Variations of the musculofascial axillary arch with the adjacent lymph nodes.

PURPOSE: This unique case gives the extent of knowledge in the axilla area with axillary arch (AA) and a discussion of its clinical importance. MATERIALS AND METHOD: The anatomical anomaly was found during the dissection class for the brachial plexus. It was identified through the precise dissection of the structures bilaterally. RESULTS: The cadaver had fascial and muscular AA bilaterally. The fascial AA was separated into the superficial and deep arch group. The superficial arch group connected to the clavipectoral fascia and the axillary fascia. The deep arch group attached to the subscapular fascia. The muscular AA had superficial and deep variations. The superficial muscular AA attached between accessory slip of latissimus dorsi muscle (LDa) and pectoralis quartus muscle (PQ). The deep muscular AA attached to the crest of lesser tubercle of the humerus from LDa. The adipose tissue with the level one central lymph node was located lateral to the pectoralis minor muscle expand from pectoral lymph node through between LDa and PQ. CONCLUSION: This case showed the fascial and muscular AA together. The muscular AA had both complete and incomplete attachment types. It could give functional and neurological problems in the axilla, such as thoracic outlet syndrome. Additionally, the structures presented with the axillary lymph node. It helps to understand the patient's condition with the AA in the axilla and could provide.

Anatomy of the nerves to the teres minor and the long head of the triceps brachii for electromyography.

BACKGROUND: We investigated the branching pattern and topographic anatomy of the nerves to the teres minor (Tm) and the long head of the triceps brachii (LHT) in relation to reference lines extending between surface landmarks, to identify the innervation patterns of, and the optimal needle placement points within, the Tm and the LHT. METHODS: The anatomical courses of the nerves to the Tm and the LHT were investigated in 37 upper limbs of fresh-frozen cadavers. Distances from the acromion to nerve penetration points, and crossing points of reference lines with the Tm and LHT were measured in 27 cadaveric upper limbs. RESULTS: The Tm was innervated by the axillary nerve in all specimens in three patterns, and the LHT was innervated exclusively by the radial nerve. Our dissection and measurements indicate that the midpoint of the reference line from the acromion to the inferior angle of the scapula is the optimal needle insertion point for the Tm. The target point for the LHT appears to be the one-third point of the reference line from the acromion to the medial epicondyle, or the two-thirds point of the reference line from the acromion to the axillary fold. CONCLUSIONS: We investigated the branching pattern of the nerves to the Tm and the LHT and propose optimal needle placement points for electromyography of the Tm and LHT.

The axillary arch inserted to the coracoid process compressing the brachial plexus / El arco axilar insertado en el proceso coracoideo comprimiendo el plexo braquial

The axillary arch is a variant slip extending between the latissimus dorsi muscle and the pectoralis major. During educational dissection, a variant muscle was found in left arm of 70-year-old female cadaver. A slip muscle originated from the lateral margin of the latissimus dorsi and crossed the axilla obliquely. Therefore, we defined this muscular variation as axillary arch. It ran anterior (superficial) to the medial and lateral cords of the brachial plexus, and then it inserted to coracoid process. We reported this variant muscle and discussed its clinical significances.

El arco axilar es una variante que se extiende entre el músculo dorsal ancho y el pectoral mayor. Durante la disección educativa, se encontró una variante muscular en el brazo izquierdo de un cadáver de una mujer de 70 años. El músculo deslizante se originó en el borde lateral del dorsal ancho y cruzó la axila oblicuamente. Por lo tanto, definimos esta variación muscular como el arco axilar. Se extendió anterior (superficial) a los cordones medial y lateral del plexo braquial, y luego se insertó en el proceso coracoideo. Reportamos esta variante muscular y discutimos sus significados clínicas.

Ultrasonographic study of a modified axillary approach to block the major branches of the brachial plexus in dogs.

OBJECTIVE: To provide ultrasonographic mapping of the axillary region of dogs to facilitate identification of the major branches of the brachial plexus in relation to the axillary artery. STUDY DESIGN: Prospective study. ANIMALS: A total of two dog cadavers and 50 client-owned, healthy dogs weighing >15 kg. METHODS: In Phase 1, anatomical dissections were performed to identify the relation of the major brachial plexus nerves to the axillary artery. In Phase 2, with the dogs in dorsal recumbency with thoracic limbs flexed naturally, the axillary space was scanned using a linear array probe oriented on the parasagittal plane until the axis transverse to nerves was found. Then, the transducer was rotated to a slight lateral angle approximately 30° to midline. The examination aimed to identify the axillary artery and the musculocutaneous, radial, median and ulnar nerves in addition to determining their position and distribution in four predefined sectors. RESULTS: The musculocutaneous nerve was observed in all animals cranial to the axillary artery. The radial, ulnar and median nerves were distributed around the axillary artery, with >90% on the caudal aspect of the axillary artery (sectors 1 and 2). CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography identified the location of the brachial plexus nerves near the studied sectors, providing useful guidance for performing a brachial plexus nerve block.

Expresión morfológica del músculo axilopectoral: un estudio anatómico directo en una muestra de población colombiana / Morphological expression of the axillary pectoral muscle: a direct anatomical study in a sample of Colombian population

El músculo axilopectoral (MAP) es una estructura fibromuscular accesoria de la región axilar, que se relaciona con el plexo braquial, vasos y linfonodos axilares, y es reportado en los diferentes grupos poblacionales con incidencia variable. Se evaluaron un total de 106 axilas correspondientes a 53 cadáveres frescos que fueron sometidos a autopsia. El MAP se presentó en 5 regiones axilares (4,7 %), con tres casos unilaterales (2,8 %) y uno bilateral (0,9 %). La longitud total del MAP estuvo en un rango de 81,6-119,7 mm, mientras que su segmento tendinoso midió 13,3-28,1 mm. El espesor de su vientre muscular fue de 7,1-52 mm y del tendinoso 6,920,1 mm. En todos los casos, el MAP se originó del músculo latísimo del dorso y se insertó en el labio lateral del surco intertubercular del húmero, adyacente a la inserción del músculo pectoral mayor. Los MAP evaluados fueron inervados por el nervio toracodorsal. En dos casos, el vientre muscular del MAP cursó con trayectoria antero medial a las fibras infraclaviculares del plexo braquial, mientras que en los tres restantes, los segmentos fibrosos de inserción del MAP estuvieron relacionados con el plexo. La incidencia del MAP encontrada en el presente estudio es similar a los reportes previos realizados en cadáveres y considerablemente mayor a los reportes anatomoquirúrgicos. La importancia del MAP radica en su implicación con el síndrome de salida torácica, trombosis profunda del miembro superior y en las complicaciones en la linfadenectomía axilar.

The axillary pectoral muscle (APM) is an accessory fibromuscular structure of the axillary region. It is related to the brachial plexus, axillary vessels and lymph nodes, and is reported with variable incidence in different population groups. A total of 106 axilla were evaluated corresponding to 53 fresh cadavers. The APM was presented in 5 axillary regions (4.7 %), with three unilateral cases (2.8 %) and one bilateral (0.9 %). The total length of the APM ranged from 81.6-119.7 mm, while its tendinous segment measured 13.3-28.1 mm. Muscular belly thickness was 7.1-52 mm and the tendinous segment measured 6.9-20.1 mm. In all cases, the APM originated from the latissimus dorsi muscle and inserted into the lateral lip of humerus intertubercular sulcus, adjacent to the pectoralis major muscle insertion. The evaluated APMs were innervated by the thoracodorsal nerve. In two cases, the APM muscular belly had an anterior medial trajectory to brachial plexus fibers, while in the remaining samples, long fibrous segments of APM insertion were related to the plexus. The incidence of the APM found in the present study is similar to previous reports carried out in cadavers; it was considerably higher than previous anatomy-surgical reports. The importance of APM relies on its involvement with thoracic outlet syndrome, deep thrombosis of the upper limb and complications in axillary lymphadenectomy.

The dorsoepicondylar medial muscle a clinically relevant anatomical variation / El músculo dorsoepicondylar medial: una variación anatómica clínicamente relevante

Anatomical variations in the axillary region do not always appear in modern human anatomy texts, which leaves the risk of diagnostic and surgical errors by doctors unaware of these variations. This work presents an anatomical variation of muscular type in the axillary region that can potentially generate clinical manifestations or iatrogenic results during surgical procedures. Routine dissection of an upper limb in a male cadaver. An atypical muscle was found in the axillary region, located at the base of the right axilla, and conformed by three muscle fascicles that give rise to a common muscular belly. The three fascicles are joined at the base of the axilla, and form a thin flat muscle 120 mm long from this join to its tendon, with a cross-section diameter of 15 mm and a thickness of 2 mm. The common belly of the muscle establishes a posterior relationship with the neurovascular elements of the axillary fossa and partially covers them. The tendon 150 mm in length originates at the level of the union of the upper and middle thirds of the arm and ends inserted in the medial epicondyle of the humerus, relating in its path with muscular and neurovascular elements of the arm. Being familiar with this variation enriches diagnostic and surgical abilities and reduces the possibility of iatrogenia in surgery of the axillary and brachial regions.

Las variaciones anatómicas son frecuentes en la región axilar, sin embargo no siempre figuran en los textos modernos de anatomía humana, existiendo un potencial riesgo de error diagnóstico y quirúrgico para quienes no las consideren. Se presenta una variación anatómica en la región axilar de tipo muscular que potencialmente puede generar manifestaciones clínicas o inducir iatrogenias durante un abordaje quirúrgico. Disección de rutina de miembro superior realizada en un cadáver adulto de sexo masculino. Se detectó un músculo atípico en la región axilar ubicado en la base de la axila derecha, compuesto por 3 fascículos musculares que dieron origen a un vientre muscular común. Los 3 fascículos, se unían en la base de la axila, formando un músculo delgado y plano de 120 mm longitud desde la unión de los fascículos hasta su tendón, con un diámetro transversal de 15 mm y un grosor de 2 mm. El vientre común del músculo establecía una relación posterior con los elementos neurovasculares de la fosa axilar y los cubría parcialmente. A nivel de la unión de los tercios superior y medio del brazo, desde el vientre muscular común se originaba un delgado tendón de 150 mm de longitud, que terminaba insertándose en el epicóndilo medial del húmero, relacionándose en su trayecto con los elementos musculares y neurovasculares del brazo. Conocer esta variación enriquece la capacidad diagnóstica y quirúrgica reduciendo la posibilidad de iatrogenia en la cirugía de las regiones axilar y braquial.

Accessory muscles of the anterior thoracic wall and axilla. Cadaveric, surgical and radiological incidence and clinical significance during breast and axillary surgery.

BACKGROUND: The present study aims to summarise the accessory muscles of the anterior thoracic wall and axilla that can be encountered during breast and axillary surgery and record their incidence and clinical significance. Moreover, the laterality of the atypical muscles is highlighted and possible gender dimorphism is referred. Accessory anterior thoracic wall muscles include: Langer's axillary arch, sternalis muscle, chondrocoracoideus, chondroepitrochlearis, chondrofascialis, pectoralis minimus, pectoralis quartus and pectoralis intermedius. MATERIALS AND METHODS: The anatomical, surgical and radiological literature has been reviewed and an anatomical study on 48 Greek adult cadavers was performed. RESULTS: Literature review revealed the existence of accessory muscles of the anterior thoracic wall and axilla that have a significant incidence that can be considered high and may, therefore, have clinical significance. For the most common of these muscles, which are axillary arch (Langer's) and sternalis muscle, the cadaveric incidence is 10.30% and 7.67%, respectively. In the current cadaveric study, accessory thoracic wall muscles were identified in two cadavers; namely a bilateral sternalis muscle (incidence 2.08%) extending both to the anterior and posterior surface of the sternum and a left-sided chondrocoracoideus muscle (of Wood) (incidence 2.08%). CONCLUSIONS: Despite the fact that accessory anterior thoracic wall and axillary muscles are considered to be rare, it is evident that the incidence of at least some of them is high enough to encounter them in clinical practice. Thus, clinicians' awareness of these anatomical structures is advisable.

Prevalence and anatomy of the axillary arch and its implications in surgical practice: A meta-analysis.

PURPOSE: The following research aimed to investigate the prevalence and anatomical features of the axillary arch (AA) - a muscular, tendinous or musculotendinous slip arising from the latissimus dorsi and that terminates in various structures around the shoulder girdle. The AA may complicate axillary lymph node biopsy or breast reconstruction surgery and may cause thoracic outlet syndrome. METHODS: Major electronic databases were thoroughly searched for studies on the AA and its variations. Data regarding the prevalence, morphology, laterality, origin, insertion and innervation of the AA was extracted and included in this meta-analysis. The AQUA tool was used in order to assess potential risk of bias within the included studies. RESULTS: The AA was reported in 29 studies (10,222 axillas), and its pooled prevalence estimate in this meta-analysis was found to be 5.3% of the axillas: unilaterally (61.6%) and bilaterally (38.4%). It was predominantly muscular (55.1% of the patients with the AA), originated from the latissimus dorsi muscle or tendon (87.3% of the patients with the AA), inserted into the pectoralis major muscle or fascia (35.2% of the patients with the AA), and was most commonly innervated by the thoracodorsal nerve (39.9% of the patients with the AA). CONCLUSION: The AA is a relatively common variant, hence it should not be neglected. Oncologists and surgeons should consider this variant while diagnosing an unknown palpable mass in the axilla, as the arch might mimic a neoplasm or enlarged lymph nodes.

Surgical Technique and Anatomical Considerations for the Modified L'Episcopo Tendon Transfer.

BACKGROUND: Birth brachial plexus injury usually affects the upper trunks of the brachial plexus and can cause substantial loss of active shoulder external rotation and abduction. Due to the unbalanced rotational forces acting at the glenohumeral joint, the natural history of the condition involves progressive glenohumeral joint dysplasia with associated upper limb dysfunction. Surgical reconstruction methods have been described previously by Sever and L'Episcopo, and modified by Hoffer and Roper to release the adduction contracture and to restore external rotation and shoulder abduction. METHODS: The authors describe their preferred technique for contracture release and tendon transfer to improve external rotation and shoulder abduction. Pertinent anatomy and highlights of surgical exposure are reviewed. RESULTS: The senior author has utilized this technique with consistent clinical outcomes to improve shoulder function for patients with persisting nerve palsy associated with birth brachial plexus injury. A review of the literature supports utilization of this technique. CONCLUSIONS: Transfer of the latissimus dorsi and teres major to the posterior rotator cuff for reanimation of shoulder abduction and external rotation deficits associated with birth brachial plexus injury is a safe and reliable technique. Careful patient selection and attention to surgical detail are critical for optimal outcomes.

The Accessory muscles of the Axilla.

The axilla is a region of clinical and surgical importance with plenty of anatomical variations. One of these is the presence of accessory muscles. The literature was reviewed in order to identify the different supernumerary muscles that are described in the axilla. Variant muscle slips arising from the pectoral muscle or latissimus dorsi muscle have been described. There still remains controversy regarding the phylogenetic origin of these different muscles. We described the most frequently reported muscles, their origin, and course. Further research is required regarding the innervation and influence on glenohumeral and scapulothoracic kinematics.

Ultrasound-guided anterior approach to the axillary and intercostobrachial nerves in the axillary fossa: an anatomical investigation.

BACKGROUND: The posterolateral and medial aspect of the arm is supplied by the axillary (AXN) and intercostobrachial nerves (ICBN), which are not anaesthetised by an axillary brachial plexus block (ABPB). Blockade of the AXN and the ICBN has been reported in the quadrangular space (QS) posteriorly or by serratus plane block, respectively. An anterior ultrasound-guided approach to block the AXN and ICBN would be desirable to complete an ABPB at a single insertion site. METHODS: After a preliminary dissection study in six cadavers, ultrasound-guided AXN and ICBN injection was performed in 46 Thiel embalmed cadavers bilaterally. Key sonographic landmarks to identify the AXN in the QS are the humerus, teres major muscle, and subscapular muscle. With the same probe position, the ICBN was identified in the subfascial axillary space. Then, 2 ml latex was injected at each nerve and confirmed by dissection. RESULTS: Muscular and bony landmarks were identified in all cadavers. The AXN was seen in 99% in the QS or at the inferolateral margin of the subscapular muscle and surrounded by latex in 96% of cases. Latex spread to the axillary fossa, within the subscapular muscle, or to the radial nerve was noted in 8% of the injections. The ICBN was seen and surrounded by latex in 100% of cases. CONCLUSIONS: We describe a reliable ultrasonographic approach to visualise the AXN and ICBN anteriorly from the conventional ABPB approach as confirmed in this cadaver study.

What is the variability in shoulder, axillae and waist position in a group of adolescents?

The clinical assessment of scoliosis is based on the recognition of asymmetry. It is not clear what the degree of asymmetry is in a population without scoliosis, which could make the differentiation between abnormal and normal uncertain. This study defines the range of normality in certain parameters of torso shape that are also associated with the clinical assessment of scoliosis. This was done by analysing the surface topography of a group of 195 children serially measured over a 5-year period. The analysis considered both the spinal curvature and the relative position of shoulders, axillae and waist on each side. The bivariate relationships were examined using 95% confidence interval data ellipses. Our results showed that a degree of spinal curvature was seen, either as a main thoracic or main thoracolumbar curve. The distribution of the data about a mean point is illustrated by 95% confidence interval (CI) data ellipses with shoulder, axilla and waist data plotted against spinal curvature. The mean values were close to zero (exact symmetry) for all of the measured parameters, with the ellipses showing little differences in the distributions. We conclude that mild asymmetry of the measured torso parameters is normal. These results define what is normal and beyond what point asymmetry becomes abnormal. This information is of use for those managing and counselling patients with scoliosis both before and after surgery.

Aberrant Cutaneous Nerve Loops in the Axilla.

During routine dissection classes, conducted for first year undergraduate medical students, we encountered a rare anatomical variation in relation to the intercostobrachial nerve (ICBN). The ICBN represents the lateral undivided cutaneous branch of second intercostal nerve. In this case, the ICBN formed nerve loops with branches of the lateral cutaneous branch of the third intercostal nerve. These loops eventually gave branches that probably supplied the floor of the axilla and proximal arm. Nowadays, this ICBN is gaining clinical importance during the axillary lymph node dissections and mammary gland surgeries. Damage to the ICBN, may results in the sensory deficits in patients undergoing surgery. In our case report, ICBN was making aberrant nerve loop along with the branches from the third intercostal nerve. Knowledge regarding the origin, formation and route of ICBN is of clinical significance to axillary surgeons, radiologist and anesthesiologists.

Arthroscopic-assisted exploration of the axillary nerve through a posterior open approach: A novel technique.

INTRODUCTION: Previous studies have described a segment of the axillary nerve (AN) that cannot be surgically explored through standard open surgical approaches (blind zone). This study aimed to evaluate the feasibility of combining the standard posterior approach to the AN by using an arthroscope to visualize all segments of the AN. MATERIAL AND METHODS: Four fresh-frozen shoulders in two adult human torsos were included in the study. A standard posterior approach was performed on each shoulder, and a dry arthroscopy was performed through the surgical opening in an attempt to visualize all the segments of the AN. A surgical clip was placed at the most proximal and anterior segment of the AN that could be visualized with the arthroscope. A standard open deltopectoral approach was then performed to determine the exact location of the surgical clip and its relation to the origin of the AN. RESULTS: All segments of the AN (including the blind zone) were visualized from the quadrilateral space to their origin from the posterior cord in all four specimens. The surgical clip was found at an average of 1 cm (range from 0.5 to 1.5 cm) from the origin of the AN from the posterior cord. CONCLUSIONS: This cadaveric study shows that it is feasible to visualize all segments of the AN (including the blind zone) using this novel approach that combines the use of the standard posterior approach to the AN with dry arthroscopic exploration. Clinical studies are necessary to evaluate the utility of this novel approach.

Evaluation of an ultrasound-guided technique for axillary brachial plexus blockade in cats.

Objectives The aim of this study was to evaluate and refine an ultrasound (US)-guided technique to block the brachial plexus (BP) at the level of the axillary space in live cats. Methods Eight adult experimental cats were enrolled into the study. The animals were sedated and positioned in dorsal recumbency with the limb to be blocked abducted 90º. The US transducer was placed in the axillary region and a non-traumatic peripheral nerve block needle was inserted in-plane with respect to the transducer, medial to the BP up to the level of the axillary artery. Lidocaine 1% (0.4 ml/kg) was injected as the needle was being progressively withdrawn in a caudal-to-cranial direction. The efficacy of the block was confirmed by evaluation of the motor and sensory functions of the blocked forelimb. Motor blockade was assessed observing the position of the blocked leg on standing and walking patterns. Sensory blockade was evaluated by the stimulation of mechanical nociceptors in the dermatomes supplied by the four major sensory nerves of the distal thoracic limb. Results The BP was successfully located by US in all cases. The achieved BP block was complete in six cats (75%) and partial in the remaining two cats (25%). All animals recovered uneventfully from the sedation and the BP blocks. Conclusions and relevance The US-guided block at the axillary space evaluated in this study is a feasible, reproducible and safe technique to block the BP plexus in experimental live cats.

Anatomical study of prefixed versus postfixed brachial plexuses in adult human cadaver.

BACKGROUND: The brachial plexus is usually formed by the fusion of anterior primary rami of the fifth to eighth cervical and the first thoracic spinal nerves. Variations in the formation of the brachial plexus may occur. Variations in brachial plexus anatomy are important to radiologists, surgeons and anaesthesiologists performing surgical procedures in the neck, axilla and upper limb regions. These variations may lead to deviation from the expected dermatome distribution as well as differences in the motor innervation of muscles of the upper limb. This study is aimed to describe the anatomical variations of brachial plexus in its formation among 20 Ethiopian cadavers. METHODS: Observational based study was conducted by using 20 cadavers obtained from the Department of Human Anatomy at University of Gondar, Bahir Dar, Addis Ababa, Hawasa, Hayat Medical College and St Paul Hospital Millennium Medical College. Data analysis was conducted using thematic approaches. RESULTS: A total of 20 cadavers examined bilaterally for the formation of brachial plexus. Of the 40 sides, 30 sides (75%) were found normal, seven sides (17.5%) prefixed, three sides (7.5%) postfixed and one side of the cadaver lacks cord formation. CONCLUSION: The brachial plexus formation in most subjects is found to be normal. Among the variants, the numbers of the prefixed brachial plexuses are greater than the postfixed brachial plexuses.

Hiperpigmentación reticulada en pliegues / Reticulate hyperpigmentation of the flexures

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Cuando la axila se torna molecular / When the axilla shifts towards molecular

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