Feasibility, repeatability, and safety of ultrasound-guided stimulation of the first cervical nerve at the alar foramen in horses.

The research paper fundamentally focuses on exploring the possibility, repeatability, and safety of an ultrasound-guided technique for stimulating the first cervical nerve in horses, and suggests its potential application for assessing reinnervation after nerve transplantation or implantation in horses suffering from recurrent laryngeal neuropathy.

Objective and Subjects

• The main aim of this research was to formulate and evaluate the practicality, repeatability, and safety of a new ultrasound-guided technique used to stimulate the first cervical nerve (FCN) in horses at the alar foramen.
• The study was conducted on 4 equine cadavers and 6 clinically normal Standardbreds.

Procedures

• In the initial phase, the pathway of the FCN was thoroughly revealed through dissection on each cadaver, and any connexions between the first and second cervical nerves were identified.
• Following this, the six live horses under examination underwent the procedure of bilateral ultrasound-guided stimulation of the FCN, repeated three times at three-week intervals. The horses were carefully monitored for the next five days after each procedure.

Results

• The results showed that the FCN passed through the alar foramen in each cadaver. A connecting branch between the FCN and accessory nerve and anastomoses between the ventral branches of the FCN and second cervical nerve were recognized.
• The success of the ultrasound-guided electrical stimulation was verified by the twitching of the ipsilateral omohyoideus muscle in all six live horses. This was observed bilaterally in each of the three experimental sessions. No stimulation-site complications were reported.

Conclusions and Clinical Relevance

• The study concluded that the ultrasound-guided stimulation of the FCN at the alar foramen was safe and uncomplicated in horses.
• This novel procedure could be potentially useful in horses suffering from recurrent laryngeal neuropathy, providing an innovative approach to assess reinnervation post FCN transplantation or nerve-muscle pedicle implantation in the cricoarytenoideus dorsalis muscle.