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.     

A case of the scalenus anterior muscle passing behind the left subclavian artery

The scalenus anterior muscle was found to pass behind the left subclavian artery and the first thoracic nerve in a 95-year-old Japanese woman. The scalenus anterior muscle originates from the fifth and sixth cervical vertebrae and inserts on the first rib more dorsal than typical. It is innervated by the fifth and seventh cervical nerves. The muscle belly is thin. The scalenus minimus was not found. The left vertebral artery originates from the aortic arch and enters the transverse foramen of the fifth cervical vertebra. The primary vertebral artery arises from the costocervical artery. The internal thoracic artery originates from the subclavian artery more distally than typical. The axillary artery crosses the brachial plexus between the eighth cervical and first thoracic nerves. Because the first thoracic nerve joins the brachial plexus more distally than usual, the plexus has no typical inferior trunk. Comparative anatomy shows that the muscles, nerves and arteries of the lateral cervical region of the present case maintains primitive characteristics. From the functional viewpoint, the mechanical efficiency of the scalenus anterior muscle is probably lower than usual due to the lower point of origin and the dorsal shift of the insertion.     

Common trunk of left internal thoracic artery and thyrocervical trunk arising from the ipsilateral vertebral artery

The sites of origin of the branches of the subclavian artery depict numerous anatomical variations. However, a common trunk of the internal thoracic artery (ITA) and thycocervical trunk (TCT) arising from the vertebral artery is a rare anatomical finding. Herein, we present the first case in which the common trunk of the left ITA and TCT arose from the ipsilateral proximal vertebral artery as discovered on pre-therapeutic evaluation by multidetector-row computed tomography and clearly confirmed by selective angiography. It is important to recognize such anatomic variations for surgical, diagnostic, and interventional radiologic procedures in the head, neck, thorax, and abdomen.     

Origin and incidence of xiphoid branch of the internal thoracic artery

The study presents the incidence of a variant terminal branch of the internal thoracic artery (ITA). The ITA’s were cannulated in situ, injected with coloured latex and dissected together with its branches in 62 cadavers. Unlike the usual termination of the ITA bifurcating into the musculophrenic and superior epigastric arteries, this third branch arose from the medial border of the ITA at the level of the 6th costal cartilage. As it descends it inclines medially towards the angle between the xiphoid process and the 7th costal cartilage, giving off 2 or 3 fine branches to the lower sternum. It then passes deep to this angle and can be observed on the anterior surface of the xiphoid process, terminating in fine branches distributed to the inferior aspect of the xiphoid cartilage. It is proposed that this branch at the “trifurcation” of the ITA be termed the xiphoid branch. This branch was noted in 61.3%. An incidence of 30.7% was seen on the right and 21% on the left with bilateral presence in 9.7%. The xiphoid branch contributes to the supply to the lower sternal region and may be of special importance when the collateral supply to the region is compromised in the event of the internal thoracic or superior epigastric artery damage or when used as a conduit in coronary artery by-pass grafts.     

Bilateral double axillary artery: embryological basis and clinical implications

An unusual bilateral variation in the arterial pattern of the axilla was observed in an embalmed cadaver. Each axilla contained two axillary arteries of similar origins but different patterns of branching and fate. The first part of each axillary artery was a single vessel as is the norm. It gave off a supreme thoracic artery and then bifurcated into two medium-sized arteries hence referred to as regular and variant. The variant artery ran in an antero-medial course, partly covered by the one axillary vein. The regular artery gave off the thoracoacromial and two posterior branches from its second part, the anterior and posterior humeral circumflex arteries from its third part, and then continued as the brachial artery with all the usual branches except the profunda brachii on the right side. The variant gave off five arteries from the second part, a thoracoacromial artery, two separate long thoracic arteries each with a branch that ran along the intercostobrachial nerve to the arm, and two posterior branches. In the third part of the variant, the subscapular artery arose with its usual branches plus a common origin for two additional humeral circumflex arteries. The variant terminated as the profunda brachii artery to the right side while on the left side it terminated in muscular branches to the triceps. Hence, the arterial blood supply to the upper limb, and the axillary region in particular, was shared on both sides by two major arteries instead of one. These two arteries emanated from the first part of the axillary artery and may represent persisting branches of the capillary plexus of the developing limb buds. The findings have an embryological basis and clinical relevance considering the frequency of procedures in this region.     

Lateral costal branch of the internal thoracic artery

The lateral costal branch (LCB) of the internal thoracic artery (ITA) was studied because its presence sometimes may reduce the blood flow of the ITA when it is used for myocardial revascularization (Singh and Sosa, 1981). The ITA of 90 cadavers of adults of both sexes, whose ages ranged from 20 to 84 years, was studied after neoprene latex injection to determine its incidence, its relation to the phrenic nerve and first rib, its diameter, and the distance between the origin of the ITA and the origin of the LCB. We found the LCB in 16.6% of the cases, with bilateral presence in 5.5%. Unilateral rightside incidence was 11.1%, and left unilateral incidence was not observed. The LCB originated from the ITA in all cases, with a distance of origin along the ITA of 23.7 + 6.7 mm on the right side and 29.5 ± 6.4 mm on the left side. The mean diameter of the LCB was 1.7% ± 0.8 mm. © 1993 Wiley-Liss, Inc.     

Lateral costal artery: accessory thoracic vessel of clinical interest

The lateral costal artery (LCA), a supernumerary branch of the internal thoracic artery (ITA), occurs in several ethnic groups on one side of the thorax or on both, in 15-30% of cases. It has been considered responsible for the "steal-syndrome" of the coronary blood after coronary artery bypass grafting and it used occasionally for myocardial revascularization. To clarify its functional significance, an interpretation based on our findings and human and comparative anatomy and embryology has been attempted. We report on a case where a right LCA of about 2 mm in caliber, rising from the ITA 2.5 cm below the subclavian, coursed as far as the 4th intercostal space for a distance of 13 cm after the anterior axillary line. Anastomosing with the intercostal arteries, it can act as a blood derivative circuit of the thoracic wall. Embryologically, this artery, like the normal parietal arteries of the trunk, might form a longitudinal channel connecting the intersegmental arteries. In mammals having a thoracic cage transversely restricted (quadrupeds), the ITA is more lateral than in primates having a circular thorax, and gives off a ventral branch toward the sternum. It might be hypothesized that the sternal branch occurring in quadrupeds, undergoing adaptation to the thoracic shape of primates, may become the main trunk of the ITA, whereas the LCA may be the remnant of the ITA of quadrupeds. Because the LCA ran partly along the "milk line" of humans, it might be regarded as a supernumerary mammary artery.     

Rare coronary anastomoses between the aorta,pulmonary trunk,left coronary artery,and subclavian artery

We report a rare case of coronary anastomoses in an 83‐year‐old male cadaveric heart. Anomalous vessels arose from the right sinus of the aorta, left main coronary artery, left anterior descending artery, left anterior medial atrial artery, and left subclavian artery. These vessels bifurcated and anastomosed, and finally connected to the pulmonary trunk. The present case is categorized as a multilateral coronary artery fistula in cardiology. Clin. Anat. 25:969–972, 2012. © 2012 Wiley Periodicals, Inc.     

翻转胸廓内动脉冠状动脉旁路术的实验研究

目的 研究翻转胸廓内动脉用于冠状动脉旁路术的可行性。方法 对１０具成人尸体胸廓内动脉的特性进行观察,并测量左、右各助间点到ＩＴＡ起点、冠状动脉左前降支中点的距离。结果 于近端切断胸廓内动脉可以保证该动脉逆向供血,血供来源于下位肋间动脉、肌隔动脉和腹壁上动脉。左侧第３肋间以下的各肋间中点,到ＩＴＡ起点处的长度明显长于其到冠状动脉左前降支中点的距离;右侧第４肋间以下的各肋间中点,到ＩＴＡ起点处的长距离     

Development of the subclavian artery in the loggerhead turtle (Caretta caretta) studied by the injection method]

In the turtle, the left aorta and the pulmonary trunk originate from the right ventricle, while the right aorta takes its origin from the left ventricle as a functional systematic arch. The subclavian artery arises from the brachiocephalic artery on each side, and passes ventral to the vagus nerve and the jugular vein. These features are basically the same as in birds, and the subclavian artery of the adult turtle corresponds to a secondary artery from the viewpoint of comparative anatomy. Many investigators, including one of the present authors (Suzuki, 1987), have studied the development of the aortic arch and the subclavian artery in the chick embryo, but not in the turtle. The present authors examined it in Loggerhead turtle (Caretta caretta) embryos, from 14 days of incubation to completion of the aortic arch (27 days incubation). All blood vessels were injected with Berlin blue solution using a fine glass needle inserted into the aortic trunk through the ventricle of the heart. The following results were obtained. 1. In the turtle embryo the primary subclavian artery develops first, but is replaced by the secondary subclavian artery as in the chick. 2. The primary subclavian artery arises from the 12th dorsal intersegmental artery and passes dorsal to the posterior cardinal vein. In the 16-day embryo, it gives rise to capillary nets both cranially and caudally at the base of the forelimb bud along the inner surface of the thoracic wall. 3. At 19 days of incubation, a small blood vessel arises from the aortic sac at the origin of the third aortic arch and passes laterally, ventral to the anterior cardinal vein. The vessel then extends caudally, and finally, at 21 days of incubation, connects to the cranial part of the capillary net of the primary subclavian artery at about the middle of the lateral thoracic wall. After the completion of the connection, the vessel from the aortic sac is called by the name "the secondary subclavian artery." 4. The secondary subclavian artery gradually increases in size, while the proximal part of the primary one begins to atrophy and finally disappears at 27 days of incubation. After this, the forelimb bud receives its blood supply only from the newly-formed secondary subclavian artery. 5. In conclusion, in the turtle, the secondary subclavian artery is formed by connection of the primary artery with the caudally extending artery arising from the aortic sac, while in the chick it is derived from an outgrowth of the primary artery.(ABSTRACT TRUNCATED AT 400 WORDS)     

Bilateral high origins of testicular arteries: a rare variant

We report a very rare case of bilateral high origins of testicular arteries in a 66-year-old Chinese male cadaver. The arteries originated from the antero-lateral aspect of the abdominal aorta, cranially to the origins of ipsilateral renal arteries. Approximately 1.1 cm after its origin, the right testicular artery gave off the middle suprarenal artery. During its course, the artery crossed anterior to the right renal vessels. The left testicular artery coursed posterior to the left suprarenal vein, anterior to the left renal vessels. Variants of the origin and course of the testicular artery are important during renal and testicular surgeries.     

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)     

Altered course of the right testicular artery

An unusual course of the right testicular artery was observed during routine dissection of the posterior abdominal wall of a 60-year-old male cadaver. It arose from the abdominal aorta, inferior and posterior to the origin of the right renal artery, and passed posterior to the inferior vena cava and right renal vein; it then arched anterior to the inferior pole of the right kidney and descended anterior to the psoas major muscle, crossing anterior to the genitofemoral nerve, ureter and the proximal part of the external iliac artery. Finally, it passed to the deep inguinal ring and through the inguinal canal to enter the spermatic cord with the other constituents. The left testicular artery arose from the abdominal aorta about 1 cm higher than the right testicular artery and followed a normal course. The embryologic basis and clinical importance of this case are discussed.     

Bilateral subclavian arteries passing in front of the scalenus anterior muscles

Herein, we present a very rare case of bilateral subclavian arteries passing in front of the scalenus anterior muscles in a cadaver. This abnormality was observed in a 73-year-old Japanese male cadaver during a dissection session for students in 2004 at Osaka Dental University. The bilateral scalenus anterior muscle originated from the anterior tubercle of the transverse processes of the fifth and sixth cervical vertebrae and inserted into the scalene tubercle of the first ribs. The right scalenus minimus muscle was observed, but no left scalenus minimus muscle was observed. The aortic arch was a type A according to Adachi's classification. The origin of the internal thoracic artery was distal to that of the thyrocervical trunk. The bilateral brachial plexuses was formed by the union of the ventral rami from the fifth cervical to the first thoracic nerves and passed between the scalenus anterior and the scalenus medius muscles. To our knowledge, such a case has not been reported previously.     

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.     

A retroesophageal right subclavian artery with the right vertebral artery originating from the right common carotid artery

The right subclavian artery was found to be retroesophageal, and the right vertebral artery originated from the right common carotid artery in a 46-year-old female cadaver. The right subclavian artery stemmed from the upper portion of the thoracic aorta, posterior and inferior to the origin of the normal left subclavian artery. The right and left common carotid arteries originated from the aortic arch in close proximity. Compression of the trachea anteriorly could not be demonstrated. The right inferior laryngeal nerve was nonrecurrent. A brief review of the literature shows the importance of knowledge concerning the aberrant right subclavian artery for the roentgenologist and the surgeon in the treatment of patients with this vascular anomaly.     

A case of the right subclavian artery as the last branch of the aortic arch in the human fetus and a new classification on these variations

An anomalous case of the right subclavian artery arising from the aortic arch as the last branch, in which the first branch was the right common carotid, the second the left common carotid and the third the left subclavian artery, was found in a 10 months human fetus among 173 fetuses. The right subclavian artery arose from the posterior wall of the aortic arch at the level of the Th4 and passed obliquely between the esophagus and the thoracic vertebrae. The right and the left vertebral arteries arising from the subclavian arteries on the same side entered the transverse foramen of the C6 of each side. This case belonged to type G of Adachi's classification and as well type 5 of Holzapfel's. The present authors wish to offer a new trial classification on these variations, including the origins and numbers of the vertebral arteries, by investigating many original reports in Japanese, as follows: 1) A new classification is fixed on the basis of the type G and H of Adachi-Williams et al.-Nakagawa in the classification of the branching types of the aortic arch. The type G represents that the right common carotid, the left common carotid, the left subclavian and the right subclavian arteries arise from the aortic arch in this order. The type H represents that the bicarotid trunk, the left subclavian and the right subclavian arteries arise from the aortic arch. 2) When the left vertebral artery arising from the aortic arch is found in the type G and H, "C" is prefixed G or H, as type CG, type CH. 3) When the right vertebral artery arising from the right common carotid artery is found, a prime mark, "', is put on G or H, as type G', type H'. 4) In order to represent a compound type of the above 2) and 3), both "C" and "' are put, as type CG', type CH'. 5) When the bilateral vertebral arteries arising from the respective subclavian artery are found in the above 2), 3) and 4) "2" postfixed "C" and the prime mark "', as type G'2, type C2G, type CG'2, type C2G', type C2G'2, type H'2, type C2H, type CH'2, type C2H', type C2H'2. According to the above new classification, Adachi's type G can be arranged into 18 branching types. This classification may be helpful and sufficient to provide more than 100 cases of the type G and H reported on Japanese.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Arterial supply to the thyroid gland and the relationship between the recurrent laryngeal nerve and the inferior thyroid artery in human fetal cadavers

The aim of this study was to identify the arterial supply to the thyroid gland and the relationship between the inferior thyroid artery (ITA) and the recurrent laryngeal nerve (RLN) in fetal cadavers using anatomical dissection. The anterior necks of 200 fetuses were dissected. The origins of the superior thyroid artery (STA) and the ITA and location of the ITA in relation to the entrance of the thyroid lobe were examined. The relationship between the ITA and the RLN was determined. The origins of the STA were classified as: external carotid artery, common carotid artery (CCA), and the thyrolingual trunk. The origins of the ITA were the thyrocervical trunk and the CCA. The ITA was absent on the left side in two cases. The relationship of the RLN to the ITA fell into seven different types. Type 1: the RLN lay posterior to the artery; right (42.5%), left (65%). Type 2: the RLN lay anterior to the artery; right (40.5%), left (22.5%). Type 3: the RLN lay parallel to the artery; right (11.5%), left (7%). Type 4: the RLN lay between the two branches of the artery; right (1%), left (3.5%). Type 5: The extralaryngeal branch of the RLN was detected before it crossed the ITA; right (4.5%), left (0%). Type 6: the ITA lay between the two branches of the RLN; right (0%), left (0.5%). Type 7: the branches of the RLN lay among the branches of the ITA; right (0%), left (0.5%). The results from this study would be useful in future thyroid surgeries. Clin. Anat. 27:1185–1192, 2014. © 2014 Wiley Periodicals, Inc.