Aortic origin of right hepatic artery and superior mesenteric origin of splenic artery two rare variations demonstrated angiographically

Abstract Anatomical variations of the celiac trunk and superior mesenteric artery are not infrequent. Knowledge of the existing aberrations is important in planning and conducting surgical or radiological procedures. A case of right hepatic artery arising independently from the aorta supplying an hepatocellular carcinoma was identified, through which transarterial chemoembolization was successfully performed. A second case is presented with a common splenomesenteric trunk branching into the splenic and superior mesenteric arteries. These two cases represent exceptional arterial variations in the upper abdomen.     

Bilateral variations of the vertebral arteries: The left originating from the aortic arch and the left and right entering the C5 transverse foramina

During the dissection course for second year medical students at the University of Toyama in 2005, we encountered variations of the bilateral vertebral arteries: the left directly came off from the aortic arch as the third branch between the left common carotid artery and the left subclavian artery and entered the transverse foramen of C5, instead of C6, whereas the right originated from the right subclavian artery and entered the transverse foramen of C5. The present vertebral artery of each side was possibly formed by the 6th cervical intersegmental artery linked with the longitudinal anastomoses between the cervical intersegmental arteries. Detailed knowledge of vertebral artery variations is crucially important for surgical treatment of blood vessels in the brain, neck and chest.     

Comparison of left and right vertebral artery intracranial diameters

Background: The vertebral artery is vulnerable to mechanical injury, especially in the region of the first and second cervical vertebrae, with resultant thrombus and/or emboli formation, often found at the vertebro-basilar junction. Such vascular injuries and associated neurological insults have been documented repeatedly in the literature as following cervical spine manipulation, when movements of the head and neck can cause compression and/or stretching of the vertebral artery and alterations in its blood flow. This has particular clinical relevance if a patient has a hypoplastic vertebral artery. Such persons may be considered at risk as regards vascular accidents following manipulation of the cervical spine. The aim of this study was to measure and compare the intracranial diameters of the left and right vertebral arteries in groups of black and white male and female South African subjects. Methods: Cadaver material from 58 specimens was processed for light microscopy, and measurements of inner (lumen only) and outer (lumen, tunica intima, and tunica media) diameters taken and compared, using the t-test. Results: Data analysis revealed a significant difference between the left and right vertebral artery intracranial diameters in the white female group only (N=8). Conclusions: Such a statistically significant difference implies a difference of biological importance and it is suggested that this particular group of subjects may be a high-risk group as regards vascular accidents following cervical spine manipulation. © 1995 Wiley-Liss, Inc.     

Anomalous origin and cervical course of the vertebral artery in the presence of a retroesophageal right subclavian artery

The vertebral artery is usually described as the first branch of the subclavian artery, originating medial to the scalenus anterior muscle. During its cervical course, the vertebral artery presents a prevertebral segment and then enters the foramen transversarium of the sixth cervical vertebra. We describe a case of an unusual origin and course of the right vertebral artery in a cadaver specimen wherein the right vertebral artery originates from the right common carotid artery at the inferior border of the thyroid gland. In its cervical course the vertebral artery ascends outside and anteriorly to the foramen transversarium of vertebrae C VI to C III, and enters the foramen transversarium of the axis. In the same specimen, a retroesophageal right subclavian artery is also present. These vascular abnormalities are presented for physicians to keep in mind such variations during diagnostic investigation and surgical procedures of the neck.     

Continuation of the ascending cervical artery as the occipital artery in man

We report an elderly male cadaver with unilateral anomalous continuation of the ascending cervical artery as the occipital artery. The ascending cervical artery was enlarged from its origin and supplied segmental branches through the intervertebral foramina. At the upper cervical spine, the ascending cervical artery continued as the occipital artery providing the branches normally seen stemming from this artery. No other vascular anomalies were noted in this specimen. This anatomical curiosity should be kept in mind by the clinician or academic who may manipulate this anatomical area.     

Unusual origin and course of the left pulmonary artery.

An infant with a cardiac murmur was found to have a patent arterial duct and an anomalous left pulmonary artery. The duct was surgically ligated at the age of 8 months, and she remained free of cardiac or respiratory symptoms up to her death at 6 years from an unrelated intestinal condition. An anomaly was discovered at post mortem examination; the left pulmonary artery arose from the right pulmonary artery and passed behind the trachea to enter the left lung. We describe and illustrate the anatomic features of this well-recognized entity, discuss the embryological substrate, and refer to the clinical implications.     

A case of double aortic arch accompanied by sub-aortic and pre-aortic left brachiocephalic veins and anomalous origin and course of left vertebral artery

During the elective course of human dissection at the University of Toyama in 2007, we encountered a rare case of double aortic arch accompanied by sub- and pre-aortic left brachiocephalic veins (LBV), and anomalous origin and course of the left vertebral artery in a Japanese elderly female. The double aortic arch formed a complete vascular ring that encircled the trachea and the esophagus. The sub-aortic LBV traversed below the aortic arches between the ascending aorta and the trachea. In addition, there was a small pre-aortic LBV passing anterior to the origins of the aortic arches. The left vertebral artery originated from the left aortic arch and entered the transverse foramen of C3, while the right vertebral artery originated from the right subclavian artery and entered the transverse foramen of C6.     

下颈椎椎动脉孔及其毗邻的解剖学和影像学观测

目的：为下颈椎前路手术预防椎动脉损伤提供解剖学数据。方法：(1)取20具尸体的C3～7段作为解剖标本,作两侧椎动脉孔内缘间距、椎体横、矢径、椎动脉孔内缘和椎弓根内缘间距、椎动脉孔内缘和椎体外缘间距、 椎动脉孔内缘和钩突关节内外缘间距、椎动脉孔前后缘与椎体前后缘的垂直距离、 椎动脉孔矢径的测量。(2)选30例已确诊为颈椎病患者和50例正常人作为检测对象,用CT测量上述数据。 结果： (1) C_3～7两侧横突孔内缘间距、椎体横径、椎体矢径、C_3～6椎动脉孔矢径逐渐增大。(2) 钩突内缘与椎动脉孔内缘间距在6 mm之内, C_3～6椎体外缘与椎动脉孔内缘间距不超过3 mm。(3) C_3～6 横突孔矢径和椎体矢径比值恒定(30.32%～31.86%), C_3～5 椎动脉孔前缘与椎体前缘距离逐渐减小,C_3～5椎动脉孔后缘与椎体后缘距离逐渐增加。结论：本文的测量数值与不同个体的椎动脉资料相结合,为预防椎动脉损伤提供了解剖学依据。     

Origins of the gonadal artery: embryologic implications

The gonadal arteries are paired vessels that usually originate from the abdominal aorta at the level of second lumbar vertebra. In 5-20% of cases, the gonadal artery has a high origin (superior to L2) and in 5-6% of cases it originates from the main or accessory renal artery. The latter is referred to here as an aberrant gonadal artery. Ninety-eight kidneys of 50 healthy potential renal transplant donors were prospectively studied by conventional angiography. The renal artery, either main or accessory, was detected and individually injected to highlight their perihilar divisions and possible extrarenal branches. The gonadal arteries were recorded if they originated from the renal arteries. We found that 39% (n = 38) of kidneys had at least one accessory renal artery. In 14 sides (14% of kidneys), the gonadal artery (11 right and 3 left) originated from the renal artery, either main (n = 5) or accessory (n = 9). Ten out of 14 kidneys with an aberrant gonadal artery had an associated accessory renal artery. In nine cases, the gonadal artery originated from the accessory renal artery, and in one case, although it originated from the main renal artery, the same kidney had an accessory arterial supply. The results of this study demonstrate that aberrant gonadal arteries tend to originate from kidneys that possess an accessory arterial supply. We hypothesize that aberrancies of the gonadal artery are a part of a common embryologic error resulting in the persistence of the future accessory renal arteries. We believe that this study is the first to hypothesize and study such an association with these arterial anomalies of the renal pedicle.     

Quantitative anatomy of vertebral artery groove on the posterior arch of atlas in relation to spinal surgical procedures

Background The location of the vertebral artery on a groove on the superior surface of the posterior arch of atlas makes it vulnerable to injury during surgical procedures in this region. Knowledge of the quantitative anatomy of the vertebral artery groove is therefore necessary. Methods In 55 dry adult atlas vertebrae, the distance of the medial edges of the vertebral artery groove were measured from the posterior midline at both the inner and outer cortices of the posterior arch of atlas. In addition, the distance between the vertebral artery grooves on either side as well as the length of the vertebral artery groove was also measured. Results It was found that a minimum of 1.5 cm of the posterior arch could be safely exposed at both the outer and inner cortices. In addition, with mobilization of the vertebral artery from its groove on both the sides, an additional 1 cm of posterior arch could be exposed on either side. Conclusions Exposure of the posterior arch of the atlas is an important step in surgical procedures for treatment of diverse conditions of the upper spinal cord and foramen magnum region. Injury to the vertebral artery in its position on the vertebral groove may lead to disastrous complications. The present study reveals that the neurosurgeon can safely expose up to 3.5 cm of the posterior arch of atlas and knowledge of this anatomic fact may help in planning surgical approaches.     

Landmarks for the identification of the cutaneous nerves of the occiput and nuchal regions

Although surgical procedures are often performed over the posterior head and neck, surgical landmarks for avoiding the cutaneous nerves in this region are surprisingly lacking in the literature. Twelve adult cadaveric specimens underwent dissection of the cutaneous nerves overlying the posterior head and neck, and mensuration was made between these structures and easily identifiable surrounding bony landmarks. All specimens were found to have a third occipital nerve (TON), lesser occipital nerve (LON), and greater occipital nerve (GON), and we found that the TON was, on average, 3 mm lateral to the external occipital protuberance (EOP). Small branches were found to cross the midline and communicate with the contralateral TON inferior to the EOP in the majority of sides. The mean diameter of the main TON trunk was 1.3 mm. This trunk became subcutaneous at a mean of 6 cm inferior to the EOP. The GON was found to lie at a mean distance of 4 cm lateral to the EOP. On all but three sides, a small medial branch was found that ran medially from the GON to the TON approximately 1 cm superior to a horizontal line drawn through the EOP. The GON was found to pierce the semispinalis capitis muscle on average 2 cm superior to the intermastoid line. The mean diameter of the GON was 3.5 mm. The GON was found to branch into medial and lateral branches on average 0.5 cm superior to the EOP. The LON was found to branch into a medial and lateral component at approximately the midpoint between a horizontal line drawn through the EOP and the intermastoid line. The main LON trunk was found on average 7 cm lateral to the EOP. In specimens with a mastoid branch of the great auricular nerve (GAN), this branch was found at a mean of 9 cm lateral to the EOP. The main trunk of this branch of the GAN was found to lie on average 1 cm superior to the mastoid tip. Easily identifiable bony landmarks for identification of the cutaneous nerves over the posterior head and neck can aid the surgeon in more precisely identifying these structures and avoiding complications. Although the occipital nerves were found to freely communicate with one another, avoiding the main nerve trunks could lessen postoperative or postprocedural morbidity. Moreover, clinicians who need to localize the occipital nerves for the treatment of occipital neuralgia could do so more reliably with better external landmarks.     

Right aortic arch with aberrant left subclavian artery report of two cases

Summary Two cases of adult asymptomatic right aortic arch with an aberrant subclavian artery are reported. They were discovered at time of coronary surgery. Preoperative coronary arteriography failed to demonstrate the anomalies. In one case, the right arch was suspected on chest x-ray and preoperative barium oesophagography. In one case, the proximal suture of one saphenous bypass graft was performed on the left common carotid artery. Right aortic arch is a malformation rarely discovered in adults. It generally produces no symptoms when not associated with cardiac disease.

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Crosse aortique droite avec artère sub-clavière gauche aberrante: rapport de deux cas

Résumé Deux cas de crosse aortique droite avec a. sous-clavière aberrante sont rapportés. Ils ont été découverts fortuitement à l'occasion d'un pontage coronaire. La coronarographie préopératoire n'a pas montré la variation. Dans un cas, la dextro-position de l'aorte a été suspectée sur les radiographies du thorax et sur l'oesophagographie. Dans l'un des deux cas, le greffon veineux saphène a été implanté sur l'a. carotide primitive gauche. La dextroposition de l'aorte est une variation rarement découverte chez l'adulte. En général, elle n'engendre aucun symptome quand elle n'est pas associée à d'autres malformations cardiaques.

     

Anatomical study of the internal nasal branch of the infraorbital nerve

The internal nasal branch of the infraorbital nerve (ION) runs down the nose and around the ala to be distributed to the nasal septum and vestibule. The aim of this study was to measure the internal nasal branch around the ala of the nose and discuss its possible relevance in clinical/surgical practice. Twelve sides from seven specimens derived from fresh frozen and embalmed Caucasian cadaveric heads were dissected. The specimens included three males and four females. The ages of the cadavers at death ranged from 65 to 84 years. The diameter of the internal nasal branch, horizontal distance from the lateral contour of the ala (Point A) to the branch (distance H) and vertical distance from the bottom part of the ala (Point B) to the branch (distance V) were recorded. Distance H ranged from ?1.6 to 1.5 mm on right sides and ?1.0 to 1.5 mm on left sides. The diameter of the nerves at Point A ranged from 1.3 to 1.8 mm on right sides and 1.3 to 1.6 mm on left sides. Distance V ranged from ?1.5 to 1.0 mm on right sides and ?2.3 to 1.1 mm on left sides. The diameter of the nerves at Point B ranged from 0.7 to 1.3 mm on right sides and 0.8 to 1.2 mm on left sides. The results of this study are the first to detail the topography of the internal nasal branch of the ION. Clin. Anat. 30:817–820, 2017. © 2017Wiley Periodicals, Inc.     

Right vertebral artery as the fourth branch of the aortic arch

The present report describes an anomalous case of the right vertebral artery arising as the last branch of the aortic arch identified in a 76-year-old Japanese male cadaver during dissection in the anatomical laboratory of Kanazawa Medical University. The aortic arch itself coursed normally but the right vertebral artery was uniquely situated at the fourth branch next to the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. The anomalous right vertebral artery branched into the esophageal branch, the prevertebral branch, and the second right posterior intercostal artery, and finally entered the first costotransverse foramen at the thoracic region as it passed upward through the first to the seventh transverse foramina of the cervical vertebra. The left vertebral artery was normal. The development of the right vertebral artery may be described as follows: (i) the distal portion of the right dorsal aorta, which usually disappears, persisted and became united, via post-costal longitudinal anastomosis; (ii) the right dorsal aorta between the seventh and eighth intersegmental arteries lost its connection to the main structure; and (iii) the fusion of the originally paired dorsal aorta extended around the 11th segment, which was two segments away from the normal portion of the structure.     

Anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters (Mesocricetus auratus)

This study describes the coronary artery distribution patterns associated with the anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters. The hearts of 15 affected animals were examined by means of a corrosion-cast technique, histology and scanning electron microscopy. The hamsters belonged to a laboratory inbred colony with a high incidence of coronary artery anomalies and bicuspid aortic valves. The aortic valve was tricuspid in eight hamsters and bicuspid in the other seven. In all cases, the right coronary artery was normal, whereas the left main coronary artery trunk arose from the right aortic sinus or from the right side of the ventral aortic sinus when the aortic valve was bicuspid. In 12 specimens, the left main trunk crossed the infundibular septum and then divided into the left circumflex branch and the obtuse marginal branch. In another specimen, the course of the left main trunk was ventral to the right ventricular outflow tract; in the remaining two, it surrounded the aorta dorsally. In man, some of these distribution patterns may cause myocardial ischaemia and sudden death. The present findings prove that the origin of the left coronary artery from the right aortic sinus occurs in primitive mammals such as the Syrian hamster, suggesting that the defect may occur in other mammalian species. Its possible occurrence should be borne in mind in domestic animals, especially in those with signs of myocardial ischaemia after strenuous activity.     

远外侧经枕髁手术入路防止椎动脉损伤的应用解剖

目的:为远外侧经枕髁入路手术保护椎动提供较详细的解剖资料。方法:应用20具(40侧)成人尸头湿标本进行显微解剖研究。结果:寰椎横突、第2颈神经前支、肩胛提肌、椎动脉周围静脉丛、头外侧直肌为确认第2、3段椎动脉的重要标志。寰、枢椎横突孔间距左侧为(15.3±1.6)mm,右侧(15.8±2.2)mm;枕骨大孔后缘中点距椎动脉入硬脑膜口处左侧(21.6±2.0)mm,右侧(21.5±2.0)mm;椎动脉于寰椎后弓上方向后呈弓形弯曲,其外侧跨度左侧(17.9±3.2)mm,右侧(17.7±3.2)mm;内侧跨度左侧(9.8±2.5)mm,右侧(9.8±2.2)mm;向后距椎板高左侧(7.4±2.3)mm,右侧(6.3±3.3)mm。结论:熟悉椎动脉第2、3、4段的毗邻关系及解剖标志,对保护椎动脉、安全地施行远外侧经枕髁入路手术至关重要。     

Unusual fibrous band on the left aspect of the aortic arch

During dissection of a 63-year-old female cadaver, a firm ribbon-like band was found on the left aspect of the aortic arch. Careful dissection showed that the band (6 cm long, 8 mm wide, 2 mm thick) connected the left superior intercostal vein with the accessory hemiazygos vein. Histological examination showed the fibrous structure of the band and showed the presence of a thread-like vascular lumen. The topography and venous connections of the band indicated its origin from persistence of the embryonic anastomosis between the left superior intercostal and accessory hemiazygos veins. This anastomosis derives from the rostral portion of the supracardinal vein that usually regresses on the left side but forms the terminal arch of the azygos vein on the right side. The severe atherosclerosis present in this patient at the level of the aortic arch may have enhanced the effects of arterial pressure on the adjacent venous anastomotic vessel causing reduction of blood flow and progressive fibrosis. The persistence of this venous anastomosis and its possible age-related fibrosis may have clinical relevance in central venous catheter placement.     

Histometrical investigation of the pulmonary artery in severe hepatic disease

Histological changes of the pulmonary vasculature in comparison with that of the portal vein in necropsy cases of severe hepatic injury that had not been associated with clinical pulmonary hypertension were analysed qualitatively and quantitatively. The main changes of the intra-hepatic portal vein were dilatation (88.3 per cent), thickening of the wall (58.5 per cent) and thrombi (22.3 per cent). The changes of the pulmonary vasculature were limited to muscular type arteries, which showed dilatation (31.9 per cent), thickening of the wall (30.9 per cent) and thrombi (10.6 per cent). Association of wall thickening of the portal vein and the small pulmonary artery was observed in 30.9 per cent, these associations being statistically significant. Coincidence of thrombus formation in the portal vein and pulmonary vasculature was observed only in 4.3 per cent, which was not statistically significant. After the circumferences of the internal and external elastic laminae of small pulmonary arteries and the cross-sectional area of the media were measured, the anatomical radius and wall thickness of each artery were calculated according to Furuyama 's method. The relations between the anatomical radii and wall thickness of small pulmonary arteries in controls and hepatic cirrhosis groups were investigated by analysis of covariance to compare the equality of the two corresponding regression lines. The wall thickness and the ratio of wall thickness to the anatomical radius of small pulmonary arteries were significantly larger in the cirrhotic group than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Variant origin of the superior thyroid artery in a Kenyan population

Variant anatomy of the superior thyroid artery is important during surgical procedures, interpretation of angiograms, and interventional radiography in the neck. Pattern of the variations shows population differences but there is no data from the Kenyan population. This study therefore investigated the variations in origin of the superior thyroid artery in a Kenyan population. Forty six necks (36 males and 10 females) from 46 cadavers of black Kenyans in Department of Human Anatomy University of Nairobi, Kenya were bilaterally dissected to expose the origin of the superior thyroid artery. Pattern of origin of the vessel was determined on both sides in males and females. It originated from the external carotid artery common carotid artery and linguo-facial trunk in 80%, 13%, and 6.5% of the cadavers respectively on the right side. All but one of the superior thyroid arteries were ventral branches. There was asymmetric origin in 6.5% of cases. Origin from the common carotid artery was associated with high carotid bifurcation. Nearly 20% of superior thyroid arteries showed variant origin. Of these, 6.5% arose from the linguo-facial trunk, much higher than in the Caucasian and Oriental populations. Origin from common carotid artery is substantially lower than prevailing figures from other populations. These findings support ethnic variations. Preoperative angiographic evaluation is recommended.