gms | German Medical Science

Objective: High-resolution sonography is a noninvasive readily applicable imaging modality, wich is able of depicting morphological information of peripheral nerves and their surrounding tissues. This is the reason why ultrasound gets more and more important as a complementary tool in the preoperative evaluation of peripheral nerves.Since surgical treatment of traumatic nerve lesions in continuity still remains difficult our group started to use intraoperative sonography so that we were capable of displaying the affected nerve in its fascicular structure.

Methods: Intraoperative high frequency sonography (15 MHz transducer) was applied in 19 traumatic or iatrogenic nerve lesions of different extend. The information obtained was correlated with intraoperative electrophysiology, microsurgical intraneural dissection and histopathology of resected nerve segments.

Results: Fascicles crossing the damaged nerve segment were depicted with high precision. Ultrasound enabled gross assessment of the degree of intraneural fibrosis. The information obtained correlated well with the intraoperative electrophysiology. Electrophysiologically silent nerve segments showed marked scarring, and a loss of fascicular structures in sonography, whereas in those patients with recordable NAP without exception the internal nerve architecture was preserved, fascicular structures could be obtained throughout the damaged nerve segment despite of scarring or caliber changes. Pathohistological examination of the resected nerve segments revealed unexceptionally neuromatous tissue without any potential for spontaneous recovery.

Conclusion: This is the first study dealing with intraoperative high resolution ultrasonography in surgery for traumatic nerve lesions. The morphological information obtained by intraoperative ultrasound allows a non invasive assessment of the extend of the lesion. In our preliminary study intraoperative ultrasound imaging proved to be very reliable, easy to handle and correlated without exception with the electrophysiological investigations, microsurgical dissection and histopathological findings. Even in partial nerve lesions preserved fascicles passing the neuroma were depicted.