The Ansa Hypoglossi: Quantifying Axonal Density of a Donor Nerve for Facial Reinnervation.

Background

There are a number of nerve grafting options for facial reanimation and the ansa hypoglossi (AH) may be considered in select situations.

Objective

To compare axonal density, area, and diameter of AH with other nerves more usually used for facial reanimation.

Methods

AH specimens from patients undergoing neck dissections were submitted in formalin. Proximal to distal cross sections, nerve diameters, and the number of axons per nerve, proximally and distally, were measured and counted.

Results

Eighteen nerve specimens were analyzed. The average manual axon count for the distal and proximal nerve sections was 1378 ± 333 and 1506 ± 306, respectively. The average QuPath counts for the proximal and distal nerve sections were 1381 ± 325 and 1470 ± 334, respectively. The mean nerve area of the proximal and distal nerve sections was 0.206 ± 0.01 and 0.22 ± 0.064 mm2, respectively. The mean nerve diameter for the proximal and distal nerve sections were 0.498 ± 0.121 and 0.526 ± 0.75 mm, respectively.

Conclusion

The histological characteristics of the AH support clinical examination of outcomes as a promising option in facial reanimation.