Do Asians have Higher Carotid Bifurcation? A Computed Tomographic Angiogram Study of the Common Carotid Artery Bifurcation and External Carotid Artery Branching Patterns

Is low carotid bifurcation determined by vertebral level always convenient for surgical approach?

Although high-level carotid bifurcation (HCB) could lead to notable surgical difficulty, the definitive reference point for HCB is unclear. HCB is typically characterized as carotid bifurcation (CB) located higher than the level of the third cervical vertebra (C), however, a major obstacle regarding carotid artery surgical exposure is angle of the mandible (AM). The objective of this study was to investigate CB level, define HCB in relation to AM and vertebral levels, and measure the vertical distance from HCB to ipsilateral AM. Moreover, the percentage of surgically challenged CBs, misclassified as low CBs (LCB) based on vertebral level, was investigated. Patients who underwent neck computed tomography angiography were retrospectively studied. HCBs were classified into two categories: CBs above the C3 and either at or above the ipsilateral AM. Of 172 CBs (86 patients; 57 men, 29 women), CB was mostly found at C3 (44.19%), whereas AM was commonly located at C2 (51.16%). Based on vertebral level and AM, HCBs were detected in 10.47% and 20.35% of CBs, respectively. The association of HCBs determined by either C3 or AM between both sides in each individual was nonsignificant (p>0.05), but HCBs determined by C3 level were predominant in women (OR = 3.58, 95%CI = 1.31-9.80). Considering both C3 and AM, there was 8.72% of HCBs. The remaining 91.28% was classified as LCBs, including 11.63% of CBs located at both C3 and AM which were actually classified as HCBs if determined by AM. In cases of CBs above AM level, the mean vertical distance was as high as 6.56 ±2.41mm.

Smoking and secondhand smoke exposure and carotid intima-media thickness: Baseline data from the Aidai Cohort Study in Japan

INTRODUCTION

Epidemiological evidence regarding the relationship between smoking and secondhand smoke (SHS) exposure and carotid intima-media thickness (CIMT) has been limited in Asian populations. Employing baseline data from the Aidai Cohort Study, Japan, we evaluated the evidence in this cross-sectional study.

METHODS

Study subjects were 727 men aged 35-88 years and 1297 women aged 34-85 years. Information on smoking, SHS exposure, and confounders was obtained through a self-administered questionnaire. An automated carotid ultrasonography device was used to measure the right and left CIMT. The greatest CIMT measurement in the left or right common carotid artery was considered the maximum CIMT, and a maximum CIMT >1.0 mm was indicative of carotid wall thickening. Age, alcohol consumption, leisure time physical activity, hypertension, dyslipidemia, diabetes mellitus, body mass index, waist circumference, employment, and education level were adjusted at one time.

RESULTS

The prevalence of carotid wall thickening was 13.0%. The prevalence of never smoking was 30.5% in men and 90.1% in women. Among those who had never smoked, the prevalence of never SHS exposure at home and work was 74.3% and 48.2% in men and 38.3% and 56.3% in women, respectively. Active smoking and pack-years of smoking were independently positively related to carotid wall thickening regardless of sex, although the association with current smoking in women was not significant. Independent positive relationships were shown between former smoking and pack-years of smoking and maximum CIMT in men but not in women. No significant relationships were found between SHS exposure at home and work and carotid wall thickening or maximum CIMT in either men or women.

CONCLUSIONS

Active smoking, especially pack-years of smoking, was positively associated with carotid wall thickening in both sexes. Such positive associations with maximum CIMT were found only in men; however, interactions between smoking and sex were not significant.

Morphometric Study and Branching Patterns of External Carotid Artery Using Computed Tomography Angiography Among the South Indian Population: A Retrospective Study

INTRODUCTION

The prime source of vascularization to the head and neck region is through the carotid arteries. The terminal branches of common carotid arteries, such as external carotid artery (ECA) and internal carotid artery (ICA), and their branches are crucial due to the wide area of distribution and variations in their branching pattern. The branching pattern and morphometry are essential for surgeons in the planning and execution of head and neck surgeries. Therefore, this study was conducted to observe the branching patterns of ECA and analyze them morphometrically.

MATERIALS AND METHODS

This retrospective study includes 100 CT images, inclusive of 32 females and 68 males. The branching pattern and luminal diameter of CCA and ECA were measured and analyzed statistically.

RESULTS

The luminal diameter of CCA in males were as follows: 7.4 ± 1.01 (R), 7.1 ± 0.8 (L), and in females: 7.3 ± 0.9 (R), 7 ± 0.9mm (L); and the luminal diameter of ECA in males: 5.2 ± 1.0mm (R), 5.2 ± 0.9mm (L), and in females: 5.0 ± 0.9mm (R), 5.1 ± 1.0mm (L). The level of the carotid bifurcation and ECA branching pattern was observed, and variations were commonly seen in the superior thyroid artery (STA), lingual artery (LA), and facial artery (FA).  Conclusion: The findings of the present study with regard to the external carotid artery and its branching pattern correlate with previous studies. The most common variations were observed in the superior thyroid and lingual and facial arteries. Knowledge about the morphology and branching pattern of the carotid artery is essential for procedures such as intra-arterial chemotherapy, carotid artery stenting, endarterectomy, and extra-intra cranial bypass revascularization procedure where it is harvested as a donor's vessel.

Geometric morphometric study of anterior branches of external carotid artery and carotid bifurcation by 3D-CT angiography

PURPOSE

The aim of our study was to determine the variations of the anterior branches of the external carotid artery (ECA) and investigate the morphometric and geometric features of the anterior branches of the ECA and carotid bifurcation (CB).

METHODS

A total of 563 ECAs were included from 288 patients in the study. Classification and exit angles of anterior branches of ECA and determination of vertebral levels of CB and anterior branches were performed.

RESULTS

The anterior branch variants of the ECA were observed in 8 different subgroups. The most common variations were type Ia 42.3% (n = 120) on the right and type Ib 40.9% (n = 114) on the left. When looking at the vertebral levels, CB was detected at C4 level in 32.9% of total ECAs (n = 185), STA was at C4 level in 33.4% of total ECAs (n = 188), LA was at C3 level in 50.1% of total ECAs (n = 282), and FA was at C2 level in 37.3% of total ECAs. The mean CB angle in all cases was 59.93° ± 16.04. In the anterior branches of the ECA in cases belonging to the Type I group, the widest angle belonged to FA (R = 116.88 ± 27.04°, L = 110.32° ± 25.94).

CONCLUSION

In conclusion, a new classification of the variations of the anterior branches of the ECA was made on the basis of the CTA images to gain more practicality in surgical procedures. This study revealed for the first time the angular and level relationship between CB and ECA anterior branches.

The carotid axis revisited

The aim was to determine the variations in the level of origin of carotid bifurcation and diameters of the common, internal, and external carotid arteries which is clinically important for several interventional procedures. Therefore, 165 human embalmed corpses were dissected. The data collected were analyzed using the Chi square-test and the Pearson correlation test. The results of previous studies have been reviewed. In relation to the level of the carotid bifurcation, taking as a reference point the hyoid bone, the values ranged from 4 cm below the hyoid body to 2.5 cm above the body of the hyoid, being the average height—0.33 cm, with a standard deviation of 1.19 cm. The right carotid bifurcation was established at a higher level (x = − 0.19 cm.) than the left one (x = − 0.48 cm.) (p = 0.046). On the contrary, no significant gender differences could be observed. The arterial calibres of the common and internal carotid arteries were higher in male than female. In the internal carotid artery (X = 0.76 cm.), the left was greater than the right (X = 0.72 cm.) (P = 0.047). However, no differences in the distribution of the calibre of the external carotid artery were found neither by side nor gender. Variations in the level of bifurcation and calibres of carotid arteries are relevant for interventional radiology procedures and head and neck surgeries. Knowledge of these anatomical references might help clinicians in the interpretation of the carotid system.

Imaging features of internal maxillary artery and extracranial middle meningeal artery and their relationships on head CTA

BACKGROUND

The internal maxillary artery and extracranial middle meningeal artery are vitally important. Anatomical studies of the relationship of between them using computed tomography angiography are rare.

MATERIAL AND METHODS

This study assessed 75 cases involving 150 sides. And the vascular diameters and lengths of the internal maxillary artery and middle meningeal artery were measured using a GE workstation. The distance between the zygomatic arch midpoint and the internal maxillary artery, the angle between the internal maxillary artery and middle meningeal artery were measured, and the middle meningeal artery branch and internal maxillary artery aneurysm were recorded. The internal maxillary artery course classifications were recorded. All of these parameters were statistically analysed.

RESULTS

Ages ranged from 18 to 72 (average 40.2) years, and there were 30 women (40%, 30/75) and 45 men (60%, 45/75). Internal maxillary artery length from its origin to middle meningeal artery origin was 1.37 ± 0.59 cm. The extracranial middle meningeal artery length was 1.79 ± 0.48 cm. The vessel diameters of internal maxillary artery origin, middle meningeal artery origin, and middle meningeal artery at the skull base were 2.93 ± 0.52 mm, 1.58 ± 0.43 mm, and 1.33 ± 0.43 mm, respectively. Among the 150 sides of internal maxillary artery course type, there were 138 superficial (92%, 138/150) and 12 (8%, 12/150) deep course cases. The angle between the internal maxillary artery and middle meningeal artery was 116.2 ± 35.76°.

CONCLUSIONS

The findings of this study elucidate the imaging features of the internal maxillary artery and extracranial middle meningeal artery and their relationships, which are helpful for the extracranial-intracranial bypass and endovascular treatment via the internal maxillary artery and middle meningeal artery.