Considerations on the morphology of the thyroid ima artery.

PURPOSE AND BACKGROUND: Detailed knowledge of the thyroid ima artery is essential for surgeons consequently we conducted an analysis investigating the arterial vasculature of the thyroid gland in 290 cases by dissection of formalin-fixed cadavers and by studying computed tomography angiographies. METHODS: Our study was conducted on 82 cases obtained from the dissection of formalin-fixed cadavers while 208 cases were computed tomography angiographies. The following aspects were observed: the frequency of the thyroid ima artery, its origin, course, and diameter. All were studied, comparing right to left and according to sex. RESULTS: Following the study of thyroid gland vasculature on a number of 290 cases, the thyroid ima artery was discovered in 16 cases (5.52% of cases), from which 3.45% of cases were in male subjects, and 2.07% of cases in female subjects. Of these, 4.14% of the total cases were left thyroid ima artery, and 1.38% of cases were on the right, found only in female subjects. In 5.17% of the total cases, the thyroid ima artery originated from the aortic arch, of which 3.45% were in the male sex and 1.72% were in the female sex. In one case only (0.35%) in the female sex did the thyroid ima artery originate from the brachiocephalic trunk. In 2.76% of cases, the thyroid ima artery existed with a left-sided inferior thyroid artery originating from the subclavian artery, either directly or from a thyrocervical trunk. CONCLUSIONS: The thyroid ima artery has proven to be one of the highly variable arteries in terms of its presence and origin and the knowledge surrounding it is useful for surgical interventions.

The dominance of dorsal scapular artery as the blood supply to muscles of the back in the absence of two primary vessels: a cadaveric case report.

PURPOSE: Understanding of rare or unknown anatomical variations of the vasculature of the neck is critical to reduce the risk of complications during surgeries and other invasive procedures in the neck and shoulder regions. METHODS: Bilateral dissection of the neck and muscles of the back of an 87-year-old Caucasian male donor was performed to demonstrate the origin, course and termination of the arteries that arise in the neck. RESULTS: Several anatomical variations were noted on the right side of the neck of the donor body - (i) only inferior thyroid and ascending cervical arteries originated from the thyrocervical trunk (TCT), from the first part of the subclavian artery (SA), whereas the transverse cervical (TCA) and suprascapular (SSA) arteries were entirely absent, (ii) Dorsal scapular artery (DSA) emerged normally from the third part of the SA. However, after supplying the rhomboids and levator scapulae muscles, DSA provided two additional branches to the trapezius muscle and a branch to the supraspinatus muscle. Interestingly, the branches to the trapezius muscle from the DSA were the only sources of blood supply to the muscle. CONCLUSION: We report a unique anatomical variation involving the absence of the TCA and SSA from the TCT. The unilateral absence of these major vessels and the branches of DSA supplying the trapezius and supraspinatus muscles have not been reported previously in the literature in a single case report. This case study may provide useful information for head and neck reconstruction and shoulder repair surgeries.

The costocervical trunk: A detailed review.

The number of studies on the anatomy of the costocervical trunk (CCT) is scarce, and the actual prevalence of this structure is unknown. Therefore, the authors of the present study would like to propose a set of four types of CCT, which were created based on observations of computed tomography angiographies (75 CCTs). A retrospective study was conducted to establish variations and the morphometric properties of the CCT. The results of 55 consecutive patients who underwent neck and thoracic computed tomography angiography (CTA) were analyzed in March 2022. The analysis was performed on a total of 75 CCTs. Of these, 32 were from women (42.7%) and 43 were from men (57.3%). Branching variations of each CCT were thoroughly analyzed. A classification of the branching pattern of the CCTs was made and consisted of four types. In the present study, the variety of branching and morphology of CCT was analyzed, proposing its novel classification based on the four most frequently observed types. Type 1 was the most prevalent (76.1%), having a similar origin and branching pattern as described in the major anatomical books. CCT was found to be absent in 23.94% of the cases, making it a somewhat less consistent branch of the SA. Understanding the variability of the anatomy of the CCT can be a great tool for physicians performing endovascular procedures in the cervical region.

A systematic classification of the left-sided aortic arch variants based on cadaveric studies' prevalence.

INTRODUCTION: Typical branching pattern of the left-sided aortic arch consists of the brachiocephalic trunk (BCT), the left common carotid artery (LCCA) and the left subclavian artery (LSA). Variant patterns have been associated with a broad spectrum of pathologies. The meticulous knowledge of potential aortic arch variants is of utmost importance to radiologists, interventional cardiologists, vascular and thoracic surgeons. The current systematic review collects all aortic arch branching patterns and their frequency as published by various cadaveric studies, calculates prevalence taking into account the gender and the different people background, as well. All extracted variant patterns are classified into types and subtypes according to the number of emerging (major and minor) branches (1, 2, 3, 4 and 5) and to the prevalence they appear. In cases of similar prevalence, total cases were taken into consideration; otherwise the variants were classified under the title "other rare variants". METHODS: A systematic online search of PubMed and Google books databases was performed only in cadaveric studies. RESULTS: Twenty studies with typical (78% prevalence) and variable (22%) branching patterns were included. Types 3b, 2b, 4b, 1b and 5b had a prevalence of 81%, of 13%, of 5%, 0% and of 0%, respectively. Common variants were the brachiocephalico-carotid trunk (BCCT, 49% prevalence), the aberrant left vertebral artery (LVA, 41%) and the aberrant right subclavian artery (ARSA, 8%). LVA of aortic origin was detected in 32%, the bicarotid trunk (biCT) in 5% and the bi-BCT trunk in 3%. Thyroidea ima artery, a minor branch emerging from the aortic arch was found in 2%. Coexisted variants were detected in 4% (ARSA with a distinct RCCA and LCCA origin), in 3% (BCCT with a LVA of aortic origin), in 2% (ARSA with a biCT and a vertebrosubclavian trunk). CONCLUSION: No significant gender or ethnic differences exist among the 5 branching types. The proposed classification scheme aims to become a valuable and easy to use tool in the hands of all physicians involved in diagnosis and treatment of aortic arch pathology. It could be also useful in anatomical education, as well.

The brachial plexus - explaining its morphology and variability by a generic developmental model.

In classic anatomy teaching, the brachial plexus generally features as an enigmatic rote-learned structure, leaving the student with a feeling of complexity. The notion of complexity may increase in dissections, where plexuses significantly differing from the standard plexus model are readily found. This raises questions: what determines the existence and prevalence of variants and to what degree should they be considered anomalous? A model linking brachial plexus morphology and its variability to causative morphological parameters which would also standardize plexus description and teaching would be beneficial. The present study aims to provide such a model by analyzing the context of plexus development and applying this model in the analysis of plexus variability in anatomical specimens. Based on a thorough literature review, a generic developmental model was formulated and different factors of variability defined. In 56 plexuses, the proposed generic principles of plexus variability were found consistent with the variations encountered. Summarized, the modeled generic principles are as follows. Brachial plexus axon bundles grow out into an environment of chemical tracer paths in which constraints and obstacles are present: the geometry of the arm bud, cartilaginous bone precursors and vessels. The overall constancy of these factors generates a gross plexus outline, while the variability in these factors gives rise to typical plexus variations. The usefulness of the model derives from the fact that the variability of the main morphologically determining factors is not random but is the expression of the possibilities of the embryological substrate. Within the model, the major plexus morphological determinant is the segmental position of the subclavian artery, which is determined by the segment level of the intersegmental artery from which it develops. Normally, the subclavian artery develops from intersegmental artery i7. However, the subclavian artery can develop from inferior or superior segmental levels, from intersegmental artery i8 or i6, and possibly also from i9 or i5. Each of these arterial variants creates a typical, morphologically distinct, predictable plexus configuration. Superimposed on these basic plexus configurations, the underlying embryological substrate may develop further variability by integrating remnants of other intersegmental arteries into the arterial network. The resulting plexus configurations are further modified by local factors, e.g. the splitting of outgrowing axon bundles around vessels. A large split in the lateral cord around a large vein or veins crossing from lateral to medial, tangentially cranially over the subclavian artery was found in 54% of the 56 investigated BP and therefore might be added to plexus teaching. The distinct plexus morphologies associated with the subclavian artery segmental levels were further found associated with, among others, typical variations in the pectoral nerves and their ansas; these associations were also modeled. The presented models could allow brachial plexus rote learning to be replaced by a more insightful narrative of formative principles suitable for teaching. Clinically, improved understanding of the relationship between plexus variability and the local anatomical environment should be relevant to brachial plexus surgery and reconstruction.

Applicability of a standardized thoracic endograft with a single branch for the left subclavian artery to treat aortic disease involving the distal arch.

OBJECTIVE: Coverage of the left subclavian artery (LSA) origin during thoracic endovascular aortic repair (TEVAR) is associated with increased neurologic complications. Our group is involved in the development of an off-the-shelf (OTS) thoracic endograft incorporating a left common carotid artery (LCCA) scallop and a retrograde inner branch for LSA perfusion. This study aimed to evaluate the arch morphology of patients treated by TEVAR and requiring LSA coverage to determine the applicability of this OTS device. METHODS: The preoperative anatomy of consecutive patients from three separate cohorts treated with TEVAR with LSA coverage was studied. High-quality preoperative computed tomography angiography images were analyzed on an imaging workstation. Location of the origin of the supra-aortic trunks and their anatomic relationship were depicted in all patients; the LCCA origin was set as reference point. We determined the proportion of arch morphology in our cohort of patients eligible for this OTS device configuration. RESULTS: There were 196 patients included in this study, 132 in the dissection cohort and 64 in the aneurysm cohort. The median length from the lower margin of the LCCA to the proximal aspect of the pathologic process was 25.0 mm (18.2-35.2 mm), with 68.4% (n = 134) of our cohort presenting with a proximal sealing zone length >20 mm. The median LCCA-LSA distance was 20.8 mm (16.6-25.4 mm). The median clock position of the LSA from the LCCA was -10 minutes (-30 to 0 minutes). In total, 127 patients (64.8%) could have been treated with the current OTS branched TEVAR configuration; 59 were excluded for proximal neck length distal to the LCCA <20 mm and 10 because of the clock position of the LCCA, and 9 first required a vertebral artery transposition. CONCLUSIONS: The low variability of LSA and LCCA locations in patients with distal aortic arch disease offers wide applicability of a new standardized thoracic branched endograft.

Insights into Arch Vessel Development in the Bovine Aortic Arch.

A bovine arch is the most common aortic arch variant, characterized by a common origin of the innominate artery and the left common carotid artery. Data have shown that children with bovine arch anatomy and coarctation are at a significantly higher risk of recoarctation following coarctation repair. This study aims to explain the higher coarctation rates, assess the branching of the arch vessels, understand their embryologic origins, and delineate the patterns of displacement of the arch vessels in bovine versus normal anatomy. This retrospective study reviewed the medical records of 178 infants ( < 1-year-old) who had a chest CT Angiogram (58) or CT (120) at our institution between 2007 and 2017. Multiplanar reconstruction software was used to obtain the best image plane to display the sinotubular junction, innominate artery, left common carotid artery, and left subclavian artery. We measured the distances between the branches as HV1, HV2, and HV3. All distances were standardized to body surface area and sinotubular junction diameter, which is a novel method. Bovine arches were found in 32.6% of patients. The total arch length of both arch anatomies was similar. HV3 is longer in bovine arches. HV1 + HV2 and HV2 + HV3 are longer in the normal arches than the bovine arches. The left subclavian artery moves proximally, and the innominate artery moves slightly distally to form the bovine arch and decreasing the clamping distance for coarctation repair. Aortic arch distances were similar when standardized to either sinotubular junction diameter and body surface area.

A Detailed Analysis of the Blood Supply to the Subscapularis Muscle.

This study aimed to provide a comprehensive description of the arterial supply to the subscapularis (SSC) muscle. This will provide critical information for various surgical procedures. Ten specimens of embalmed Korean cadavers were dissected and subjected to modified Sihler's method to reveal the branching pattern of the arteries surrounding the subscapularis, and its intramuscular blood supply. The SSC muscle was generally supplied by branches from the subclavian artery (suprascapular artery, supraSA; circumflex scapular artery, CxSA; and dorsal scapular artery, dSA) and the axillary artery (subscapular artery, subSA; lateral thoracic artery, LTA; posterior circumflex humeral artery, PCxHA; and a branch of the axillary artery, AAbr). The anterior aspect of the muscle was supplied by the subSA, LTA, CxSA, supraSA, and AAbr. The posterior aspect of the muscle was supplied by the supraSA, PCxHA, and subSA. The dSA was more scarcely distributed than the other arteries. In two cases, the dSA supplied the portion of the muscle near the medial border of the scapular. The anterior side of the muscle tendon was supplied by the CxSA, and its posterior side was supplied by the PCxHA. The subSA can be considered to be the main branch supplying the SSA based on its distribution area of arteries. It was mostly situated within the lower region of the SSC. After distributing to the anterior surface of the SSC, some branches of the subSA reached the posterior surface as perforating branches. Clin. Anat. 32:642-647, 2019. © 2019 Wiley Periodicals, Inc.

An unusual origin and course of the thyroidea ima artery, with absence of inferior thyroid artery bilaterally.

We report an unusual origin and course of the thyroidea ima artery in a male cadaver. The ima artery originated from the right subclavian artery very close to origin of the right vertebral artery. The artery coursed anteriorly between the common carotid artery medially and internal jugular vein laterally. It then coursed obliquely, from below upwards, from lateral to medial superficial to common carotid artery, to reach the inferior pole of the right lobe of thyroid and branched repeatedly to supply the anteroinferior and posteroinferior aspects of both the thyroid lobes and isthmus. The superior thyroid arteries were normal. Both the inferior thyroid arteries were absent. The unusual feature of this thyroidea ima artery is its origin from the subclavian artery close to vertebral artery origin, the location being remarkably far-off from the usual near midline position, and the oblique and relatively superficial course. This report is a caveat to neck surgeons to consider such a superficially running vessel to be a thyroidea ima artery.

Redefining the morphometry of subclavian vessels for clavicle fracture treatments.

PURPOSE: Clavicle fractures are common injuries in adults and children. Although neurovascular damage is rarely seen, acute subclavian artery pseudoaneurysms and injuries to subclavian vessels were reported for closed fractures of the clavicle. The aim of this study was to identify the morphological details of the subclavian vessels and their relation to the sternoclavicular joint and body of the clavicle. METHODS: 127 patients (66 females and 61 males) were evaluated using reconstructed three-dimensional computed tomographic angiographies. The point at which the subclavian artery crossed posterior to the clavicle was detected as a landmark. The medio-lateral distance between the sternal end of the clavicle, landmark, antero-posterior distance between the clavicle and the subclavian artery, diameter of the artery and vein, angle between the subclavian artery and vein, distance of the subclavian vein to the subclavian artery and the clavicle at the landmark were measured. Measurements were compared according to gender and right and left sides, and age correlation was determined. RESULTS: Morphometric relationship between the subclavian vessels and clavicle presented differences between genders. We measured the antero-posterior distance between the subclavian artery and the clavicle to be less than 1 cm (0.91 cm). CONCLUSION: The subclavian artery travelled longer distances in men than women to reach the point that it crossed the clavicle. Our results demonstrated that the subclavian artery does not pass from the inferior margin of the clavicle, thus, superior plate osteosynthesis does not have any risk to injury against the subclavian vessels during the management of the clavicle fractures.

The zonal pattern of arterial supply to the brachial plexus and its clinical significance.

PURPOSE: To provide the anatomical basis of blood supply of brachial plexus for the clinical microsurgical treatment of brachial plexus injury. METHODS: Thirteen adult anticorrosive cadaveric specimens (8 males, 5 females) were dissected in this study. 3 fresh cases (2 males, 1 female) were used to observe the zonal pattern of arteries supplying brachial plexus, and 10 cases (6 males, 4 females) were used to observe the source and distribution of the brachial plexus arteries under microscope. RESULTS: The brachial plexus is supplied by branches of the subclavian-axillary axis (SAA), and these branches anastomose each other. According to distribution feature, blood supply of the brachial plexus could be divided into three zones. The first zone was from the nerve roots of intervertebral foramina to its proximal trunks, which was supplied by the vertebral artery and the deep cervical artery. The second zone was from the distal nerve trunks of the brachial plexus, encompassing the divisions to its proximal cords, which was supplied by direct branches of the subclavian artery or by branches originating from the dorsal scapular artery. The third zone was from the distal portion of the cords to terminal branches of the brachial plexus, which was supplied by direct branches of the axillary artery. CONCLUSIONS: The zonal pattern of arterial supply to the brachial plexus is a systematic and comprehensive modality to improve anatomical basis for the clinical microsurgical treatment for brachial plexus injury.

[Data on ultrasonographic anatomy of precanal segment of the vertebral artery]. / Dannye po ul'trazvukovoi anatomii dokanal'nogo segmenta pozvonochnoi arterii.

Described in the article are the results of using ultrasonographic duplex scanning for studying anatomical peculiarities of the precanal segment of the human vertebral artery. PATIENTS AND METHODS: Ultrasonographic duplex scanning (USDS) of the extracranial portions of brachiocephalic vessels was performed in a total of 215 inpatients without haemodynamically significant stenoses of the arteries of the vertebrobasilar basin. The patients found to have pathological alterations in the vertebrobasilar basin were excluded from the examined group. We studied the first segment of the vertebral artery from the origin to its entry into the canal of the transverse processes of cervical vertebrae (V1 segment according to the ultrasonographic nomenclature). We measured the diameter of the vertebral artery, assessing the pattern the vessel's passage, presence of pathological tortuosity, topographic interrelations between the V1 segment of the vertebral artery and structures of the neck, as well as analysing age-specific alterations in the anatomy of the vertebral artery. RESULTS: By means of duplex scanning we in a non-invasive manner managed to gain a deeper insight into the anatomical peculiarities of the passage and structure of the initial portion of the human vertebral artery, as well as the differences in the structure between the contralateral vertebral arteries. We determined the average values of the diameters of the vertebral artery, its area, topographical relationships with the surrounding anatomical reference points along the length of the precanal segment, available for visualization by this method of study, and age-related peculiarities of the anatomy of the vertebral artery. CONCLUSIONS: Ultrasonographic duplex scanning of the extracranial portions of brachiocephalic vessels in humans is an effective, available and accurate technique making it possible to assess the anatomy of the initial portion of the vertebral artery. The average values of the diameters and area of the transverse section of the left vertebral artery turned out to be significantly greater than similar values of the right vertebral artery in the overwhelming majority of cases. Due to structural peculiarities of the aortic arch branches, in particular, independent origin of the left subclavian artery from the aortic arch, the left vertebral artery has, as a rule, greater length than the right one and differs by the topographical correlations with the surrounding structures on the neck, which is confirmed by the ultrasonographic method of study. The ultrasonographic method of study makes it possible to sufficiently effectively assess the difference in depth of the passage of the trunk of the vertebral artery in tissues of the fascial spaces of the neck in representatives of various types of the body-build. We also revealed a tendency towards a tortuous passage of the vertebral artery in the precanal segment in 35-44% of cases irrespective of the body-build, age and gender.

Spontaneous Subclavian Artery Dissection Causing Ischemia of the Medulla Oblongata and Cerebellum.

BACKGROUND: Spontaneous subclavian artery dissection is a rare etiology. Spontaneous artery dissection causing brain ischemia is rare in all ischemic strokes. However, in young to middle-aged patients with brain ischemia, spontaneous carotid or vertebral artery dissection causing ischemic stroke accounts for 10-25%. CASE REPORT: A 58-year-old man with a history of hypertension presented to the Emergency Department with a sudden onset of left-arm paresthesia and numbness followed by symptoms of vertigo and vomiting. A neurological examination showed left-arm paresthesia, horizontal-rotational nystagmus, and left-side dysmetria according to a finger-to-nose test. Contrast-enhanced computed tomography showed left subclavian artery dissection. Diffusion-weighted imaging demonstrated hyperintensity in the left medulla oblongata and inferior part of the cerebellum. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Spontaneous artery dissection is an important etiology of ischemic stroke among young patients. Cervical magnetic resonance angiography is the gold standard for the diagnosis of arterial dissection. Cervical disc disease is a common etiology in a patient with neck and shoulder pain without cause or neurologic symptoms, when cervical MRI is negative, however, spontaneous subclavian artery dissection should be considered in the differential diagnosis when a patient, especially in a case of younger patient, presents with acute new-onset neck and shoulder pain followed by the onset of neurological symptoms.

Dynamic alterations in cerebral, celiac and renal flows resulting from ascending aorta, subclavian artery and femoral artery cannulations of extracorporeal devices.

INTRODUCTION: The aim of this study was to assess the relationships among cardiac output, extracorporeal blood flow, cannulation site, right (RCa) and left carotid (LCa), celiac (Ca) and renal artery (Ra) flows during extracorporeal circulation. METHODS: A mock circulatory circuit was assembled, based on a compliant anatomical aortic model. The ascending aorta, right subclavian and femoral artery cannulations were created and flow was provided by a centrifugal pump (Cp); cardiac output was provided by a roller pump (Rp). Five volume flow rates were tested. The Rp was set at 4 L/min with no Cp flow (R4-C0) and the basic volume flow rates of the vessels were measured. The flow of the Cp was increased while the Rp flow was decreased for other measurements; R3-C1, R2-C2, R1-C3 and R0-C4. Measurements were repeated for all cannulation sites. RESULTS: The RCa flow rate at R4-C0 was higher compared to the R3-C1, R2-C2, R1-C3 and R0-C4 RCa flows with subclavian cannulation. The RCa flow decreased as the Cp flow increased (p<0.05). The RCa flow with ascending aortic and femoral cannulation was higher compared to subclavian cannulation. Higher flows were obtained with subclavian cannulation in the LCa compared to the others (p<0.05). R4-C0 Ca and Ra flows were higher compared to other Ca and Ra flows with femoral cannulation. Ca and Ra flows decreased as Cp flow increased. Flows of the Ca and Ra with ascending and subclavian cannulations were not lower compared to the R4-C0 flow (p<0.05). CONCLUSION: This study shows that prolonged extracorporeal circulation may develop flow decrease and ischemia in cerebral and abdominal organs with both subclavian and femoral cannulations.

Prevalence of the aberrant right subclavian artery reported in a published systematic review of cadaveric studies: The impact of an outlier.

The aberrant or anomalous right subclavian artery (ARSA), which arises directly from the aortic arch and crosses to the right side usually behind the esophagus, is a rare but clinically important anatomical variant. A published systematic review (SR) of 15 cadaveric studies on ARSA reported that prevalence ranged from 0.2% to 13.3% of the general population; the total unweighted prevalence of ARSA was 325 cases in 13,208 bodies or 2.46%. The present review, however, found that the 13.3% figure was for 133 cases from a larger case series without a denominator. Three other studies either had an imprecise denominator or were limited to congenital conditions associated with ARSA. After exclusions and modifications, ARSA prevalence for the remaining 11 studies in the SR ranged from 0.19%, with a 95% confidence interval (CI) of 0.00-1.08%, to 2.52% (CI= 0.69-6.32%). The unweighted prevalence for all 11 studies combined was 1.23%, and the pooled prevalence estimate from a meta-analysis was 1.30% (CI = 0.86-1.82%). In conclusion, overall findings from SRs on the prevalence of rare anatomical variants such as ARSA may be affected by outliers. Clin. Anat. 30:1024-1028, 2017. © 2017 Wiley Periodicals, Inc.

Unilateral occurrence of five different thyroid arteries-a need of terminological systematization: a case report.

This article highlights an unusual and unilateral variation in the blood supply to the inferior portion of the thyroid gland observed on the right lobe during anatomy dissection course. The rare variation of the occurrence of two anomalous arteries: the middle thyroid artery and the aberrant accessory inferior thyroid artery, and one uncommon variant, the thyroid ima artery, was detected in an adult female cadaver. The two generally constant arteries, the superior thyroid artery and the inferior thyroid artery, have been found in their usual anatomical location. Both the middle thyroid artery and aberrant accessory inferior thyroid artery arose from the right common carotid artery. The middle thyroid artery coursed as a very short branch ventromedially to enter the inferior lateral portion of the right lobe of the thyroid gland. It was at the same level, in which the inferior thyroid artery reached the lateral border of the thyroid gland. The aberrant accessory inferior thyroid artery originated similarly, from the ventromedial surface of the right common carotid artery and passed to supply the inferior pole of the right lobe. The thyroid ima artery was found to arise from the brachiocephalic trunk, entering the isthmus of the thyroid gland. Information about the embryological background might be helpful to clarify why such a type of variation occurs. It is necessary to understand the possible existence of this anomaly, to carry out successful radical neck dissection and to minimize the risk of postoperative complications in patients.

Duplicate origin of the right vertebral artery in which both channels arose from the extreme proximal right subclavian artery: a case report.

Rarely, two channels of the right vertebral artery (VA) arise from the right subclavian artery (SA) and fuse at the level of the C5 or C4 transverse foramen, a variation of the artery termed duplicate origin. Usually, one channel arises from the normal position, and the second arises from the extreme proximal segment of the SA. We report a case of duplicate origin of the right VA in which both channels arose from the extreme proximal segment of the SA, which we diagnosed by computed tomography (CT) angiography. The smaller channel entered the C5 transverse foramen and the larger channel, the C4 transverse foramen, and they fused at the level of the C4. Careful scrutiny of CT angiographic source images is important to detect rare arterial variations, especially to identify the level at which the VA enters the transverse foramen.

The potential risk of left subclavian artery injury from excessively long thoracic pedicle screws placed in the proximal thoracic regions of Lenke type 2 adolescent idiopathic scoliosis patients and normal teenagers: an anatomical study.

PURPOSE: The altered anatomic positions of important structures adjacent to the vertebrae in adolescent idiopathic scoliosis (AIS) patients have been comprehensively investigated by previous radiographic studies. However, no study has evaluated the altered position of left subclavian artery (SA) in these patients. The purpose of this study is to evaluate the altered position of left subclavian artery in AIS patients with a double thoracic curve pattern. METHODS: Nineteen Lenke type 2 AIS patients and thirteen normal teenagers were included in this study. Axial computed tomography images at T2 and T3 levels were obtained in all these subjects to evaluate the subclavian artery-vertebral angle (SAVA, defined as 0° when the artery was located directly lateral to the left and 180° when directly lateral to the right) and subclavian artery-vertebral distance (SAVD, the shortest distance between the artery and vertebral body). The percentage of left subclavian arteries at potential risk of injury from excessively long pedicle screws was calculated. RESULTS: The SAVA was significantly larger in AIS patients than that in normal teenagers at both T2 and T3 levels (P < 0.05) while the SAVD was significantly smaller in AIS patients compared with normal teenagers at both T2 and T3 levels (P < 0.05). The left SA was at potential risk of injury from excessively long left pedicle screws in 6 (31.6 %) AIS patients at T2 level and in 10 (52.6 %) patients at T3 level. The patients with risk of left SA injury had larger proximal thoracic (PT) and larger AVT of PT curve when compared with those without. No left SA was at potential risk of injury from excessively long left pedicle screws in normal teenagers. CONCLUSIONS: The left SA is located much closer to the vertebrae in the proximal thoracic curve of Lenke type 2 AIS patients when compared with normal teenagers. The spine surgeons should be aware of such altered position of left SA and choose appropriate pedicle length to avoid anterior cortical penetration in Lenke type 2 AIS patients.

The origin of the dorsal scapular artery: anatomic variations and surgical applications.

The dorsal scapular artery (DSA) can be either a direct branch of the subclavian artery (SCA), or a branch of the transverse cervical artery (TCA). In mandibular reconstruction, when a free flap is contraindicated a pedicled scapular flap has been described vascularized by the DSA. During the dissection of this flap, there is a risk of lesion of the TCA, which could be fatal to the flap if the DCA is a branch of the TCA. To evaluate the frequency of this anatomic situation, a dissection and radiologic study has been performed. 50 anatomic dissections on fresh cadavers and 93 arteriographies from 47 patients have been studied, to determine what was the DSA origin. In our dissections we found the origin of the DSA was a type I origin in 19 cases (38 %), a type II in 19 cases (38 %) and a type III in 12 cases (24 %). In our radiologic study, the DSA and the TCA had a common origin from the SCA (Type I) in 57/93 cases (61.3 %), the DSA was a direct branch of the SCA and the TCA (type II) in 22/93 cases (23.7 %), the DSA and the TCA had a common origin from the TCT (type III) in 14/93 cases (15 %). The DSA is coming from the TCA in 1/5 cases. A careful dissection of this flap in the subclavian area is necessary in all cases, a preoperative arteriography could be proposed to limit the risk of pedicle injury.

Coexisting right nonrecurrent and right recurrent inferior laryngeal nerves: a rare and controversial entity: report of a case and review of the literature.

Variations in the course of the recurrent laryngeal nerve (RLN) can occur, including the development of a nonrecurrent inferior laryngeal nerve (NRILN). Rarely, both a right RLN and a right NRILN have been reported in the same patient, merging before they enter the larynx. A case is presented, including images, and the literature concerning this rare anatomical finding is reviewed, including studies suggesting alternative explanations for these cases. Fourteen previously reported cases of coexisting RLN and NRILN were identified, all involving the right side. Some cases were associated with an anomalous origin of the right subclavian artery and some were not. The alternative explanations that a communicating branch of the sympathetic nerve, which joins the RLN, is mistaken for an NRILN or that a collateral branch from an NRILN is mistaken for an RLN in these cases are also considered. Surgeons must be aware of these unusual variations to minimize nerve injury during neck surgery.