The diameters of common carotid artery and its branches in newborns

The common carotid artery (CCA) bifurcation is of clinical importance due to its vascular access site for intravascular intervention. Additionally, it is also one of the most common sites of atherosclerotic plaque formation. There are numerous studies on the diameters of CCA, internal carotid artery (ICA), and external carotid artery (ECA) in adults, but few studies on newborns. Cadaver and angiographic studies have shown dimensional variations in the carotid arteries within/between individuals and also between different sexes. It is well known that the initial lesions of atherosclerosis begin very early in fetal life. Therefore, it is important to know the anatomical details of the CCA and its branches. In the present study, the neck regions of 20 (11 males and 9 females) fixed newborn cadavers were dissected. The CCAs were cut below the bulb of the carotid bifurcation further; ICA and ECA were cut above the bulb of the carotid bifurcation. The internal diameters of the CCA, ICA, and ECA were measured using a light microscopy. ECA/CCA, ICA/CCA, ICA/ECA ratios, and outflow to inflow area ratio were calculated. The mean outflow to inflow area ratio was 1.14±0.28. Our results highly correlated with the defined optimal ratio (1.15). The ECA/CCA, ICA/CCA, and ICA/ECA ratios were 0.78±0.12, 0.71±0.13, and 0.93±0.16, respectively. There were no statistically significant differences between male and female and also between right and left sides. These findings are of importance in understanding the anatomy of carotid artery during newborn period.     

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.     

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.     

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.     

Superior thyroid artery origin in Caucasian Greeks: A new classification proposal and review of the literature

Studies on the origin of the superior thyroid artery, define that it could originate either from the external carotid artery, (at the level of common carotid bifurcation), or from the common carotid artery. However, there is a classical anatomic knowledge that the superior thyroid artery is a branch of the external carotid artery. Variability in the anatomy of the superior thyroid artery was studied on 100 carotids. Moreover, a review about the origin of superior thyroid artery between recent and previous cadaveric, autopsy, and angiographic studies, on adults and fetuses, was carried out. The superior thyroid artery originated from the external carotid artery in 39% and at the level of carotid bifurcation and common carotid artery in 61% of cases. The anterior branches of the external carotid artery were separate in 76% of cases, while common trunks between the arteries were found in 24% of the specimens. A new classification proposal on the origin of the superior thyroid artery is also suggested. In this study, the origin of superior thyroid artery is considered at the level of the carotid bifurcation and not from the external carotid artery as stated in many classical anatomy textbooks. This has a great impact on the terminology when referring to the anterior branches of the external carotid artery, which could be termed as anterior branches of the cervical carotid artery. Head and neck surgeons must be familiar with anatomical variations of the superior thyroid artery in order to achieve a better surgical outcome.     

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.     

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.     

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.     

颈动脉的形态与动脉粥样硬化的解剖学观测

目的研究颈动脉的形态与动脉粥样硬化的情况,为颈总、颈内动脉狭窄的诊治提供形态学基础。方法解剖观测成尸30(男24、女6)侧颈动脉,观测颈动脉的形态及动脉粥样硬化情况。结果①颈总动脉中段外径,左侧(8.75±1.56)mm;右侧(8.31±0.99)mm。②颈内动脉根部外径,左侧(8.15±1.42)mm;右侧(7.51±1.63)mm。③颈外动脉中段外径,左侧(4.87±1.09)mm;右侧(4.39±0.89)mm。④颈动脉粥样硬化发生率占60%(18侧),其中颈内动脉根部四壁明显动脉硬化,内腔直径1.6mm严重狭窄1侧,占总数的3.33%。结论颈动脉粥样硬化发生率最高为颈动脉窦,占颈动脉硬化标本的100%,可致颈内动脉内腔狭窄。     

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.     

喉罩对颈总动脉和颈内动脉血流动力学的影响

目的 研究喉罩对颈总动脉(CCA)和颈内动脉(ICA)内径、血流速率和血流量等血流动力学参数的影响.方法 随机选择择期全麻下行腹腔镜胆囊切除术患者60例,为美国麻醉医师协会(ASA)Ⅰ～Ⅲ级.根据不同年龄分为中青年组(A组,20～59岁)和老年组(B组,60～85岁).按不同的喉罩套囊内压力将A组和B组分为4个亚组,即A1、B1(套囊内压为20～30 cm H2O)(1 cm H2O=0.098 kPa)和A2、B2(套囊内压为40～50 cm H2O),每组15例.所有患者术毕后送入ICU复苏,尚未清醒时拔除气管导管,而后置入喉罩.记录置入喉罩前(T0),置入喉罩后3 min(T1)、10 min(T2)和拔除喉罩后(T3)各时点CCA和ICA的内径、血流速率和血流量等血流动力学参数以及生命体征参数.结果 CCA、ICA的内径和CCA血流量的基础值B组比A组要大(P<0.05).与T0比较,在T1和T2时点,A组和B组CCA内径分别减少9.5%～12.9%和14.5%～24.3%(P<0.05或P<0.01),其中以B2组减少最为显著,A2组和B2组ICA内径分别减少10.9%和16.3%(P<0.05).CCA和ICA的血流速率无明显变化(P>0.05).与T0比较,A组和B组,T1和T2时CCA的血流量分别减少9.3%～10.7%和12.2%～19.1%(P<0.05),其中以B2组减少最为显著,A组和B组ICA血流量分别减少10.0%～13.5%和13.9%～16.6%(P<0.05).在T3时点各观察指标均恢复至T0水平.结论 喉罩通气时,CCA和ICA的内径有所缩小,其血流量相应减少,老年患者减少更为明显,而其血流速率则无明显改变.     

颈内动脉床突段的解剖特点及毗邻关系

目的　观察颈内动脉床突段的解剖特点,探讨该结构的毗邻关系,为临床工作的开展提供依据。 方法　成人尸头标本7例,分别以红色和蓝色硅胶对动脉、静脉进行灌注;应用显微解剖技术,观察并测量颈内动脉的床突段及与眼动脉、远/近侧硬膜环等重要毗邻结构的位置关系。 结果　(1)与颈内动脉床突段相关的参数：床突段的外径为（5.11±0.81）mm,床突段外侧面远、近侧硬膜环中点间距离为（5.46±1.90）mm,远侧硬膜环形成颈内动脉窝的出现率约为78.6%。(2）床突段与眼动脉的关系：①眼动脉起点与远侧硬膜环的位置关系为近侧约7.1%、恰于远环处约14.3%、远侧78.6%;②眼动脉起点与颈内动脉横截面的位置关系为内1/3约78.6%、中1/3约21.4%（未观察到外1/3的情况）。 结论　(1)术前影像学检查十分必要。(2)对侧翼点入路有利于眼动脉起点处病变的暴露。(3)提出两点术中注意事项：①环切远侧硬膜环时,应注意避免伤及眼动脉或其它视神经管内结构;②磨除前床突时注意其内侧的重要血管、神经组织,应以邻近硬膜瓣加以保护。     

Occipital artery arising from the superior aspect of the carotid bifurcation identified by three-dimensional computed tomography angiography

Variation of the branches of the external carotid artery is well known, but it is extremely rare for the occipital artery (OA) to arise from the carotid bifurcation (CB). A 73-year-old man was found to have this anatomical variation on the right side by three-dimensional CT angiography for vascular mapping of the carotid arteries before superselective intra-arterial catheterization. The OA arose from the CB and the inner diameter of the origin of the OA was 1.5 mm. The CB was located at the level of C3–C4 and 7.9 mm above the tip of the greater horn of the hyoid bone.     

Microsurgical anatomy of the maxillary artery for extracranial‐intracranial bypass in the pterygopalatine segment of the maxillary artery

The extracranial‐intracranial (EC‐IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC‐IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension‐free EC‐IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC‐IC bypass. Clin. Anat. 31:724–733, 2018. © 2017 Wiley Periodicals, Inc.     

Anomalous artery directly connecting the external and internal carotid arteries

An anomalous artery directly connecting the external with the internal carotid artery was encountered on the right side of a 68-year-old Japanese female cadaver. This anomalous artery (5 mm in diameter, 12 mm in length) branched out from the posterior aspect of the external carotid at the level of the origin of the lingual artery, ran obliquely upward posteriorly along the course of the hypoglossal nerve, and was confluent with the anterior aspect of the internal carotid artery. No other variations were found in the morphological aspects of, or in the anatomical relationships between, the carotid arteries and their surrounding structures on either side. The carotid body-like structure was observed at the carotid bifurcation and was innervated by small branches of the glossopharyngeal, the vagus and the sympathetic trunk. Embryologically, it is conceivable that this anomalous artery may have derived from the right second branchial arch artery, although there is no abnormality in other derivative structures of the second pharyngeal arch. There may have been no effect from this anomaly on the functions of the arterial blood flow and blood supply under normal circumstances in the present case, but this report may be of embryological significance and contribute some insight into the mechanisms of the formation of the carotid circulation systems.     

Clinically relevant variations of the superior thyroid artery: an anatomic guide for surgical neck dissection

The superior thyroid artery (STA) is the dominant arterial supply of the thyroid gland, upper larynx and the neck region. The knowledge of variations in possible patterns of origin, courses, and branching pattern of the STA is also important for surgical procedures in the neck region, such as emergency cricothyroidotomy, radical neck dissection, catheterization, reconstruction of aneurysm and carotid endarterectomy. The surgical anatomy of the STA was studied in 20 adult Anatolian preserved cadavers between the age of 40 and 70 years. The outer diameter of the STA origin was observed to be 3.53 ± 1.17 mm. The location of the origin of the STA according to the carotid bifurcation was evaluated as above (25%), below (35%) and at the same level (40%). The distribution patterns of the STA were classified into six types depending on the branching pattern. The outer diameter of the infrahyoid branch, superior laryngeal artery, sternocleidomastoid artery and cricothyroid branch at their origins were observed to be 1.13 ± 0.14, 1.42 ± 0.47, 1.54 ± 0.96 and 1.30 ± 0.41 mm, respectively. Typical and variant glandular branching patterns were observed in 85 and 15% of the specimens, respectively. The outer diameters of anterior, anteromedial, anterolateral and posterior glandular branches were measured as 2.05 ± 0.46, 1.41 ± 0.43, 1.51 ± 0.41 and 1.73 ± 0.53 mm, respectively. It is necessary to understand the surgical anatomy of the STA to carry out successful radical neck dissection and to minimize postoperative complications in a bloodless surgical field.     

咽升动脉分支的解剖分组及其临床意义

目的:探讨咽升动脉及其主要分支在颈部颅底区域走行规律及其在血管内外治疗中的临床意义。方法:选择以10%甲醛固定并用乳胶灌注的8具（16侧）成人颅颈部标本,自颈总动脉分叉水平向上解剖至颅底骨质,分离显露咽升动脉及周围相关结构,观察咽升动脉的起源部位及主要分支,测量相关解剖学参数。依据咽升动脉主要分支与颈动脉鞘的位置关系分...     

颈内动脉床突上段的显微外科解剖学

目的 :探讨颈内动脉床突上段的毗邻关系、分支特点及其手术意义。方法 :在手术显微镜下观察 3 0侧标本颈内动脉床突上段的形态及周围关系。结果 :颈内动脉床突上段实为出海绵窦后的一段 ,常以纤维结构与周围牵连 ,主干分为眼动脉段、后交通动脉段及脉络膜动脉段 3段。后交通动脉大致发自中点水平 ,脉络膜前动脉大致发自后半的中点。眼动脉段均发出垂体上动脉 ,多数还发出眼动脉 ,少数发出前床突支。在视交叉池内 ,垂体柄前方所见的小动脉几乎均属于垂体上动脉的分支。结论 :有些颈内动脉床突上段术中推移有困难 ,需先松解其纤维连系。打开颈动脉池时应特别留意前床突支 ,防止损伤出血。供垂体柄的分支可以切断 1～ 2支小支 ,而至视路的分支均宜妥善保留。