Abstracts Presented at the Summer Meeting of the British Association of Clinical Anatomists, Laboratory of Human Anatomy, University of Glasgow, Glasgow, United Kingdom from 21st to 22nd of July, 2010^†

Abstract

. Surgical anatomy of the orbital floor.The aim of this study is to describe the morphometric and geometric relationships of the orbital floor. Exenterations of 47 orbits from 24 formalin fixed cadavers were performed. Morphometric measurements were taken between anatomical landmarks located along the orbital floor and the orbital apex. The mean measurements were used to calculate geometric data. These results were analysed according to sex and side and compared to results from other ethnic populations. The average distances from the tip of the infraorbital groove to the tip of the inferior orbital fissure, lateral aspect of the inferomedial strut, optic canal and the intersection with the inferior orbital fissure were 14.10 mm (+/À2.43 mm), 12.19 mm (+/À2.41 mm), 34.68 mm (+/À3.24 mm), and 19.91 mm (+/À2.89 mm), respectively. The distances from the tip of the inferior orbital fissure to the optic canal, the intersection with the inferior orbital groove and the optic canal were 29.56 mm (+/À2.73 mm), 13.43 mm (+/ À2.67 mm), and 16.14 mm (+/À3.44 mm) respectively. Our findings were used to create the first three-dimensional representation of the anatomical landmarks of the Caucasian orbital floor. This may potentially be used as a navigational template for surgeons particularly for operations such as fracture repair and orbital decompression which may compromise the infraorbital nerve. Department of Anaesthetics, University of Glasgow, Glasgow, Scotland, United Kingdom. Posterior injections can reach the musculocutaneous nerve in regional anaesthesia of the brachial plexus.Regional anesthesia of the brachial plexus by an axillary or infraclavicular approach is safe and convenient, but does not always reach the musculocutaneous nerve. Our clinical experience suggests that anesthetic injected behind the axillary artery is more likely to reach all the nerves. To test this hypothesis we dissected four cadaver axillae, and injected 10-15 cc of colored latex into two embalmed axillae, by a standard axillary approach, and by Wilson's infraclavicular method, using the coracoid process as a landmark. In each axilla injections were made anterior and posterior to the axillary artery with different colored latex. At dissection the latex was found in the fibrous axillary sheath which surrounds the plexus. In the axilla the anterior and posterior injections did not mix and both were needed to reach the main nerves. In contrast a single posterior infraclavicular injection travelled 18 cm along the plexus and spread circumferentially to reach all the nerves. Histology confirmed the latex inside the sheath, which is remarkably delicate. The septa between the nerves are fatty rather than fibrous and thicker in the infraclavicular region. This looser texture might allow greater circumferential spread in this region.ALBASHIR, ALZAHARA, DANIELLE CZUPRYNSKI, ASHA VENKATESH, Department of Anatomy, Suttie Centre, School of Medicine and Dentistry, University of Aberdeen, Aberdeen, Scotland, United Kingdom. How safe is a temporal artery bi...