The morphology and topography of the superior laryngeal artery

Abstract

The aim of this study was to investigate and correlate the anatomical parameters of the superior laryngeal artery (SLA). For the study, 50 adult, human specimens were used; laryngeal pieces were drawn from 16 cadavers and the arteries were dissected intralaryngeally. In 68%, the SLA originated from the superior thyroid artery and in 32%, directly from the external carotid artery. In five sides, an aberrant superior laryngeal artery (ASLA) was entering the larynx through a foramen thyroideum. The normal superior laryngeal artery (NSLA) had a short extralaryngeal part and continued intralaryngeally, with two segments and a point of inflexion; the first segment ran along the superior border of the thyroid cartilage, the point of inflexion of the NSLA was at a minimal distance of 1.1 cm anterior to the superior horn of the thyroid cartilage and from this point the NSLA continued in the paraglottic space. The ASLA had a constant origin from the superior thyroid artery; it then traversed the foramen thyroideum and reached the paraglottic space-at the superior border of the lateral cricoarytenoid muscle, it ended in two terminal branches. We constantly evidenced the following collateral branches of the NSLA: superior, anterior and postero-medial. The terminal branches are the antero-inferior branches that constantly anastomose with the cricothyroid artery and the postero-inferior branch anastomosed with the inferior laryngeal artery. Occasionally, additional branches of the NSLA were found. In conclusion, the intralaryngeal branching patterns of the NSLA and the ASLA are similar, the differences being given by the entry point into the larynx that will make the superior and anterior branches of the ASLA longer, will eliminate the transversal segment of the NSLA, and will shorten the descending segment in the paraglottic space in the case of ASLA. The base of the upper horn of the thyroid cartilage, the oblique line and its tubercles, the cricothyroid membrane and the cricothyroid joint are constant landmarks that allow a precise intralaryngeal identification of the SLA. These findings can improve performances during surgical manipulations of the larynx and laryngeal transplants.

Variations in the origin of superior laryngeal artery

“…In 5% cases, SLA arose from ECA. This is more or less in agreement with the studies by Terayama et al [3], Lang et al [8], and Ozgur et al [10], but differ from that of Rusu et al [6] who reported a higher incidence of 32%. There are also case reports of SLA taking origin from ECA.…”

“…The commonest origin of SLA is from STA, the reported range being 68% to 92.7% [36789]. In the present study we observed the origin of SLA from STA in 91.7% cases.…”

“…Moreover SLA being the principal artery of the larynx, is used for administering chemotherapeutic drugs for treatment of laryngeal cancers, as the drugs administered through the feeding artery directly to the tumour site can achieve a greater therapeutic effect [21]. A good and detailed knowledge of SLA will also ensure a correct decision and a safe approach prior to neuro-radiological procedures involving SLA [6]. …”

Proposal of landmarks for clamping neurovascular elements during endoscopic surgery of the supraglottic region

“…For the above‐mentioned reasons, before CO 2 laser surgery is performed, a sound knowledge of the vascular anatomy of the region is required if the risk for development of complications is to be minimized. However, in the older classical studies and the more recently published reports describing the vascular5–15 and neural16–29 supply of the larynx, no references are made to the topographical relations of the neurovascular structures from an endoscopic approach, an essential aspect when undertaking microsurgery. Therefore, the aim of this study was to describe the topographic relations of the vascular elements within the supraglottic region that could be subjected to damage during endoscopic surgery and to suggest some constant, easily recognizable endoluminal landmarks that enable their reliable localization before surgery.…”

The morphometric development of the fetal larynx during the fetal period

“…Anatomic variations as anatomic openings (foramen thyroideum) in the posterosuperior portion of the thyroid lamina must be taken into consideration [22,23], because superior laryngeal vessels and a subdivision of the external branch of the superior laryngeal nerve may transit from these openings [24,25]. Knowledge of the incidence and location of these foramina is important because their contents may be preserved.…”