A case of atypical insertion of the levator scapulae

Anatomical variations in the musculature of the spine have the potential to cause functional and postural abnormalities, which in turn could lead to chronic myofascial and skeletal pain. We present a unilateral case of a 71-year-old Caucasian female in which the left levator scapulae muscle gave rise to an accessory head that inserted, by way of a flat aponeurotic band, to the ligamentum nuchae, the tendon of the rhomboideus major and the superior aspect of the serratus posterior superior muscle. The innervation was provided by a branch of the dorsal scapular nerve. By exerting unilateral traction on the vertebrae and surrounding musculature, this unusual variation might have resulted in clinical consequences including scoliosis and movement abnormalities of the head and neck as well as myofascial pain syndrome

An unusual union of the intercostobrachial nerve and the medial pectoral nerve

Variations in the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present the case of an 87-year-old Caucasian female, in whom the intercostobrachial nerve joined with a separate branch from the medial pectoral nerve. The clinical consequences of such a variation may include pectoral muscle motor loss, in addition to the commonly reported sensory loss resulting from the accidental injury or intentional sacrifice of the intercostobrachial nerve during axillary dissection

A case of an anomalous pectoralis major muscle

We present a case of a right sided accessory head of the pectoralis major muscle located inferior to its abdominal head. This variation was found during a routine anatomy dissection at the American University of the Caribbean School of Medicine. The muscle fibres of the accessory head of the pectoralis major muscle arose from those of the serratus anterior muscle and travelled superolaterally towards the axilla. The accessory muscle terminated by fusing with the tendinous fibres of the pectoralis major muscle as they underwent their normal anatomical rotation before insertion upon the lateral lip of the bicipital groove of the humerus. Although variations in the pectoral muscles are not uncommon, this case appears to be unique in the literature. The possible clinical implications are discussed

A retrotracheal right subclavian artery in association with a vertebral artery and thyroidea ima

The retro-oesophageal right subclavian artery is an anatomical abnormality encountered by anatomists and pathologists and, more recently, interventional cardiologists and thoracic surgeons with an incidence of 0.2-2% in the population. We report a case of a retrotracheal right subclavian artery which originated distally along the left aortic arch and coursed between the trachea and the oesophagus. Additionally, the aortic arch gave rise to a common trunk, which subsequently bifurcated to yield to a right vertebral artery and a left thyroidea ima, replacing the left inferior thyroid artery. Consequently the right and the left recurrent laryngeal nerves were found to recur normally. The possible embryonic development of these branching patterns and their clinical significance is discussed

Morphologic variation of the diaphragmatic crura: a correlation with pathologic processes of the esophageal hiatus?

The contributions of muscle fibers from the right and left diaphragmatic crura to the formation of the esophageal hiatus have been documented in several studies, none coming to a complete consensus on the number of anatomic variations or the prevalence of these variations in the human population. These variations may play a role in the pathogenicity of specific diseases that involve the esophageal hiatus, such as hiatal hernias. We examined a total of two hundred adult cadavers during 2000-2007. The variations in the diaphragmatic crura, particularly their muscular contributions to the formation of the esophageal hiatus, were grossly examined and revealed a bilateral occurrence of diaphragmatic crura in all 200 specimens. The results of the various morphological patterns of circumferential muscle fibers forming the esophageal hiatus were classified into six groups. The most common type (Type I, 45%) formed the esophageal hiatus from muscular contributions arising solely from the right crus. In Type II (20%) the esophageal hiatus was formed by muscular contributions from the right and left crura. In Type III (15%), the right and left muscular contributions arose from the right crus with an additional band from the left crus. Type IV (10%) showed that the right and left muscular contributions arose from the right crus, with two additional (anterior and posterior) bands arising from the left crus. Type V (5%) demonstrated the contributions arising solely from the left crus. In Type VI (5%) the right and left contributions originated from the left crus with two additional bands, one from the right crus and one from the left crus. These variations may play a role in the pathogenicity of specific diseases that involve the esophageal hiatus such as hiatal hernia, gastroesophageal reflux disease and Dunbar’s syndrome

Iliolumbar membrane, a newly recognised structure in the back

Despite intensive research in the anatomical sciences for the last two centuries, some structures of the human body still remain controversial or incompletely described. We describe a new membranous fascial anatomical entity, which we refer to as the iliolumbar membrane (ILM). During the 2004-2005 academic semesters at the American University of the Caribbean School of Medicine we dissected 40 human cadavers fixed in formalin-alcohol-phenol solution. Iliolumbar membrane is a thick connective tissue structure, deep to the skin, originating from the fibres of the thoracolumbar fascia at the lateral border of the erector spinae. It runs inferior to the superior border of the iliac crest, lateral to the posterior superior iliac spine, overlying the iliac crest at the level of the 4th lumbar vertebra. Iliolumbar membrane terminates within subcutaneous fat, where it divides into multiple layers. All cadavers showed considerable variation in the blending of the membrane’s multiple layers with the subcutaneous fat. However, all specimens consistently showed a uniform appearance of ILM at the point of origin. Iliolumbar membrane could be demonstrated objectively by ultrasound examination with a frequency of 7.5 MHz and also with a Stryker endoscope. A hypothesis is put forth, conjecturing that this new structure may have relevance in creating a natural barrier between the musculature of the back and the muscles of the gluteal region, similar to Scarpa’s fascia of the anterior abdominal wall

The ansa cervicalis revisited

Recurrent laryngeal nerve paralysis represents a major complication in oesophageal cancer surgery. Nerve-muscle transplantation to the paraglottic space after resection of the recurrent laryngeal nerve with the ansa cervicalis (AC) has recently become the procedure of choice. The aim of this study was to investigate the anatomical variations of AC in order to avoid iatrogenic injuries and facilitate surgical procedures. We examined 100 adult human formalin-fixed cadavers. The ansa cervicalis showed a great degree of variation regarding origin and distribution. The origin of the superior root of AC was found to be superior to the digastric muscle in 92% of the cases. Its vertical descent was found to be superficial to the external carotid artery in 72% and superficial to the internal carotid artery in 28% of the specimens. The inferior root of AC was derived from the primary rami of C2 and C3 in 38%, from C2, C3 and C4 in 10%, from C3 in 40% and from C2 in 12% of the cases. The inferior root passed posterolaterally to the internal jugular vein in 74% and anteromedially in 26% of the cases. The roots of AC were long (70%) or short (30%), and the union between the two roots was situated inferior or superior to the omohyoid. Not only is knowledge of the anatomy of the ansa cervicalis important for nerve grafting procedures, but surgeons should be aware of AC and its relationships to the great vessels of the neck in order to avoid inadvertent injury during surgical procedures of the neck

Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination

The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module

The clinical anatomy of the internal thoracic veins

The branching pattern and adequacy of the internal thoracic veins (ITV) are important factors, providing useful information on the availability of vessels and their appropriateness as an option for anastomoses in plastic and reconstructive surgery. During 100 cadaveric examinations of the anterior thoracic wall it was observed that ITVs were formed by the venae commitantes of ITAs, which united to form a single vein (one for the right side and one for the left) draining into the right and left brachiocephalic veins. The tributaries of ITVs corresponded to the branches of ITA. The right internal thoracic vein bifurcated at the 2nd rib in 36% of the specimens, at the 3rd rib in 30% of the specimens, at the 4th rib in 10% of the specimens and in 24% of the specimens it remained a single vein. The left internal thoracic vein bifurcated at the 3rd rib in 52% of specimens, at the 4th rib in 20% of specimens and in 28% of the specimens it remained as a single vein. In addition, it was observed that in 78% of specimens ITVs were connected to each other by a venous arch. This arch displayed four distinct morphologies: transverse (n = 7), oblique (n = 16), U-shaped (n = 51) and double-arched (n = 4). All 78 arches were posterior to the xiphisternal joint and no artery accompanied them. In the remaining specimens, RITV and LITV exhibited a venous plexus formation. The distance from the sternum to ITV gradually decreased as the vessel passed caudally; the diameter of the vessel similarly decreased along the vein`s caudal course. The frequent appearance of two concomitant veins on both sides of the thorax may offer the opportunity to reduce venous congestion by two vein anastomoses. More detailed knowledge of the anatomy of ITV may prove useful in planning surgical procedures in the anterior thorax in order to avoid unexpected bleeding