DRS/FS Help Identify Nerves from Adjacent Tissues

by Amy E. Hamaker •

Is a combination of diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy (FS) able to identify small nerve branches during operative procedures in head and neck surgery?

Bottom line
DRS/FS is a potentially useful intraoperative tool for identification of nerves from adjacent tissues.

Background: Careful identification of nerves during head and neck surgery is essential to prevent nerve damage. Currently, nerves are identified based on anatomy and appearance, optionally combined with electromyography (EMG). In challenging cases, nerve damage is reported in up to 50%. Recently, optical techniques, such as DRS and FS, show potential to improve nerve identification.

Setting: Netherlands Cancer Institute–Antoni van Leeuwenhoek, Amsterdam.

synopsis: Patients undergoing total parotidectomy, mandibulectomy, and partial glossectomy combined with block dissection of cervical lymph nodes and cervical lymph node dissection alone were randomly selected. A total of 212 intra-operative DRS/FS measurements were performed. Small nerve branches (1–3 mm) on near-nerve adipose tissue, muscle and subcutaneous fat were measured during 11 surgical procedures. Tissue identification was based on quantified concentrations of optical absorbers and scattering parameters.

Clinically comprehensive parameters showed significant differences between the tissues. Classification using k-Nearest Neighbors resulted in 100% sensitivity and a specificity of 83% (accuracy 91%) for the identification of nerve against surrounding tissues.

Citation: Langhout GC, Kuhlmann KFD, Schreuder P, et al. In vivo nerve identification in head and neck surgery using diffuse reflectance spectroscopy [published online ahead of print August 9, 2018]. Laryngoscope Inv Otol.