Anatomical study of the vertebral artery in japanese adults

The aim of the present study was to examine the vertebral arteries. The origins of the right and left vertebral arteries and their entrance points into the cervical transverse foramen were examined in dissections of 515 Japanese cadavers (303 males, 212 females) at Kurume University School of Medicine from 1990 to 2003. There were 515 right vertebral arteries and 514 left vertebral arteries. The right vertebral artery originated from the right subclavian artery in 514 of 515 arteries and one of the arteries arose from the bifurcation of the brachiocephalic trunk. The mean distance between the origin of the right subclavian artery and the right vertebral artery was 20.9 mm. The left vertebral artery originated from the left subclavian artery in 484 of 514 arteries and the mean distance between the origin of the left subclavian artery and the left vertebral artery was 32.1 mm. The remaining 30 arteries (5.8%) originated from the aortic arch between the left common carotid artery and the left subclavian artery and this frequency is similar to previously published data. There was no right-left difference for the entrance point of the vertebral arteries into the cervical transverse foramen and the 6th cervical vertebra (C6) was the most common entrance point. Seventy-eight percent of our cases had right and left vertebral arteries that originated in the subclavian arteries and entered the cervical transverse foramen at C6. Among the 30 left vertebral arteries that originated from the aortic arch, 20 arteries (66.7%) entered a cervical transverse foramen at a level higher than C6. This frequency was higher than that for the left vertebral artery that originated from the subclavian artery.     

动脉导管三角的应用解剖

目的　为动脉导管三角区的临床手术提供形态学基础。  方法　随机选用经福尔马林固定的尸体50具,解剖观测动脉韧带（AL）、左迷走神经、左喉返神经(LRLN)等相关结构,所得结果进行统计学处理。  结果　（1）有94%（47例）AL连于主动脉弓和左肺动脉（LPA）,即经典的动脉导管三角内,6%(3例)AL连于降主动脉与LPA之间。（2）根据AL与主动脉弓和LPA附着关系的不同,可分为6种类型：Ⅰ.附于主动脉弓下缘和LPA上缘之间(76%); Ⅱ.附于主动脉弓前壁与LPA上缘之间(8%); Ⅲ.附于主动脉弓前壁与LPA前壁之间(8%); Ⅳ.附于降主动脉内侧缘与LPA上缘之间(4%); Ⅴ.附于降主动脉内侧缘与LPA后壁之间(2%); Ⅵ.附于主动脉弓下缘与LPA前壁之间（2%）。（3）LRLN在主动脉弓下缘由左迷走神经发出者占36%;在主动脉弓前壁下1/3、中1/3和上1/3段发出者分别占30%、14%和14%;在降主动脉内侧缘发出者占6%。（4）AL中轴与LPA中轴的夹角平均为（45.08±19.06）°,其中6%(3例)夹角仅为0°,4%(2例)夹角为90°。（5）所有LRLN均贴近动脉韧带主动脉端由左迷走神经发出并向后上方返折。  结论　AL的附着关系与经典描述之间存在差异。由于附着关系的不同,使其与LPA、LRLN等周围解剖结构的毗邻关系亦发生了改变。熟悉这些变化,对防止动脉导管结扎术并发症的发生有指导意义。     

The portal bifurcation and the termination of the hepatic veins: an anatomical investigation into the projection of the ultrasonographically important hepatic vessels onto the anterior body wall

Summary An investigation was carried out on 50 cadavers, in which the projection onto the anterior abdominal wall of the following vascular points was examined: the portal bifurcation, the direction of the course of the right and left branches of the portal vein and the terminal course of the hepatic veins near their entry into the inferior vena cava (IVC). The results are related to a transverse axis passing through the apex of the xiphoid process and the median plane in the supine position. The average position of the portal bifurcation is projected onto a point between a vertical line passing through the midpoint of the right hemithoracic width and a horizontal line passing through a point on the midclavicular line (MCL) corresponding to 57% of the height of the liver measured upwards from its inferior margin. The axis of the prehepatic course of the portal vein makes an anagle of about 50°, open downwards, with a vertical line drawn through the apex of the internal angle of the portal bifurcation. A line parallel to the course of the right and left branches of the portal vein is projected on to a surface line cranial to the right costochondral margin, which runs upwards at an angle of approximately 20° towards the apex of the xiphoid process. The termination of the three great hepatic veins is projected at about the level of the xiphisternal joint, one sternal width to the right of the midline. Close to the IVC, the right hepatic vein runs upwards and medially at an angle of between 20° and 30° with the transverse plane. The final segment of the intermediate hepatic vein has a relatively steeper course medially of between 60° and 70°, and the left hepatic vein runs laterally and towards the right at an angle of between 50° and 60°. The nearly vertical projection of the fissure for the ligamentum teres of the liver bisects the angle included by the final course of the intermediate and the left hepatic vein.

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La bifurcation portale et la terminaison des veines hépatiques: étude anatomique de la projection échographique des gros vaisseaux hépatiques sur la paroi abdominale antérieure

Résumé Cette étude a été réalisée sur 50 dissections cadavériques, dans le but de préciser la projection sur la paroi abdominale antérieure des éléments vasculaires suivants: la bifurcation portale, la direction du trajet des branches droite et gauche de la veine porte et la terminaison des veines hépatiques dans la veine cave inférieure. Les résultats sont donnés par rapport à un axe transversal passant par le sommet du processus xiphoïde et au plan sagittal médian en décubitus dorsal. La situation moyenne de la bifurcation portale se projette au point de croisement d'une ligne verticale passant par le milieu de l'hémithorax droit et d'une ligne horizontale coupant la ligne médio-claviculaire (LMC) à 57% de la hauteur du foie mesurée de bas en haut à partir de son bord inférieur. L'axe du tronc de la veine porte fait un angle ouvert en bas d'environ 50° avec la verticale passant par la bifurcation portale. Une parallèle au trajet des branches droite et gauche de la veine porte se projette sur une ligne située cranialement par rapport au rebord chondrocostal droit, qui monte vers l'extrémité du processus xiphoïde en faisant un angle de 20° avec le plan transversal. La terminaison des trois veines hépatiques se projette environ au niveau de l'articulation sternoxiphoïdienne à une largeur de sternum à droite de la ligne médiane. A proximité de la veine cave inférieure, la veine hépatique droite se dirige cranialement et médialement en formant un angle de 20 à 30° avec le plan transversal. Le segment terminal de la veine hépatique moyenne a un trajet relativement plus vertical avec un angle de 60 à 70° et la veine hépatique gauche se dirige vers la droite en formant un angle de 50 à 60°. La fissure du ligament rond du foie se projette presque verticalement sur la bissectrice de l'angle formé par la portion terminale des veines hépatiques moyenne et gauche.

     

Anomalous origin of both vertebral arteries

The authors describe a case of an unusual origin of both vertebral arteries in a singular cadaver. On the left, the artery arises directly from the common trunk of vertebral and subclavian artery at the aortic arch and enters the transverse cervical foramina at C VI. On the right, the artery originates from the right common carotid artery and enters the transverse foramina at C III. Additional anomalies were observed on the aortic arch: the common trunk of both common carotid arteries, the common trunk of the left vertebral and subclavian artery, and as a last branch, the retroesophageal right subclavian artery. The morphometric measurements of the vertebral arteries were performed. The literature on the variations of the vertebral arteries is reviewed and their clinical importance for diagnostical procedures and head and neck surgery stressed. Clin. Anat. 12:281–284, 1999. © 1999 Wiley‐Liss, Inc.     

A case of the right aortic arch with the left subclavian artery as its last branch]

A case of the right aortic arch with the left subclavian artery as its last branch was found in an 80-year-old Japanese female cadaver during the 1990 dissection for students. The main findings were as follows. The ascending aorta arose from the left ventricle and ran right and upward to the level of the intervertebral disc between the 2nd and 3rd thoracic vertebrae. It then curved right and backward to form the aortic arch. The aortic arch joined the thoracic aorta that descended along the right side of the vertebral column and crossed obliquely the vertebral column at the level of the 8th thoracic vertebra. Finally it entered the abdomen through the aortic hiatus behind the esophagus. Four branches were given off from the aortic arch in the following order from left to right: the left common carotid, the right common carotid, and the right subclavian and the left subclavian arteries. The left subclavian artery, which had an aortic diverticulum at the origin of the aortic arch, ran left and upward behind the esophagus. The ligamentum arteriosum connected the left pulmonary artery with the aortic diverticulum of the left subclavian artery. The left common carotid artery, which normally had no branches before entering the cranium, gave off an accessory esophageal branch about 20 mm distally from its origin. The right and left vertebral arteries entered the transverse foramen of the 6th cervical vertebra. The left recurrent laryngeal nerve hooked around from the left dorsal to the right ventral part of the ligamentum arteriosum.(ABSTRACT TRUNCATED AT 250 WORDS)     

A Study of Variations in Coronary Ostia

Introduction: The year 1928 saw the first human coronary angiograph when Werner Forssmann inserted a ureteral catheter into his left anticubital vein and advanced it to the heart. Today coronary angiographies and selective coronary angiographies are being done quite frequently. Presence of supernumerary ostia can make it difficult to correctly interpret angiographic films. Also during selective angiography such ostia are difficult to cannulate. The knowledge of position of coronary ostia with respect to aortic sinuses and possible variations in their locations will aid in carrying out these procedures as well as in interpreting them.High position of ostia in comparison to the aortic sinuses has been found to be related to poor filling of coronary arteries during diastole. The knowledge of position of ostia, could help in correct interpretation of patient's symptoms and could help in channalizing the further line of treatment.Aim: To study the variations in the number and position of coronary ostia in relation with aortic sinuses.Materials and Methods: A total of 50 human hearts were included in this study irrespective of sex. The hearts were procured from dissection room adult cadavers of Dr D Y Patil Medical College, Pune and were preserved in 10% formalin.The origins of both the coronary arteries were noted while looking out for presence of any extra ostia in either of the three aortic sinuses. Depending on whether the ostia were situated below, at or above the cuspal margin they were classified as those taking origin from the sinus, sinuaortic junction or ascending aorta.Results: In this study the ostium for right coronary artery was located in the anterior aortic sinus in 98% cases and in right posterior aortic sinus in 2% cases. The ostium for left coronary artery was located in the left posterior aortic sinus in 100% cases. The maximum height of ostium from the sinuaortic junction in case of coronary arteries taking origin directly from aorta was found to be 1.5mm.Regarding study of number of ostia found in the aortic sinuses-22% hearts showed presence of 2 ostia, 2% hearts showed 3 separate ostia and 2% hearts showed 5 ostia in the anterior aortic sinus region. No supernumerary ostia were found in the left posterior aortic sinus region. 2% incidence of circumflex artery taking origin from the anterior aortic sinus was observed.     

Anatomical evaluation and clinical importance of the tibiofibular syndesmosis ligaments

The aim of this study was to describe the detailed anatomical arrangement of ligaments of the tibiofibular syndesmosis and to highlight the clinical aspects of fracture dislocations. This study was performed on 42 legs of adult human embalmed cadavers. Tibiofibular syndesmosis ligaments attachments and their mutual relationships were described and their dimensions were measured. The anterior tibiofibular ligament is usually composed of three parts. This ligament runs obliquely at laterodistaly direction making 35° angle with horizontal plane and posteriorly 65° angle with sagittal plane. The posterior tibiofibular ligament runs almost horizontally 20° angle with horizontal plane. The mean thicknesses of tibial and fibular attachments are 6.38±1.91 mm and 9.67±1.74 mm, respectively. The inferior transverse ligament originates from just below the posterior tibiofibular ligament, which has variations on the shape and dimensions due to its attachment points. The average length is 36.60±9.51 mm. The network between the fibular notch and the distal fibula has been filled with the interosseous tibiofibular ligament whose fibers follow the laterodistal and anterior direction from the tibia to the fibula. It lies proximally 30–40 mm from the mortise. At the inferior view of the tibiofibular syndesmosis a pyramidal shaped cartilaginous facet was observed which was attached to the fibula. The length of this cartilage was variable. Some of synovial plicas from the ankle joints synovial membrane were observed at this view. We conclude that the results of this study may be useful to both orthopedic surgeons and radiologists for anatomic evaluation of the tibiofibular syndesmosis area.     

无症状青年人群股骨颈α角CT测量多个平面之间的比较

目的　比较无症状青年人群中多个平面CT测量股骨颈α角的差异，并对凸轮型股髋撞击综合征（FAI）形态改变的发生率进行评估。  方法　回顾性分析2009年5月至2013年11月120例无髋关节病症患者（20～40岁）的腹部或盆腔CT扫描资料。α角的测量采用平行于股骨颈长轴的斜轴位平面以及以股骨颈中心作为旋转轴的4个方向辐射状层面,两者差异的比较采用方差分析，α角大于55°提示凸轮型FAI形态异常。  结果　斜轴位平面α角均值为(39.5±6.51) º，共有12人（占10%，12/120）、14个关节α角大于55 º，10人为单侧、2人为双侧；在12点、1点、2点及3点方向各平面的α角均值分别为(42.8±7.3) º,(48.8±7.6)º,(47.3±7.2)º,(40.2±6.7)º，在所有辐射状平面中共有106个关节α角大于55 º，其中在1:00方向有54个关节α角增大，占受试者的35%（42 /120）（30人为单侧，12人为双侧）；斜轴位平面与12点、1点、2点方向平面测量的α角之间的差异有统计学意义（P<0.05）。  结论　在辐射状平面测量α角可能更准确；无症状青年人群中，其类似凸轮型FAI的形态改变有较高的发生率。     

The ophthalmic artery and its branches,measurements and clinical importance

Summary Seventy-one Caucasian orbits (36 right, 35 left) were studied by dissection. The diameter of the ophthalmic a. (2 mm from the origin) was 1.54 ± 0.04 mm (male) and 1.31 ± 0.05 mm (female). In individual cases, there were no significant differences in vessel diameter between the right and left sides but, differences in vessel diameter between males and females were more commonly observed in the arteries which leave the orbit (extraorbital group), the individual vessels having a larger diameter in males. The incidence of the ophthalmic a. passing in the orbit medially under the optic n. was 18.6%. The lacrimal a. was observed to arise from the ophthalmic a. in only 82.5% of the cases examined, 15.9% of the cases showed the origin to be at the anastomotic branch of the middle meningealThis article is dedicated to Pr Dr Hoepke on occasion of his 100th birthday     

Digital fluoroscopic assessment of the scapulohumeral rhythm

Previous studies have shown that abnormal rotation of the scapula is associated with shoulder pathology. Among the methods which have been proposed, planar x-ray measurements are probably the only methods, which enable clinicians to assess accurately and objectively the scapulohumeral function in vivo. The aim of this study was to develop a method for the assessment of scapulohumeral kinematics using digital fluoroscopy. Anteroposterior images of the right glenohumeral joint were taken, in thirty-four healthy males, with the arm at rest, 30°, 60°, 90°, 120°, 150° and maximum abduction, in the scapular plane. High inter- and intra-examiner reliability was observed regarding the arm and scapular angle measurements (ICC = 0.92–0.99). The positioning of the arm at the proposed angles was also highly accurate (< 2.3° misplacement) and reproducible (CV% < 5.3%). The mean radiation dose was 0.075 mSv (± 0.027 mSv). At the resting position the scapula was in slight downward rotation (−2.4° ± 4.3°) and the arm in slight abduction (1.5° ± 6.6°). The mean maximum scapular rotation and the mean maximum arm abduction was 61.4° (± 5.2°) and 162.4°(± 6.6°) respectively. A curvilinear relationship was found between the arm angle (AA) and the scapular angle (SA) (p < 0.0001). The AASA ratio for the entire range of abduction was 2.51. The greatest contribution of the scapula (1.71) achieved at 30°-60° of arm. The high accuracy and reliability of our method and the low radiation recordings suggests that digital fluoroscopy may be considered for further investigation of the scapulohumeral kinematics in both healthy and pathological shoulders.     

Head and trunk movements in the frontal plane during complex dynamic equilibrium tasks in humans

Eight normal human subjects were asked to maintain monopodal equilibrium on a narrow beam (task 1) or bipodal equilibrium on an unstable rocking platform (task 2) for 5 s. Each task was performed under four experimental conditions: (1) in light, (2) in darkness, (3) in light while subject had to hold a full cup of water, and (4) as in 3, but with additional instructions to fix the gaze on the cup. The movements of the trunk and head in the frontal plane were recorded by means of a 50-Hz TV image analyzer that computed the coordinates of small reflective markers glued on the skin of the subjects. On the beam the trunk was inclined on the side of the supporting foot (13 ± 9°), on the rocking platform the mean trunk orientation during the tests was nearly vertical (2 ± 7°). Nevertheless, in both tasks the mean head position was the same and close to vertical: 1.5 ± 4° on the rocking platform and 1.5 ± 5° on the beam. For both tasks and all experimental conditions the head remained stabilized relative to vertical, despite large translations in the frontal plane. Standard deviations of head orientation from its mean value were 2.8 ± 2° for task 1 and 2 ± 1.5° for task 2. The changes of trunk orientation were significantly higher: 6.2+4.8° and 4.5 ± 4°, respectively. The differences in angular stability of head and trunk, measured through the standard deviations of angular displacements, were especially pronounced in trials with large trunk movements. It was concluded that head angular stabilization, providing the central nervous system with necessary visual and vestibular references, is essential for effective dynamic postural control in the frontal plane during complex equilibrium tasks.     

Anatomical variations of the human suprarenal arteries

This is on anatomical study of the suprarenal arteries and their variations in 30 cadavers aimed at providing in a subsequent article the anatomical basis of arterial segments of the gland. The suprarenal glands were supplied by 3 main groups of suprarenal arteries: superior, middle and inferior. Only the superior and the inferior groups were present in all cases, since the middle vessels appeared in only 93.3% +/- 4.6 of the cases. The superior group included on each side 4 arteries in males and 5 in females; the middle group presented only 1 artery on each side in both males and females, and the inferior group exhibited on each side 2 arteries in males and 1 artery in females. The most variable group was the middle one, the aortic origin being the most frequent but with a relatively low incidence (53.3% +/- 9.1 on the right and 46.7% +/- 9.1 on the left). The superior group originated from the posterior branch of the ipsilateral inferior phrenic artery in 83.3% +/- 6.8 on the right and 80% +/- 7.3 on the left. The arteries of the inferior group were branches of the ipsilateral renal artery in 70% +/- 8.4 on the right and 50% +/- 9.1 on the left. The origin of the middle suprarenal arteries from the trunk of the inferior phrenic artery on both sides (26.7% +/- 8.1 on the right and 36.7% +/- 8.8 on the left) should be considered relevant. The anatomical findings warrant a further investigation for the identification, illustration and nomenclature of arterial anatomicosurgical segments.     

Aortic arch origin of the left vertebral artery

Complications from anterior approaches to the cervical spine are uncommon with normal anatomy. However, variant anatomy might predispose one to an increased incidence of injury during such procedures. We hypothesized that left vertebral arteries that arise from the aortic arch instead of the subclavian artery might take a more medial path in their ascent making them more susceptible to iatrogenic injury. Fifty human adult cadavers were examined for left vertebral arteries having an aortic arch origin and these were dissected along their entire cervical course. Additionally, two radiological databases of CTA and arteriography procedures were retrospectively examined for cases of aberrant left vertebral artery origin from the aortic arch over a two‐year period. Two cadaveric specimens (4%) were found to have a left vertebral artery arising from the aortic arch. The retrospective radiological database analysis identified 13 cases (0.87%) of left vertebral artery origin from the aortic arch. Of all cases, vertebral arteries that arose from the aortic arch were much more likely to not only have a more medial course (especially their preforaminal segment) over the cervical vertebral bodies but also to enter a transverse foramen that was more cranially located than the normal C6 entrance of the vertebral artery. Spine surgeons who approach the anterior cervical spine should be aware that an aortic origin of the left vertebral artery is likely to be closer to the midline and less protected above the C6 vertebral level. Clin. Anat. 30:811–816, 2017. © 2017Wiley Periodicals, Inc.     

局部血管几何构型与动脉粥样硬化性肾动脉狭窄的关系

目的:研究局部血管几何构型与动脉粥样硬化性肾动脉狭窄(ARAS)的关系.对动脉粥样硬化性疾病患者,经肾动脉磁共振血管成像检查的资料,分别进行三维图像分析,比较狭窄肾动脉与非狭窄肾动脉的局部几何构型参数变化.结果表明:对48例肾动脉磁共振血管成像的检查结果均显示,右肾动脉狭窄的发生率明显高于左侧.通过对肾动脉磁共振血管成像构建的三维图像分析显示,狭窄的左侧肾动脉与矢状面的夹角大于左侧正常的肾动脉与矢状面的夹角,右侧狭窄肾动脉所对应的腹主动脉横径,大于右侧正常肾动脉所对应的腹主动脉横径,在单纯右侧肾动脉狭窄的患者中,其患侧肾动脉与矢状面的夹角,要大于其相应健侧肾动脉与矢状面的夹角.在动脉粥样硬化性肾动脉狭窄的患者中,左、右侧肾动脉的发病率有明显差异.部分局部几何构型参量的改变,可能与动脉粥样硬化性肾动脉狭窄的发生有关.     

Simultaneous occurrence of an aberrant right subclavian artery and accessory lobe of the liver

We herein report a case showing the simultaneous occurrence of an aberrant right subclavian artery (ARSA) and accessory lobe of the liver in a 75-year-old female cadaver. In the thorax, the left aortic arch branched into the right common carotid artery, left common carotid artery, left subclavian artery, and ARSA, in that order. The ARSA was dilated at its origin to form Kommerell’s diverticulum and coursed behind the esophagus. This diverticulum seemed to press the esophagus. A right-sided thoracic duct was identified that emptied into the angulus venosus. In the right-sided neck, a nonrecurrent laryngeal nerve was found. In the abdominal cavity, an accessory lobe protruded from the anterior margin of the left liver lobe. The accessory lobe was separated from the left lobe by a transverse furrow on the anterior side. We discuss possible common causes of these anomalies during development.     

Methods for Three-Dimensional Geometric Characterization of the Arterial Vasculature

Complex vascular anatomy often affects endovascular procedural outcome. Accurate quantitative assessment of three-dimensional (3D) in-vivo arterial morphology is therefore vital for endovascular device design, and preoperative planning of percutaneous interventions. The aim of this work was to establish geometric parameters describing arterial branch origin, trajectory, and vessel curvature in 3D space that eliminate the errors implicit in planar measurements. 3D branching parameters at visceral and aortic bifurcation sites, as well as arterial tortuosity were determined from vessel centerlines derived from magnetic resonance angiography data for three subjects. Errors in coronal measurements of 3D branching angles for the right and left renal arteries were 3.1 ± 3.4° and 7.5 ± 3.7°, respectively. Distortion of the anterior visceral branching angles from sagittal measurements was less pronounced. Asymmetry in branching and planarity of the common iliac arteries was observed at aortic bifurcations. The renal arteries possessed considerably greater 3D curvature than the abdominal aorta and common iliac vessels with mean average values of 0.114 ± 0.015 and 0.070 ± 0.019 mm⁻¹ for the left and right, respectively. In conclusion, planar projections misrepresented branch trajectory, vessel length, and tortuosity proving the importance of 3D geometric characterization for possible applications in planning of endovascular interventional procedures and providing parameters for endovascular device design.     

Cortical interactive network during mental rotation of Chinese character

Mental rotation (MR) of Chinese characters has been proposed to employ distinct strategies depending on task difficulty. Cognitive process in MR is associated with multi-component neural networks, and elucidation of specific cortical interactions taking place during MR will assist understanding of the cognitive processes involved. In this study, we investigated cortical interactive networks involved in Chinese character MR tasks of different difficulties. Scalp electroencephalogram (EEG) signals were recorded from nine subjects (male/female = 6/3) during MR of a Chinese character presented at different orientations (0°, ±60°, ±120° and 180°). Partial directed coherence (PDC) analysis based on multivariate Granger causality (GC) was used to assess cortical interactions. At ±60° and ±120°, lateral interactions from right to left counterparts were found in both the parietal and motor-related areas, and they were enhanced with the increase of rotation angle. The main interactions between parietal and motor-related areas showed feedforward at rotations of ±60° and ±120°, while feedback interactions appeared at rotations of ±120°. However, at 180° of rotation, neither lateral interactions within motor-related areas nor feedback interactions from motor-related to parietal areas were found. These findings show that during MR of Chinese character (1) cortical interactive networks change according to task difficulty, and (2) the right hemisphere plays an initiating role in bilateral cortical activation.     

Comparative anatomical study of the kidney position in amniotes using the origin of the renal artery as a landmark

The anatomical relationship between the kidney position and its arterial supply was investigated in 21 mammals, 1 bird, and 3 reptiles (n = 1 for each species) and in 43 human cadavers. The following observations were made. (1) Although the right kidney was located caudal to the left kidney in 29 out of 43 human cadavers (67.4%), the origin of the right renal artery from the aorta was located cranial to the origin of the left renal artery in 36 human cadavers (83.7%). Therefore, the relative positions of the kidneys do not correspond with the relative origins of the renal arteries in humans. (2) Among the mammals that were examined, the position of the kidney and the branching level of the renal artery on the right side were usually cranial to those on the left side. (3) In the bird and most reptiles that were examined, kidneys were typically located in the pelvic region and were supplied by segmental arterial branches. These results suggest that the right kidney and its arterial supply are generally located cranial to the left kidney in phylogeny of mammals. While the presence of a human accessory renal artery in 9 out of 86 sides (10.5%) and a cranial origin of the left renal artery relative to the right renal artery in 7 out of 43 cadavers (16.3%), shows some variation in the arterial supply to the kidneys, the origin of the renal arteries can generally be used as phylogenetic landmarks indicating the relative positions of the kidneys. Hence, from an ontological perspective, the human right kidney may be initially situated cranial to the left kidney during the early stages of development. Thereafter, the human right kidney may shift downwards secondary.     

Rare origin of supernumerary renal vessels supplying the lower pole of the left kidney

The current observations have documented rare vascular anomalies in the right and left kidneys from a male and female cadaver, respectively. In the female left kidney in addition to being supplied by the normal renal artery and vein it contained a left lower polar renal artery and vein. The polar artery took origin from the inferior mesenteric artery to supply the lower pole and was drained by the left lower polar vein that opened into the left common iliac vein. The right kidney from a male cadaver showed supernumerary renal arteries and veins. The supernumerary upper renal artery took origin from the aorta and after a short course it gave rise into a cranial branch that took a long course to supply the lower pole and a caudal branch that entered the right kidney at the hilum. The supernumerary lower renal artery also took origin from the aorta and passed to supply the lower pole of the right kidney. Therefore, the lower pole of the right kidney received two arteries, but was not associated with a polar vein. The right kidney in addition to the normal right renal vein contained a supernumerary right renal vein. The vein was seen at the hilum and was the most posterior structure; passing behind the supernumerary lower renal artery to open into the posterior surface of the inferior vena cava. The anomalies described in the current observation present a unique pattern of congenital renal vascular abnormalities that may be of surgical importance.