Combined ultrasound imaging/neurophysiological evaluation for surgical planning in upper limb traumatic nerve injuries with concomitant vascular damage: Two emblematic cases and a review of litterature.

Background: Traumatic injuries and penetrating traumas of the upper limb are at high risk of combined neurovascular lesion, due to anatomical proximity of main vessels and nerves. Occasionally, post-traumatic pseudoaneurysms or thrombi can develop in the site of trauma or surgery; these vascular complications represent a real urgency and require an accurate and timely diagnosis. The neurophysiological investigation still represents the gold standard for quantification, localization of nerve injuries and outcome prediction.

Methods: We reviewed a database of cases of upper limb trauma from the last two years with concomitant vascular and nervous damage evaluated using a combined ultrasound imaging/neurophysiological approach. Furthermore, among these, we have selected two emblematic cases of proximal upper limb injury with late-onset of vascular complications which came to our attention almost a month after trauma. Compound motor action potentials (CMAP) and sensory nerve action potentials (SNAP) were recorded by superficial electrodes and compared with the contralateral electrodes to estimate the percentage of affected fibres and possible recovery. Maximal cross-sectional area (CSA) of each nerve in the traumatic site and in the typical entrapment zones was recorded measuring at the inner hyperechogenic part of each nerve. Finally, a literature review was conducted.

Results: Our study confirms the importance of the use of electrophysiology in the diagnostic process of post-traumatic nerve injuries, with a diagnostic accuracy that increases significantly if associated with ultrasonography possibly integrated by Doppler.

Conclusions: The results reported in this study are very encouraging in the combined use of neurophysiology and ultrasonography in the approach to upper limb trauma with concomitant vascular and nervous damage; larger-scale studies are desirable to strengthen results.