen Realität (VR) in der Lehre sollte eine höhere Zufriedenheit durch eine Verbesserung der Lehrqualität zu erwarten sein. Material und Methoden Es wurden Studierende (n = 180) nach Absolvierung des HNO-Blockpraktikums im Sommersemester 2023 mittels standardisiertem Fragenbogen befragt. Ziel der Evaluation war es, die Zufriedenheit und die Einschätzung der Effektivität der neu implementierten Methode VR zu ermitteln. Die VR wurde zur Vermittlung der Ohranatomie und der Koniotomie eingesetzt. Vergleichend wurde die VR mit den Inhalt Koniotomie auch bei Assistenzärzt:innen eingesetzt und evaluiert. Ergebnisse Die Lehrveranstaltung wurde mit einem Mittelwert von 11,7 auf einer Punkteskala bis 15 (wie in der Oberstufe der Schulen) von den Studierenden positiv wahrgenommen. Die Effektivität und der Stellenwert des Einsatzes der VR im HNO-Lernportfolio wurden von den Studierenden unterschiedlich bewertet und fand nicht den erwarteten uneingeschränkten Zuspruch. Anders gestaltete sich die Beurteilung bei den Assistenzärzt:innen. Schlussfolgerung Die VR stellt einen innovativen und vielseitigen Baustein im Lehrportfolio der HNO-Heilkunde dar. Diese neue Lehrmethode wird als zukunftsorientiertes Tool angesehen und akzeptiert. Dabei votierten die beteiligten Ärzte durchweg positiv, während die Studierenden im individuellen und subjektiven Bereich eher kritische Beurteilungen abgaben und Limitationen aufzeigten. Dies steht im Gegensatz zu den von den Interessenvertretungen der Studierenden geforderten Weiterentwicklung innovativer Lehrmethoden.

Background Analogous to the situation in other disciplines, digital ENT teaching made significant progress during the pandemic. Most ENT clinics nationwide were able to offer a complete virtual teaching program in time. Innovative teaching methods were also used early on. This was recognized in student teaching evaluations. Due to the expansion of virtual reality (VR) in medical teaching, even greater satisfaction should be expected through improved teaching quality. Materials and methods Surveys were performed with students (n = 180) of the ENT block internship in the summer semester of 2023. The aim of the evaluation was to determine the students' satisfaction with and subjective effectiveness of the newly implemented VR digital teaching method for teaching ear anatomy and coniotomy. A survey was also carried out among resident physicians. Results The ENT teaching was perceived favorably by the students, with an average rating of 11.7 out of 15. The learning effectiveness and the value of VR in the ENT learning portfolio was evaluated varyingly by the students. The physicians' assessment was different, with a more positive perception. Conclusion Virtual reality represents an innovative component in the teaching portfolio of otolaryngology. This new teaching method is viewed and accepted as a future-oriented tool. Remarkably, the physicians involved voted consistently positively, while the students gave more critical assessments and pointed out limitations in the individual and subjective areas. These findings are in contrast to the further development of innovative teaching methods demanded by student interest groups.

BACKGROUND:The study aimed to assess the impact of different training modalities on otoscopy performance during a practical exam using a high-fidelity simulator and to determine if objective evaluation of otoscopy is feasible using a simulator that records insertion depth and tympanic membrane coverage.METHODS:Participants were assigned to one of four groups: control and three intervention groups with varying training approaches. Participants received otoscopy training and then were assessed through a practical exam on a high-fidelity simulator that uses virtual reality to visualize the ear canal and middle ear. Performance was evaluated using a modified Objective Structured Assessment of Technical Skills checklist and Integrated Procedural Performance Instrument checklist. Insertion depth, tympanic membrane coverage, and correct diagnosis were recorded. Data were tested for normal distribution using the Shapiro-Wilk test. One-way ANOVA and, for non-normally distributed data, Kruskal-Wallis test combined with Dunn's test for multiple comparisons were used. Interrater reliability was assessed using Cohen's κ and Intraclass correlation coefficient.RESULTS:All groups rated their training sessions positively. Performance on the OSATS checklist was similar among groups. IPPI scores indicated comparable patient handling skills. The feedback group examined larger tympanic membrane areas and had higher rates of correct diagnosis. The correct insertion depth was rarely achieved by all participants. Interrater reliability for OSATS was strong. IPPI reliability showed good correlation.CONCLUSION:Regardless of training modality, participants perceived learning improvement and skill acquisition. Feedback improved examination performance, indicating simulator-guided training enhances skills. High-fidelity simulator usage in exams provides an objective assessment of performance.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death and the fifth most common kind of cancer worldwide. Anti-cancer immune responses are often hampered by upregulation of co-inhibitory receptors on the surface of CD8 T-cells accompanied by reduced T-cell functionality, described as T-cell-exhaustion. We have utilized the Sleeping beauty" (SB)/transposon system for the development of an autochtonous HCC mouse model. Using adoptive T-cell transfer allowed us in-depth phenotyping of tumor-specific CD8 T-cells and we could demonstrate upregulation of co-inhibitory receptors, including PD-1 and TIM-3 on the T-cell surface. The tumor-specific CD8 T-cells also showed a reduced IFNγ expression, indicating T-cell exhaustion. We have performed the first whole transcriptome microarray analysis of tumor-specific CD8 T-cells in a murine autochthonous liver cancer model, that allowed us to compare the mRNA profiles of naive, functional effector and exhausted tumor-specific CD8 T-cells. Transcriptomic data was analyzed for identification of candidate genes and pathways that play a role in T-cell exhaustion. Particularly, the substantial upregulation of TIGIT suggested the involvement of this inhibitory T-cell receptor in T-cell exhaustion in liver cancer. Utilization of immune checkpoint-blockade against TIGIT in combination with PD-1 inhibition prolonged survival of tumor-bearing mice, compared to anti-PD-1-monotherapy. We could further verify the expression of TIGIT on tumor-infiltrating CD8 T-cells in HCC-patients. Our results suggest that TIGIT is involved in the appearance of T-cell exhaustion in human HCC and presents a potential target for combination treatment by immune checkpoint blockade.

Objective: The acquisition of surgical skills requires motor learning. A special form of this is intermanual transfer by transferring motor skills from the nondominant hand (NDH) to the dominant hand (DH). The purpose of this study was to determine the learning gains that can be achieved for the DH by training with the DH, the NDH, and by non-surgical alternative training (AT). Methods: 124 preclinical (n=62) and clinical (n=62) dental students completed surgical knot tying and suturing technique training with the DH, with the NDH, and an AT in a controlled randomized trial. Results: A statistically significant learning gain in knot tying and suture technique with the DH was evident only after training with the DH when compared to training with the NDH (p<0.001 and p=0.004, respectively) and an AT (p=0.001 and p=0.010, respectively). Of those students who achieved a learning gain ≥4 OSATS points, 46.4% (n=32) benefited in their knot tying technique with the DH from training with the DH, 29.0% (n=20) from training with the NDH, and 24.6% (n=17) from an AT while 45.7% (n=32) benefited in their suturing technique with the DH from training with the DH, 31.4% (n=22) from training with the NDH, and 22, 9% (n=16) from an AT. Conclusions: Training with the DH enabled significantly better learning gains in the surgical knot tying and suturing techniques with the DH.

Zusammenfassung Hintergrund Die Facharztweiterbildung ist häufig durch lokal geprägte Weiterbildungsschwerpunkte bestimmt, was zu einem heterogenen Weiterbildungsergebnis führen kann. Repetitorien vor Facharztprüfungen könnten dies harmonisieren. Ziel der Arbeit Ziel ist die Darstellung eines Qualitätssicherungssystems zur Bewertung eines Repetitoriums für HNO-Facharztkandidaten. Material und Methoden Die Lehreinheiten eines in Präsenz durchgeführten Facharztrepetitoriums wurde mittels Fragebogen evaluiert. Sowohl eine deskriptive Auswertung als auch eine multivariable binär-logistische Regressionsanalyse wurden durchgeführt. Zur Evaluation der Faktoren, die zu einer negativen Wahrnehmung einer Lehreinheit führen, erfolgte eine Fokussierung auf die schlechtesten 15 % aller Gesamtbewertungen. Für ein individuelles Dozentenfeedback wurde exemplarisch ein Stärken-Schwächen-Profil eines Dozenten erstellt. Ergebnisse Die Auswertung der Evaluationsergebnisse zeigte eine durchschnittlich sehr gute Gesamtbewertung von 12,8 (±2,4) bei maximal 15 möglichen Punkten. Die multivariable Regression bestimmte die Items „Freundlichkeit“, „Systematischer Aufbau“, „Eigene Mitarbeit“, „Vorwissen“ und „Unterrichtseinheit effizient“ als maßgeblich für eine Negativwahrnehmung einer Lehreinheit. Anhand des Dozentenprofils lassen sich in einer objektiven Form die Stärken und Schwächen des individuellen Dozenten aufzeigen. Schlussfolgerung Der entwickelte Fragebogen bildet eine gute Möglichkeit zur Qualitätssicherung einer Lehrveranstaltung in der Weiterbildung. Diese erfolgt zum einen über die Regressionsanalyse aller Fragebögen, zum anderen über die Erstellung eines individuellen Dozentenprofils, welches eine objektive Grundlage zur Verbesserung der einzelnen Lehreinheit durch ein detailliertes Feedback an den Dozenten ermöglicht.

BACKGROUND AND AIMS:Programmed death 1 (PD-1) checkpoint inhibition has shown promising results in patients with hepatocellular carcinoma, inducing objective responses in approximately 20% of treated patients. The roles of other coinhibitory molecules and their individual contributions to T-cell dysfunction in liver cancer, however, remain largely elusive.APPROACH AND RESULTS:We performed a comprehensive mRNA profiling of cluster of differentiation 8 (CD8) T cells in a murine model of autochthonous liver cancer by comparing the transcriptome of naive, functional effector, and exhausted, tumor-specific CD8 T cells. Subsequently, we functionally validated the role of identified genes in T-cell exhaustion. Our results reveal a unique transcriptome signature of exhausted T cells and demonstrate that up-regulation of the inhibitory immune receptor T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitor motif domains (TIGIT) represents a hallmark in the process of T-cell exhaustion in liver cancer. Compared to PD-1, expression of TIGIT more reliably identified exhausted CD8 T cells at different stages of their differentiation. In combination with PD-1 inhibition, targeting of TIGIT with antagonistic antibodies resulted in synergistic inhibition of liver cancer growth in immunocompetent mice. Finally, we demonstrate expression of TIGIT on tumor-infiltrating CD8 T cells in tissue samples of patients with hepatocellular carcinoma and intrahepatic cholangiocarcinoma and identify two subsets of patients based on differential expression of TIGIT on tumor-specific T cells.CONCLUSIONS:Our transcriptome analysis provides a valuable resource for the identification of key pathways involved in T-cell exhaustion in patients with liver cancer and identifies TIGIT as a potential target in checkpoint combination therapies.

BACKGROUND:Residency training is often characterized by locally influenced training content and focus, which can lead to heterogeneous training outcomes. Refresher courses before the speciality certificate examinations can harmonize the situation. OBJECTIVE:The current publication aims to present a quality management system for evaluation of a postgraduate refresher course for otolaryngology residents. MATERIALS AND METHODS:The teaching sessions of a postgraduate course were evaluated using questionnaires. Descriptive statistics and multivariable binary logistic regression analysis were performed. To evaluate the factors leading to a negative perception of a teaching session, the focus was set on the worst 15% of all total ratings. An exemplary strength/weakness profile of a lecturer was created for individual feedback. RESULTS:Analysis of the evaluation results showed an overall average rating of 12.8 (±2.4) out of a maximum of 15 possible points. Multivariable regression determined the items "friendliness," "systematic structure," "own involvement," "prior knowledge," and "efficient teaching session" to be significant for a negative perception of a teaching session. Using the lecturer profile, the strengths and weaknesses of the individual lecturer can be shown in an objective manner. CONCLUSION:The developed questionnaire represents a good tool for quality management of a postgraduate refresher course for otolaryngology residents. This is achieved by regression analysis and creation of an individual lecturer profile, which provides an objective basis for improving the individual teaching session through detailed feedback to the lecturer.

Clinical xenotransplantation will only be feasible when present limitations can be controlled sufficiently. Activation of endothelium and complement as well as coagulopathy and thrombotic microangiopathy (TMA) is important barriers. Transgenic expression of hTBM on porcine endothelial cells is a reasonable approach to reduce activation of haemostasis. Endothelial cells from wild-type pigs as well from pigs expressing hTBM alone or in combination with hCD46 and knockout of the alpha-1,3,-galactosyltransferase (GTKO) were perfused with platelet-rich plasma in a microfluidic flow chamber. Platelet aggregation and activation, coagulation, complement and endothelial cell activation were assessed. Perfusion of wild-type porcine aortic endothelial cells (PAEC) resulted in distinct platelet aggregation. Expression of hTBM in either mono-transgenic or triple-transgenic (GTKO/hCD46/hTBM) PAEC showed significantly reduced or absent platelet aggregation. Flow cytometric analysis of platelets showed an increased CD62P expression in wild-type PAEC and significantly reduced expression in mono- or triple-transgenic PAEC. Activation of coagulation measured by TAT occured in WT PAEC and was clearly reduced in hTBM and GTKO/hCD46/hTBM PAEC. Activation of complement and endothelial cells was only reduced in GTKO/hCD46/hTBM but not in PAEC expressing hTBM alone. Expression of hTBM was able to prevent activation of coagulation and platelet aggregation in mono- and triple-transgenic PAEC, while activation of complement and endothelial cells was not reduced in mono-transgenic PAEC.

Background Students’ ratings of bedside teaching courses are difficult to evaluate and to comprehend. Validated systematic analyses of influences on students’ perception and valuation of bedside teaching can serve as the basis for targeted improvements. Methods Six hundred seventy-two observations were conducted in different surgical departments. Survey items covered the categories teacher’s performance, student’s self-perception and organizational structures. Relevant factors for the student overall rating were identified by multivariable linear regression after exclusion of variable correlations > 0.500. The main target for intervention was identified by the 15% worst overall ratings via multivariable logistic regression. Results According to the students the success of bedside teaching depended on their active participation and the teacher’s explanations of pathophysiology. Further items are both relevant to the overall rating and a possible negative perception of the session. In comparison, negative perception of courses (worst 15%) is influenced by fewer variables than overall rating. Variables that appear in both calculations show slight differences in their weighing for their respective endpoints. Conclusion Relevant factors for overall rating and negative perception in bedside teaching can be identified by regression analyses of survey data. Analyses provide the basis for targeted improvement.

Background: The ante situm-technique allows for luxation of the liver in front of the situs, enabling the experienced HPB-surgeon to resect liver malignancies invading the hepatic veins/inferior vena cava. Single-center experience with ante-situm liver resection over the past 10 years is presented. Methods: Retrospective analysis on patients receiving ante situm liver resection comprising demographical and basic clinical data as well as perioperative courses. Results: Ante situm liver resection was performed on 7 patients suffering from primary (n=5) or secondary (n=2) liver tumors. Patients received trisegmentectomy (n=4), extended left hemihepatectomy (n=1) or atypical liver resection (segments 8/4a; n=2) combined with dissection of the suprahepatic vena cava/liver veins. Venous reconstruction was performed as reinsertion of liver veins (n=3) or vascular replacement with allogeneic donor veins (n=3) or PTFE-graft (n=1) in total vascular occlusion (mean of 29.6 min.). Severe morbidity defined as Dindo Clavien >3a was found in 3 patients; one patient died due to small-for-size syndrome. Mean length of stay at ICU and hospital were 9.0 and 34.3 days, respectively. R0-resection was achieved in 5 cases (twice a R1-situation). Disease-free survival was 24.6 months with an overall survival of 34.4 months. Conclusion: Ante situm liver resection offers the opportunity to achieve surgical cure in otherwise unresectable tumors. Nevertheless, this approach remains challenging with need for complex vascular reconstruction.

Background: ALPPS has been described as a promising method to increase the resectability of liver tumors. Optimal timing of hepatectomy at the point of sufficient hypertrophy of the future liver remnant (FLR) is essential for the morbidity and mortality of this procedure. The recently developed LiMAx-test can be applied to monitor postoperative liver function and hence might represent a useful tool for decision-making regarding the timing of the second step of ALPPS. Methods: A 73-year-old female patient presented with metachronous colorectal liver metastasis comprising the complete right liver lobe as well as segment IV. Due to an insufficient FLR (19.3%) and a low FLR: body weight ratio (0.28%) the decision was made to perform ALPPS. Results: Despite a formally sufficient increase of the FLR to 30.8% within 7 days after the first step of ALPPS, the liver function was seen to only slowly increase as expressed by a LiMAx value of 245 μg/h/kg. By means of the LiMAx-test, sufficient increase of liver function eventually was detected by postoperative day 11 (LiMAx value of 371 μg/h/kg; FLR 35.2%) so that second step of ALPPS was performed with no signs of liver failure during further clinical course. Conclusion: Applying LiMAx during ALPPS, we have found a significant difference between increase in volume and function of the FLR. LiMAx hence might proof valuable for application in two-stage liver resection to avoid postoperative small-for-size syndrome.

During pig-to-primate xenotransplantation or perfusion of porcine organs with human blood, a xenogeneic coagulopathy with consecutive development of thrombotic microangiopathy (TMA) can be observed. The aim of this study was to elucidate the influence of the reduction of xenoreactive natural antibodies on the coagulopathy using an ex vivo perfusion system. Thirteen perfusion experiments using landrace wild-type porcine kidneys were performed in three different experimental groups: autologous, xenogeneic, and immunoadsorption. During and after perfusion, blood and tissue samples were collected to assess markers of coagulation, complement, inflammation, and endothelial activation. Immunoadsorption prior to perfusion did not prolong perfusion time (174 min ±28) compared to xenogeneic (182 min ±22) experiments, whereas autologous perfusion was possible for maximum of 240 min in all experiments. Activation of coagulation was similar comparing perfusions after immunoadsorption (D-Dimer 24 186 μg/l ±5813; TAT 566 μg/l ±34) to xenogeneic (D-Dimer 22 175 μg/l ±7826, TAT 600 μg/l ±0) experiments. But antibody-mediated complement activation was reduced in the immunoadsorption group. TNF-alpha and markers of endothelial cell activation were lower in the immunoadsorption group compared to the xenogeneic experiments. In this ex vivo perfusion model, we observed that marked removal of xenogeneic antibodies can reduce complement activation via the classical pathway as well as endothelial cell activation and inflammation. Immunoadsorption cannot prevent the activation of the terminal complement cascade and coagulation.

Hepatocyte transplantation is a promising therapeutic approach for various liver diseases. Despite the liver's tolerogenic potential, early immune‐mediated loss of transplanted cells is observed, and longterm acceptance has not been achieved yet. Patients deemed tolerant after liver transplantation presented an increased frequency of regulatory T cells (Tregs), which therefore also might enable reduction of posttransplant cell loss and enhance longterm allograft acceptance. We hence characterized hepatocyte‐induced immune reactions and evaluated the immunomodulatory potential of Tregs applying mixed lymphocyte cultures and mixed lymphocyte hepatocyte cultures. These were set up using peripheral blood mononuclear cells and primary human hepatocytes, respectively. Polyclonally expanded CD4+CD25highCD127low Tregs were added to cocultures in single‐/trans‐well setups with/without supplementation of anti‐interferon γ (IFNγ) antibodies. Hepatocyte‐induced alloresponses were then analyzed by multicolor flow cytometry. Measurements indicated that T cell response upon stimulation was associated with IFNγ‐induced major histocompatibility complex (MHC) class II up‐regulation on hepatocytes and mediated by CD4+ T cells. An indirect route of antigen presentation could be ruled out by use of fragmented hepatocytes and culture supernatants of hepatocytes. Allospecific proliferation was accompanied by inflammatory cytokine secretion. CD8+ T cells showed early up‐regulation of CD69 despite lack of cell proliferation in the course of coculture. Supplementation of Tregs effectively abrogated hepatocyte‐induced alloresponses and was primarily cell contact dependent. In conclusion, human hepatocytes induce a CD4+ T cell alloresponse in vitro, which is associated with MHC class II up‐regulation on hepatocytes and is susceptible to suppression by Tregs. Liver Transplantation 24 407–419 2018 AASLD.

Treatment of malignancies invading the hepatic veins/inferior vena cava is a surgical challenge. An ante situm technique allows luxation of the liver in front of the situs to perform tumor resection. Usually, cold perfusion and veno-venous bypass are applied. Our experience with modified ante situm resection relying only on total vascular occlusion is reported.

Background and objectives: This study evaluates predictive factors for observed long-term survival of more than 5 and 10 years for patients after liver resection for hepatocellular carcinoma and compares their life expectancy to the normal national population matched for sex, year of birth and age at resection.Methods: 230 patients after primary liver resection for HCC (01.01.1995-31.12.2004) were analyzed. Multivariable logistic regression models were determined based on Cox regression results and their prognostic capability evaluated with areas under the receiver operating characteristic curve (AUROCs).Results: Life years after surgery in deceased patients compared to the normal national population matched for sex, year of birth and age at resection was reduced by median 21.7 years. Independent predictive factors for 10-year survival were age at resection (p < 0.001; OR = 0.898; 95%-CI: 0.846 -0.954), UICC 7 tumor staging (p = 0.003; OR = 0.344; 95%-CI: 0.126-0.941) and ASAT (GOT) in U/l divided by Quick in percent multiplied by the extent of liver resection graded in points labelled as the resection severity index (p < 0.001; OR = 0.136; 95%-CI: 0.022-0.843) enabling prediction of 10-year survival with an AUROC of 0.884. The same factors plus revision surgery (yes/no) predict 5-year survival (AUROC 0.736).Conclusions: Liver resection enables predictable long-term survival >5 and >10 years. The proposed resection severity index quantifies the prognostic relevance of liver cellular damage, synthesis and loss of parenchyma for long-term survival. (C) 2017 Elsevier Ltd. All rights reserved.