Improved facial nerve identification during parotidectomy with fluorescently labeled peptide

Abstract

Objectives/Hypothesis Additional intraoperative guidance could reduce the risk of iatrogenic injury during parotid gland cancer surgery. We evaluated the intraoperative use of fluorescently labeled nerve binding peptide NP41 to aid facial nerve identification and preservation during parotidectomy in an orthotopic model of murine parotid gland cancer. We also quantified the accuracy of intraoperative nerve detection for surface and buried nerves in the head and neck with NP41 versus white light (WL) alone. Study Design Twenty-eight mice underwent parotid gland cancer surgeries with additional fluorescence (FL) guidance versus WL reflectance (WLR) alone. Eight mice were used for additional nerve-imaging experiments. Methods Twenty-eight parotid tumor-bearing mice underwent parotidectomy. Eight mice underwent imaging of both sides of the face after skin removal. Postoperative assessment of facial nerve function measured by automated whisker tracking were compared between FL guidance (n = 13) versus WL alone (n = 15). In eight mice, nerve to surrounding tissue contrast was measured under FL versus WLR for all nerve branches detectable in the field of view. Results Postoperative facial nerve function after parotid gland cancer surgery tended to be better with additional FL guidance. Fluorescent labeling significantly improved nerve to surrounding tissue contrast for both large and smaller buried nerve branches compared to WLR visualization and improved detection sensitivity and specificity. Conclusions NP41 FL imaging significantly aids the intraoperative identification of nerve braches otherwise nearly invisible to the naked eye. Its application in a murine model of parotid gland cancer surgery tended to improve functional preservation of the facial nerve.

Oncologic Procedures Amenable to Fluorescence-guided Surgery

“…82–85 In 1 preclinical study, facial nerve imaging in murine models with the fluorescently labeled peptide NP41 demonstrated increased nerve to surrounding tissue contrast by a factor of 2.86 ( P = 0.005). 86 FI significantly improved detection of additional nerve branches, particularly those underlying surrounding tissue (7.50 ± 1.60 small nerve branches vs 3.25 ± 0.89 with white light). 86 Although nerve imaging has not yet translated into clinical trials, these data suggest that concurrent nerve imaging, when combined with current imaging and monitoring techniques, can improve the functional outcomes and QOL in patients by improving nerve preservation.…”

“…86 FI significantly improved detection of additional nerve branches, particularly those underlying surrounding tissue (7.50 ± 1.60 small nerve branches vs 3.25 ± 0.89 with white light). 86 Although nerve imaging has not yet translated into clinical trials, these data suggest that concurrent nerve imaging, when combined with current imaging and monitoring techniques, can improve the functional outcomes and QOL in patients by improving nerve preservation. With emerging preclinical studies, there is, however, evidence to suggest that future intraoperative imaging will expand to include visualization of extratumoral structures and tissues.…”

Evaluation of collimated polarized light imaging for real-time intraoperative selective nerve identification in the human hand

“…Recent developments in intraoperative nerve visualization can be found in new uses of ultrasonography, fluorescent markers and optical coherence tomography (OCT) [15][16][17][18][19]. However, these methods have their drawbacks; blunt dissection of nerves is not without risk, due to the risk of traction-stretch neuropathy [10,20].…”

Fluorescence labeling of a NaV1.7-targeted peptide for near-infrared nerve visualization

“…Oncologic surgery, in particular, poses a risk of nerve injury as anatomy is often distorted by the disease [10][11][12][13][14][15][16][17]. Tools for pre and perioperative nerve enhancement exist [18][19][20] and fluorescent nerve imaging agents, as well as multimodal optical imaging techniques, are raising interest for intraoperative applications [21][22][23][24][25][26][27][28][29][30][31].…”