Our paper on "Virtual reality volumetric rendering versus cross-sectional imaging for pancreatic cancer resectability assessment: a pilot randomized controlled reader study" is available here. Authors are K. Eisenträger, K. Saribeyoglu, U. Fehrenbach, M. Felsenstein, L. Timmermann, P.L.M. Pereira, W. Schöning, B. Strücker, J. Pratschke, A. Pascher, T. Malinka, I.M. Sauer, H. Morgul, and M. Queisner.
This study evaluated whether virtual reality (VR) visualization of CT scans improves the assessment of pancreatic cancer resectability compared with conventional cross-sectional imaging (CSI) on 2D screens. Ten hepatopancreatobiliary surgeons assessed twelve CT cases using either VR volumetric rendering or standard CSI. Results showed that CSI outperformed VR. CSI achieved substantial inter-rater agreement (κ = 0.609), whereas VR showed only slight agreement (κ = 0.127). Diagnostic accuracy was also higher with CSI (84.7% vs. 79.7%), particularly for determining resectability (83.3% vs. 58.3%). Surgeons using VR reported lower confidence, while assessment time was similar between the two methods.
Overall, this preliminary study suggests that the tested VR visualization strategy performed worse than conventional imaging. However, previous research indicates that different or hybrid VR visualization approaches may still improve agreement, implying that the specific visualization method—rather than VR technology itself—determines clinical usefulness.

T-cell-mediated rejection (TCMR) remains a major cause of kidney transplant failure, despite being considered treatable. Its impact reflects a limited understanding of the underlying molecular mechanisms and their clinical consequences. To address this, we induced acute TCMR in mouse kidney transplants and profiled molecular changes using single-nucleus RNA sequencing (snRNA-seq), spatial transcriptomics and immunofluorescence. Results were compared with human snRNA-seq data from TCMR and stable allografts, as well as single-cell deconvolution analysis of bulk transcriptomic data from kidney transplant biopsies. Here we show that TCMR induces injured epithelial cell states in mouse kidney allografts, particularly in proximal tubules and thick ascending limbs. Spatial transcriptomics of these injured epithelial states demonstrated heterogeneous localization, interactions with immune cells and cellular microenvironments. Cross-species analysis confirmed similar severely injured epithelial states in human samples, whose abundances correlated with transplant survival and persisted despite TCMR resolution. Collectively, our results identify epithelial injury cell states as a determinant of outcome after TCMR.

The paper entitled "Injured epithelial cell states impact kidney allograft survival after T-cell-mediated rejection." by A.M. Pfefferkorn, L. Jahn, P.T. Gauthier, V.A. Kulow, J. Roeles, N. Müller-Bötticher, L.M.S. Gerhardt, J. Leiz, S. Sarfraz, I. Plumbom, R. Greite, S. Lovric, J. Gamrekelashvili, F. Limbourg, J. Schmitz, J.H. Bräsen, I. Scheffner, I.M. Sauer, F. Aigner, J. Altmüller, T. Conrad, W. Gwinner, N. Ishaque, M. Fähling, K.M. Schmidt-Ott, P.F. Halloran, M.I. Ashraf, and C. Hinze is available in the January 2026 issue of Nature Communications.

L.M. Skrip, L. Boerger, K.A. Walter, A. Arnold, L.A. Böhne, E. Keshi, A.S. Pietsch, N. Raschzok, T.A. Auer, U. Fehrenbach, F. Krenzien, J. Pratschke, I.M. Sauer, J. Guo, J. Braun, M. Tzschätzsch, I. Sack, K.H. Hillebrandt, and S. Moosburner evaluated whether magnetic resonance elastography (MRE) can assess liver graft quality after normothermic machine perfusion (NMP) in the context of liver transplantation. Because of organ shortages, extended criteria donor livers are increasingly used, but factors such as older donor age and prolonged cold ischemia time (CIT) can impair graft quality.
Using a rat liver NMP model, 24 livers underwent 6 or 12 hours of cold ischemia followed by 6 hours of NMP. Ex vivo multifrequency MRE was used to measure liver viscoelastic properties, including the power-law exponent (α) and shear modulus (μ).
Results showed that all liver samples displayed predominantly viscous-fluid characteristics (α > 0.5). The highest α values were found in young livers with short CIT, indicating better tissue properties, while older livers with prolonged CIT had significantly lower α values, suggesting impaired viscoelasticity. Additionally, shear modulus was lowest in young livers with short CIT, distinguishing them from the other groups.
Overall, the findings indicate that extended cold ischemia and older donor age impair liver tissue mechanics even after NMP. MRE may serve as a complementary imaging tool alongside MRI and histological analysis to evaluate liver graft quality during machine perfusion.
The paper "Assessing age and cold ischemia effects on liver tissue viscoelastic properties: Implications for graft quality assessment with MRE during machine perfusion" is available in Journal of the Mechanical Behavior of Biomedical Materials 2026; 175: 107291.

"Lipocalin-2 modulates recipients alloimmune responses to the murine kidney transplants." was published by A.M. Pfefferkorn , R. Fritsche-Guenther, A. Kusch, H. Schwelberger, S. Liu, R. Klopfleisch, Y. Li, R. Catar, S. Liu, F. Aigner, J. Pratschke, I.M. Sauer, and M.I. Ashraf in the December Issue of Frontiers in Immunology 2025.

This study investigated the mechanisms behind the renoprotective effects of recombinant Lipocalin-2 (rLcn2) in kidney transplantation (KTx). Lipocalin-2 is known as an early biomarker for acute kidney injury, delayed graft function, and transplant rejection. Using a mouse kidney transplant model, researchers examined how rLcn2 affects immune responses after transplantation.
Treatment with rLcn2 (Lcn2:Siderophore:Fe³⁺ complex) significantly reduced T-cell activation and frequency, particularly effector memory T cells and their cytotoxic (CD8⁺) and helper (CD4⁺) subsets, in graft tissue, lymphoid organs, and blood by postoperative day 7. In graft-infiltrating CD8⁺ T cells, rLcn2 also reduced cytotoxic activity, including lower degranulation capacity and decreased interferon-γ and perforin expression, as well as fewer NKG2D⁺ activated cytotoxic T cells. Effects on innate immune cells were limited and selective, affecting only some neutrophils, macrophages, and NK cell subsets.
Importantly, rLcn2 did not influence inflammation or tissue injury in syngeneic (non-alloimmune) transplants, indicating that its protective effect is primarily through modulation of adaptive immune responses, particularly T-cell activity.
Overall, the findings suggest that rLcn2 improves kidney graft outcomes by selectively suppressing alloimmune T-cell responses rather than altering non-immune injury pathways.

The anatomical complexity of the thyroid region presents significant challenges in surgical training, particularly regarding the identification and preservation of the recurrent laryngeal nerve and parathyroid glands. We present a prototype of a virtual reality simulator designed to support thyroidectomy training by enabling the immersive, interactive exploration of CT-derived, deformable anatomical models in a photorealistic operating room environment. Structures not detectable in CT, such as nerves and glands, were manually integrated. The simulator was evaluated qualitatively by three surgeons using a structured questionnaire. Feedback indicated high usability, visual realism, and potential for improving anatomical recognition skills. Limitations include the absence of instrument interaction, haptic feedback, and full procedural simulation. This prototype demonstrates feasibility and outlines a clear development roadmap toward a high-fidelity, scalable training platform for endocrine surgery.

The paper "Prototype of a Virtual Reality Simulator for Thyroidectomy: A Proof of Concept." by K. Eisentraeger, E.M. Dobrindt, M. Queisner, C. Remde, I.M. Sauer, J. Pratschke, M. Mogl, F. Butz, and C. Müller-Debus was published in Cureus Journal of Medical Science. 2025;17(9):e92724

Today Agnes Klara Böhm successfully defended her doctoral thesis entitled "Multidimensional analysis of different decellularization methods for diaphragmatic extracellular matrices in a murine model" summa cum laude!

Congratulations !

Prof. Dr. Nathanael Raschzok received a grant of € 1.85 million for the first three years from the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) for the Pilot, open, prospective, randomized, multicenter trial on expanding the donor pool by quality assessment of liver grafts declined for transplantation by normothermic ex vivo liver perfusion – ExTra. Co-applicants and/or significantly involved in the preparation of the study were Prof. Dr. Johann Pratschke, Prof. Dr. Igor M. Sauer, Prof. Dr. Dominik Modest, and Priv.-Doz. Dr. Simon Moosburner.

Liver transplantation in Germany is severely limited by a critical shortage of acceptable grafts and a high mortality rate on the waiting list. Furthermore, a significant number of organs are declined due to quality concerns. As demonstrated in pilot studies in the UK, Netherlands, Australia, and the United States, declined liver grafts can and should be used for transplantation after quality assessment by normothermic ex vivo liver machine perfusion (NMP).

The ExTra trial is a randomized controlled trial with a specific focus on patients with a model for end-stage liver disease (MELD) score ≤25 that are not eligible for (non)standard MELD exceptions. This cohort of patients faces an unacceptably long wait time for transplantation, which increases their mortality risk while on the waitlist. The ExTra trial aims to demonstrate that the time-to-transplant for these patients is shortened through the use of grafts that were initially declined for transplantation but fulfill specified quality criteria on normothermic ex vivo machine perfusion assessment. A total of 186 patients will be randomized in a 1:1 fashion to the experimental arm, which consists of a 12-month option to receive a liver graft that was declined by all German transplant centers but meets specified quality criteria, in addition to listing for liver transplantation through the standard allocation process. The control arm will consist of patients who are waitlisted for liver transplantation through the standard allocation process. Liver grafts that have been declined for transplantation must meet specific quality criteria. These include a maximum of 60% macrovesicular steatosis, no fibrosis greater than stage F3, and no cirrhosis. In line with previously published viability criteria for initially declined liver grafts, the decision to use or decline the graft will be made at least four hours after the start of perfusion.

The ExTra trial aims to show that by expanding the donor pool to include the ExTra option of non-transplantable organs, which appear to be usable after machine perfusion, patients without a high MELD score can be transplanted significantly faster. The ExTra trial is thus the first study worldwide in which this concept will be investigated in a randomized clinical trial. The study should make an important contribution to expanding the donor pool for liver transplants and thus ultimately help all patients on the waiting list for liver transplantation.