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Shorter working hours and shift systems are limiting trainee clinical experience. Essential technical skills are being developed in environments other than the operating theatre. The ideal model for regional anaesthesia training should simulate the passive and dynamic components of nerve block such as nerve anatomy, needle movement, fascial penetration, perineural fluid injection, and inadvertent intraneural and intravascular injection. A new development in regional anaesthesia simulation is the Thiel embalmed cadaver, preserved using a novel technique which minimizes formaldehyde use, enables full flexibility of the limbs, and is compatible with ultrasound imaging, unlike cadavers preserved conventionally. As the University of Dundee is the first to introduce Thiel cadavers to the UK, an opportunity existed to evaluate the visibility of anatomical structures during cadaver regional anaesthesia. The interscalene axillary, femoral, and popliteal nerves were scanned at 2, 3, 5, 8, 11, and 14 weeks after embalming. Scanning of all nerves was performed with a 10-5 MHz linear probe using a self-optimization facility. Once the best image site was identified, 1 ml of Thiel moistening solution was injected around each nerve, and a 30 s video recording made. Visibility of nerves, muscle, fascia, blood vessels, and needle passage was ranked using a seven-point ordinal scale. Rater agreement was assessed using the intraclass correlation. In addition, nerve visibility was assessed with the Vienna score, an ordinal scale from 1 to 4, the spread of solution measured as the log area under the curve of spread using ultrasound elastography (log AUC), and Zone Speed Index (ZSI). Distribution of data used the Shapiro- Wilk test, parametric data were analysed by the t-test (SD), non-parametric with Mann-Whitney, and paired comparisons with the Wilcoxon signed-rank test. Correlation of data used Pearson's and Spearman's test as appropriate. Results are presented for the interscalene block. All blocks were performed on the left side of the body. Full rotation of the neck was possible. Mean (SD) distance from the skin was 1.2 (0.3) cm. With regard to ultrasound image quality, mean (SD) visibility score for scalenus anterior was 5 (0.9), scalenus medius 4.8 (1.2), sternocleidomastoid 5.3 (0.8), and nerve roots 5.2 (1.2). Median (IQR) Vienna score for nerve roots was 2.5 (2-3). With regard to nerve block, mean (SD) needle visibility was 2.8 (1.2), needle tip visibility 1.3 (0.5). There was a difference in median (IQR) visibility of spread for B-mode ultrasound 4.5 (3-5) and elastography 7 (6.25-7), P¼0.04. This pilot study of Thiel cadavers has shown good image quality of nerves, muscle, and vasculature over an initial 12 week period. Subjective visibility scores correlated well with elastography and Zone Speed Index. On the basis of these findings, the Thiel cadaver should be considered. [ABSTRACT FROM AUTHOR]

Introduction: Thiel soft-embalmed human cadavers are increasingly being used as a model to train surgeons and anesthetists because they look and feel like patients. However, there is a need to validate quantitatively the tissue properties of this model. Thus, the main objective of this study was to measure the elasticity of tissue in the Thiel soft-embalmed cadaver, using results in the literature for human volunteers for comparison., Materials and Methods: Two independent ultrasound-trained operators measured the elasticity (Youngs modulus), E, of the thyroid, parotid and submandibular glands, the gastrocnemius and masseter muscles and the supraspinatus tendon in six Thiel soft-embalmed human cadavers using quantitative shear wave elastography. Each measurement was repeated 10 times. The elasticity values of Thiel soft-embalmed human cadavers were compared with human values reported in the literature. The relationship between elasticity and gender, age at death and number of days after embalming was also investigated., Results: Elasticity data for the cadavers displayed similar patterns as in the literature for human volunteers. The results show a positive correlation between Young's modulus (YM) and time after embalming, but no correlation with cadaver age at death or gender., Conclusions: The stiffness of the Thiel embalmed soft cadaver was validated against historical human data, confirming the life-like quality of the cadavers. Our results indicate that shear wave elastography is a promising tool to evaluate the stiffness of Thiel embalmed soft cadavers., (Copyright © 2015 Elsevier GmbH. All rights reserved.)