may have bronchomalacia and a tendency toward bronchospasm.48

Congenital Cystic Adenomatoid Malformation

CCAM lesions are the second most common cause (25%) of newborn respiratory distress, secondary to

structural problems. Children will present either at birth or in early childhood with recurrent

respiratory infections. The anomalies are due to an overgrowth of bronchioles, likely during the acinar

phase of fetal lung development. Lesions can occur on either side and are usually isolated to one lower

lobe. The classification system by Stocker (Table 80-3) organizes these lesions based on pathologic

appearance and clinical outcome. Prenatal MRI best serves to evaluate these lesions, while postnatal

chest x-ray and/or chest CT scan can be used to differentiate CCAMs from other lesions.46 Even though

lesions may be small and asymptomatic, these lesions possess the potential for malignant transformation

and should be resected (Fig. 80-29).48

Table 80-3 The Stocker Classification of CCAM

Figure 80-29. Specimen removed from an infant with a cystic adenomatoid malformation. Microscopically, there was marked

proliferation of terminal bronchioles, and cartilage was lacking. (Reproduced with permission from Shields TW, ed. General

Thoracic Surgery. 6th ed. 2005.)

Bronchogenic Cysts

Bronchogenic cysts are formed from primitive foregut tissue present in the airway. They can present as

single or multiple cysts in a wide variety of locations in the thorax. They usually present in young

children who develop symptoms such as stridor due to airway obstruction or compression caused by the

cysts.47 Alternatively, cysts located within the lung parenchyma can become infected and present as an

abscess. Therapeutic aspiration may be temporizing, but ultimately surgery is needed.49 Resection may

have a mortality of upto 14%, but untreated lesions have a 100% mortality.47 Most cases of congenital

lung disease will present in the first 6 months of life. The main symptom is usually respiratory distress,

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but once children reach 1 year in age, chronic infections become the most common symptom. Diagnostic

tests begin with chest x-rays, but can include ultrasound, MRI, CT scans, angiography, and

bronchoscopy, depending on the lesion and location.50 Decision-making regarding the timing of surgical

resection should incorporate the patient’s acuity due to symptoms and their overall ability to tolerate

surgery based on size.

Pleural Disease

Pleural diseases include benign complications from systemic disease, postoperative infections, local

infections, and cancers from primary and metastatic sites. Diseases involving the pleura can lead to

limitations to respiration and symptoms of dyspnea. Surgical intervention may be indicated, and it is

imperative for the surgeon to be able to recognize which disease processes require a surgical procedure.

Pneumothoraces are discussed earlier in this chapter, and here we will cover pleural effusions, including

empyemas, and malignant pleural mesotheliomas.

DIAGNOSIS

Table 80-4 Differential Diagnosis of Pleural Effusions

PLEURAL EFFUSIONS

Pleural effusions are a common condition that elicits a surgical consult for potential drainage and even

thoracoscopic intervention to assist in the diagnosis and treatment of the condition. The essential first

step in the evaluation of a new effusion is to determine if it is a transudative or exudative process. A

transudative fluid collection is the result of a poorly balanced hydrostatic and/or osmotic pressure

across the pleural membrane resulting in increased serum leak across the pleural barrier. Exudative

processes result from inflammation or neoplastic processes that cause increased capillary leak at the

pleural membrane. Because of the leaky membrane, larger proteins can enter the pleural fluid resulting

in higher protein and lactate dehydrogenase (LDH) levels in the exudative fluid compared to the

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transudative fluid (Table 80-4).51 One of the tests used most often to make the diagnosis is Light

criteria, where the serum and pleural fluid protein and LDH levels are measured (Table 80-5). If one or

more of the criteria are met, then the fluid is considered exudative.52 Other tests have been evaluated,

including measuring cholesterol ratios and the albumin gradient, but Light criteria is still the best

overall test.51

6 Transudative effusions are most often caused by congestive heart failure. Even if a patient does not

have other symptoms of heart failure, in the setting of a transudative effusion, a complete cardiac

workup should be considered. Other causes include cirrhosis which may or may not be associated with

ascites. Isolated right- and left-sided effusions due to liver disease have been described. Effusions can be

seen in more than 20% of patients with nephrotic syndrome, and so all patients with new effusions

should be evaluated for the presence of proteinuria. Rarer causes include retroperitoneal urine leaks or

cerebrospinal fluid leaks.52 Surgical interventions, such as chest tube placement, should be avoided in

transudative disease settings, as patients will continue to drain fluid from their chest until the primary

cause is treated. Aspiration of fluid may help temporarily while systemic treatment is instituted, but

should only be done as part of a larger treatment plan.

Table 80-5 Criteria for Exudative Effusions Based on Ratio of Pleural Fluid

Protein and LDH Concentrations to Serum Concentration

Exudative effusions have a number of etiologies, but malignancy is the number one cause.52

Approximately a quarter of pleural effusions in a community hospital setting have been attributed to

cancer. The malignancies that cause the effusions are, in order of decreasing frequency: lung cancer,

breast cancer, and hematologic cancers such as lymphoma. Other malignancies can also cause effusions,

such as ovarian cancer.53 The next most common causes of exudative effusions are infections, and

include pneumonias causing parapneumonic effusions, tuberculosis (TB), and fungal infections. Although

rarer in the United States, TB is still a common etiology worldwide. If someone is suspected of having

pleural TB, the pleural fluid should be evaluated for adenosine deaminase (ADA) and gamma-interferon

levels, which if low will rule out the diagnosis of TB. If other infections are suspected, the pleural fluid

should be cultured. Pancreatitis may also cause an exudate, and elevated serum amylase levels will

support the diagnosis. Autoimmune processes, such as rheumatoid disease and lupus, can also cause

effusions. A chylothorax may present after problems with thoracic duct lymphatic drainage leading to

an accumulation of lymphatic fluid, “chyle”, in one or both thoraces. The thoracic duct collects lymph

from the cysterna chyli, the plexus of lymphatics in the upper abdomen, and travels anterior to the

spine and just posterolateral to the aorta. It follows behind the aorta and enters the left neck where it

empties into the confluence of the left internal jugular and subclavian veins (Fig. 80-30). Chylous leaks

are due primarily to thoracic duct injury from trauma or surgery or lymphomas resulting in obstructed

lymphatics. Pleural triglyceride and cholesterol levels will be elevated and the fluid will have a milky

color. Treatment for persistent chylothoraces include thoracic duct ligation by surgery or by

embolization of the site of leak in the interventional suite.52

The management of malignant pleural effusions includes a variety of options, but critical to the

decision-making process is the knowledge of the median life expectancy in that patient due to the

underlying malignancy. Chest tube drainage may be therapeutic and diagnostic, allowing fluid drainage

and alleviation of symptoms of dyspnea. It will also allow determination of whether the underlying lung

is able to expand. If not, it is described as a “trapped lung” and although the fluid may be gone, a

persistent pneumothorax appears on chest x-rays as the lung cannot expand and fill the thorax. In these

settings, an indwelling pleural drainage catheter may be the best option to intermittently drain

accumulating fluid. Decortication is not recommended, as most patients with malignancy in this setting

have a limited life expectancy and the success rate is low compared to decortication in the setting of an

empyema. VATS exploration may also be used to remove loculated fluid collections and to evaluate for

lung reexpansion after the procedure. If the lung reexpands, further treatment includes pleurodesis,

utilizing talc, doxycycline, or bleomycin. These medications will cause an inflammatory reaction

between the parietal and visceral pleura resulting in the lung being “stuck” in an expanded state.

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Mechanical pleurodesis can also be performed by mechanical debridement of the pleura via VATS.

Chemical pleurodesis may be performed via VATS or through an existing thoracostomy tube. The goal

of treatment in the setting of a malignant pleural effusion is palliation.53

Empyema

7 Empyemas are defined as frank pus in the thoracic cavity. This represents part of the continuum of

disease that begins with simple parapneumonic effusion, where exudative fluid is not infected and not

loculated. As the disease progresses, fluid becomes loculated with fibrinous septations and becomes

infected, leading to pus and ultimately the development of a fibrinous peel. Upto half of pneumonias

have an associated effusion, but less than 5% of cases lead to an empyema.54 Other causes include

surgical thoracotomies and/or other infections from nearby organs, such as esophageal injuries. Pleural

infections have been categorized into three overlapping stages. The first is the exudative stage, where

the fluid is thin, sterile, has a lower white blood cell (WBC) count and LDH levels, and the glucose level

is still above 40 mg/dL (Table 80-6). Treatment usually involves addressing the underlying etiology,

such as pneumonia. The second stage is the fibrinopurulent stage, where the fluid becomes infected and

fibrin deposits accumulate on the pleura. The LDH and WBC count increases, the glucose and pH levels

drop. The fluid becomes thick and purulent and the lung is often unable to expand. Chest tube drainage

alone at this stage may not be effective to remove the fluid. The third stage is the organizing stage, and

a thick pleural peel is created by migrating fibroblasts. At this point, a formal debridement and

decortication is required to allow the lung to return to full function.54

Figure 80-30. Schematic drawing of the most usual pattern and course of the thoracic duct. The single duct that enters the chest

through the aortic hiatus between T12 and T10 is a relatively consistent finding and the usual site for surgical ligation.

Organisms causing empyemas have shifted from predominately Streptococcus pneumoniae in the

preantibiotic era, to anaerobic organisms in upto three-quarters of empyemas in the current era.

Imaging to evaluate the presence of an empyema begins with a simple chest x-ray, but requires a chest

CT to show potential loculations. After the institution of antibiotic therapy, surgical intervention

depends on the stage of the disease, but may require a VATS exploration or even a thoracotomy to

debride the thorax effectively and to decorticate the pleural peel off of the lung to allow reexpansion.54

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Postpneumonectomy empyemas are an especially difficult problem as there is no lung tissue to occupy

the empty thorax. Risk factors in this setting include right pneumonectomies (vs. left), the need for

postoperative ventilation, lower starting hematocrit levels, and poor preoperative pulmonary function

test results.55,56 Treatments of these empyemas are particularly difficult and may include an Eloessor

flap or the Clagget procedure which allow for the creation of an open wound that allows for packing

and granulation tissue to form in the empyema cavity.57

Table 80-6 Diagnostic Criteria for Pleural Fluid in Empyema

Mesothelioma

Malignant pleural mesothelioma (MPM) is a cancer of the serosal pleura, related to the exposure to

asbestos. Multiple hypotheses have been formed regarding how asbestos causes mesothelioma, and

include the idea that asbestos fibers are inhaled deeply into the lung and penetrate the parenchymal

surface, causing irritation of the pleura and repeated episodes of inflammation, ultimately leading to

cancer. Other potential mechanisms include asbestos interfering with mitosis, inducing free-radical

production, and induction of protooncogene kinases by asbestos fibers.58 Exposure to asbestos usually

occurs decades prior to presentation with mesothelioma, and has been seen in miners exposed to

asbestos dust, industrial workers such as plumbers and carpenters who used asbestos products, and even

in 20% of patients with no known exposure but living in industrial countries. Mesothelioma is a

relatively rare malignancy, with less than 5,000 cases in the United States per year.59

Patients with mesothelioma may present with dyspnea or chest pain. Often, patients are

asymptomatic and the diagnosis is made after abnormalities are seen on a chest x-ray performed for

another reason. Radiographs may show unilateral effusions and a loss of volume on the affected side, as

the lung capacity is diminished due to disease. As the disease progresses, patients may have weight loss,

worsening pain, and night sweats. Median survival may be as little as 1 year from the time of

diagnosis.60 Diagnostic studies include a chest CT scan or MRI to show the extent of pleural thickening

(Fig. 80-31). Lymphadenopathy or signs of local spread through the diaphragm or chest wall can also be

seen with three-dimensional imaging. The pathologic diagnosis almost always requires a tissue biopsy.

Cytologic examination of pleural fluid from a thoracentesis cannot differentiate between mesothelioma

cells and other potential lung cancers. CT-guided biopsy of pleural thickening can often give the

diagnosis, but ultimately a VATS approach or limited thoracotomy may be needed to obtain a diagnosis.

If the patient is being considered for surgical resection, a limited thoracotomy in the site of a potential

later incision is optimal to limit seeding of the tumor.60

Mesotheliomas can be categorized into epithelial, sarcomatoid, and mixed histologies. Patients with

epithelial histology do better than those with a sarcomatoid histology.60 There are a variety of staging

systems for mesothelioma, including the Butchart system, the revised Brigham and Women’s Hospital

system, and the TNM-based system by the International Mesothelioma Interest Group (IMIG) (Table 80-

7).60,61 The IMIG system allows for better reproducibility of the interpretation of local and regional

lymph node spread. Laparoscopy may be useful to evaluate the patient for transdiaphragmatic spread of

the tumor, differentiating between T3 and T4 tumors.61

Treatment for mesothelioma may include chemotherapy, radiation therapy, and surgery. Surgical

treatment ranges from a pleurodesis for palliation in the setting of effusions and unresectable disease, to

pleurectomy/decortication for limited disease, and to the most aggressive treatment of an extrapleural

pneumonectomy (EPP), with the goal of complete tumor resection. Less than a third of patients are

candidates for any surgical intervention. Preoperative workup for an EPP should include a cardiac

evaluation, and optimal surgical candidates have pulmonary function tests with an FEV1 of greater than

2 L/sec and an age under 70.61 Surgery involves an en bloc removal of the lung, pleura, pericardium

and diaphragm with reconstruction of the pericardium and diaphragm. Pleurectomy and decortication is

reserved for very early-stage disease and involves removal of the pleura only with preservation of the

lung parenchyma. Multimodality approaches have shown better results, with neoadjuvant chemotherapy

and adjuvant radiation therapy.62 Chemotherapy for advanced disease includes pemetrexed and cisplatin

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or the combination of gemcitabine and cisplatin. Both have shown similar levels of palliation.

Radiotherapy may also be used, but is limited by the large field requiring treatment and the risks of

pneumonitis and esophagitis.58 It is best used in combination with EPP for local control after surgery, or

to treat local painful areas.61 Because of the rarity of surgical cases, most patients who are considered

for surgery should be referred to high-volume centers where surgeons and other clinicians are

comfortable treating this disease.

Figure 80-31. Magnetic resonance imaging of the patient in Figure 80-25 shows a large amount of tumor within the pleural space

and into the diaphragmatic sulcus with no evidence of extension outside the hemithorax. (Reproduced with permission from Flores

RM, Sugarbaker DJ. Malignant mesothelioma of the pleural space. Ann Thorac Surg 2000;70:306.)

STAGING

Table 80-7 The International Mesothelioma Interest Group (IMIG) Staging System

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Trachea

The trachea is a well-known structure to the general surgeon who may perform tracheostomies and

bronchoscopies as part of their clinical practice. A thorough knowledge of the anatomy and vascular

supply is essential to minimize complications such as postintubation tracheal stenosis and

tracheoinnominate fistulas after tracheostomies.

Anatomy

The trachea is the connection from the cricoid cartilage to the carina that allows ventilation and mucous

clearance from the lungs. It is oval shaped, with C-shaped cartilaginous rings creating the anterior and

lateral borders. A soft tissue membrane forms the posterior wall to complete the oval shape. In the

average male, the anterior–posterior dimension is 1.8 cm, while the lateral aspect is 2.3 cm. Tracheal

length reaches almost 12 cm with almost 2 rings per centimeter. Tracheae in women are 10% to 20%

smaller in size. In children, the shape is more circular, but becomes gradually more ovoid as people age.

There is a significant amount of flexibility in the normal trachea, and remodeling can occur in chronic

disease states such as emphysema. The inner lining consists of ciliated pseudostratified columnar

epithelium with goblet and mucous cells interspersed. At the carina, the right and left mainstem bronchi

split off. The right side is characterized by the quick takeoff of the right upper-lobe bronchus, with the

bronchus intermedius continuing into the middle and lower-lobe bronchi. The left side has a longer

mainstem bronchus with a split into the upper and lower lobes.63 The blood supply begins with the

inferior thyroid artery supplying the cervical trachea through three tracheoesophageal branches. The

lower trachea is supplied by bronchial arteries arising off the aorta. As the arteries approach the

trachea, they further split to supply separate segments. Even within segments, it will branch into

anterior and posterior transverse intercartilaginous arteries (Fig. 80-32). Because of this segmental

blood supply, there should be minimal circumferential dissection around the trachea to limit impairment

of the blood supply and healing in tracheal/bronchial surgery.

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Figure 80-32. Semischematic view of the tracheal microscopical blood supply. Transverse intercartilaginous arteries derived from

the lateral longitudinal anastomosis penetrate the soft tissues between each cartilage to supply a rich vascular network beneath the

endotracheal mucosa.

Surgical Airways

The most common tracheal procedure is a tracheostomy. Over the last 20 years, there has been an

increasing utilization of percutaneous tracheostomy. For patients who are intubated, the indication for

and timing of tracheostomy depends on a multitude of factors, of which there is very little consensus in

the medical literature. The goal of a tracheostomy is to limit the risk of laryngeal stenosis caused by

prolonged endotracheal intubation, to improve pulmonary toilet, and to improve oral hygiene.

Generally, tracheostomy should be considered after a patient has been intubated for more than 7 days,

without clear expectation for immediate extubation.64 Ideally, patients should be on minimal ventilator

settings, but tracheostomy may be performed in patients with elevated oxygen (FiO2 of upto 60%) and

ventilatory (PEEP under 10) requirements. Patients requiring more support are at high risk of

decompensating if they lose their airways, even if just for a moment, and the decision to perform a

tracheostomy should be carefully considered in this setting.65

Tracheostomies are performed with the neck extended. A 2- to 3-cm incision is made approximately 2

cm above the sternal notch. Dissection is carried down through the platysma, and the strap muscles are

divided longitudinally. Exposure of the trachea and the 2nd and 3rd rings may require elevation of the

thyroid. Lateral traction sutures may be placed around the 2nd or 3rd rings. A vertical incision is made

between rings 2 and 4 and gradually dilated. A tracheostomy tube is placed under direct vision.64,66

Percutaneous tracheostomy placement is based on the Seldinger technique. A needle is placed

percutaneously into the trachea at the estimated level of the 2nd or 3rd rings with bronchoscopic

visualization. A guidewire is placed into the airway, and serial dilations performed, until a tracheostomy

tube is able to be advanced over the wire.65 Cricothyroidotomy should only be performed in the

emergent setting. The cricothyroid membrane is palpated below the superior thyroid notch. A

transverse incision is made to the lateral borders of the thyroid cartilage. Rapid dilation is followed by

tube insertion.64

Complications can vary depending on the technique. For open tracheostomy, they include damage to

the carotid artery, internal jugular vein, the posterior tracheal wall/anterior esophagus, and to the apex

of the lung.65 Also reported are fires due to the use of electrocautery in the setting of nitrous oxide and

oxygen.64 In percutaneous tracheostomies, complications include pneumothorax, mediastinal

emphysema, paratracheal insertion, tracheoesophageal fistula, and airway loss.65,67 Common

complications include local hemorrhage and infection. Major late complications include tracheal stenosis

and tracheoinnominate fistulas. Fistulas result from erosion of the tracheostomy tube into the

innominate artery. I8 mproper placement of the tracheostomy into rings lower than the 3rd ring place

patients at higher risk for this complication. A sentinel bleed may be the initial presentation. Pressure

on the fistula with immediate repair or ligation of the vessel is required (Fig. 80-33).68 Postintubation

stenosis is usually due to necrosis caused by high-pressure cuffs resulting in impaired blood flow to the

segmental area of the trachea. This leads to the long-term loss of cartilage and narrowing of the airway.

The use of low-pressure cuffs has reduced the incidence of this complication, but not eliminated it.

Bronchoscopy and dilation may alleviate symptoms, but resection of the stenotic area may be needed

(Fig. 80-34).66

Tracheal Tumors

Benign lesions of the trachea are less common than malignant ones. They include papillomas,

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