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Duplex ultrasound of the left distal internal carotid artery demonstrating change of flow velocity and diameter based by head positioning. (A) Head straight (131 cm/second and 6 mm) (B) Head turned to the right (213 cm/second and 2.3 mm).
Source publication
The tortuous carotid artery is a rare anatomic abnormality defined as vascular elongation leading to an altered course. It can be discovered incidentally or have clinically significant manifestations. The most common location is the internal carotid artery or, less commonly, the common carotid artery. Bilateral tortuous carotid arteries can also oc...
Context in source publication
Context 1
... carotid ultrasound was performed with the head straight and then turned to the right, demonstrating an increase in peak systolic velocity (131 cm/second and 213 cm/second, respectively) and a decrease in the diameter of the vessel (6 mm and 2.3 mm, respectively) ( Figure 3). After a multidisciplinary discussion, the patient underwent a 5 cm segmental resection of the kinked segment of the left ICA with end-to-end primary anastomosis (Figure 4). ...
Citations
... Various surgical techniques for arterial ligatures in the carotid triangle are based on the usual disposition of the ECA and ICA [37]. The standard anatomical disposition could be modified either by a twisted CB variant or by different tortuosities of carotid arteries [45][46][47], but not exclusively. ...
(1) Background: Twisted carotid bifurcations (CBs) lead to lateralized external carotid arteries (ECAs). Such variants are usually reported on a case-by-case basis. We aimed to study the anatomical possibilities of the axial spin of CB. (2) Methods: Determinations were made bilaterally on a retrospectively assessed sample of 150 cases, 88 males and 62 females. The following types of the axial spin of the CB were determined: type CK1–CB in the coronal plane, with ICA lateral of ECA; type CK3–CB in the coronal plane, with ECA lateral of ICA; the oblique type OK1, with the ECA antero-medial of ICA; the oblique type OK3a, with the ICA antero-medially; the oblique type OK3b, with the ICA postero-laterally; the sagittal type SK2a, with ECA anterior of ICA. (3) Results: In the overall group of 300 CBs, type OK1 was found in 40%, type OK3a in 1%, type OK3b in 2%, type CK1 in 9%, type CK3 in 5.67%, and type SK2a in 42.33% of the bilateral BC group. The types SK2a (46.67%) and OK1 (33.33%) prevailed on the right side. The types OK1 (46.67%) and SK2a (38%) prevailed on the left side. There was no statistically significant association between gender and left or right subtypes. A very strong symmetry existed between the left and right sides (Pearson Chi2 = 53.93 p < 0.001) for types OK1 and SK2a. Asymmetrical types were found in different bilateral combinations. (4) Conclusions: The spin of the CB is relatively symmetrical bilaterally, especially for the variants with the ECA antero-medial or anterior to ICA.
Objective:
Transcarotid artery revascularization (TCAR) has emerged as an effective method for carotid artery stenting. However, anatomic eligibility for TCAR is most often limited by an inadequate clavicle-to-carotid bifurcation length of <5cm. Preoperative clavicle-to-carotid bifurcation distances may be underestimated when using conventional straight-line measurements on computed tomographic angiography (CTA) imaging. We therefore compared clavicle-to-carotid bifurcation lengths as measured by straight-line CTA, center-line CTA, and intraoperative duplex ultrasound (US), to assess potential differences.
Methods:
We conducted a single-center, retrospective review of consecutive TCAR procedures performed between 2016-2019 for atherosclerotic carotid disease. For each patient, we compared clavicle-to-carotid bifurcation lengths measured by straight-line CTA, center-line CTA using TeraRecon image reconstruction, and intraoperative duplex US with neck extension and rotation. We further assessed patient and imaging characteristics in individuals with a ≥0.5cm difference among the measurement methods. In particular, common carotid artery (CCA) tortuosity, defined as the inability to visualize the entire CCA from clavicle to carotid bifurcation on both a single coronal and sagittal imaging cut, was examined as a contributing factor for these discrepancies.
Results:
Of the 70 TCAR procedures identified, 46 had all three imaging modalities available for review. The median clavicle-to-carotid bifurcation length was found to be 6.4cm [IQR 5.4-6.7] on straight-line CTA, 7.0cm [IQR 6.0-7.5] on intraoperative duplex US, and 7.2cm [IQR 6.5-7.5] on center-line CTA (p<0.001). Patients with a ≥0.5cm difference between their straight-line CTA and either their intraoperative duplex US or center-line CTA measurements were more likely to have tortuous CCAs (60.0% vs. 19.1%, p=0.01; 51.4% vs. 0.0%, p=0.01). There were no notable differences in age, gender, prior neck/cervical spine surgery, or neck immobility among these individuals. In patients with tortuous CCAs, duplex US and center-line CTA measurements added 1.0cm [0.6-1.5] and 1.1cm [0.9-1.6] more in length than straight-line CTA measurements, respectively. There was a strong linear correlation between the additional lengths provided by duplex US measurements and those provided by center-line CTA measurements for each individual within the tortuous CCA group (r=0.83).
Conclusions:
The use of straight-line CTA during pre-operative planning can underestimate the clavicle-to-carotid bifurcation lengths in patients undergoing carotid revascularization, particularly in those with tortuous CCAs. Both duplex US performed with extended-neck surgical positioning and center-line CTA provide similar and longer carotid length measurements, and should be utilized in patients with tortuous carotid vessels to better determine TCAR anatomic eligibility.
