ABSTRACT
Clavicle is the bone that forms anterior border of shoulder arch. It lies on anterosuperior of thorax with first rib. Clavicle is very near to major vascular structures, brachial plexus, esophagus and trachea at thoracic inlet. Because of this, clavicular lesions fractures and sternoclavicular dislocations -especially posterior dislocations- may cause symptoms due to compressing symptoms due to these structures. In this article we present a case with enostosis of clavicle causing respiratory failure by compressing on trachea.
Introduction
Clavicle is the bone that forms anterior border of shoulder arch. It lies on anterosuperior of thorax with first rib (1). At the upper thoracic inlet, around sternoclavicular joints area, both of clavicle are anotamically near with subclavian arteries and veins, both brachial plexuses esophagus and trachea, both carotid arteries and jugulary veins. Because of nearness to major vascular structures, brachial plexus, esophagus and trachea at thoracic inlet clavicle lessions, fractures and sternoclavicular dislocations -especially posterior dislocations- causes symptoms due to these structures being affected.
Case Report
A six-year-old girl was referred to pediatric pulmonology outpatient clinic with complaint of irritative cough and dyspnea that continues for a long time in spite of medical treatment. Three months before, she was hospitalized in intensive care unit because of occurrence of respiratory failure after a caughing crisis. Flexible bronchoscopy revealed a pulsatile externally compressing lesion on anterior wall of trachea (Figure 1).
Thorax CT angiography revealed a lession protruding into mediastinum which was thought to behyperthrophy of the bone or osteophyte. It was below the right subclavian artery and was compressing on trachea at the junction of right common carotid artery and right subclavian artery (Figure 2).
Mediastinal vascular structures were normal. On physical examination, thoracic inlet was close-fitting because of wide interclavicular ligament. It was thought that pulsatile, external compression seen at flexible bronchoscopy was due to the lession of clavicle, and operation was decided. Clavicle was reached by an incision started at upper point of sternum through laterally to the medial head of clavicle. Approximatelly, 1 cm long and 4-5 mm wide, hard and tight interclavicular ligament was seen and excised. Head of right clavicle was explored by opening the periost (Figure 4-5).
Hypertrophic tissue protruding posteriorly was excised. Mediastinum was controlled by finger disection as it was relaxed. Procedure was finished after placing a minivac drain into the disection area. At postoperative CT, compression on mediastinal structures was disappeared (Figure 3). The patient was discharged on the first postoperative day. Pathology was reported as enostosis (bone island). The patient was seen on the postoperative sixth month and she was having neither cough nor dyspnea.
Discussion
Posterior dislocations may cause some symptoms due to compression of head of clavicle on contiguous structures and injuries or lacerations may occur due to direct effect or trauma. In the literature, there have been cases of injury or laceration of innominate vein, innominate artery, esophagus, trachea, brachial plexus, and even vena cava or compression on vena cava because of posterior dislocation and cases having symptoms due to compression of tumours of head of clavicle (2-9). We did not encounter such a case withenositosis in the literature. Pathologies on this area may have crucial risks. Until now, mortality because of posterior dislocation of clavicle due to injury was reported in five cases (10). In this article, we aimed to emphasize the importance of pathologies in the head of clavicle in cases with external compression to trachea causing respiratory failure.
Bone Iisland (enositosis) is a focus of compact bone located in cancellous bone. This is a benign entity that is rarely symptomatic and that is usually found incidentally in radiological studies. Symptoms are pain and protuberance due to enlargement of the lesion. In our case, in physical examination there was no protuberance but it was determined that thoracic inlet was close-fitting because of wide interclavicular ligament. In radiological examination, there was a lesion on the head of right clavicle protruding to mediastinum which was considered as hyperthrophy or osteophyte. Under this lesion, right subclavian artery was bending to posterior and the lesion was compressing the trachea at the junction of right common carotid artery and right subclavian artery.
Tracheal stenosis caused by external compression may cause recurrent pulmonary infections, symptoms like wheezing, chronic cough and even respiratory failure. Diseases with vascular abnormalities, aneurysms, mediastinal masses, lymphadenopathies may cause tracheal stenosis. Lesions on the head of clavicle are extremely rare. In differential diagnosis of this clinical situations, lesions compressing to trachea externally, and foreign body aspirations must be considered. For diagnosis, flexible bronchoscopy and thorax CT with intravenous contrast must be used. So, that localization and severity of stenosis, and lesion causing stenosis may be determined and treatment may be planned.
In cases with external compression to trachea causing respiratory failure, pathologies of the head of clavicle must be kept in mind. Bone island is one of them. In treatment, removing the compression on vascular structures or trachea by excising the head of clavicle partially may be performed and results are satisfactory in terms of symptoms.