Plexus brachialis Strain and Compression Deformation in the Costo-Axillary-Brachial Region: A Cadaveric Study

Edgars Vasilevskis¹, Sandra Skuja², Irina Evansa¹, Eva Šteina¹, Anna Sondore Pīlipa¹, Grigorijs Vābels³, Uldis Teibe⁴, Haralds Jansons⁵, Valērija Groma², Indulis Vanags¹

¹Department of Anesthesiology, Riga Stradins University, Latvia, ²Department of Histology, Riga Stradins University, Latvia, ³State Forensic Medicine Center, Riga, Latvia, ⁴Department of Physics, Riga Stradins University, Latvia, ⁵Riga Stradins University, Latvia

Key words: postoperative neuropathy; plexus brachialis; strain deformation; compression deformation.

Summary. Objective. The aim of this study was to clarify the role of different mechanisms in nerve injury during arm abduction positions. The tasks were to determine the strain deformation of the plexus brachialis during arm abduction, to measure the pressures in the neurovascular bundle in the cervico-costoclavicular-axillary area, and evaluate the histological changes of nerve after the stretch test.

Material and Methods. During the cadaveric study on 7 specimens 7–20 h after death, strain deformation of plexus brachialis as well as compression deformation caused by the surrounding structures of the neurovascular bundle were investigated in the arm abduction position of 0°, 90°, 12°, 150°, and 180°. One nerve sample was studied histologically after 15% stretch on the bench.

Results. The relative strain deformation of 3%–23% was documented during 0° to 180° abduction tests. The strain deformation from 0° to 90° was significant (P<0.001). The mean pressure change in the bundle was 13.6 mm Hg at 90°, 53.7 mm Hg at 120°, 73.4 mm Hg at 150°, and 89.0 mm Hg at 180° arm abduction. An increase in pressure was significant in the intervals: 0°–90° (P<0.001), 91°–120° (P<0.001), 121°–150° (P<0.001) and 151°–180° (P<0.05).

Conclusions. Nerve traction and tissue compression arising during the arm abduction above 90° were found to be sufficient to induce lesions in neural bundles of the plexus brachialis.

Correspondence to E. Vasilevskis, Riga Hospital No. 2, Gimnastikas iela 1; 1004 Riga, Latvia. E-mail: edgars.vasilevskis@inbox.lv

Received 6 September 2010, accepted 31 October 2011