Intraoperative Ultrasound applications in Brachial Plexus Tumoral Lesions

Ultrsonography is useful for exploring peripheral nerves and it is an established modality for the pre-operative evaluation of peripheral nerve tumoral pathology, surgical planning and approach. Brachial plexus is one area where US is difficult because of complex anatomy and bony relations hindering exploration. Anesthesiological US techniques for brachial plexus block are consolidated because of high spatial and contrast resolution of the method. The same technical tricks can be used during the intra- and perioperative planning. Neurofibromas are hyperechoic, with well defined homogeneous margins. Doppler shows intratumoral blood vessels. The roots are usually clearly hypoechoic and the tumor relatively hyperechoic. The lesion is centrally positioned relative to the nerve fibers and intraoperative techniques give a very useful indication for the better pathway to be followed for the tumor removal reducing nerve damage. Schwannomas are eccentric relative to the nerve fibers, well encapsulated, hypoechoic at US and with regular margins. Sometime an echogenic capsule can be distinguished, but it is difficult to recognize in the fat which is hyperechoic. Doppler may show an internal vascular circulation. When the peripheral fat is removed, the capsula and tumor borders can be very well defined, allowing complete and safe removal.