Minimally Invasive Therapy. 2013; Early Online, 1–6 ORIGINAL ARTICLE Liver displacement during ventilation in Thiel embalmed human cadavers – a possible model for research and training in minimally invasive therapies ROOS EISMA 1 , MARIANA GUEORGUIEVA 2 , ERWIN IMMEL 2 , RACHEL TOOMEY 2 , GRAEME MCLEOD 3 , ROGER SOAMES 1 , ANDREAS MELZER 2 1 Centre for Anatomy and Human Identification (CAHID), College of Life Sciences, University of Dundee, Dundee, UK, 2 Institute for Medical Science and Technology (IMSAT), University of Dundee, Dundee, UK, and 3 Institute of Academic Anaesthesia, University of Dundee, Dundee, UK Abstract Respiration-related movement of organs is a complication in a range of diagnostic and interventional procedures. The development and validation of techniques to compensate for such movement requires appropriate models. Human cadavers embalmed with the Thiel method remain flexible and could provide a suitable model. In this study liver displacement during ventilation was assessed in eight Thiel embalmed cadavers, all of which showed thoracic and abdominal motion. Four cadavers displayed realistic lung behaviour, one showed some signs of pneumothorax after prolonged ventilation, one had limited filling of the lungs, and two displayed significant leakage of air into the thorax. A coronal slice containing the largest section through the liver was imaged with a real-time Fast Gradient Echo (FGR) MRI sequence: Craniocaudal displacement of the liver was then determined from a time-series of slices. The maximum liver displacement observed in the cadavers ranged from 7 to 35 mm. The ventilation applied was comparable to tidal breathing at rest and the results found for liver displacement are similar to values in the literature for respiratory motion of the liver under similar conditions. This indicates that Thiel embalmed cadavers have potential as a model for research and training in minimally invasive procedures. Key words: Cadaver model, respiration, liver displacement Introduction Organ movement related to respiration is a complica- tion in a range of diagnostic and interventional procedures, affecting the accuracy and efficacy of radiotherapy and focused ultrasound, either by including surrounding tissues in the treatment area or by excluding the intended target during certain phases of the respiratory cycle (1,2). Respiratory motion can also cause artefacts in CT and MR imaging, as well as affect needle or instrument placement during percutaneous minimally invasive procedures (3). A number of techniques can be used to compensate such movements (1,3). Breath-holding approaches aim to reduce organ movement; respiratory gating limits treatment to a set phase in the respiratory cycle, while tracking methods attempt to move the focus of the intervention with the organ. Gating and tracking methods can be underpinned by real- time tracking of the organ or by modelling to predict organ position. The development and validation of such techniques requires appropriate models. Clinical trials are regu- lated to ensure safety of participants and robustness of the proposed study. Preclinical tests on models allow the identification of weaknesses to improve the product, as well as collecting evidence for taking the product forward to clinical trials. Models are also a valuable tool for training once a product or procedure has been approved. Ideally, a model will provide an accurate and lifelike representation of human anatomy, be ethically sound and uncontroversial, present few Correspondence: R. Eisma, Centre for Anatomy and Human Identification, University of Dundee, Dundee DD1 5EH, UK. Fax: +44 01382 386817. E-mail: r.eisma@dundee.ac.uk ISSN 1364-5706 print/ISSN 1365-2931 online Ó 2013 Informa Healthcare DOI: 10.3109/13645706.2013.769451 Minim Invasive Ther Allied Technol Downloaded from informahealthcare.com by University of Dundee on 03/27/13 For personal use only.