Shib Shankar Paul1 , Subrata Kumar Sahu2 , Indranil Chatterjee3
Both the cases discussed here had right sided NRLN, out of which one had
associated aberrant right subclavian artery. None had iatrogenic nerve palsy.
Dissection was difficult as during the routine procedure of dissection, the nerve
was not found in its usual route and was found that the right laryngeal nerve was
not recurrent and originated directly from the vagus nerve.
The non-recurrent laryngeal nerve (NRLN) is a rare embryologically derived
variant of the recurrent laryngeal nerve and is found in 0.25 to 0.99% of patients
who undergo thyroid surgery. On the right side, NRLN is found in 0.3% to 0.8%
of patients and it is extremely rare on the left (0.004%).[1-2] The right NRLN is
found to be associated with an aberrant right subclavian artery (86.7%)
In experienced hands, meticulous dissection in the region of the
tracheoesophageal groove will result in identification of RLN. In any case, if the
nerve is not seen / found longitudinally along the tracheoesophageal groove, then
dissecting transversely along the fascial spaces between the carotid sheath and
the larynx, will allow identification of the presence of NRLN.
Recurrent laryngeal nerve is a branch of the vagus nerve that is associated
with both motor function and sensation of the larynx. It supplies all the intrinsic
muscles of the larynx except the cricothyroid muscles. The non-recurrent laryngeal
nerve (NRLN) is a rare embryologically derived variant of the recurrent laryngeal
nerve and occurs in 0.25 to 0.99% of patients who undergo thyroid surgery and
was first reported by Steadman in 1823.[3] on the right side, NRLN is found in
0.3% to 0.8% of patients and on the left side, it is extremely rare (0.004%).[1-2]
The right NRLN is found to be associated with an aberrant right subclavian artery
(86.7%).
