Nonrecurrent inferior laryngeal nerve without vascular anomaly as a genuine entity.

Inferior laryngeal nerve (ILN), which usually arises from vagus nerve, runs recurrent course and is called recurrent ILN (RILN). Intimate knowledge of normal and anatomic variants of the ILN reduces the risk of nerve injury and vocal cord paralysis in thyroid and parathyroid surgery. The nonrecurrent ILN (NRILN) is a rare nerve anomaly that is associated with a right aberrant subclavian artery. We encountered 2 patients with NRILN during thyroid surgery. Patient 1, a 57-year-old woman, had mediastinal thyroid tumor without vascular anomaly. Patient 2, a 47-year-old woman with a history of esophageal foreign body (fish bone), was suspected to have NRILN with vascular anomaly before surgery, as judged by preoperative enhanced CT. In the patient 1, we verified laryngeal mobility function of the NRILN by nerve stimulation, and confirmed the absence of RILN in usual recurrent course. The findings in the patient 1 indicate that NRILN without subclavian artery anomaly is a genuine entity. In both patients we performed thyroid surgery safely and fast by expectation and identification of NRILN by use of nerve stimulator. In conclusion, we confirm the existence of NRILN without vascular anomaly and show effectiveness of preoperative enhanced CT and valuable use of nerve stimulator for nerve preservation in the patients with NRILN.

Non-recurrent laryngeal nerves. The role of digital subtraction angiography to identify subjects.

Three cases of non-recurrence of the right recurrent laryngeal nerve are reported. In one, the predicted anomaly of dorsal origin of the right subclavian artery was confirmed by intravenous digital subtraction angiography (IVDSA). The surgical anatomy and embryology of this rare condition are discussed. Non-recurrent laryngeal nerves are at increased risk of injury, especially during re-operative thyroid surgery. It is, therefore, suggested that an IVDSA be performed in that small subset of patients in whom re-operative thyroid surgery is contemplated on the right, and in whom the nerve was not found at the previous operation.

[Laryngeal immobility after intubation]. / Les immobilités laryngées après intubation.

Based on findings in 14 cases of post-intubation laryngeal immobility simulating a paralysis, it is demonstrated that a mechanical cause bringing into play the arytenoids exists in every case. The origin may be from a synechia between the vocal cords, crico-arytenoid ankylosis, inter-arytenoid and plate of the cricoid fibrosis, or a combination of these lesions. Conclusive evidence of the type of lesion involved is rarely apparent from clinical or paraclinical examinations, an exact diagnosis requiring a median thyrotomy. This emphasizes the need for pathologic investigation of the arytenoidectomy surgical specimens. These findings suggest that neurogenic theories concerning the etiopathogenicity of post-intubation laryngeal immobility be revised.