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inoperable. Pneumothorax is the main complication of this procedure.

Pleural biopsy. Either percutaneous or open pleural biopsy yields a positive diagnosis in 60%–80% of patients with tuberculosis or cancer when a pleural effusion or pleural -based mass is present. Pneumothorax is the main complication of this procedure.

Lung biopsy

Diagnostic uses. Percutaneous lung biopsy may be used for either a localized peripheral lesion or a diffuse parenchymal process.

Types

CT––directed fine needle aspiration biopsy is an excellent method for obtaining tissue for tumor diagnosis. However, sampling errors do exist, and a biopsy negative for a tumor does not rule out the existence of a tumor. Needle biopsy may also be useful for the diagnosis of infections and inflammatory processes.

Complications of needle biopsy are pneumothorax and hemorrhage.

Open lung biopsy is necessary if needle biopsy fails to diagnose the problem. Open biopsies or resections are ultimately necessary for many lesions of the chest.

Thoracic exposure for various diseases is provided by different thoracic incisions , for example:

Median sternotomy (Fig. 4-4) for exposure of the heart, pericardium, and structures in the anterior mediastinum

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FIGURE 4-7 Anterolateral thoracotomy.

II Thoracic Trauma

Most thoracic trauma can be managed nonoperatively, using expeditious control of the airway and thoracostomy tube drainage of the pleural space. Less than 25% of chest injuries require surgical intervention. Thoracic trauma can be divided into immediate life -threatening injuries and potentially life -threatening injuries, according to the designation by the American College of Surgeons Committee on Trauma.

A

Immediate life -threatening injuries are those that can cause death in a matter of minutes and, therefore, must be rapidly identified and treated during the initial evaluation and resuscitation.

Airway obstruction quickly leads to hypoxia, hypercapnia, acidosis, and cardiac arrest. The highest priority is rapid evaluation and securing the upper airway by clearing out secretions, blood, or foreign bodies; endotracheal intubation; or cricothyroidotomy.

Tension pneumothorax implies that the pleural air collection is under positive pressure that is significant enough to cause a marked mediastinal shift away from the affected side.

Causes. Tension pneumothorax is caused by a check -valve mechanism in which air can escape from the lung into the pleural space but cannot be vented. It is a cause of sudden death.

Clinical presentation. The collapsed lung results in chest pain, shortness of breath, and decreased or absent breath sounds on the affected side. Hypotension results from mediastinal shift to the contralateral side, which compresses and distorts the vena cavae and obstructs venous return to the heart.

Treatment. The thorax must be decompressed with a needle, which is replaced by an intercostal tube with underwater seal and suction.

Open pneumothorax describes an injury in which an open wound in the chest wall has exposed the pleural space to the atmosphere.

Clinical presentation. The open wound allows air movement through the defect during spontaneous respiration, causing ineffective alveolar ventilation.

Treatment involves covering the wound and inserting a thoracostomy tube. Later, debridement and closure of the wound may be necessary.

Massive hemothorax occurs with the rapid accumulation of blood in the pleural space, which causes both compromised ventilation as well as hypovolemic shock.

Treatment entails securing intravenous access and beginning volume restoration followed immediately by placement of a thoracostomy tube.

Complications

If the hemothorax is inadequately drained, the patient may develop an empyema or fibrothorax, both of which would require subsequent thoracotomy and decortication.

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Initial drainage of at least 1000 mL or continued hemorrhage at the rate of 200 mL/hour for 4 hours is an indication for prompt surgical exploration.

Cardiac tamponade occurs with the rapid accumulation of blood in the pericardial sac, which causes compression of the cardiac chambers, decreased diastolic filling, and thus, decreased cardiac output.

Clinical presentation includes hypotension with neck vein distention.

Treatment is prompt pericardial decompression either by pericardiocentesis (if in extremis) or via median sternotomy or left anterior thoracotomy (if more stable).

Flail chest. Blunt chest trauma, causing extensive anterior and posterior rib fractures or sternocostal disconnection, results in paradoxical chest wall movement.

Clinical presentation. Paradoxical chest wall movement interferes with the mechanics of respiration and, if severe, causes acute alveolar hypoventilation. Morbidity is also related to underlying lung injury.

Treatment includes adequate pain control (intercostal blocks or epidural narcotics) and aggressive pulmonary toilet. Mechanical ventilation may be required in severe cases.

B Potentially life-threatening injuries

Potentially life -threatening injuries are those that, left untreated, would likely result in death, but that usually allow several hours to establish a definitive diagnosis and institute appropriate treatment.

Tracheobronchial disruption usually occurs within 2 cm of the carina.

Diagnosis is made by bronchoscopy and is suspected when a

Collapsed lung fails to expand, following placement of a thoracostomy tube

Massive air leak persists

Massive progressive subcutaneous emphysema is present

Treatment is by primary repair.

Aortic disruption is the result of a deceleration injury in which the mobile ascending aorta and arch move

forward while the descending thoracic aorta remains fixed in position by the mediastinal pleura and intercostal vessels. This movement causes a tear at the aortic isthmus, just distal to the takeoff of the left subclavian artery.

Clinical presentation. The aortic injury usually results in fracture of the intima and media with the adventitia remaining mainly intact. However, complete disruption of all layers can occur with the hematoma contained only by the intact mediastinal pleura.

Chest radiograph findings include:

Widened mediastinum

Indistinct aortic knob

Depressed left main stem bronchus

Apical cap

Deviation of trachea to the right

Left pleural effusion

Diagnosis is confirmed by an aortogram.

Treatment involves repair by interposition graft with or without some method of distal perfusion.

Diaphragmatic disruption results from blunt trauma to the chest and abdomen, producing a radial tear in the diaphragm, beginning at the esophageal hiatus.

Diagnosis is by chest radiograph, which shows evidence of the stomach or colon in the chest.

Treatment

The immediate placement of a nasogastric tube (if not already in place) will prevent acute gastric dilatation, which can produce severe, life -threatening respiratory distress. This is followed by urgent transabdominal repair with simultaneous treatment of any associated intra - abdominal injuries.

If rupture is not diagnosed until 7–10 days later, transthoracic repair is recommended to free any adhesions to the lung that might exist.

Esophageal disruption usually results from penetrating trauma rather than blunt trauma.

Clinical presentation. It causes rapidly progressive mediastinitis.

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Treatment is wide mediastinal drainage and primary closure with tissue reinforcement (pleura, intercostal muscle, or stomach).

Cardiac contusion results from direct sternal impact. It ranges in severity from subendocardial or subepicardial petechiae to full -thickness injury.

Functional complications

Arrhythmias (i.e., premature ventricular contractions, supraventricular tachycardia, and atrial fibrillation)

Myocardial rupture

Ventricular septal rupture

Left ventricular failure

Diagnosis is made by an electrocardiogram, isoenzymes, and two-dimensional (2D) echocardiogram.

Treatment includes cardiac and hemodynamic monitoring, appropriate pharmacologic control of arrhythmias, and inotropic support if cardiogenic shock develops.

Pulmonary contusion is the most common injury seen in association with thoracic trauma (30%–75% of all patients have a major chest injury).

Causes. It is caused by blunt trauma, which produces capillary disruption with subsequent intra - alveolar hemorrhage, edema, and small airway obstruction.

Diagnosis is made by chest radiograph, arterial blood gas, and clinical symptoms of respiratory distress.

Treatment includes fluid restriction, supplemental oxygen, vigorous chest physiotherapy, adequate analgesia (epidural narcotics), and prompt chest tube drainage of any associated pleural space complication.

Chapter 5

Chest Wall, Lung, and Mediastinum

D. Bruce Panasuk

William R. Alex

Richard N. Edie

I Disorders of the Chest Wall

A Chest wall deformities

Pectus excavatum (funnel chest). An exceedingly depressed sternum is the most common chest wall deformity. It is usually asymptomatic, but it may cause some functional impairment. Surgery is indicated for moderate to severe deformities and is performed at 4–5 years of age. The operation involves

Subperichondrial resection of all involved costal cartilages

An osteotomy of the sternum

Overcorrection of the sternal defect with a bone wedge

Use of a retrosternal support (optional)

Pectus carinatum (pigeon breast). An overly prominent sternum is less likely to cause functional impairment than a depressed sternum. The repair is similar to that used for pectus excavatum.

A distal sternal defect occurs as part of the pentalogy of Cantrell (see Chapter 29, III A 2 d).

Poland's syndrome is a unilateral absence of costal cartilages, pectoralis muscle, and breast. Surgery is indicated for protection of the underlying thoracic structures and for cosmetic reasons.

Thoracic outlet syndrome (TOS)

Clinical presentation

Compression of the neurovascular bundle at the thoracic outlet (by fibromuscular bands, the anterior scalene muscle, the first rib, or the cervical ribs) causes pain and paresthesia in the neck, shoulder, arm, and hand.

Brachial plexus compression (neurogenic TOS) occurs most often. Pain affects the neck, shoulder, anterior chest wall, and arm. Paresthesia predominantly affects the hand, often in an ulnar nerve destination.

Vascular compression (vasculogenic TOS) occurs much less frequently.

Diagnosis is clinical and is based on a careful history and detailed physical examination. Electrodiagnostic studies provide little help in establishing brachial plexus compression, although these studies more reliably rule out peripheral neuropathies. Cervical disk disease must be ruled out by magnetic resonance imaging (MRI).

Treatment is initially conservative, using a focused physical therapy program for 3–6 months. Patients with refractory symptoms can be offered surgery, which involves brachial plexus decompression by way of supraclavicular scalenectomy, brachial plexus neurolysis , or first rib resection.

B Chest wall tumors

Benign tumors

Fibrous dysplasia of the rib occurs posteriorly or on the lateral portion of the rib. It is not painful, and it grows slowly. It may occur as part of Albright's syndrome.

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Chondroma is the most common benign tumor of the chest wall. It occurs at the costochondral junction.

Osteochondroma occurs on any portion of the rib.

Malignant tumors include fibrosarcoma, chondrosarcoma, osteogenic sarcoma, myeloma, and Ewing's sarcoma.

Treatment of chest wall tumors involves wide excision and reconstruction, using autologous grafts, prosthetic grafts, or both.

II Disorders of the Pleura and Pleural Space

A

Spontaneous pneumothorax occurs when a subpleural bleb ruptures into the pleural space with resultant loss of negative intrapleural pressure, allowing the lung to collapse.

Incidence. Young adults 18–25 years of age are most commonly affected, although older persons with asthma or chronic obstructive pulmonary disease are also susceptible.

Symptoms include chest pain, cough, and dyspnea and range from mild to severe.

Diagnosis is made by physical examination and chest radiograph.

Treatment is achieved by chest tube drainage of the pleural space.

Indications for surgery

Recurrent pneumothorax (ipsilateral or contralateral)

Persistent air leak for 3–5 days

Incomplete lung expansion

Hemopneumothorax

Procedure is stapling of apical blebs and pleural abrasion. This is an excellent indication for videothoracoscopy and repair.

B Pleural effusions

Transudative effusions result from systemic disorders that alter hydrostatic or oncotic pressures, allowing the accumulation of protein-poor plasma filtrate in the pleural space.

Treatment is directed toward the underlying systemic process. Thoracentesis may be helpful for both

diagnosis and symptomatic relief. Tube thoracotomy should be avoided if possible.

Exudative effusions result from the local pleural pathology, which alters the permeability characteristics of the pleura, allowing accumulation of a protein-rich plasma filtrate within the pleural space.

Treatment usually requires tube thoracostomy, videothoracoscopy, or thoracotomy to resolve effusion.

C Pleural empyema

Pus in the pleural space usually accumulates secondary to pulmonary infection.

Pathophysiology of empyema evolves in three stages.

Acute or serous phase (onset to 7 days) during which pleural fluid is initially produced

Transitional or fibrinopurulent phase (7–21 days) during which fluid gravitates to dependent areas and undergoes septation and loculation

Chronic or organized phase (>21 days) in which fibrin and pleura fuse and thicken around the periphery of the fluid, resulting in frank abscess formation

Diagnosis is made by thoracentesis in a patient with pleural effusion and fever.

The aspirated fluid is sent for laboratory studies. If organisms are seen on a Gram stain, if organisms are cultured out, or if the pH is below 7.4, the diagnosis is probably an empyema.

On gross examination, if the fluid is very cloudy or smells foul, an empyema is likely to be present.

Treatment

Early empyemas associated with pneumococcal pneumonia may be treated with repeated aspiration and antibiotics.

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Established empyemas , which usually have thicker fluid, need continuous closed drainage. If the empyema is loculated and, therefore, not completely drained by the intercostal tube, then thoracotomy, debridement, and decortication are necessary.

Small, dependent empyemas that do not respond to chest tube drainage may require open drainage via localized rib resection, especially in poor -risk patients.

Recent use of computed tomography (CT)–guided catheters followed by pleural lytic therapy using TPA has demonstrated impressive results in successfully draining empyemas and avoiding surgical intervention.

D Pleural tumors and mesothelioma

Localized benign mesotheliomas are not related to asbestos exposure. They usually arise from the visceral pleura and are treated by local excision.

Malignant mesothelioma is related to prior asbestos exposure, arises in the parietal pleura, and presents with a pleural effusion. It is almost always a fatal disease. The role of surgery is primarily for diagnosis and palliation of symptomatic malignant effusion—usually by way of thoracoscopy and talc sclerosis.