The Frequency of Mediastinal Injury in Acute Posterior Sternoclavicular Dislocations: A Multicenter Study.

BACKGROUND: Acute posterior sternoclavicular dislocations (APSCD) are rare injuries that historically have prompted concern for injury to the great vessels and other mediastinal structures from initial trauma or subsequent treatment, resulting in the recommendation that a thoracic or vascular surgeon be present or available during operative treatment. The objectives of the study were to characterize the demographic, clinical, and radiographic characteristics of a large series of APSCDs in skeletally immature patients and to describe the rate and nature of any vascular or mediastinal complications that occurred during treatment. METHODS: Following Institutional Review Board approval, records of consecutive patients under 25 years of age treated for APSCD were collected from each of 6 participating centers. Only acute injuries (sustained fewer than 10 days before presentation) were included. Patient demographics, injury mechanism, associated mediastinal injuries, and need for thoracic/vascular surgery were recorded. Mediastinal structures injured or compressed by mass effect were specifically characterized by review of preoperative computed tomography imaging. RESULTS: Review identified 125 patients with a mean age of 14.7 years; 88% were male. APSCD most commonly resulted from a sporting injury (74%) followed by falls from standing height (10%) and high-energy motor vehicle trauma (10%). The most common finding on cross-sectional imaging was compression without laceration of the ipsilateral brachiocephalic vein (50%). Eleven patients had successful closed reduction, and 114 (90%) had open reduction and internal fixation, with 25 failed or unstable closed reductions preceding open treatment. There were no vascular or mediastinal injuries during reduction or fixation that required intervention. CONCLUSIONS: In this multicenter series of 125 APSCDs no injuries to the great vessels/mediastinal structures requiring intervention were identified. Although more than half of patients had evidence of extrinsic vascular compression at the time of injury, careful open reduction of acute injuries can be safely performed. Although vascular injuries following APSCD seem to be quite rare, vascular complications can be catastrophic. Treating providers should consider these data and their own institutional resources to maximize patient safety during the treatment of APSCD. LEVEL OF EVIDENCE: Level III-therapeutic case control study.

The Importance of the Mediastinal Triangle in Traumatic Lesions of the Aorta.

Background: Trauma-induced aortic injuries continue to be an important factor in morbimortality in patients with blunt trauma. Objectives: To determine the characteristics of aortic lesions in patients with closed thoracic trauma and associated thoracic injuries. Methods: Multicenter cohort study conducted during the years 1994 to 2014 in the radiology service in the University Hospital Complex of A Coruña. Patients >15 years with closed thoracic trauma were included. Sociodemographic and clinical variables were studied in order to determine the lesion cause, location, and degree. Results: We analyzed 232 patients with a mean age of 46.9 ± 18.7 years, consisting of 81.4% males. The most frequent location was at the level of the isthmus (55.2%). The most frequent causes of injury were traffic accidents followed by falls. Patients with aortic injury had more esophageal, airway, and cardiopericardial lesions. More than 85% of the patients had lung parenchyma and/or chest wall injury, which was more prevalent among those who did not have an aortic lesion. Conclusions: Patients with trauma due to traffic accidents or being run over presented three times more risk of aortic injury than from other causes. Those with an aortic lesion also had a higher frequency of cardiopericardial, airway, and esophageal lesions.

Intracardiac foreign body resulting from a transmediastinal gunshot mimics an extracardiac foreign body: An image presentation.

A transmediastinal gunshot wound (TMGW) is one of the most severe traumatic injuries, with a high mortality rate. Prompt diagnosis and emergency surgical intervention with or without cardiopulmonary bypass are usually required to save lives. We report a particular case of TMGW in which the computed tomography imaging findings indicated an extracardiac foreign body. However, intraoperative findings revealed an intracardiac foreign body, and urgent cardiopulmonary bypass was performed to remove the foreign body. We suggest that cardiopulmonary bypass should be on standby during an exploratory sternotomy for TMGW, when the trajectory of the bullet hints at a cardiac-penetrating injury according to imaging studies and the location of the bullet remains unaffected by the patient's postural changes.

Esophageal and Mediastinal Lesions Following Multielectrode Duty-Cycled Radiofrequency Pulmonary Vein Isolation: Simple Equals Safe?

BACKGROUND: The development of esophageal lesions following atrial fibrillation (AF) ablation has frequently been reported. Mediastinal tissue layers and the posterior wall of the left atrium are in close proximity to the site of ablation. Hence, mucosal lesions might solely represent the "tip of the iceberg." We therefore investigated patients undergoing multielectrode phased radiofrequency (RF) ablation (PVAC®, Medtronic Inc., Minneapolis, MN, USA) for symptomatic AF by radial endosonography (EUS) in conjunction with conventional endoscopy esophago-gastro-duodenoscopy (EGD) to visualize potential mediastinal injuries following pulmonary vein isolation (PVI). METHODS AND RESULTS: Eighteen patients (six women, mean age 52.8 ± 12.8 years, range 32-72 years) underwent PVI using multielectrode phased RF ablation and EGD and EUS following PVI within 48 hours. Postablation periesophageal lesions were detected by EUS in 10 out of 18 patients (56%). Four out of 10 lesions consisted of mild changes like small pericardial effusions, whereas six out of 10 patients had more severe lesions of the mediastinum, including one patient with changes of the esophageal mucosa. No atrio-esophageal fistula developed during follow-up (FU; mean FU 215 ± 105 days). CONCLUSIONS: Mediastinal and esophageal structural changes occurred in a substantial number of patients. These findings highlight the necessity of close FU and the awareness of the potential development of an atrio-esophageal fistula also after multielectrode catheter ablation.

Late pacemaker lead tip perforation documented by chest CT.

Late cardiac perforation by a right ventricular (RV) pacemaker lead may be a challenge to diagnose. Echocardiography often will not adequately demonstrate lead tip migration, but chest computed tomography (CT) readily identifies the lead and tip location. A patient presented one month after dual-chamber pacemaker implantation with fever, sepsis and failure of RV pacer lead capture. Echocardiography demonstrated vegetations on the RV lead and a pericardial effusion, but the lead tip location could not be identified. CT identified the tip as having migrated through the pericardium into the anterior mediastinum. These complimentary echo and CT findings helped make a diagnosis and direct patient therapy.

[Thoracic and abdominal and limb wounds by gun shot].

In Japan, we are permitted to own fire arms only for hunting and clay pigeon shooting, but gunshot wound victims have neen rarely seen due to the strict laws against owing guns, and the lack of related crimes. Therefore, surgeons should be familiar with ballistics, practical gunshot wound management, and the possibility of delayed lead poisoning ssociated with bullet residue. A 69-year-old man was brought to our hospital because he was accidentally shot by his companion's shotgun during hunting. On admission, although he had stable vital sign and multiple gunshot wounds on his right forearm and femur, chest X-ray and computed tomography (CT) revealed a few of bullets and its flagments on his back, into spleen and pericardium. Following local debridment after removal of the bullets in his right forearm and femur at an emergency room, broken heart muscle and diaphragm were repaired and hematoma in the anterior mediastinum was removed at the operating room. The patient was discharged on the 25th post-operative day and his post-operative course was uneventful. In case of gunshot injuries, in addition to prompt diagnosis and evaluation of organ injuries, careful follow up for possible delayed lead poisoning is important.

Penetrating knitting needle through the mediastinum in a child.

Thoracic injuries are second only to central nervous system injuries as the leading cause of traumatic death in patients of all ages. Penetrating chest injury is very uncommon in children, but it comes with significant morbidity and mortality. Presentation of penetrating thoracic injury in the child is unique with inherent opportunities for learning. The purpose of this case report was to disseminate information regarding rare thoracic trauma in the pediatric patient.

Current concepts in imaging evaluation of penetrating transmediastinal injury.

Penetrating transmediastinal injuries (TMIs) are injuries that traverse the mediastinum. These injuries are most commonly caused by firearms and knives. The investigation and management algorithms for TMI have undergone changes in recent years due to increasing evidence that computed tomography (CT) in useful in the evaluation of hemodynamically stable TMI patients. Initial investigation of TMI patients depends on the question of hemodynamic stability. In unstable patients, imaging (if any) should be limited to bedside radiography and focused ultrasonography. In hemodynamically stable patients in whom a mediastinal trajectory of injury is suspected, the primary imaging modality after radiography should be multidetector CT. CT is invaluable in the assessment of TMI due to its capacity to depict the injury track as well as demonstrate both direct and indirect signs of organ injury. On the basis of the suspected trajectory and specific findings, radiologists can play an essential role in determining future patient management and investigations for each mediastinal organ, thereby expediting appropriate investigation and treatment and avoiding unnecessary and sometimes invasive tests or surgery. The authors provide an up-to-date and evidence-based approach for the management of hemodynamically unstable and stable patients with suspected TMI, discuss management algorithms and CT protocols, and highlight common and uncommon imaging findings and diagnostic pitfalls associated with vascular, cardiac, esophageal, tracheobronchial, pleural, and pulmonary injuries. Online supplemental material is available for this article.

Methemoglobinemia after a mediastinal stab wound.

BACKGROUND: Methemoglobinemia is a relatively common, potentially fatal syndrome resulting from oxidative stress. Of the numerous causes identified, toxins are the most common precipitating event. OBJECTIVES: Describe methemoglobinemia after a stab wound in a man with previously undiagnosed cytochrome b5 reductase deficiency. CASE REPORT: In this case report, we describe a 27-year-old man with no past medical history who developed clinically significant methemoglobinemia after a mediastinal stab wound. After an extensive toxicologic work-up failed to reveal the etiology of the symptoms, genetic testing was performed, which revealed the individual to have a previously undiagnosed cytochrome b5 reductase deficiency. It is hypothesized that the physiologic stress from the expanding mediastinal stab wound resulted in enough oxidative stress to cause methemoglobinemia in this predisposed individual. A discussion of methemoglobinemia ensues. CONCLUSION: This case describes an uncommon presentation of a common toxicologic condition and presents a discussion regarding the evaluation, management, and pathophysiology of methemoglobinemia.

Pediatric thoracic and abdominal trauma.

Thoracic and abdominal injuries in children are commonly the result of blunt trauma, making their diagnosis difficult. Unidentified injuries can cause significant morbidity and mortality and must be identified early. Understanding the anatomic and physiologic differences between children and adults is important to adequately manage children with these injuries. The following review provides salient points in the recognition and management of both thoracic and abdominal injuries in children from blunt trauma.

[Thoracoscopic surgery for traumatic mediastinal hematoma].

We report a rare case of traumatic mediastinal hematoma treated by thoracoscopic surgery. A 78-year-old man accidentally fell down from the roof, and he was urgently transferred to our hospital. Soon after the arrival, he showed breathlessness followed by cardiopulmonary arrest, necessitating tracheal intubation and resuscitation. Computed tomography (CT) showed a large cervical hematoma extending to the tracheal bifurcation level of mediastinum, causing tracheal obstruction. Five days later, the large mediastinal hematoma was removed by thoracoscopic surgery. The patient recovered without any complications after our treatments.

Intrathoracic hernia of a retrosternal colonic graft after esophagectomy: report of a case.

We report a case of intrathoracic herniation of the colonic interposition pulled up through the retrosternal space after subtotal esophagectomy for esophageal cancer. The patient, a 68-year-old man, presented with progressive dysphagia about 1 year after this operation. We performed left thoracotomy and laparotomy, which revealed the reconstructed colon herniating into the left thoracic cavity through a large defect in the left mediastinal pleura. The redundant colon was resected, and the colonic graft was shortened and straightened. We concluded that the defect in the mediastinal pleura and colonic redundancy had permitted the colonic graft to herniate into the left thoracic cavity.

Recent firsts in cadaveric impact biomechanics research.

High-speed biplane x-ray and neutral density targets were used to examine brain displacement and deformation, as well as aortic motion and deformation within the mediastinum, during impact. Thirty-five impacts using eight human cadaver head and neck specimens and eight impacts of the intact cadaver thorax are summarized. During impact, local brain tissue tends to keep its position and shape with respect to the inertial frame, resulting in relative motion between the brain and skull and deformation of the brain. The local brain motions tend to follow looping patterns. Similar patterns are observed for impact in different planes, with some degree of posterior-anterior and right-left symmetry. Clinically relevant damage to the aorta was observed in seven of the thorax tests. The presence of atherosclerosis was demonstrated to promote tearing. The isthmus of the aorta moved dorsocranially during frontal impact and submarining loading modes. The aortic isthmus moved medially and anteriorly during impact to the left side.

"HOOAH!" A case of pneumomediastinum in the military training environment; Hamman's sign 71 years later.

A previously healthy 20-year-old male trainee developed chest pain, shortness of breath, and neck pain after repeatedly shouting "Hooah!" during a motivational squad competition. He was found to have developed a pneumomediastinum with soft tissue crepitus of the neck. He had an uneventful recovery. Unique to the military training environment, vigorous shouting, including "Hooah!" as a motivational stimulus, can have barotraumatic consequences. The term "spontaneous" as applied to a pneumomediastinum diagnosis is examined and the auscultatory finding of "Hamman's sign" is reviewed.

Tension pneumothorax and subcutaneous emphysema during retrieval of an ingested lithium button battery.

We present a case of a child with an ingested lithium battery causing esophageal perforation with mediastinal injury extending to the pleural cavity. During the endoscopic retrieval of the battery, the child developed the rare complication of subcutaneous emphysema, tension pneumothorax, and pneumomediastinum from excessive iatrogenic air insufflation. The patient developed mediastinitis and had a complicated postoperative course.

Chest radiography in thoracic polytrauma.

OBJECTIVE: Chest radiography is the first-line imaging examination for assessment of thoracic polytrauma, serving to evaluate the extent of injury and facilitate early triage to observation, further imaging, or immediate surgical intervention. The objective of this article is to review the spectrum of injuries that occur in the chest and upper abdomen after blunt and penetrating trauma. Pathophysiology, imaging findings, and management recommendations will be discussed for injuries to the chest wall, diaphragm, pleura, lungs, mediastinum, heart, aorta, and great vessels. CONCLUSION: Chest radiography plays an important role in the initial evaluation of blunt and penetrating chest trauma, providing rapid imaging information to supplement the history and physical examination. In the emergency department, familiarity with the spectrum of injuries that can occur in the chest and upper abdomen is important for accurate interpretation of chest radiographs as well as establishment of appropriate recommendations for management and follow-up.

[Therapeutic approach in hemodynamically stable transmediastinal gunshot wounds]. / Hemodinamisi stabil transmediastinal atesli silah yaralanmalarinda tedavi yaklasimi.

Transmediastinal gunshot wounds may result in damage to the heart, large blood vessels, esophagus or lung. In hemodynamically stable patients, diagnostic examinations have critical importance and the preferred therapies still have unresolved points. In this paper, we present our experience with five patients, three of whom were operated for transmediastinal gunshot wounds after diagnostic tests; all were hemodynamically stable. Before deciding on operation, diagnostic tests should be performed in hemodynamically stable patients with transmediastinal gunshot wounds.