Anatomic evaluation of the carotid artery bifurcation in cadavers: implications for open and endovascular therapy

Knowledge of carotid bifurcation (CB), common carotid artery (CCA) and its branches and their recognition during diagnostic imaging are also important for vascular surgical procedures in the region, such as carotid endarterectomy or radical neck dissection, catheterization and aneurysms. The surgical anatomy of the carotid arteries was studied in 20 cadavers. Micrometric values of the CB and its relation with surrounding structures, measurements belonging to the external carotid artery (ECA) and internal carotid artery (ICA), and metric data, such as lower face including the greater horn, laryngeal prominence have been evaluated by making linear measures. The diameter of the CCA at the CB under 2 cm and CB diameter was measured as 8.1 +/- 2.24 mm and 12.79 +/- 2.87 mm, respectively. Evaluating data related to the ICA and the ECA in samples, the aspect was measured the ICA and the ECA in the CB discrimination point as 21.52 +/- 20.53 degrees . In the most location of the ECA origin according to the ICA has been determined as medial position in 35 specimens. The origin of the superior thyroid artery (STA) was found to be at the same level with the CB in 40% and below it in 25% specimens. This study has provided measured objective criteria for the arterial features of the neck region, which are crucial during surgery. The origins of the branches of the CCA act as key landmarks for adequate and appropriate placement of the cross-clamp on the carotid arteries.     

颈内动脉狭窄对体循环系统影响的集中参数模型研究

研究颈内动脉病变时对整个颈动脉系统的影响。建立了一个带颈动脉分岔血管分支的体循环系统集中参数模型,基于一组可较好地模拟正常生理曲线的参数,通过改变颈内动脉段的集总参数来模拟颈内动脉狭窄,研究了其对颈动脉系统的影响。结果表明:颈内动脉发生狭窄时,会使其自身的流量、压力和颈总动脉的流量发生显著变化。这些变化主要是由液阻和液容的改变引起的,其中液阻的影响更显著。此外,颈内动脉发生狭窄对于颈外动脉的影响较小,对颈总动脉入口压力则不产生影响。由此说明:利用三维计算模型对颈动脉分岔血管进行血流动力学数值模拟时,入口边界条件用入口压力比用入口流量更合适。     

Thyrolingual trunk arising from the common carotid artery identified by three-dimensional computed tomography angiography

It is well-known that the branches of the external carotid artery (ECA) can show anatomical variation, but it is extremely rare that thyrolingual trunk originates from common carotid artery (CCA). Here we report a case of the thyrolingual trunk arising from the CCA on the right side in a 73-year-old female as revealed by three-dimensional computed tomography angiography for vascular mapping of the carotid vessels before head and neck microsurgical reconstruction. The thyrolingual trunk arose from the anterior surface of the right CCA, with an origin 14.5 mm (difference between the carotid bifurcation and upper border of the origin 12.7 mm) below the carotid bifurcation. The inner diameter of origin of the thyrolingual trunk was 3.5 mm, and the angle between the thyrolingual trunk and the CCA was 130°. After a 10.2-mm course, the thyrolingual trunk divided into the superior thyroid artery (STA) and lingual artery (LA). The inner diameters of the origins of the STA and LA were 1.7 and 1.9 mm, respectively, and the angle between the branches was 94°. It is important to recognize this anatomic variation of the branches of the ECA before the microsurgical reconstruction or super-selective intra-arterial chemotherapy for head and neck cancer.     

Investigation of the bifurcation level of the common carotid artery and variations of the branches of the external carotid artery in human fetuses.

Variations in the position of the bifurcation of the common carotid artery (CCA) and the origin or branching pattern of the external carotid artery (ECA) are well known and documented. In this study, the bifurcation levels of the CCA and origin variations of the branches of the ECA have been extensively investigated in human fetuses. Bilaterally, 40 carotid bifurcations and 40 ECA and their branches have been examined. A latex solution, which had been diluted with water at a ratio of 25% and colored with red India ink, was injected into the aortic arch. Fetuses were kept at room temperature for 24 h before the ECA and its branches were dissected under the microsurgery microscope. Cases of variation were determined and photographed. The bifurcation level of the CCA was determined to be 55% at the C3 level, 35% at the C4 level, 10% at the C5 level on the right side and 60% at the C3 level, 40% at the C4 level on left side. The distribution of the ECA trunks was determined as follows: A linguofacial trunk was present in 20% of the cases, a thyrolingual trunk in 2.5%, a thyrolinguofacial trunk in 2.5% and an occipitoauricular trunk in 12.5%. Beyond this the ascending pharyngeal artery (APA) was observed in one fetus to originate from the internal carotid artery (ICA). Knowledge of variations in the origin and course of the ECA and its branches is of great importance in surgery and radiological examinations.     

Association of high carotid bifurcation and thyrolinguofacial trunk: a rare variation

Variations in the origins and the branching pattern of the carotid system of arteries are not uncommon. Here we report a rare case of higher bifurcation of the common carotid artery (CCA) (at the level of the greater cornu of the hyoid bone), thyrolinguofacial trunk (TLFT) originating from the CCA, superior laryngeal artery (SLA) arising from the external carotid artery (ECA) on the left side, and linguofacial trunk arising from the ECA on the right side. In the present case, the CCA and carotid bifurcation may have arisen from the second aortic arch. The ECA bud could have developed from parts of the first aortic arch and ventral aorta. Thus, the altered blood flow through these vessels due to high carotid bifurcation could have caused disproportionate growth and shift in the origins of the branches of the ECA. An understanding of the bifurcation of the CCA and the branching pattern of the ECA should prove useful to surgeons performing selective intra-arterial chemotherapy for head and neck cancer.     

Emerging patterns of the human superior thyroid artery and review of its clinical anatomy

Purpose

There is wide variability of the location of the superior thyroid artery (STA). Our purpose was to describe variations of the STA origin, with great respect to different anatomical patterns which could be observed in humans.

Methods

The material was 68 formalin-embalmed adult cadavers of both sexes (45–70-year-old). Methodologically, we dissected the neck region bilaterally and focused on studying the external carotid artery (ECA) branches, especially the STA emerging pattern. We also measured the distance of the STA origin from the common carotid artery (CCA) bifurcation (using the latter as a landmark).

Results

Based on our results we categorized the STA emerging pattern into three major types A, B and C according to its origin (which was CCA, ECA and CCA bifurcation, respectively). Regarding type B, we found that the left STA arises approximately 2 mm closer to the CCA bifurcation compared to the right STA (p < 0.05).

Conclusions

The STA is a carotid branch with variable origin, which can be CCA, ECA or CCA bifurcation. It is also an artery of great clinical importance in head and neck surgery. The present study provided data of the STA emerging patterns, as well as a review of its clinical anatomy.     

Association between internal carotid artery morphometry and posterior communicating artery aneurysm

PURPOSE: The goal of this study was to directly measure the association between the internal carotid artery (ICA) morphometry and the presence of ICA-posterior communicating artery (PCOM) aneurysm. MATERIALS AND METHODS: The authors intraoperatively measured the length of the supraclinoid ICA because it is impossible to radiologically determine the exact location of the anterior clinoid process. We used an image analyzer with a CT angiogram to measure the angle between the skull midline and the terminal segment of the ICA (ICA angle), as well as the diameter of the ICA. The lengths and diameters of the supraclinoid ICA and the ICA angle were compared among PCOM aneurysms, anterior communicating artery (ACOM) aneurysms, and middle cerebral artery (MCA) bifurcation aneurysms (n=27 each). Additionally, the lengths and the diameters of M1 and A1 were compared for each aneurysm. RESULTS: The lengths of the supraclinoid ICA were 11.9+/-2.3 mm. The lengths of the supraclinoid ICA in patients with ICA-PCOM aneurysms (9.7+/-2.8 mm) were shorter than those of patients with ACOM aneurysms (13.8+/-2.2 mm, Student's t-test, p<0.001) and with MCA bifurcation aneurysms (12.2+/-1.9 mm, Student's t-test, p<0.001). The diameters of the supraclinoid ICA and A1 in patients with ACOM aneurysms were larger than those in patients with MCA bifurcation aneurysms (Student's t-test, p<0.05). There were no significant differences in the lengths of M1 and A1, ICA angle, or diameter of M1 for each aneurysm. CONCLUSION: These results suggest that the relatively shorter length of the supraclinoid ICA may be a novel risk factor for the development of ICA-PCOM aneurysm with higher hemodynamic stress.     

Thyrolinguofacial trunk arising from the carotid bifurcation determined by three-dimensional computed tomography angiography

It is recognized that the branches of the external carotid artery (ECA) can show variation, but the presence of a thyrolinguofacial trunk is extremely rare and always originates from the ECA. We report a case of the thyrolinguofacial trunk arising from the carotid bifurcation (CB) on the left side in a 76-year-old man with advanced tongue cancer, as revealed by three-dimensional computed tomography angiography for vascular mapping of the carotid vessels prior to superselective intra-arterial catheterization. The thyrolinguofacial trunk arose 1.6 mm below the CB from the anterior surface of the left CB. The inner diameter of the thyrolinguofacial trunk at origin was 4.4 mm and the angle between the thyrolinguofacial trunk and CB was 128°. After a 1.7-mm course, the trunk divided into the superior thyroid artery and a linguofacial trunk, the inner diameters of which were 1.5 and 3.4 mm, respectively, at origin. The angle between the two arteries was 88°. After a 9.8-mm course from the bifurcation, the linguofacial trunk divided into the lingual artery and facial artery, the inner diameters of which were 1.8 and 1.9 mm, respectively, at origin. The angle between the two arteries was 61°. It is important to recognize such an anatomic variation of the branches of the ECA prior to superselective intra-arterial catheterization or microsurgical reconstruction for head and neck cancer.     

Cervical lymph nodes are found in direct relationship with the internal carotid artery: Significance for the lymphatic drainage of the brain

The brain has no conventional lymphatics, but solutes injected into it drain along artery walls and reach lymph nodes in the neck. This study seeks to identify cervical lymph nodes related to the human internal carotid artery (ICA) that could act as the first regional lymph nodes for the brain. Bilateral dissections were carried out on four embalmed human heads, from the level of the carotid bifurcation in the neck, to the base of the skull. Lymph nodes from every specimen were processed for histological examination. A total of 51 deep cervical lymph nodes were identified: 12 lymph nodes (confirmed by histological examination) were observed to be in direct relationship with the ICA. These lymph nodes were found within the carotid sheath and had average diameters of 13.5 × 4.8 mm. Solutes and interstitial fluid from the brain may drain along the walls of cerebral arteries and reach these lymph nodes. They may be sites of stimulation of immune responses against antigens from the brain. Clin. Anat. 23:43–47, 2010. © 2009 Wiley‐Liss, Inc.     

经翼点入路鞍区手术间隙解剖学研究

目的　为鞍区显微外科手术提供解剖学参数。方法　对 10具成人尸体头颅的鞍区手术间隙及邻近血管、神经进行解剖学观察、测量。结果　大脑中动脉M1段在距颈内动脉分叉部 18.4± 3.2mm处形成初级分叉 ,向后上方发出约 14支穿支 ,分布至基底节区。鞍结节后缘至视交叉前缘相距 5 .6± 1.1mm ,两侧视神经内侧缘间最大距离 10 .5± 1.4mm。颈内动脉从内侧壁发出 3.2支垂体上动脉 ,终止于视神经、视交叉、视束和垂体柄 ;视神经 -颈内动脉三角三边长度分别为 6 .6± 0 .6mm ,6 .9± 0 .7mm ,4 .0± 0 .4mm。颈内动脉 -小脑幕三角三边长度为 8.8± 0 .7mm ,6 .7± 0 .7mm ,4 .4± 1.0mm ,后交通动脉起自颈内动脉后外壁距分叉部 7.7± 0 .5mm ,止于大脑后动脉 ,全长 18.7± 2 .3mm ,途中发出 7.4条穿通支。脉络膜前动脉从距分叉部 4 .4± 0 .6mm处发出 ,向后方走行 ,发出细小分支 ,分布于钩回、脉络丛。前交通动脉全长 1.9± 0 .3mm ,在前交通动脉上方 0 .9± 0 .2mm ,大脑前动脉A2段前外壁发出Heubner回返动脉 ,分布于胼胝体、基底节、下丘脑及额叶脑组织。结论　应用这些间隙的解剖学测量可指导与鞍区相关的手术 ,安全显露鞍区解剖结构 ,不损伤重要的血管和神经。     

Different ophthalmic artery origins: Embryology and clinical significance

This retrospective study gives a summary of ophthalmic artery (OA) variations to serve as guidelines for surgical interventionists and trainees. Pubmed and Medline searches were conducted. The OA usually arises intradurally (superomedial, anteromedial, or rarely superolateral) from the internal carotid artery (ICA). Rare extradural origin (primitive dorsal OA) (PDOA) remnant and extremely rare interdural origin (primitive ventral OA) (PVOA) remnant are of significance when sectioning the dural ring. Rarely, a persistent PDOA with ICA origin, or a PDOA remnant with inferolateral trunk origin, enters the orbit via the superior orbital fissure (SOF) for sole or partial orbital supply. Extremely rare, the PDOA and PVOA persist and form double OAs that arise from the ICA and run via the SOF and optic foramen. Occasionally, the OA arises from the middle meningeal artery (MMA), when both the PDOA and VDOA regress and enter the orbit via the SOF. Sole orbital supply via the external carotid artery (ECA), i.e. meningo‐ophthalmic artery and/or MMA branches, or dual OAs (ECA and ICA origins) may occur. Other rare OA origins include anterior or posterior communicating artery; anterior or middle cerebral artery; basilar artery; posterior inferior cerebellar artery; and the carotid bifurcation. Primitive arteries (persistent or remnant), and/or abnormal anastomoses play pivotal roles in manifestations of OA variations. Of clinical importance are orbital collateral routes and dangerous extracranial‐intracranial anastomoses. Awareness of OA origins and collateral routes is imperative for transarterial embolizations or infusion chemotherapy in the ECA territory to prevent visual complications. Clin. Anat. 28:576–583, 2015. © 2014 Wiley Periodicals, Inc.     

Anomalous branching pattern of external carotid artery: Clinical relevance to cervicofacial surgery

Anomalous branching pattern of the left external carotid artery (ECA) was detected in an old man. The ECA branched into high submental artery and large transverse facial artery ending as angular artery compensating for concurrent agenesis of ipsilateral facial artery. The lingual artery gave direct branch to the submandibular gland, whereas the superior thyroid artery arose directly from common carotid artery with high bifurcation level. This unreported branching pattern of the ECA may have important clinical relevance to cervicofacial surgery.     

Carotid atherosclerosis and the risk factors in early postmenopausal Chinese women

Objectives

To describe the distribution of intima-media thickness (IMT) and the prevalence of plaque by carotid segments, walls and sides, and to examine their associated risk factors in asymptomatic, early postmenopausal Chinese women in Hong Kong.

Methods

Between 2002 and 2004, the study recruited 518 postmenopausal women aged 50–64 years. They were examined by B-mode ultrasound to measure the IMT and the prevalence of plaque at the near and far walls of common carotid (CCA), bifurcation (bulb), and internal carotid (ICA) of both the left and right carotid arteries. Blood pressures, obesity indices, lipids and glucose levels, sociodemographic, medical and lifestyle factors were also obtained.

Results

The mean IMT was 0.76 ± 0.12 mm (range: 0.53–1.33 mm). IMT was significantly thicker on the far wall than on the near wall and differed among segments (being thickest at the bulb and the narrowest at the ICA). 21.8% had at least one plaque in the carotid artery with most of the plaque found at the bulb area. Systolic blood pressure had statistically significant relationship with IMT that were fairly homogeneous among different segments. Lipids were associated with the CCA and bulb IMT, but not the ICA IMT. Diabetes predicted only CCA IMT. Older age, higher waist–hip-ratio and low-density lipoprotein cholesterol were significant predictors of plaques at all sites combined.

Conclusions

We described the distribution of IMT and the prevalence of plaque in asymptomatic, early postmenopausal Chinese women. Associations of risk factors with IMT of different arterial segments were also observed.     

Surgical anatomy of hypoglossal nerve as a guide for important head and neck surgeries

Introduction

The hypoglossal nerve (HN) may be damaged during neck surgeries. A detailed understanding of the anatomy of the hypoglossal nerve in relation to various anatomical landmarks and surrounding structures is important to reduce procedural complications and the risk of nerve damage.

A description of arterial variants in the transoral approach to the parapharyngeal space

This study demonstrates variations in the vascular anatomy of the parapharyngeal space (PPS) as seen from the transoral approach compared with the transcervical approach. The PPS was dissected in injected cadaveric specimens. Anatomical measurements, including those of branches of the external and internal carotid arteries (ECA and ICA) and the styloglossus and stylopharyngeus muscles, were recorded and analyzed. In 67% (8/12) of cases, the ascending palatine artery (APA) originated from the facial artery and crossed the styloglossus muscle. The diameter of the APA at its origin was 1.4 ± 0.3mm. In 75% (9/12) of cases, the ascending pharyngeal artery (aPA) arose from the medial surface of the ECA near its origin. In 58% (7/12) of cases, the aPA ascended vertically between the ICA and the lateral pharynx to the skull base, along the longus capitus muscle. The aPA crossed the styloglossus muscle 12.6 ± 3.9mm from the insertion into the tongue. In 92% (11/12) of cases, the ECA and ICA were separated by the styloid diaphragm and pharyngeal venous plexus. In 8% (1/12), the ECA bulged into the parapharyngeal fat between the styloglossus and stylopharyngeus muscles adjacent to the pharyngeal constrictors. Knowledge of the precise anatomy of the PPS is important for transoral robotic surgery (TORS). Control of the vessels that supply and traverse the PPS can help the TORS surgeon avoid those critical structures and reduce surgical morbidity and potential hemorrhage. Clin. Anat. 27:1016–1022, 2014. © 2014 Wiley Periodicals, Inc.     

彩色多普勒超声对颈动脉粥样硬化与脑梗死的相关性分析

目的探讨颈动脉粥样硬化与脑梗死的关系。方法应用彩色多普勒超声检测82例脑梗死患者和46例非脑梗死患者颈动脉内-中膜厚度（intima-media thickness,IMT）、斑块检出率、管腔狭窄率,并观察斑块性质。结果脑梗死组斑块检出率及颈动脉内膜厚度较对照组明显增加,两组比较差异有统计学意义（P〈0.01）,脑梗死组斑块检出率（70.7%）明显高于对照组（32.6%）;脑梗死组颈总动脉（CCA）内膜厚度（1.38±0.14）明显高于对照组（0.89±0.16）,脑梗死组颈内动脉（ICA）内膜厚度（1.16±0.27）明显高于对照组（0.78±0.17）。斑块多发生于颈动脉分叉处（44.4%）,以软斑块、溃疡斑块（59.2%）居多。结论颈动脉粥样硬化程度与脑梗死的发病关系密切,彩超评估颈动脉粥样硬化程度,对脑梗死的早期预防和治疗具有重要的临床价值。     

Association of self-reported snoring with carotid artery intima-media thickness and plaque

Previous studies have suggested that self‐reported snoring is associated with atherosclerotic vascular diseases. However, the role of self‐reported snoring as an independent risk factor for subclinical atherosclerosis has not been well established. This study aimed to evaluate whether and to what extent self‐reported snoring is associated with subclinical carotid atherosclerosis after adjusting for traditional cardiovascular risk factors. Carotid intima‐media thickness and plaque were investigated with ultrasonography in 1245 urban Chinese aged 50–79 years between September 2007 and November 2007. Information on self‐reported snoring and measurements of traditional cardiovascular risk factors was also collected. A total of 1050 participants were involved in the final analysis. The prevalence of self‐reported snoring habitually (snoring frequency ≥5 days per week) was 31.5, and 64.3% of the participants in this population had a history of snoring. The mean values of the maximum intima‐media thickness of bifurcation and common carotid arteries in snorers were significantly higher than in non‐snorers (1.08 ± 0.14 mm versus 1.04 ± 0.14 mm, P < 0.001, in carotid bifurcation; 1.03 ± 0.15 mm versus 1.00 ± 0.15 mm, P = 0.002, in common carotid artery). After adjustment for traditional cardiovascular risk factors, logistic regression analysis showed that the odds ratio of self‐reported snoring habitually for increased intima‐media thickness and carotid bifurcation plaque was 1.71 [95% confidence interval (CI): 1.22–2.39; P = 0.002] and 3.63 (95% CI: 2.57–5.12; P < 0.001), respectively. In conclusion, the current study suggested that self‐reported snoring is associated significantly with carotid bifurcation intima‐media thickness and the presence of plaque, independent of traditional cardiovascular risk factors.     

缺血性脑血管病患者颈动脉粥样硬化的研究

目的:探讨颈动脉粥样硬化与缺血性脑血管病的关系。方法:将缺血性脑血管病患者99例分成TIA组,脑梗塞组,均接受颈部动脉多普勒超声检查,观察指标为动脉粥样硬化斑块的好发部位,超声分型及颈内动脉(ICA)颅外段狭窄度。结果:颈部动脉多普勒超声检查显示TIA组和脑梗塞组异常率均明显高于健康人,差异有显著性(P<0.01),TIA组与脑梗塞组异常率相比也有显著性差异(P<0.05)。病变血管分布与症状间有相关关系P<0.01)。从动脉粥样硬化斑块好发部位及超声分型来看,动脉粥样硬化斑最多见于颈总动脉分叉处(BIF).其次是颈总动脉(CCA),再其次是ICA起始部,TIA组与脑梗塞组均以扁平斑多见,其次是软斑和硬斑,溃疡斑少见。另外ICA颅外段狭窄度与症状间呈显著相关(P<0.01)。结论:颈动脉粥样硬化班块,是缺血性脑血骨病发生的重要危险因素之一。颈动脉粥样硬化程度越重.发生严重缺血性卒中的危险性越高。     

An anatomical study on the lingual–facial trunk

Purpose  We quantified variations of the lingual artery origin, measured the lingual artery origin distance from clinical relevant landmarks and compared the lingual artery diameters with normal and variable origin. Methods  Forty-two formalin fixed male cadavers were bilaterally evaluated. Measurements were performed with the aid of an electronic digital caliper. Results  The origin distances from the common carotid artery bifurcation was 1.05 ± 0.11 and 1.02 ± 0.11 cm for the right and left lingual arteries respectively with no differences compared to the lingual–facial trunks. The diameters of the lingual arteries were 0.25 ± 0.01 and 0.26 ± 0.01 cm for the right and left sides, respectively, while the lingual–facial trunks showed diameters of 0.21 ± 0.02 and 0.24 ± 0.02 cm for the right and left sides, respectively. Conclusions  The present study adds information on the lingual artery diameter and its anatomical relation to clinically useful landmarks.