Clinically significant anatomical variation of the retropharyngeal internal carotid arteries

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

PURPOSE

To determine the prevalence of different extracranial internal carotid artery (EICA) variations in CT angiography (CTA) of the neck and its predisposing factors.

METHODS

In this retrospective study from 2021 to 2023 conducted in the radiology department of Shafa Hospital, Kerman, Iran, all patients who had undergone neck CTA were included. Expert radiologists blindly examined each CTA image for the following: EICA variations-coiling, kinking, straight morphology, and tortuosity-and the distance between the internal carotid artery and the apex of the epiglottis and the C2 lower margin.

RESULTS

Of the 106 patients, the mean age was 55.9 ± 16.9 years. 64.2% were men, and 35.8% were women. Considering each patient's bilateral anatomy, the reported 70.28% (149/212) frequency of EICA variations of all arteries. Tortuosity, kinking, and coiling variation were found in 61.8%, 4.2%, and 4.2% of arteries, respectively. Also, 54.72%, 1.89%, and 0.94% of the participants had bilateral tortuosity, kinking, and coiling, respectively. There was a significant relationship between the prevalence of EICA variations and female sex, age, and hypertension.

CONCLUSION

The frequency of EICA variations in arteries and patients was 70.28% and 73.58%, respectively. Tortuosity was the most common variation. Female sex, old age, and hypertension were significant risk factors for EICA variations.

[Efficacy and safety of surgical treatment of patients with pathological tortuosity of the internal carotid artery]

No multicenter randomized clinical trial has been conducted worldwide to date on indications, types of surgery and their comparison with conservative treatment in patients with PI BSA.

OBJECTIVE

Of the study is to improve the results of surgical treatment in patients with pathological tortuosity of the internal carotid artery.

MATERIAL AND METHODS

The study included 119 patients (41 (34%) men and 78 (66%) women) with PI ICA aged 34 to 71 years (average age 53.2±7.5 years) divided into 2 groups. 64 patients (54%) of group I underwent BSA resection with lower mouth and 55 patients (46%) of group II underwent BSA prosthetics. Depending on the degree of neurological disorders, patients were distributed according to the classification of A.V. Pokrovsky.

RESULTS

In the early postoperative period, TIA was noted in one patient, and transient lesions of the cranial nerves were observed in 5 patients. During 5 years of follow-up, none of the patients developed TIA, IS or other vascular events. In the early surgical period, there were no significant differences in effectiveness between the groups of patients. In the long-term period (5 years after surgery), a higher frequency of asymptomatic patients was noted in group I.

CONCLUSION

Resection and replacement of a pathologically tortuous internal carotid artery (ICA) is a safe and effective surgical treatment. A multicenter randomized trial should be conducted to compare the effectiveness of surgical treatment of PI ICA with a conservative approach to effectively treat patients.

[Clinical analysis of cervical internal carotid artery malformation]

Objective:To introduce the clinical features and clinical imaging grading methods of cervical internal carotid artery（ICA） malformation. Methods:The clinical data of 6 cases with cervical ICA malformation admitted to the department of Otolaryngology, Head and Neck Surgery, the First Affiliated Hospital of Chengdu Medical College from April 2018 to February 2021 were retrospectively analyzed and graded according to the clinical imaging grading method. Results:All 6 patients were confirmed by enhanced CT or CT angiography. The minimum distance from deformity ICA to pharyngeal mucosa was 0 - 2.0 mm, while the median distance was 1.3 mm. According to the clinical imaging grading standards, the four cases with oropharyngeal ICA were grade Ⅳ, which is considered extremely high risk of ICA injury. The two cases with hypopharyngeal ICA were grade Ⅲ, which is considered high risk of ICA injury. Conclusion:ICA malformation is not a rare condition, and can be definitively diagnosed by enhanced CT and CT angiography. The clinical imaging grading can be used to assess the risk of damaged ICA malformation, which has great clinical significance. Otolaryngologists and anesthesiologists should pay attention to this malformation to prevent ICA damage in the operation which could lead to fatal hemorrhage.

Retropharyngeal internal carotid artery: a potential risk factor during nasotracheal intubation

PURPOSE

To investigate the potential risk of the retropharyngeal internal carotid artery (RICA) during nasotracheal intubation (NTI).

METHODS

We retrospectively surveyed 2028 patients and 90 healthy controls (HC) with neck computed tomography angiography (CTA). The incidence of RICA was analyzed, as well as the correlation between the average minimum carotid-pharyngeal distance (CPD) and the carotid-median plane distance (CMD). We also compared CPD between RICA and HC.

RESULTS

RICA was observed in 91 out of the 2028 patients, reaching an incidence of 4.5% (91/2028). RICA in female patients was 65.9% (60/91) compared to 34.1% (31/91) in male patients. The incidence of RICA at nasopharynx (NP), oropharynx (OP), and hypopharynx (HP) was 31.9% (29/91), 61.5% (56/91), and 6.6% (6/91), respectively. The incidence of the mucosal eminence of the posterior wall of the pharynx in RICA was 30.8% (28/91). In 15 cases, RICA caused the pharyngeal cavity to become narrow, with an incidence of 16.5% (15/91). Moreover, CPD and CMD was positively correlated (r = 0.56, p < 0.01). The average minimum CPD of RICA was only 2.25 ± 1.26 mm, which was much shorter than HC (17.62 ± 1.98 mm) (t = 62.46, p < 0.01). Some CPD of RICA was even less than 1 mm, with an incidence of 20.9% (19/91).

CONCLUSION

RICA is not uncommon in asymptomatic adults. It is very close to the midline and posterior wall of the pharynx and is more likely to occur in the nasopharynx (NP) and oropharynx (OP). RICA tear is likely to occur during NTI.

Retropharyngeal internal carotid artery: a review of three cases

INTRODUCTION

The internal carotid artery (ICA) can take multiple pathways as it extends from the carotid bifurcation to the skull base. An aberration of its normal pathway may place the ICA in a retropharyngeal position in close proximity to the posterior pharyngeal wall. Radiographic classification is based on its proximity to the pharynx and/or pathway. We present a series of three cases of retropharyngeal ICAs, our goal is to report and classify these variations.

CASE PRESENTATION

CASE 1: Retropharyngeal right ICA. Minimum distance to the pharyngeal wall was ~ 4.9 mm (high risk of vascular injury) with a tortuous pathway. CASE 2: Bilateral retropharyngeal ICA. ICAs were in contact with the posterior pharyngeal wall (very high risk of vascular injury). The left has a kinking pathway, the right tortuous. CASE 3: Bilateral retropharyngeal ICA. Minimum distances of the right and left ICAs to the posterior pharyngeal wall were ~ 3.5 mm and ~ 3.3 mm, respectively (high risk of vascular injury). The right has a kinking pathway, the left tortuous.

DISCUSSION

Closeness of the vessel to the retropharyngeal wall increases the risk of surgical and non-surgical complications. Noteworthy is that the position of the artery is not constant and can change in position over periods of time.

CONCLUSION

Knowledge of the anatomy and variations of the ICA is important for oral and maxillofacial radiologists and surgeons to enable clinicians to take necessary precautions to decrease complications if performing any procedure in the region.