Superior Approach of Recurrent Laryngeal Nerve: Review of the Literature

Abstract

The identification and dissection of the recurrent laryngeal nerve is essential to guarantee its anatomical and functional integrity. The superior approach of the recurrent nerve is a reliable surgical alternative. Various indications are recognized with a reliable landmark. This is the entry point into the larynx under the inferior horn of the thyroid cartilage. The limits of this technique, namely, the extralaryngeal divisions and the hemorrhages encountered at the point of entry of the larynx are a source of morbidity of the recurrent laryngeal nerve. A careful dissection, respect for the surgical steps, and the surgeon's experience are guarantees of a good result. We wanted through a review of the literature and our experience in the superior approach to discuss surgical indications, to identify landmarks at the point of entry of the larynx, to determine the limits of this approach, and to take precautions to mitigate the risk of recurrent laryngeal nerve injury.

Predictors and consequences of recurrent laryngeal nerve injury during open thyroidectomy: An American College of Surgeons National Surgical Quality Improvement Project database analysis

“…1,2 This was demonstrated within the results of our analysis as well, as RLN injury or dysfunction was independently associated with an increase in respiratory morbidity, defined as one or more occurrence of postoperative pneumonia, ventilator requirement >48 h after operation, or reintubation. The association between intraoperative hemorrhage and RLN injury has been described in the literature 21 ; increased bleeding during the case can make visualization difficult, and higher rates of RLN injury are seen. Increased bleeding is also associated with postoperative hematoma formation.…”

Is craniocaudal dissection of recurrent laryngeal nerve safer than lateral approach: a prospective randomized study comparing both techniques by using continuous intraoperative nerve monitoring

“…A revision of studies including large numbers of patients revealed that the rates of permanent RLN injury and hypoparathyroidism following thyroidectomy in experienced hands ranged from 0.2% to 6.6% and to 3%, respectively [ 19 ]. There are few studies in the literature evaluating morbidity rate related to the craniocaudal approach to RLN in OT [ 9 10 11 12 13 ]. In these studies, the rate of permanent VCP and hypoparathyroidism was reported to range between 0%–0.4%, and 0%–3%, respectively [ 9 10 11 12 13 ].…”

“…There are few studies in the literature evaluating morbidity rate related to the craniocaudal approach to RLN in OT [ 9 10 11 12 13 ]. In these studies, the rate of permanent VCP and hypoparathyroidism was reported to range between 0%–0.4%, and 0%–3%, respectively [ 9 10 11 12 13 ]. Page et al [ 20 ] suggested that the superior approach could be useful in cases of the presence of fibrous adherences in reoperations, large goiters with retrosternal extension, morphological variations as short neck, or lack of neck extension which obscures the identification of RLN at the level of ITA.…”

“…However, after the definition of the transoral endoscopic thyroidectomy vestibular approach (TOETVA) technique, the identification and dissection of the RLN had to be changed to the craniocaudal approach in patients who undergo this procedure [ 8 ]. There are only a few studies in the literature that evaluated the morbidity rates of the craniocaudal approach or that compared the morbidity rates of craniocaudal and lateral approaches in open thyroidectomy (OT) [ 9 10 11 12 13 ]. The aims of our study were to compare the rates of adverse electromyographic (EMG) changes, loss of signal (LOS), and RLN injury in craniocaudal and lateral approaches to the RLN during thyroidectomy under CIONM, and to evaluate the clinicopathological and anatomical features which affected the occurrence of adverse EMG changes and LOS.…”