(477) Tension-free Anastomosis Between RLN and Ansa Cervicalis via Tunneling Technique

Introduction: Vocal cord paralysis due to injury to Recurrent Laryngeal Nerve is a morbid condition. Various techniques for RLN anastomosis with either Ansa cervicalis or Vagus nerve have been attempted with variable outcomes. There is limited literature available on soft tissue dissection and approach used for exposure and to obtain tension free anastomosis We have carried out a cadaveric study during COVID pandemic to know feasibility of anastomosis between RLN with Ansa cervicalis common branch that was done by tunneling Ansa cervicalis under the Sternothyroid to reach distal stump of RLN and achieve a tension free anastomosis.

Methods: Observational Cadaveric study was done on 16 necks, between June 2020 to July 2021 in the Dissection Hall, Department of Anatomy after obtaining approval from Institute Ethical Committee (NK/6804/MS/072). 8-10 cm transcervical skin incision was given and omohyoid, sternohyoid and sternothyroid muscles, Ansa cervicalis with its all branches were delineated. RLN was delineated till its entry at cricothyroid joint and 1 cm of RLN, 2 cm proximal to its entry point in larynx, was cut and sent for morphometry. Sternothyroid muscle was lifted and a tunnel created without cutting the muscle, the cut ends of RLN and proposed AC branch to be anastomosed was relocated and tunelled under the sternothyroid muscle for neurorraphy and photodocumentation of same was done, morphometry was done for all branches of Ansa. An attempt was also made to assess for second best option available of ansa cervicalis branch for anastomosis

Results: Comparable diameters of RLN, common branch of Ansa and nerve to sternohyoid muscle were noted and also tension free neurorrhaphy was achieved via tunneling beneath sternothyroid muscle.

Conclusions: Tension free neurorrhaphy can be achieved between RLN and Ansa cervicalis common branch via tunelling technique and nerve to sternohyoid can also be used as second alternative for neurorrhaphy. This novel technique can be used in situations where the strap muscles are not cut for thyroidectomies.