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.

Supraclavicular artery flap.

Supraclavicular artery-based flaps provide aesthetic and functional coverage for the head and neck region. Fourteen formalin-fixed cadavers were dissected bilaterally, and 28 supraclavicular arteries were evaluated. The origin of the supraclavicular artery was transverse cervical artery in 62.9% and suprascapular artery in 37.1% of the cases. The origin of the artery was at the level of the medial third of the clavicle in 3.7%; 3.7% of the cases were at the junction of medial and middle third of the clavicle, 33.3% at the level of middle third of the clavicle, 11.1% at the junction of middle and lateral thirds, 44.4% at the level of lateral third, and 3.7% at the level of acromioclavicular joint. The mean values of the results were as follows: The diameter of the artery was 1.0 mm at the origin. The distance of the origin of the artery from sternoclavicular joint and from the upper border of the clavicle was 76.4 and 22.2 mm, respectively. The average length of the artery was 70.8 mm. In all dissections, the artery was deep to the platysma muscle. Forty-one percent of supraclavicular arteries accompanied the middle supraclavicular nerve, whereas 59% of the arteries run with lateral supraclavicular nerve. The supraclavicular artery had a parallel course to the 2 horizontal imaginary lines passing from the coracoid process and acromion in 63% of the cases; 18.5% of the arteries were oblique, and 18.5% were vertical to the imaginary lines. The venae comitantes were double in all dissections.

Safe drilling angles and depths for plate-screw fixation of the clavicle: avoidance of inadvertent iatrogenic subclavian neurovascular bundle injury.

BACKGROUND: Plate fixation is frequently used to repair clavicle fractures, but over drilling can cause subclavian neurovascular bundle damage. The aims of this study were to investigate the anatomic relationship between the clavicle and subclavian neurovascular bundle and to determine safe drilling angles and depths. METHODS: Twenty-six healthy subjects underwent magnetic resonance imaging. Coronal and sagittal images of the periclavicular region including the whole clavicle and nearby vital anatomic structures were obtained. The clavicle was divided into three sections: section I: between the sternoclavicular joint and point N (where the subclavian neurovascular bundle coursed below the midaxial level of the clavicle); section II: from N to the projection point of the coracoid process to the clavicle (CP'); and section III: from CP' to the acromioclavicular joint. Dangerous drilling depths and angles were determined for each section. RESULTS: In section I, the safe drilling angle was >59.7 degrees cephalad and >95.3 degrees caudad, while safe drilling depth was <17.0 +/- 2.4 mm. Corresponding values in section II were <1.2 degrees caudad and >142.4 degrees caudad. Safe drilling depth was no more than 36.2 mm +/- 12.4 mm. Depth and direction limitations were not assessed for section III, because the neurovascular bundle coursed well below the level of the coracoid process. CONCLUSIONS: We have used magnetic resonance imaging to determine safe drilling directions and depth for plate-screw fixation of the clavicle. On confirmation, these findings could be used in the clinical setting to reduce the risk of inadvertent iatrogenic subclavian neurovascular bundle injury during surgical clavicle fracture repair.

Middle thymothyroid artery arising from the common carotid artery: case report of a rare variation.

A middle thymothyroid artery, arising from the anterior aspect of the right common carotid as an anomalous branch was observed in a 71-year-old Japanese male cadaver. It soon divided into a thyroidea ima artery, a branch supplying the sternoclavicular joints, and a thymic branch. In addition, twigs from these three main branches supplied the sternohyoid and sternothyroid muscles, right inferior parathyroid gland and also some deep cervical lymph nodes. Anatomical features, clinical implications and a brief account of the developmental aspects of this rare variation are included in this report.

The segmental pectoralis major free flap: anatomical features of its vascular pedicle.

BACKGROUND: The pectoralis major muscle may be suited for free transplantation of a segment of the muscle. We investigated the length and diameter of its vascular pedicle to determine its feasibility. METHODS: The length of the pedicle, its arterial diameter, and its entry point into the muscle were determined in 17 cadaveric flaps. RESULTS: The pedicle length up to the medial border of the pectoralis minor muscle averaged 6.6 cm. The mean external arterial diameter was 1.8 mm, and the venous diameter was consistently larger. The vascular pedicle consistently entered the muscle lateral to the midpoint of, and a mean of, 8.8 cm caudal to the clavicular line. CONCLUSION: The vascular length and diameter are sufficient for microvascular anastomosis. Although an anatomic landmark for the cranial border of the flap could not be defined, the sternocostal part of the pectoralis major muscle may potentially be used as a segmental free flap.

Traumatic scapulothoracic dissociation.

Scapulothoracic dissociation is an infrequent injury with a potentially devastating outcome. The diagnosis is based on clinical and radiographic findings of forequarter disruption. These include massive soft tissue swelling of the shoulder, displacement of the scapula and neurovascular injuries (brachial plexus, subclavian artery and osseous-ligamentous injuries). The mechanism of injury appears to be the delivery of severe rotational force sheering the shoulder girdle from its chest wall attachments around the scapula, shoulder joint and at the clavicle. Early recognition of the entity and aggressive treatment are crucial. Outcome is not dependent on management of the arterial injury, but rather on the severity of the neurological deficit.

[Regularities and differences in the structure of the circulatory bed of the sternum]. / Zakonomernosti i razlichiia v stroenii krovenosnogo rusla grudiny

The investigation has been carried out in 95 preparations of the anterior chest wall of corpses of humans of either sex aged from newborns to 90. It has been established that the blood supply of all the layers of sternum is brought about by the anterior and medial branches of the internal sternum artery forming subperiosteal plexuses on its anterior and posterior surfaces. The posterior plexus is better developed. Its loops are of less size and denser per a square surface unit. Three types of blood supply of the manubrium sterni posterior surface have been distinguished (right-side, balanced and left-side types) as well as two variations of blood supply of the sternum body (in the first variant two sternal branches approach the sternum at the level of every intercostal space, in the second variant--only one does). The outflow of the venous blood from the sternum is brought about into the anterior and posterior venous subperiosteal plexuses and then via one of the three anatomical variations into the internal thoracic veins. The subperiosteal network of the sternum in newborns and infants is of segmentary character and is formed in relation with developing ossification nuclei. With age, in the process of fusion of the ossification nuclei the subperiosteal network looses its segmentary character and acquires a common total character.

[Vascularization of the sternoclavicular articulation (author's transl)]. / La vascularisation de l'articulation sterno-costo-claviculaire.

The vascularization of 110 Human sternoclavicular articulations is studied after injection of China ink with gelosa. The arteries of the sternoclavicular articulation arise from the internal mammary arteria and form a periarticular arch from which start the peripheric, sub-synovial and central networks. These networks, whose architectony is in relation with the functional structure of sternoclavicular articulation, drains in peripheric venous arches which join anterior jugular and mediastinal veins.