Combined maceration procedure permits advanced microsurgical dissection of Thiel-embalmed specimens

Due to the realistic colour, texture conservation and preservation of biomechanical properties, Thiel-embalming is becoming the main embalming procedure for clinical courses and research based on human cadaver material. The aim of this study is to establish a new procedure that allows advanced microdissection of small vessels and intraorganic nerves in Thiel-embalmed material.

After a classical gross anatomical dissection, human hemipelves underwent repetitive application of 3 consecutive steps: (i) maceration with alloy of nitric acid and MiliQ water 1:10 for 24-48h. (ii) Immersion: the hemipelves were rinsed under tap water for 20-30min. and placed in a water bath for 1h. The nerves become more prominent due to the swelling and increased water content. (iii) microdissection under surgical microscope. To facilitate the organ visualization perfusion with polyurethane (Pu4ii, VasQtec^®, Switzerland) in red/blue for arteries/veins respectively has been performed.

By using the proposed procedure, we performed satisfactory microdissection on Thiel-embalmed samples. The combination with polyurethane vascular casting permits visualization of small arterioles and venules in a range of 20-25μm. The method is very suitable for demonstration of somatic and vegetative nerves. Branches of the sacral plexuses and autonomic nerves from the superior and inferior hypogastric plexus have been tracked up to the smallest intraorganic branches in a range of 12.5-15μm. In conclusion, the established combined procedure offers a new possibility for advanced microdissection, which will allow acquisition of clinically relevant information about organ specific micro- vascularization and innervation.