Experimental and Toxicologic Pathology 64 (2012) 133–139 Contents lists available at ScienceDirect Experimental and Toxicologic Pathology jo u rn al h omepage: www.elsevier.de/etp Histopathological features of the brain, liver, kidney and spleen following an innovative polytrauma model of the mouse M.J. Mirzayan a,∗,1 , C. Probst b,1 , M. Samii c , C. Krettek b , A. Gharabaghi d , H.C. Pape e , M. van Griensven f , A. Samii c a Department of Neurosurgery, Medical School Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany b Department of Traumatology, Medical School Hannover, Germany c International Neuroscience Institute Hannover, Germany d Department of Neurosurgery, University of Tuebingen, Germany e Department of Orthopaedic Trauma, University of Pennsylvania, Pittsburgh, USA f Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Vienna, Austria a r t i c l e i n f o Article history: Received 24 November 2009 Accepted 5 July 2010 Keywords: Brain injury Controlled cortical impact Fracture Mouse Neuroprotection Neurotrauma Polytrauma a b s t r a c t Object: Among the various introduced experimental traumatic brain injury models, there is a clear paucity of proper experimental polytrauma models. To overcome this experimental gap we introduced such a polytrauma model in the mouse including traumatic brain injury. Here, we report on the histopathological features of the brain, lung, kidney, spleen and liver. Materials and methods: 20 male C57BL mice with a mean weight of 23 g were anesthetized with ketamine and xylazine. The anaesthetized animals were subjected to a controlled cortical impact (CCI) over the left parieto-temporal cortex using rounded-tip impounder for application of a standardized brain injury. Following fracture of the right femur using a guillotine, a volume-controlled hemorrhagic shock was induced. The control groups included animals with CCI only (n = 20) and animals with femur fracture plus hemorrhagic shock without CCI (n = 20). Subjects were sacrified at 96 h following trauma. Brain, lung, kidney, spleen and liver of the animals underwent histopathological examinations. Results: The mortality rate at 96 h was 25% in the polytrauma group versus 10% in the control groups. Within the histopathological investigations, polytraumatized animals differ from those with a single trauma (traumatic brain injury or femur fracture with hemorrhagic shock) with various severity. Conclusion: The findings of this study show that such a polytrauma model can be standardized resulting in a reproducible damage. This model fulfills the requirements of a standardized animal model. It allows adequate analogies and inferences to the clinical situation of a polytrauma in humans. © 2010 Elsevier GmbH. All rights reserved. 1. Introduction As already mentioned in the first part of this study, polytrauma is deemed to be the most common cause of death in young adults in industrialized nations. Therefore, it has both a medical and a serious socio-economic impact. Despite the improved emergency medical aid, a large number of surviving patients with permanent post- traumatic deficits exists. These patients represent a medical and societal challenge. The survival rate and clinical outcome is often determined by the brain injury. Concomitant peripheral traumas particularly accompanied by shock deteriorate the posttraumatic course (Regel et al., 1993). ∗ Corresponding author. Tel.: +49 176 1532 7474; fax: +49 511 532 68 54. E-mail address: mirzayan@hotmail.com (M.J. Mirzayan). 1 These authors contributed equally to this study. Large numbers of experimental studies on different organs have been introduced to investigate the posttraumatic histopathology. To our best knowledge, such a polytrauma model including trau- matic brain injury, has not been described so far. The scope of this paper is to provide histopathological findigns in the brain, lung, kidney, spleen and liver of such a polytrauma model including traumatic brain injury. 2. Material and methods The experimental procedure has also been described in the first part of this study. 2.1. Animal care The study was approved by the Animal Research Committee of Medical School of Hannover and “Bezirksregierung Niedersachsen”, Nr. 03/672. 0940-2993/$ – see front matter © 2010 Elsevier GmbH. All rights reserved. doi:10.1016/j.etp.2010.07.007