Superior laryngeal nerve loop: patterns and surgical implications

An applied anatomical study on the external laryngeal nerve loop and the superior thyroid artery in the neck surgical region

“…The incidence of connection between CSC and ELN in this study is almost the same as those observed in previous studies (Sun and Chang 1991;Sun and Dong 1997;Furlan 2002;Huang et al 2012), which further proves that most ELNs are looped. However, the ELN loops found in this study differ from those seen in the previous studies in some aspects.…”

“…The nerve trunk(s), plus the single ELN, were seen to be single, double, or triple in number. On analyzing all of the papers that have investigated the morphology of ELN/ELN loops (Sun and Chang 1991;Sun and Dong 1997;Furlan 2002;Huang et al 2012), it seems that the patterns of ELN loops are so complicated that none of the previous studies were able to statistically define them-the statistical results obtained for pattern variations in all of the studies showed statistical randomness. In other words, it can be said that a1 The loop presents a glandular branch (arrowhead) and a CTB (triangle).…”

“…Furlan (2002) proposed an alternative SLN/ELN loop classification based on the number of nervous connections between the SLN/ ELN and the CSC, and confirmed that Sun's results were repeatable and that SLN loops could be observed in different racial groups. Later, Huang et al (2012) identified an additional 18 SLN loop subtypes based on variations in features and branching patterns, thus extending our knowledge of the SLN loop and its branches. In previous studies, the incidence of a CSC-ELN loop was found to be 73.3 % (Sun and Chang 1991), 92.5 % (Sun and Dong 1997), 59.0 % (Furlan 2002), and 82.0 % (Huang et al 2012).…”

“…Later, Huang et al (2012) identified an additional 18 SLN loop subtypes based on variations in features and branching patterns, thus extending our knowledge of the SLN loop and its branches. In previous studies, the incidence of a CSC-ELN loop was found to be 73.3 % (Sun and Chang 1991), 92.5 % (Sun and Dong 1997), 59.0 % (Furlan 2002), and 82.0 % (Huang et al 2012). Therefore, from a statistical point of view, the ELN is more likely to be looped than linear.…”

“…Meanwhile, a study by Huang et al (2012) showed that the relationship between the ELN loop and the superior thyroid artery (STA) is variable and complicated, making surgery in this region more challenging. Regretfully, the ELN is still described as linear in the literature and the concept of an ELN loop is rarely recognized by surgeons.…”