The anatomical relation of the extracranial internal carotid artery in the parapharyngeal space

Abstract

Background. The proximity of the internal carotid artery to the pharyngeal wall poses a risk of injury during nasopharyngeal surgery. Objectives. The aim of this study was to assess the distances between the extracranial internal carotid artery (ICA) and the pharyngeal wall. Material and methods. Measurements were taken on certain levels of the pharynx using computed tomography angiography (angio-CT) scans of 97 patients. One-tailed Student's t-test for independent variables and a comparison of expected values for dependent pairs of observations were applied. Results. The shortest distance between the ICA and the pharyngeal wall was 1. 1 mm. The ICA is closer to the pharyngeal wall at the epiglottis apex level (16.46 ±0.89 mm) than to the Eustachian tube (ET) (19.8 ±0.62 mm) (p < 0.0005). In women, the ICA is closer to the ET (19.44 ±0.78 mm) than in men (20.17 ±0.96 mm) (p = 0.04). In women, the right ICA is closer to the pharyngeal wall than the left ICA at the level of the lower margin of the 2 nd cervical corpus vertebra (C2) (right: 17.6 ±1.8 mm; left: 20.7 ±1.7 mm) (p = 0.002) and at the level of the epiglottis apex (right: 15.2 ±1.7 mm; left: 17.4 ±1.4 mm) (p = 0.028). The bifurcation of the common carotid artery (CCA) is higher in men (19.48 ±2. 19 mm below the C2) than in women (21.82 ±1.02 mm) (p < 0.001). When the bifurcation is at the level of the epiglottis apex, the ICA is closer to the pharyngeal wall (12.3 ±1.69 mm) than in other cases (16.46 ±0.89 mm) (p = 0.005). In men, the higher the bifurcation is, the closer the ICA is to the pharyngeal wall at the level of the lower margin of the C2 (p = 0.003). Conclusions. The risk of ICA incision during surgery differs between the pharyngeal levels, genders and sides of the neck. The ICA may be much closer to the pharyngeal wall than described in the literature.

Applicability of Transnasal Echography for Identification of Internal Carotid Artery

“…To evaluate the accuracy of the US estimation, we used CT as a reference method. The CT estimate of the ICA distance from the pharyngeal wall in our participants (mean 20.7 mm, range 14–27) is compatible with the data of Zając et al (mean 19.8 mm, range 10–31) 10 . According to our assessment by the CT, the mean ICA diameter was 4.22 ± 0.63 mm.…”

“…The CT estimate of the ICA distance from the pharyngeal wall in our participants (mean 20.7 mm, range 14-27) is compatible with the data of Zając et al (mean 19.8 mm, range 10-31). 10 According to our assessment by the CT, the mean ICA diameter was 4.22 AE 0.63 mm. Baz et al measured it 4.53 AE 0.50 mm.…”

Distance of the cervical part of the internal carotid artery from the selected anatomical structures in the parapharyngeal space and its relation to patient characteristics

“…Furthermore, the decreased thickness of soft-tissue and muscle layers in females is probably the causative factor of more frequent appearance of ICA anomalies in this group [15]. The Zając's study [31] also states that ICA is closer to the parapharyngeal wall in women then in men but only at the Eustachian tube opening level in nasopharynx. Furthermore, Jun et al [15] found that in nasopharynx and oropharynx, the distance was inversely proportional to the age (p = 0.00).…”

“…The mortality rate after tonsillectomy is low, but almost 30% of the deaths are due to bleeding after trauma, due to incision of ICA or external carotid artery and its branches [8]. Therefore, having the knowledge about the variability of ICA in the context of the patient characteristics (for example age, weight [24], gender [15,31]) can be helpful in estimating the risk of arterial injury during tonsillectomy, and thus, reduce post-tonsillectomy mortality. Although many cases of abnormal arterial course were reported in the literature [9][10][11][12][13], only a few of them provided applicative and accurate information about topography of ICA [14,15].…”

Anatomical variations of the extracranial internal carotid artery: prevalence, risk factors, and imaging insights from CT-angiography

“…One of the main causes of neck artery kinking is the decrease in the height of intervertebral discs due to aging [7]. Also, the results of various studies have shown that the prevalence of kinking in EICA in patients with hypertension has an increasing trend [21,22]. The results of various studies have shown that variations in different parts of the ICA are also found in infants, which are caused by embryological reasons [1,23].…”