The right nonrecurrent inferior laryngeal nerve (NRILN) is a rare occurrence generally associated with an aberrant right subclavian artery. Its prevalence ranges from 0.3 to 1.8 %. It is found mainly in thyroid surgeries, the most frequently performed cervical surgeries. This neural anomaly is almost never diagnosed preoperatively. Dysphagia may be a warning symptom, sometimes being incorrectly related to esophageal compression due to a goiter or thyroid cancer. The postoperative diagnosis of an accompanying aberrant right subclavian artery should be done to confirm the clinical picture and inform the patient of any possible future medical/ surgical procedures. The aim of this work is to determine the prevalence of the NRILN in patients undergoing total thyroidectomy in two reference centers for head and neck surgery in Paraguay. Prospective cross-sectional study in a series of 100 consecutive total thyroidectomies in the INCAN and the ORL Service in the Hospital Central of the IPS. 100 patients underwent a total thyroidectomy, 90 of whom were women. The average age was 47 years. 6 % also underwent a neck dissection for thyroid cancer. The preoperative diagnosis was multinodular goiter (MNG) in 84 cases and thyroid cancer in the remaining 16 (16 %). In one man aged 47 years (1 %) operated on for MNG and presenting slight to solid dysphagia, there was difficulty finding the right NRILN. It was located at the level of the lower edge of the inferior pharyngeal constrictor and its downward anomalous course was proven. Postoperatively, after confirmation of the diagnosis that the thyroid pathology was benign, a color echo-Doppler and a CT angiography corroborated the diagnosis of an associated aberrant right subclavian artery. Given the difficulty in locating the recurrent inferior laryngeal nerve in thyroid surgery, it is advisable to consider the possibility that it may be nonrecurrent and should be looked for at the level of its entrance to the larynx below the inferior constrictor. In such cases it is recommended that the patient be examined postoperatively to rule out an associated vascular anomaly. A tomography study of each patient with a thyroid pathology and dysphagia could contribute to the diagnosis of the vascular anomaly and maximize precautions in the nerve dissection, including use of a neurostimulator. The NRILN is a rare entity. In this case study, it represents 1 % of the patients operated on for thyroid pathology in the INCAN and IPS in a 1-year period (July 2016 - June 2017).
KEY WORDS: Right nonrecurrent inferior laryngeal nerve; Thyroidectomy; Neck.