Intraoperative Ultrasonography and Dorsal Root Entry Zone Surgery: Technique, Findings and Perspectives

Dorsal root entry zone (DREZ) ablation is a well stablished effective procedure for treatment of chronic intractable pain and brachial plexus avulsion. Many improvements have occurred over many years. The way ablation is performed has evolved from bipolar coagulation to thermic radiofrequency. Laminoplasty has become a viable alternative and may replace regular simple laminectomy. Neurophysiologic monitoring has improved safety. Nevertheless, means of effective imaging for guiding the procedure have not been yet described. A case in which intraoperative ultrasound was used to help localizing the DREZ and the damaged tissue is described, together with the proper technique. It is not uncommon to not localize the proper DREZ region in a setting of global avulsion and scarring. The use of intraoperative ultrasound has showed to be a viable and relatively non-expensive mean of real-time monitoring for such interventions and has a potential of helping not only viewing the anatomical relevant structures, but also to improve localizing the lesion and even adding pathological information as the echoic findings of the medullar damaged tissue. In conclusion, intraoperative ultrasound is a safe tool for imaging of the spinal cord during fuctional neurosurgery provided adequate technique and anatomical knowledge.