Andreas Kohler

@bern university

Clinic for Visceral Surgery and Medicine, Inselspital, Bern University Hospital, Bern, Switzerland

Andreas Kohler


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Scopus Publications

Scopus Publications

  • Shorter residual inferior mesenteric artery stump length on objective CT measurement is associated with improved oncological outcomes in rectal cancer surgery: A propensity score matched analysis
    A. Kohler, M. Khalil, G. J. A. Wilcox, J. L. Byers, J. R. Bundred, D. J. M. Tolan, J. P. Tiernan
    Colorectal Disease, 2025
    Background Studies have suggested little oncological benefit to ‘high‐tie’ resection of the inferior mesenteric artery pedicle in rectal cancer surgery but have all been based on subjective surgical intent rather than objective, quantifiable measurements. In this study, we aimed to assess the level of transection objectively and investigate its influence on long‐term oncological outcomes. Method All patients undergoing elective resection for rectal cancer with curative intent between 2012 and 2020 in a tertiary referral centre were included. IMA stump length was measured on postoperative CT scan and patients categorised as having undergone ‘high tie’ (left colic artery absent and stump <40 mm) resection or ‘low‐tie’ (left colic artery preserved or IMA stump >40 mm) resection. Propensity score matching was undertaken to produce comparable groups and multivariable regression modelling was performed pre‐ and post‐matching. Principal outcome parameters were overall survival and local recurrence‐free survival. Results 466 patients (mean 65.3 years, 33% female) were available for analysis. Mean (SD) IMA stump length was 18 (10) mm in the high‐tie group and 47 (18) mm in the low‐tie group respectively. After propensity score matching, two groups of 152 patients were compared. Multivariable survival analysis showed a significantly better overall (HR 1.84 [1.16–2.93], p = 0.010) and local recurrence‐free (HR 2.23 [1.00–4.97], p = 0.049) survival for patients in the high‐tie group. Conclusion In contrast to other studies, our study has used objective measurements to show an association between central IMA transection and improved oncological outcomes. This association is preserved on multivariable analysis of the propensity score matched cohort.
  • Small and Large Intestine
    Lukas Brügger, Andreas Kohler, Peter Studer, Heather Dawson, Alessandro Lugli, Thomas Cerny, Kirill Karlin, Samantha Dervichian
    Pathomaps Clinical Pathological Overview Charts, 2025
  • Autonomic and circulatory alterations persist despite adequate resuscitation in a 5-day sepsis swine experiment
    Marta Carrara, Pietro Antenucci, Shengchen Liu, Andreas Kohler, Rupert Langer, Stephan M. Jakob, Manuela Ferrario
    Scientific Reports, 2022
    Autonomic and vascular failures are common phenotypes of sepsis, typically characterized by tachycardia despite corrected hypotension/hypovolemia, vasopressor resistance, increased arterial stiffness and decreased peripheral vascular resistance. In a 5-day swine experiment of polymicrobial sepsis we aimed at characterizing arterial properties and autonomic mechanisms responsible for cardiovascular homeostasis regulation, with the final goal to verify whether the resuscitation therapy in agreement with standard guidelines was successful in restoring a physiological condition of hemodynamic profile, cardiovascular interactions and autonomic control. Twenty pigs were randomized to polymicrobial sepsis and protocol-based resuscitation or to prolonged mechanical ventilation and sedation without sepsis. The animals were studied at baseline, after sepsis development, and every 24 h during the 3-days resuscitation period. Beat-to-beat carotid blood pressure (BP), carotid blood flow, and central venous pressure were continuously recorded. The two-element Windkessel model was adopted to study carotid arterial compliance, systemic vascular resistance and characteristic time constant τ. Effective arterial elastance was calculated as a simple estimate of total arterial load. Cardiac baroreflex sensitivity (BRS) and low frequency (LF) spectral power of diastolic BP were computed to assess autonomic activity. Sepsis induced significant vascular and autonomic alterations, manifested as increased arterial stiffness, decreased vascular resistance and τ constant, reduced BRS and LF power, higher arterial afterload and elevated heart rate in septic pigs compared to sham animals. This compromised condition was persistent until the end of the experiment, despite achievement of recommended resuscitation goals by administered vasopressors and fluids. Vascular and autonomic alterations persist 3 days after goal-directed resuscitation in a clinically relevant sepsis model. We hypothesize that the addition of these variables to standard clinical markers may better profile patients’ response to treatment and this could drive a more tailored therapy which could have a potential impact on long-term outcomes.
  • Hepatic blood flow regulation but not oxygen extraction capability is impaired in prolonged experimental abdominal sepsis
    Shengchen Liu, Andreas Kohler, Rupert Langer, Manuel O. Jakob, Lilian Salm, Annika Blank, Guido Beldi, Stephan M. Jakob
    American Journal of Physiology Gastrointestinal and Liver Physiology, 2022
    The capacity to acutely increase hepatic O2 extraction with portal flow reduction is maintained in sepsis with accompanying liver injury, but hepatic blood flow regulation is impaired.
  • Evaluating potential delays and outcomes of patients undergoing surgical resection for locally advanced and recurrent colorectal cancer during a pandemic
    MA Javed, A Kohler, J Tiernan, A Quyn, P Sagar
    Annals of the Royal College of Surgeons of England, 2022
    Introduction The COVID-19 pandemic resulted in a significant disruption of colorectal cancer (CRC) care pathways. This study evaluates the management and outcomes of patients with primary locally advanced or recurrent CRC during the pandemic in a single tertiary referral centre. Methods Patients undergoing elective surgery for advanced or recurrent CRC with curative intent between March 2020 and March 2021 were identified. Following first multidisciplinary team discussion patients were broadly classified into two groups: straight to surgery (n=22, 45%) or neoadjuvant therapy followed by surgery (n=27, 55%). Primary outcome was COVID-19-related complication rate. Results Forty-nine patients with a median age of 66 years (interquartile range: 54–73) were included. No patients developed a COVID-19 infection or related complication during hospital admission. Significant delays were identified in the treatment pathway of patients in the straight to surgery group, mostly due to delays in referral from external centres. Nine of 22 patients in the straight to surgery group had evidence of tumour progression compared with 3 of 27 in the neoadjuvant group (p=0.015839). Seven of 27 patients in the neoadjuvant group showed evidence of tumour regression. During the study, surgical waiting times were reduced, and more operations were performed during the second wave of COVID-19. Conclusion This study suggests that it is possible to mitigate the risks of COVID-19-related complications in patients undergoing complex surgery for locally advanced and recurrent CRC. Delay in surgical intervention is associated with tumour progression, particularly in patients who may not have neoadjuvant therapy. Efforts should be made to prioritise resources for patients requiring time-sensitive surgery for advanced and recurrent CRC.
  • Mesh fixation to fascia during incisional hernia repair results in increased prevalence of pain at long-term follow up: a multicenter propensity score matched prospective observational study
    Andreas Kohler, Joël L. Lavanchy, Rahel Gasser, Roland Wyss, Lars Nowak, Andreas Scheiwiller, Peter Hämmerli, Daniel Candinas, Guido Beldi
    Surgical Endoscopy, 2022
    Background Patient-reported outcomes such as postoperative pain are critical for the evaluation of outcomes after incisional hernia repair. The aim of this study is to determine the long-term impact of mesh fixation on postoperative pain in patients operated by open and laparoscopic technique. Methods A multicenter prospective observational cohort study was conducted from September 2011 until March 2016 in nine hospitals across Switzerland. Patients undergoing elective incisional hernia repair were included in this study and stratified by either laparoscopic or open surgical technique. Propensity score matching was applied to balance the differences in baseline characteristics between the treatment groups. Clinical follow-up was conducted 3, 12 and 36 months postoperatively to detect hernia recurrence, postoperative pain and complications. Results Three-hundred-sixty-one patients were included into the study. No significant differences in hernia recurrence and pain at 3, 12 and 36 months postoperatively were observed when comparing the laparoscopic with the open treatment group. Mesh fixation by sutures to fascia versus other mesh fixation led to significantly more pain at 36 months postoperatively (32.8% vs 15.7%, p = 0.025). Conclusions At long-term follow-up, no difference in pain was identified between open and laparoscopic incisional hernia repair. Mesh fixation by sutures to fascia was identified to be associated with increased pain 36 months after surgery. Omitting mesh fixation by sutures to the fascia may reduce long-term postoperative pain after hernia repair.
  • Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling
    Joel Zindel, Jonas Mittner, Julia Bayer, Simon L. April-Monn, Andreas Kohler, Ysbrand Nusse, Michel Dosch, Isabel Büchi, Daniel Sanchez-Taltavull, Heather Dawson, Mercedes Gomez de Agüero, Kinji Asahina, Paul Kubes, Andrew J. Macpherson, Deborah Stroka, Daniel Candinas
    Nature Communications, 2021
    Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, we show that contamination of gut microbes increases post-surgical adhesion formation. Using genetic lineage tracing we show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis. In conclusion, bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.
  • Smarter medicine: From the diagnosis to the intervention in general and visceral surgery
    Sebastian Winterhalder, Andreas Kohler, Reto Kaderli, Lukas Brügger, Guido Beldi
    Therapeutische Umschau, 2021
    Zusammenfassung. Mehr ist nicht immer ein Plus. Mit diesem Motto eine gemeinsame Entscheidung zu treffen ist der Grundsatz der Smarter Medicine. In der allgemeinen und viszeralen Chirurgie gibt es viele Entscheidungen betreffend der Durchführung einer apparativen Untersuchung oder Therapie, die dem Patienten potenziellen Schaden zuführen können. Es beginnt beim Notfalleintritt, wo auf die Computertomographie bei der Abklärung des akuten Abdomens beim jungen Patienten verzichtet werden könnte. Eine mögliche akute Appendizitis könnte beim jungen gesunden Patienten durch «Watchful Waiting» demaskiert oder möglicherweise eine unnötige Intervention vermieden werden. Kann die akute Cholezystitis oder sogar eine Hohlorganperforation lediglich mit Antibiotika behandelt werden? Kann bei einer schweren Divertikulitis auf eine Operation ganz verzichtet werden? Falls eine Kolonresektion notwendig ist, kann eine direkte Anastomose gesetzt und somit eine zweite Operation verhindert werden? Welche Schilddrüsenknoten müssen nach welcher Untersuchung entfernt werden? Das Management der Erkrankungen im chirurgischen Fachbereich wird mittels evidenzbasierter Medizin im Rahmen der Smarter Medicine massgeblich hinterfragt und stetig neu beurteilt.
  • Tumour budding and CD8+ T cells: ‘attackers’ and ‘defenders’ in rectal cancer with and without neoadjuvant chemoradiotherapy
    Nadine D F Georges, Beatrice Oberli, Tilman T Rau, José A Galván, Iris D Nagtegaal, Heather Dawson, Annika Blank, Andreas Kohler, Alessandro Lugli, Inti Zlobec
    Histopathology, 2021
    AimTumour budding (‘attacker’) and CD8+ T cells (‘defender’) are recognised as important parameters for risk stratification in colon cancers and, combined, may have an even stronger clinical impact. Here, we determine the value of tumour budding and CD8+ in rectal cancer patients treated with/without neoadjuvant therapy.Methods and resultsUsing digital scans of all tumour slides/case, we analysed CD8+ T cell counts in two patient cohorts: 45 neoadjuvantly treated and 47 primarily surgically treated (totalling n = 543 slides) after double‐staining of the surgical resection specimen for pan‐cytokeratin and CD8+. Tumour buds in hot‐spots were manually counted (area = 0.785 mm2) and CD8+ T cell counts were analysed separately both in tumour budding hot‐spots and the densest CD8+ regions throughout the tumour. In neoadjuvantly treated patients, only tumour budding and not CD8+ T cells was associated with tumour features, including more advanced ypT (P = 0.0062), venous invasion (P = 0.002), lymphatic invasion (P = 0.0003) and perineural invasion (P = 0.0017), as well as higher American Joint Committee on Cancer (AJCC) tumour regression score (P = 0.0035), indicating less tumour response. Overall survival was also worse in patients with high‐grade budding in univariate analysis only. In contrast, all three variables, namely tumour budding (P = 0.0347), CD8+ T cells in budding hot‐spots (P = 0.0382) and CD8+ T cells in the densest areas (P = 0.0117) were also associated with worse (budding) and better (CD8) survival time in the multivariate setting.ConclusionIn rectal cancer, tumour budding has clinical relevance in both primarily surgically treated patients and in those with neoadjuvantly treated patients, where it characterises highly aggressive residual disease. CD8+ T cell counts appear not to have prognostic relevance in the neoadjuvant context.
  • LARS is Associated with Lower Anastomoses, but not with the Transanal Approach in Patients Undergoing Rectal Cancer Resection
    Alexandra Filips, Tobias Haltmeier, Andreas Kohler, Daniel Candinas, Lukas Brügger, Peter Studer
    World Journal of Surgery, 2021
    BackgroundLow anterior resection syndrome (LARS) is a defecation disorder that frequently occurs after a low anterior resection (LAR) with a total mesorectal excision (TME). The transanal (ta) TME for low rectal pathologies could potentially overcome some of the difficulties encountered with the abdominal approach in a narrow pelvis. However, the impact of the transanal approach on functional outcomes remains unknown. Here, we investigated the effect of the taTME approach on functional outcomes by comparing LARS scores between the LAR and taTME approaches in patients with colorectal cancer.MethodsWe conducted a retrospective cohort study including 80 patients (n = 40 LAR‐TME, n = 40 taTME) with rectal adenocarcinoma. We reviewed medical charts to obtain LARS scores 6 months after the rectal resection or a reversal of the protective ileostomy.ResultsAt the 6‐month follow‐up, 80% of patients exhibited LARS symptoms (44% minor LARS and 36% major LARS). LARS scores were not significantly associated with the T‐stage, N‐stage, or neo‐adjuvant radiotherapy. The mean distance of the anastomosis from the anal verge was 4.0 ± 2.0 cm. The taTME group had significantly lower anastomoses compared with the LAR‐TME group (median 4.0 cm [IQR1.8] vs. median 5.0 cm [IQR 2.0], p < 0.001). Univariable analysis revealed significantly higher LARS scores in the taTME group compared with the LAR‐TME group (median LARS scores: 29 vs. 25, p = 0.040). However, multivariable regression analysis, adjusting for neo‐adjuvant treatment, anastomosis distance from the anal verge, anastomotic leak rate, and body mass index, revealed no significant effect of taTME on the LARS score (adjusted regression coefficient: − 2.147, 95%CI: − 2.130 to 6.169, p = 0.359). We also found a significant correlation between LARS scores and the distance of the anastomosis from the anal verge (regression coefficient: − 1.145, 95%CI: − 2.149 to − 1.141, p = 0.026).ConclusionFifty percentage of patients in this cohort exhibited some LARS symptoms after a mid‐ or low‐rectal cancer resection. As previously described, LARS scores were negatively correlated with the distance of the anastomosis from the anal verge. TaTME was after adjustment for the height of the anastomosis not associated with higher LARS at 6 months when compared with LAR‐TME.
  • Defense mechanisms to increasing back pressure for hepatic oxygen transport and venous return in porcine fecal peritonitis
    Shengchen Liu, Pedro Paulo Zanella do Amaral Campos, Daniela Casoni, David Berger, Andreas Kohler, Andreas Bloch, David Bervini, Florian Setzer, David R. Cameron, Werner Z'Graggen, Anisa Hana, Rupert Langer, Thiago D. Corrêa, Guido Beldi, Jukka Takala, Stephan M. Jakob
    American Journal of Physiology Gastrointestinal and Liver Physiology, 2020
  • Effectiveness of terlipressin for prevention of complications after major liver resection – A randomized placebo-controlled trial
    Andreas Kohler, Stéphanie Perrodin, Andrea De Gottardi, Daniel Candinas, Guido Beldi
    HPB, 2020
  • Update: Management of colonic diverticulitis
    Andreas Kohler, Peter Studer, Lukas Brügger
    Therapeutische Umschau, 2020
  • Effects of Trendelenburg position and increased airway pressure on hepatic regional blood flow of normal and resected liver
    Shengchen Liu, Per W. Moller, Andreas Kohler, Anisa Hana, Guido Beldi, Dominik Obrist, David Berger, Jukka Takala, Stephan M. Jakob
    Journal of Applied Physiology, 2020
  • Effectiveness of Prophylactic Intraperitoneal Mesh Implantation for Prevention of Incisional Hernia in Patients Undergoing Open Abdominal Surgery: A Randomized Clinical Trial
    Andreas Kohler, Joel L. Lavanchy, Ursina Lenoir, Anita Kurmann, Daniel Candinas, Guido Beldi
    JAMA Surgery, 2019
  • Long-term results of laparoscopic versus open intraperitoneal onlay mesh incisional hernia repair: a propensity score-matched analysis
    Joël L. Lavanchy, Stefan E. Buff, Andreas Kohler, Daniel Candinas, Guido Beldi
    Surgical Endoscopy, 2019
  • Research article liver and biliary tract physiology/pathophysiology portal hyperperfusion after major liver resection and associated sinusoidal damage is a therapeutic target to protect the remnant liver
    Andreas Kohler, Per W. Moller, Sabrina Frey, Pascale Tinguely, Daniel Candinas, Dominik Obrist, Stephan M. Jakob, Guido Beldi
    American Journal of Physiology Gastrointestinal and Liver Physiology, 2019
  • Multi-Operational Selective Computer-Assisted Targeting of hepatocellular carcinoma—Evaluation of a novel approach for navigated tumor ablation
    Pascale Tinguely, Marius Schwalbe, Torsten Fuss, Dominik P. Guensch, Andreas Kohler, Iris Baumgartner, Stefan Weber, Daniel Candinas
    Plos One, 2018
  • Perioperative von Willebrand factor dynamics are associated with liver regeneration and predict outcome after liver resection
    Patrick Starlinger, David Pereyra, Stefanie Haegele, Paul Braeuer, Lukas Oehlberger, Florian Primavesi, Andreas Kohler, Florian Offensperger, Thomas Reiberger, Arnulf Ferlitsch, Barbara Messner, Guido Beldi, Stefan Staettner, Christine Brostjan, Thomas Gruenberger
    Hepatology, 2018
  • Noninvasive assessment of intra-abdominal pressure using ultrasound-guided tonometry: A proof-of-concept study
    Andreas Bloch, Michael Glas, Andreas Kohler, Ulrich Baumann, Stephan M. Jakob
    Shock, 2018
  • Gastrointestinal Impedance Spectroscopy to Detect Hypoperfusion during Hemorrhage
    Andreas Bloch, Andreas Kohler, Horst Posthaus, David Berger, Laura Santos, Stephan Jakob, Jukka Takala, Matthias Haenggi
    Shock, 2017
  • P2X1-regulated IL-22 secretion by innate lymphoid cells is required for efficient liver regeneration
    Ramesh Kudira, Thomas Malinka, Andreas Kohler, Michel Dosch, Mercedes Gomez de Agüero, Nicolas Melin, Stefanie Haegele, Patrick Starlinger, Niran Maharjan, Smita Saxena, Adrian Keogh, Deborah Stroka, Daniel Candinas, Guido Beldi
    Hepatology, 2016
  • Asymptomatic inguinal hernia: is there an indication for surgery
    Andreas Kohler, Guido Beldi
    Therapeutische Umschau Revue Therapeutique, 2014
  • Recurrence after hernia surgery: Complication or natural course?
    A. Kohler, G. Beldi
    Chirurg, 2014