Comparison of fresh and Thiel's embalmed cadavers according to the suitability for ultrasound-guided regional anesthesia of the cervical region

Introduction Ultrasound-guided punctures are a new technique in anesthesia. However, training in these techniques requires conditions resembling real life as far as possible for learning purposes. Several models are available, but none associates realistic anatomy and lifelike sensations of the passage of fascias. The aim of our study was to compare fresh and Thiel's embalmed cadavers for ultrasound-guided punctures. Methods Eight fresh cadavers and eight Thiel's embalmed cadavers were investigated. The cervical region was scanned with an ultrasound probe. Age, sex and body mass index (BMI) were recorded. Visibility of he structures, including sternocleidomastoid (SCM) muscle, anterior and middle scalene muscles, thyroid gland, nerve and the needle, was evaluated as 0 (not visible or bad visibility) or 1 (good visibility). The feeling ("pop") of passing the fascias was noted as 0 (not felt) or 1 (felt). The possibility of nerve displacement with the needle, the difficulty of intraneural injection and the possibility of nerve penetration and nerve swelling were all recorded as 0 (not possible) or 1 (possible). Results The two groups were comparable in terms of sex, age and BMI. Visibility of the SCM muscle and the needle was better in the Thiel group. Moreover, the "pop" feeling and nerve swelling were significantly more frequently present in the Thiel group. There was no significant difference in terms of the other results between the two groups. Conclusions Cadavers embalmed according to Thiel's method should be recommended for ultrasound-guided punctures as a realistic and lifelike model.