Thoracic Surgery

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Chapter 12 Thoracic Surgery

In this chapter the care of patients undergoing noncardiac thoracic surgery is discussed. The emphasis is on postoperative care, but preoperative evaluation and intraoperative management are also reviewed. Thoracic surgery patients, particularly those undergoing pulmonary resection or lung volume reduction surgery (LVRS), are commonly elderly, current or former heavy smokers, and highly likely to have other smoking-related diseases. Careful preoperative selection and optimization are essential for good postoperative outcomes.

This chapter is divided into two sections: (1) pulmonary resection; (2) other thoracic surgery. Pulmonary resection is essentially a discussion of the diagnosis, selection, treatment, and postoperative care of patients undergoing surgery for lung cancer. Other topics covered include LVRS, mediastinal tumors, and esophageal resection. Thoracic trauma, massive hemoptysis, and empyema are covered in Chapters 25, 26, and 35.

PULMONARY RESECTION

Major pulmonary resection is sometimes undertaken for infective lung disease but the great majority of patients who undergo pulmonary resection do so for lung cancer.

Surgery for Lung Cancer

Diagnosis

Patients usually have one or more symptoms related to their tumors, such as cough, chest pain, dyspnea, wheeze, or weight loss. Central tumors can obstruct a large airway, causing atelectasis or pneumonia. Other symptoms and signs are suggestive of tumor extension beyond the lung. Pleuritic chest pain may indicate direct tumor invasion of the chest wall. Dysphagia may indicate esophageal involvement. Hoarseness, Horner syndrome, and arm pain are indicative of recurrent laryngeal nerve, sympathetic chain, and brachial plexus involvement, respectively. Lung cancers commonly metastasize to the brain, skeleton, liver, and adrenals. Extrapulmonary or metastatic spread generally precludes surgery. A number of paraneoplastic syndromes are associated with lung cancer (Table 12-1).

Table 12-1 Paraneoplastic Syndromes Associated with Lung Cancer

Syndrome (hormone secretion) Clinical Manifestation Cancer
Hypercalcemia (parathyroid) Hypercalcemia, polyuria, hypovolemia, confusion NSCLC
SIADH (ADH) Hypernatremia SCLC/NSCLC
Cushing syndrome (ACTH, CRH) Hypertension, fluid retention, weakness, hypokalemia, hyperglycemia SCLC/Carcinoid
Acromegaly (GH, GHRH) Bony overgrowth SCLC/Carcinoid
Gynecomastia (HCG) Breast enlargement SCLC/NSCLC
Myositis/myopathy Proximal weakness, myalgia SCLC/NSCLC
Myasethenic syndrome Weakness, fatigability SCLC
Brain/spinal cord/peripheral neuropathy Multiple SCLC

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone; CRH, corticotropin releasing hormone; GH, growth hormone; GHRH, growth hormone releasing hormone; HCG, human chorionic gonadotropin; NSCLC, non-small cell lung cancer; SCLC, small cell cancer; SIADH, syndrome of inappropriate antidiuretic hormone secretion.

Occasionally, lung cancer is asymptomatic and is an incidental finding on a routine chest radiograph. The presence of a large noncalcified mass (<3 cm in diameter) with spiculated margins is highly suggestive of malignancy. The chest radiograph may show consolidation distal to the mass, mediastinal lymphadenopathy, or pleural effusion. Recently, there has been interest in screening high-risk, asymptomatic patients by means of computed tomography (CT) scanning.1

Surgical Suitability for Resection

Lung cancer is staged according to the TNM (tumor, node, metastases) classification (Tables 12-2 and 12-3). All patients being considered for surgery should have a CT scan of the chest, liver, and adrenal glands. Percutaneous needle biopsy may be considered for peripheral lesions but is not mandatory. Patients with mediastinal lymph nodes greater than 1 cm diameter on CT scan should undergo a staging biopsy or mediastinoscopy prior to lung resection. The presence of a malignant effusion is a contraindication to surgery, but an effusion due to consolidation distal to an obstructing lesion is not; if there is doubt, a pleural aspirate should be obtained.

Table 12-2 TMN Classification of Lung Cancer

Primary Tumor (T)
Tx Primary tumor cannot be assessed or proven
T0 No evidence of primary tumor
Tis Carcinoma in situ
T1 Tumor <3 cm in greatest dimension, surrounded by lung or visceral pleura, without evidence of invasion more proximal than lobar bronchus
T2 Tumor with any of the following features: >3 cm in greatest dimension involves main bronchus >2 cm distal to the carina invades the visceral pleura associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung
T3 Tumor of any size that directly invades the following: chest wall, diaphragm, mediastinal pleura, parietal pericardium; or tumor in the main bronchus <2 cm distal to the carina but without carinal involvement; or associated atelectasis or obstructive pneumonitis of the whole lung
T4 Tumor of any size that involves any of the following: mediastinum, heart, great vessels, trachea, esophagus, vertebral body, carina; or tumor with a malignant pleural or pericardial effusion or with satellite tumor nodule within the ipsilateral primary tumor lobe of the lung
Regional Lymph Nodes (N)
Nx Regional nodes cannot be assessed
N0 No regional lymph node metastases
N1 Metastases to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes involved by direct extension of primary tumor
N2 Metastases to ipsilateral mediastinal and/or subcarinal nodes
N3 Metastases to contralateral mediastinal, contralateral hilar, ipsilateral, or contralateral scalene or supraclavicular lymph nodes
Distant Metastases (M)
Mx Presence of distant metastases cannot be assessed
M0 No distant metastases
M1 Distant metastases present (includes those in a different lobe of the same lung)

British Thoracic Society, Society of Cardiothoracic Surgeons of Great Britain and Ireland Working Party: BTS guidelines: guidelines on the selection of patients with lung cancer for surgery. Thorax 56:89-108, 2001.

Patients who have non-small cell cancer in stage I or II are considered operable: stage I disease has a high chance of cure with surgery alone; stage II disease has a moderate chance of cure with surgery alone. Patients with stage IIIA have a low chance of cure with surgery alone but may be considered for operation in conjunction with chemotherapy. Stage IIIB with known N2 involvement and stage 4 tumors are generally considered inoperable. Adjuvant chemotherapy in all but stage IA leads to improved survival rates, but benefits resulting from postoperative radiotherapy following complete primary tumor resection have not been proven.

Fitness for Pulmonary Resection

Curative lung resection involves the removal of a considerable amount of tissue, which results in permanent loss of pulmonary function. Quantitative assessment of pulmonary function is therefore important for stratifying a patient’s surgical risk. However, given that the outcome of nonsurgical treatment of lung cancer is very poor, it may still be appropriate to proceed with pulmonary resection in a patient deemed to be at high risk based on the results of lung function tests.25

Pulmonary Assessment of High-Risk Patients

Patients who are not clearly suitable for pulmonary resection on the basis of simple spirometry should undergo further testing for pulmonary function.

Predicted Postoperative FEV1.

The predicted postoperative FEV1 (ppoFEV1) is calculated from the preoperative FEV1 (preopFEV1) and the proportion of functional lung that is to be removed (Fig. 12-1). The most accurate way to measure the functional contribution of the lung tissue to be resected is by means of split perfusion scanning using technetium (Tc99) macroaggregates or quantitative CT scanning.6 A simple alternative is to estimate the proportion on the basis of the number of anatomic pulmonary segments that are to be removed (Fig. 12-2). To allow safe resection, the predicted postoperative FEV1 should be greater than 40% of normal.

Preoperative Cardiovascular Evaluation

Patients undergoing pulmonary resection are at increased risk for coronary artery disease. All patients should have a preoperative electrocardiogram and, if a murmur is present, an echocardiogram. Surgery should be delayed for at least 6 weeks following a myocardial infarction.

Clinical predictors of increased perioperative cardiac risk are summarized in Table 12-4. Patients at major risk should have a formal cardiologic assessment, and those with severe coronary artery or valvular lesions should be considered for a revascularization procedure or valve surgery prior to pulmonary resection. Patients at intermediate risk who have good functional capacity do not require further cardiac investigation but, in the presence of poor functional capacity, referral to a cardiologist and cardiac stress testing are warranted. Patients at increased risk for cerebrovascular disease (e.g., a carotid bruit or a history of stroke or transient ischemic attack) should undergo a preoperative carotid Doppler ultrasound study.

Table 12-4 Predictors of Increased Cardiovascular Risk Following Major Noncardiac Surgery

Major Predictors
Unstable coronary syndromes: recent myocardial infarction with evidence of important ischemic risk based on symptoms or noninvasive study; unstable or severe angina
Decompensated congestive cardiac failure
Significant cardiac arrhythmias: high-grade atrioventricular block; symptomatic ventricular arrhythmias in the presence of underlying heart disease; supraventricular arrhythmias with uncontrolled ventricular rate
Severe valvular heart disease
Intermediate Predictors
Mild angina
Previous myocardial infarction based on history of pathologic Q waves
Compensated or prior congestive cardiac failure
Diabetes
Minor Predictors
Advanced age
Abnormal ECG findings (e.g., left ventricular hypertrophy, left bundle branch block, ST or T wave abnormalities)
Rhythm other than sinus rhythm (e.g., atrial fibrillation)
History of stroke
Poorly controlled hypertension

Adapted from Eagle KA, Berger PB, Calkins H, et al: ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery—executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). J Am Coll Cardiol 39:542-553, 2002; and from British Thoracic Society, Society of Cardiothoracic Surgeons of Great Britain and Ireland Working Party: BTS guidelines: guidelines on the selection of patients with lung cancer for surgery. Thorax 56:89-108, 2001.

Intraoperative Management

Pulmonary resection for cancer is usually carried out via a lateral thoracotomy incision and involves a lobectomy, bilobectomy, or pneumonectomy. Selective lung ventilation is usually achieved using a double-lumen endotracheal tube. Pneumonectomy is required for a centrally located carcinoma, particularly when the tumor is adherent to hilar structures. Pneumonectomy or bilobectomy is required for tumors that have crossed a lung fissure. Resection of part of the pericardium (intracardiac pneumonectomy) or chest wall may be required for tumor clearance. For tumors involving a bronchus, a “sleeve lobectomy” may be performed; in this surgery a segment of bronchus along with a lobe are excised. The remaining lobes are then reattached to the residual bronchus. Sleeve lobectomy is performed as an alternative to pneumonectomy with the aim of preserving lung function. Bronchotracheal resection with bronchial reattachment is required in cases in which tumors involve the carina. Limited wedge or segmental resection is appropriate for benign tumors, for metastases, and for primary lung cancer in a patient who would not tolerate full lobectomy. However, in patients with primary lung cancer, sublobar resection is associated with increased local recurrence rates compared to lobectomy. Concurrent with pulmonary resection, mediastinal lymph node sampling is usually performed for the purpose of staging the tumor.

Blood loss with routine lobectomy or pneumonectomy is usually modest but can be substantial in settings of previous thoracotomy, chronic infection, and extrapleural pneumonectomy; the latter is occasionally performed for tuberculous disease and mesothelioma.

Routine Postoperative Care Following Pulmonary Resection

For patients undergoing major pulmonary resection and those with significant cardiac or respiratory comorbidity, postoperative admission to a high-dependency or intensive care unit is appropriate. Monitoring of hourly urine output, invasive arterial pressure, and central venous pressure (if available) is warranted.

Ideally, patients are extubated following pulmonary resection to minimize air leak and to reduce the tension on bronchial or pulmonary staple lines. However, a period of elective postoperative ventilation is justified for patients with severely impaired gas exchange, hypothermia, acidosis, or ongoing bleeding. Hypothermia significantly increases the incidence of myocardial ischemia; therefore, patients who are hypothermic (<35.5°C) should be warmed to 36.5°C using a forced-air warming blanket.10 Immediately following surgery, a chest radiograph should be obtained to assess lung expansion and the position of drains and to rule out hemothorax. The absence of significant mediastinal shift should be confirmed after a pneumonectomy.

Routine supplemental oxygen via nasal cannulas (2 to 3 l/min) is appropriate but if, despite this, the arterial oxygen saturation is less than 93% to 96%, facemask oxygen should be administered. A relatively restrictive approach to postoperative fluids (e.g., 1 ml/kg/hr of a balanced crystalloid solution, maintained until the patient is able to drink) is appropriate. As with all major surgery, patients tend to retain fluid for the first few days following thoracotomy. Patients who are warm and hemodynamically stable but have relative oliguria (0.5 to 1 ml/kg/hr) should not receive aggressive fluid therapy.

Following lobectomy or bilobectomy, the residual lung lobes normally expand to fill up the hemithorax—with some shift of the mediastinum to the operative side (see subsequent material). Following pneumonectomy, the hemithorax gradually fills up with fluid at a rate of about two rib spaces per day. Thus, 1 to 2 days after surgery, it is usual to see an air-fluid level on chest radiograph on the operative side.

Analgesia

Following thoracic surgery pain arises from multiple sites: from the incision (skin, intercostal muscles, ribs, pleura); from subluxation of costochondral joints; from injury to intercostal nerves; and from pleural irritation by chest drains. Breathing and coughing cause traction on the wound and movement of the pleura, further exacerbating pain. Good postoperative analgesia is important, not only for patient comfort but also to (1) preserve pulmonary function by facilitating deep breathing and coughing; (2) reduce the likelihood of myocardial ischemia by reducing sympathetic stimulation; (3) decrease the risk of deep venous thrombosis and pulmonary embolus by improving mobilization; and (4) minimize the incidence of chronic pain. A number of analgesic modalities are available for postoperative analgesia:

Epidural Analgesia.

Thoracic epidural analgesia is a widely used and effective strategy for postthoracotomy pain, and it reduces the risk for postoperative respiratory complications in patients undergoing pneumonectomy.12 The epidural catheter should be placed at the dermatomal level of the surgical incision (usually between T5 and T8) by the anesthesiologist prior to the induction of anesthesia. Opioids, local anesthetics, or a combination of the two may be used as a continuous infusion, with top-ups if required (Table 12-5). One widely used regime is the combination of bupivacaine 0.125% and fentanyl 2 μg/ml administered as a continuous epidural infusion at 0.1 ml/kg/hr.13,14

Table 12-5 Epidural Dosing Regimes

  Top-up or Intermittent Bolus Dose Continuous Infusion
Opioid only    
Morphine 2-4 mg 0.2-0.3 mg/hr
Meperidine 25-50 mg 10-20 mg/hr
Local anesthetic only    
Bupivacaine 0.125-0.25% (maximum 24-hour dose, 400 mg) 5-10 ml 5-12 ml/hr
Ropivacaine 0.2-0.4% 5-10 ml 5-12 ml/hr
Combination    
Bupivacaine 0.125% + fentanyl 2-4 μg/ml 5-10 ml 5-12 ml/hr
Ropivacaine 0.2% + fentanyl 2-4/ml 5-10 ml 5-12 ml/hr

Epidurally administered local anesthetics reversibly inhibit nerve conduction. The intensity of the block depends on the concentration of local anesthetic and the diameter of the nerve fiber, with the smallest nerves being blocked first. The extent of the block depends on the volume of solution. Thus, blockade of pain and autonomic fibers, which are small, occurs first. After that, blockade of light touch (causing numbness) occurs; and finally, blockade of the larger motor fibers (causing weakness) occurs. Effective analgesia is theoretically possible in the absence of numbness or weakness, but in practice this is rarely achieved. Numbness and weakness are more likely when high concentrations of local anesthetic agents are used (e.g., bupivacaine 0.25%).

Blockade of the thoracic and cervical sympathetic nerves can cause hypotension and bradycardia, particularly in the presence of hypovolemia. Catheter migration into the subarachnoid space can result in a high, dense block and in marked hypotension, which may progress to a “total spinal” with profound hypotension, apnea, and loss of consciousness. Urinary retention is common with epidural analgesia so a urinary catheter should be inserted. Weakness can limit mobilization; a patient with a thoracic epidural should not be allowed to walk unaccompanied.

Unlike local anesthetics, epidurally administered opioids do not produce nerve block. However, urinary retention, nausea and vomiting, pruritis, and respiratory depression may occur. Also, the quality of the pain relief obtained by pure opioid solutions is less than that achieved by local anesthetic solutions.

Epidural catheters are contraindicated in patients with coagulopathy. Paralysis due to epidural hematoma formation is a very rare but devastating complication of epidural analgesia. Any unexpected deterioration in lower limb motor function should raise suspicion of the possibility of an epidural hematoma. In this situation, the epidural infusion should be stopped, and if the neurologic signs have not significantly resolved within 60 to 90 minutes, urgent spinal cord imaging should be obtained. The management of low molecular weight heparin for prophylaxis of deep venous thrombosis is discussed later. No specific precaution is required for aspirin. Epidural analgesia is contraindicated in patients receiving warfarin.

Despite an apparently adequately functioning epidural, patients may complain of ipsilateral shoulder-tip pain. The mechanism of this is not clear but may involve irritation of the diaphragm by the intercostal tube. Shoulder-tip pain does not respond well to intravenous opioids or to increase in the epidural infusion. It does not appear to be caused by shoulder distraction because it is not abolished by suprascapular nerve block.15

Multimodal Analgesia.

For most patients, a multimodal approach to analgesia is used. It may include regular acetaminophen and, if not contraindicated, a nonsteroidal antiinflammatory drug (see Chapter 4). To this basic regime should be added a regional technique and patientcontrolled analgesia. Nonsteroidal antiinflammatory drugs may decrease the effectiveness of a pleurodesis and should be avoided in patients undergoing this procedure.16

Assessment of Analgesia and Regional Blocks.

Pain can be subjectively graded by the patient on a scale from 0 to 10, where 0 indicates no pain and 10 indicates the worst pain imaginable; the goal is to achieve pain scores of less than 3/10 at rest and less than 5/10 with coughing (see Chapter 4).

For regional nerve blocks (epidural, paravertebral, extrapleural) with local anesthetic drugs, the extent of the block should be assessed with reference to the dermatome chart (Fig. 12-3). This should be done every 2 to 4 hours or more frequently if the block is high or after a top-up. Pain signals are carried by the same nerve fibers that carry temperature sensation. Thus, the ability to perceive cold (response to an ice cube) can be used to evaluate the distribution of the block. Block height should be measured in conjunction with pain scores and vital signs.

If the block height is above the T2 dermatome there is the potential for severe bradycardia (cervical sympathetic blockade); respiratory insufficiency (blockade of phrenic nerve); and loss of consciousness. Tingling in the fourth and fifth digits (the C8 dermatome; see Fig. 12-3) is an indication that the block is too high. In this situation, the infusion should be stopped and the patient reviewed every 15 minutes until the block height regresses.

For regional analgesia with opioids, measurements of block height are not required; however, regular monitoring of vital signs is still necessary.

Early Complications Following Pulmonary Resection

The perioperative mortality rates for lobectomy and pneumonectomy should be less than 4% and 8%, respectively.2 Respiratory and cardiac and complications are summarized in Tables 12-6 and 12-7.

Table 12-6 Causes of Acute Respiratory Failure Following Pulmonary Resection

Early (typically < 72 hours)
Residual effects of anesthesia (sedatives, neuromuscular blockade, opioids)
Inadequate analgesia
Atelectasis and retained secretions
Pneumothorax
Hemothorax
Bronchospasm
Phrenic nerve injury
Acute respiratory distress syndrome
Late (typically > 48 hours)
Pneumonia
Bronchopleural fistula
Pulmonary embolism

Table 12-7 Causes of Acute Hemodynamic Instability Following Pulmonary Resection

Mismanagement of chest drains:
Suction applied to a pneumonectomy drain, resulting in mediastinal shift toward operative side*
Kinking of drain applied to lobectomy patient, resulting in tension pneumothorax with mediastinal shift away from operative side
High regional block
Concealed hemorrhage with massive hemothorax
Arrhythmias*
Right ventricular failure*
Pericardial tamponade
Myocardial ischemia or infarction
Cardiac herniation
Pulmonary embolus

* Particularly following pneumonectomy

Particularly following intrapericardial pneumonectomy

Acute Respiratory Distress Syndrome

Pulmonary edema due to acute respiratory distress syndrome (ARDS; postpneumonectomy syndrome) is a well recognized complication of pulmonary resection (Fig. 12-5); its incidence is 3% to 7% and its mortality rate is 20% to 80%.17,18 Despite the term postpneumonectomy syndrome, the condition also occurs following lobectomy. The condition is more common following pneumonectomy than lobectomy, and more common on the right side than the left.19 It has been linked to preoperative alcohol abuse, excessive perioperative fluid administration, and peak ventilatory pressures above 25 cm H2O intraoperatively.19

Patients typically present within 3 days of surgery with respiratory distress and hypoxemia. The chest radiograph demonstrates diffuse alveolar infiltrates which, in the case of lobectomy, may be bilateral. Patients are often extremely unwell. Preventive measures include (1) fluid restriction, aiming to replace only surgical and physiologic fluid losses; (2) the use of vasopressors instead of volume to treat nonhemorrhagic hypotension; and (3) if ventilated, the use of a lung-protective strategy (see Chapter 24).20 Noninvasive ventilation may reduce the mortality rate resulting from ARDS after pulmonary resection.21

Hypotension and Low Cardiac Output

There are many possible reasons for postoperative hemodynamic instability, but certain causes must be specifically considered in patients who have undergone pulmonary resection (see Table 12-7). Patients should be carefully examined (including their chest drains). Investigations include a 12-lead electrocardiogram, a chest radiograph, and an echocardiogram.

Arrhythmias.

Supraventricular arrhythmias, particularly atrial fibrillation, occur in more than 20% of patients following pulmonary resection.22 Advanced age, pneumonectomy, upper lobectomy, and a history of chronic obstructive pulmonary disease (COPD) are risk factors.22,23 The use of amiodarone in the prevention of supraventricular arrhythmias following pulmonary resection has been implicated in the development of ARDS.24 However, this concern has not been borne out by more recent studies.25,26

Late Complications Following Pulmonary Resection

Pneumonia

Pneumonia occurs in up to 20% of patients following pneumonectomy and is associated with increased mortality rates.27 Pneumonia typically develops later than 48 hours after surgery but may present earlier if pulmonary infection was present preoperatively. The diagnosis and treatment of pneumonia is discussed in Chapter 35.

Persistent Air Leak Following Lobectomy

Persistent bubbling of the chest drain and incomplete expansion of the lung can be a troublesome problem. Various strategies have been tried to prevent this complication, including the application of fibrin glue to suture lines28 and the early cessation of chest drain suction.29,30 Treatment is usually expectant and in most circumstances the leak gradually settles. A new large air leak, with incomplete expansion of the lung, should raise suspicion of a bronchopleural fistula.

Bronchopleural Fistula

A bronchopleural fistula occurs when there is breakdown of the bronchial stump or tracheobronchial anastomosis. The incidence is 4.5% to 20% after pneumonectomy and 0.5% after lobectomy.31 Risk factors include preoperative radiotherapy, preoperative pulmonary infection, diabetes, right pneumonectomy, a long bronchial stump, residual cancer at the stump, and the need for postoperative ventilation.31

A bronchopleural fistula typically presents with fever, cough, and purulent or hemorrhagic expectoration. With pneumonectomy, the chest radiograph typically demonstrates an increased air content and reduced fluid level within the pleural space. There may be soiling of the nonoperative lung, which is identified by pulmonary infiltrates on the chest radiograph (Fig. 12-6). Less commonly, patients develop systemic sepsis and acute respiratory failure. The diagnosis may be confirmed by thoracic CT or bronchoscopy. Alternatively, dye (e.g., methylene blue) can be instilled into the pleural space and recovered from the sputum.

Initial treatment involves placement of an intercostal drain and nursing patients with the operative side down to minimize soiling of the nonoperative lung. Sputum and chest drain fluid should be sent for microbiologic analysis, and antibiotics should be given to cover the most likely causative organisms: Streptococcal species, Staphylococcus aureus, enteric gram-negative bacilli, and anerobes (see Chapter 35).

Noninvasive ventilation may worsen the air leak and increase the risk for soiling the nonoperative lung. Mechanical ventilation may not be straightforward, because positive pressure ventilation can cause preferential gas flow to the fistula and result in the inability to ventilate the nonoperative lung. If intubation and ventilation are required, placement of a double-lumen tube with ventilation only to the nonoperative lung is indicated.

Once a diagnosis of bronchopleural fistula has been confirmed, surgical reexploration is indicated to control the leak and prevent further soiling of the nonoperative lung. For fistulae that develop within 1 week of surgery, direct closure of the bronchial stump may be possible; beyond this initial period, more complex closures involving a muscle or omental flap are required. Alternatively, the chest cavity may be left open as a chronic discharging wound.

Deep Venous Thrombosis and Pulmonary Embolus

Thoracic surgery patients typically have at least two major risk factors for deep venous thrombosis: malignancy and major surgery. In one study, 26% of patients experienced thromboembolic events during their hospitalizations for thoracotomy.32 Thus, all patients undergoing pulmonary resection should receive prophylactic treatment by means of graduated compression stockings and low molecular weight heparin. Low molecular weight heparin should commence the evening before surgery so that the time interval between heparin administration and the insertion of an epidural is at least 12 hours. Similarly, prior to removal of an epidural, the evening dose should be withheld and the epidural removed the following morning.

OTHER THORACIC SURGERY

Lung Volume Reduction Surgery (LVRS)

LVRS is a palliative operation for patients with end-stage COPD in which 20% to 35% of (usually) apical lung tissue is removed from both lungs by performing a stapled wedge resection. The procedure is performed via a median sternotomy or with video-assisted thoracoscopic surgery.

The rationale for LVRS is that the removal of grossly emphysematous lung tissue will improve residual pulmonary and chest wall mechanics.33,34 In particular, it is thought that the remaining lung tissue will be repositioned on a more favorable part of the pulmonary compliance curve and that the length/tension relationship of the respiratory muscles will be optimized, resulting in reduced work of breathing.

The recently completed National Emphysema Treatment Trial demonstrated that LVRS does not confer a survival advantage but does improve exercise capacity more than medical therapy does.35 However, in the subgroup of patients with predominantly upper lobe emphysema (heterogeneous disease) and low baseline exercise capacity, a survival advantage was shown in patients undergoing LVRS. Patients with non-upper lobe disease and high baseline exercise capacities experienced increased mortality rates and negligible functional gains.

Patients undergoing LVRS have end-stage COPD and very limited exercise capacity. FEV1 and DLCO are typically less than 30% of predicted levels, and nutritional states may be poor. It is essential that patients be fully optimized with respect to pulmonary function and nutritional state prior to surgery.

Patients should be extubated at the end of the procedure, possibly reducing the risk for air leak. Intercostal tubes should be left on free drainage regardless of the size of any air leak. Provision of high-quality analgesia, preferably via an epidural, is absolutely essential for adequate postoperative respiratory function. Residual air leak and persisting pneumothorax are associated with considerable morbidity and mortality rates. Enteral feeding should be commenced within 1 to 2 days of surgery. The 90-day mortality rate for LVRS is about 8%.35

Mediastinal Tumors

The majority of mediastinal tumors are located in the anterior mediastinum, the region anterior to the heart and great vessels. Common anterior mediastinal tumors include thymoma, thyroid tumors, germ cell tumors, and lymphoma.

Symptoms and signs may be nonspecific (e.g., cough, dyspnea, weight loss, lethargy, fever) or attributable to compression of an adjacent structure (e.g., Horner syndrome secondary to involvement of the sympathetic chain near the thoracic inlet or hoarseness secondary to involvement of the recurrent laryngeal nerve). Anterior mediastinal tumors may present with life-threatening complications, including: (1) obstruction of the superior vena cava, resulting in facial swelling and dyspnea; (2) tracheal compression, causing dyspnea and orthopnea; (3) pulmonary artery or cardiac compression, causing hypotension. Patients with thymoma commonly present with the symptoms of myasthenia gravis: fatigability and weakness, particularly of the extraocular muscles, face, and proximal limbs.

If a mediastinal mass is suspected, the diagnosis may be confirmed by CT scan (Fig. 12-7). Histologic diagnosis, which is essential for treatment, may be obtained by bronchoscopy, esophagoscopy, needle biopsy, or surgical biopsy (mediastinoscopy, mediastinotomy). Some tumors are treated primarily medically (e.g., lymphoma, germ cell tumor), with surgical intervention being limited to diagnostic biopsy and postchemotherapy resection of residual mass. For other tumors, notably thymoma, surgical excision is indicated.

Esophageal Surgery

Esophageal resection is usually undertaken for carcinoma of the esophagus. Traditionally, most resections have been performed in cases of squamous cell carcinoma, with smoking and high alcohol consumption being the two major risk factors. The incidence of adenocarcinoma of the esophagus is increasing in Western societies, especially that of the distal esophagus secondary to an increase in the incidence of gastroesophageal reflux disease.

Esophageal carcinoma is locally invasive and metastasizes to regional (mediastinal and celiac) and distant lymph nodes and to organs such as the liver and the lung. At the time of presentation, the tumor has usually already spread to regional nodes. The most common symptom is dysphagia due to esophageal narrowing. Esophageal obstruction can result in weight loss, dehydration, metabolic disturbance, and aspiration pneumonitis.

The diagnosis of esophageal cancer is made by means of flexible endoscopy and biopsy. Tumor staging involves thoracic and abdominal CT scanning, which can identify the presence of liver and lung metastases and significant regional lymphadenopathy. Endoscopic ultrasound is excellent for determining the T stage of the tumor by demonstrating the depth of wall invasion, and it also allows fine-needle aspiration of regional nodes for cytology.

Treatment of Esophageal Cancer

The optimal treatment strategy for esophageal cancer remains a subject of debate. Radiation is the mainstay of treatment for squamous cell carcinoma, except for early disease. Surgery is the mainstay of treatment for adenocarcinoma, especially for localized disease. Adjuvant chemotherapy is offered for those with positive nodes. Radiation and chemotherapy can be considered for symptomatic local recurrence. For disease limited to the mucosa and submucosa, surgery is commonly curative. For patients with advanced disease, severe dysphagia can usually be managed by esophageal dilation and a self-expanding metal stent. Moderate dysphagia with advanced disease is often treated by radiotherapy.

The most common operation involves resecting the distal esophageal cancer and the proximal stomach along with the regional nodes. The greater curve of the stomach, once mobilized, can be drawn up into the chest and anastomosed to the proximal esophageal resection margin. Rarely, it may be necessary to use jejunum or colon to restore gastrointestinal continuity.

There are a number of surgical approaches to the esophagus. For lesions of the lower esophagus, an upper abdominal or left thoracotomy may be used. For more proximal lesions, a combined upper abdominal and right thoracotomy (the Ivor Lewis procedure) is used. There is also a three-staged operation (McKeown) that involves a laparotomy, right thoracotomy, and neck incision. Some surgeons perform endoscopic intrathoracic mobilization of the esophagus and intraabdominal mobilization of the stomach.37 The transhiatal approach (Orringer) avoids a thoracotomy altogether. The stomach and esophagus are freed via neck and upper abdominal incisions using blunt finger dissection. The stomach is elevated into the neck through the esophageal hiatus and anastomosed to the esophagus within the neck. The advantages of a transhiatal approach include the avoidance of a thoracotomy and the creation of the esophageal anastomosis within the neck. The main advantage of an intrathoracic approach is the ability to achieve a more complete lymph node dissection. However, pulmonary complications are more common and anastomotic leaks, although less likely, are more difficult to manage.

Postoperative Care

Esophagectomy is a major operation and is associated with an overall morbidity rate of 30% to 50% and a mortality rate of 5% to 10%.

Routine Postoperative Care.

Patients may arrive in the intensive care unit extubated or intubated. A period of elective mechanical ventilation is common following prolonged or difficult intrathoracic resection. A nasogastric drainage tube and, usually, a nasojejunal feeding tube are in situ. Following an intrathoracic resection, one or more intercostal tubes are also present and are connected to underwater seal drains. The nasogastric and nasojejunal tubes should initially be placed on free drainage. These tubes traverse the esophageal anastomosis; thus, if they are inadvertently removed, they should be reinserted only under fluoroscopic control and under the direction of the surgeon. At the time of a patient’s arrival in the intensive care unit, a chest radiograph should be obtained and inspected for the presence of pneumothorax and to confirm the correct position of all lines and tubes.

Significant third-space fluid losses are to be expected over the first 24 to 72 hours. Therefore, maintenance fluids of 100 to 200 ml/hr of a crystalloid solution are appropriate. Because of the risk for pulmonary edema (see subsequent material), close attention to intravascular volume status is required, along with invasive monitoring of arterial blood pressure, central venous pressure, and hourly urine output. A positive daily fluid balance and weight gain of a few kilograms can be expected during the first few postoperative days. Patients undergoing esophagectomy are often malnourished, and commencement of nutrition within 24 to 48 hours of surgery is indicated. If enteral feeding via a jejunal feeding tube is not possible, parenteral nutrition is appropriate. Provision of adequate pain relief, preferably by means of an epidural, is essential to avoid postoperative cardiorespiratory complications.38,39

Between 5 and 7 days after surgery, the integrity of the anastomosis is assessed by a fluoroscopic examination using water-soluble radiographic contrast; if no anastomotic leaks are identified, oral intake may be commenced. At least one chest drain is left in place until the patient has been established on oral intake.

Complications Following Esophagectomy.

A number of complications may occur following esophagectomy (Table 12-8). Respiratory failure is common; as much as 20% of patients require prolonged mechanical ventilation.40 Pneumonia is a common occurrence and has many causes, including atelectasis and retained secretions, prolonged ventilation, poor nutritional state, and aspiration. Aspiration may occur preoperatively as the result of esophageal obstruction; it may occur postoperatively due to the effects of a nasogastric tube, due to swallowing dysfunction caused by dissection of the cervical esophagus, loss of the normal gastroesophageal junction, or recurrent laryngeal nerve palsy. Patients are at particular risk for acute lung injury and ARDS following esophagectomy. There may be preexisting radiation pneumonitis or bleomycin pulmonary toxicity. Pulmonary lymphatics are partially destroyed at the time of surgery, and chylothorax is commonly noted after radical lymph node dissection. Lung injury may occur because of prolonged one-lung ventilation or as a consequence of the systemic inflammatory response syndrome. Postoperative sepsis also may precipitate ARDS. The risk factors for postoperative respiratory failure are advanced age, preoperative chemoradiation, and an FEV1 less than 65% of the predicted rate.40

Table 12-8 Complications Following Esophagectomy

Respiratory failure
Anastomotic leak
Sepsis and the systemic inflammatory response syndrome
Airway necrosis and tracheoesophageal fistula
Recurrent laryngeal nerve palsy
Chylothorax
Deep vein thrombosis
Dumping syndrome
Alcohol withdrawal

Intrathoracic anastomotic leak is one of the most feared complications of esophagectomy. The first sign of an anastomotic leak may be a nonspecific deterioration in the patient’s condition. Subsequently, the patient develops signs of sepsis and systemic inflammatory response syndrome. Chest drain fluid may increase in volume and become discolored or frankly purulent. The patient may develop subcutaneous emphysema. Fulminant septic shock and multiple organ failure may develop but usually not until late in the clinical course.

If an anastomotic leak is suspected, confirmation of the diagnosis may be made by performing a radiographic contrast swallow. However, there should be a low threshold for a thoracic CT scan with oral contrast. Particular note should be made that the drains are well positioned and that they take up the leaked contrast. The decision has to be made whether to manage the patient conservatively (with strict nil per mouth and reliance on existing or additional chest drains) or whether the thorax should be reopened (with pleural lavage and possible complete esophagectomy and formation of a cervical esophagostomy and tube gastrostomy). The mortality rate seen in intrathoracic esophageal anastomotic leak is about 35%.41

REFERENCES

1 Kawahara M. Screening for lung cancer. Curr Opin Oncol. 2004;16:141-145.

2 British Thoracic Society, Society of Cardiothoracic Surgeons of Great Britain and Ireland Working Party. BTS guidelines: guidelines on the selection of patients with lung cancer for surgery. Thorax. 2001;56:89-108.

3 Bolliger CT. Evaluation of operability before lung resection. Curr Opin Pulm Med. 2003;9:321-326.

4 Burke JR, Duarte IG, Thourani VH, et al. Preoperative risk assessment for marginal patients requiring pulmonary resection. Ann Thorac Surg. 2003;76:1767-1773.

5 Beckles MA, Spiro SG, Colice GL, et al. The physiologic evaluation of patients with lung cancer being considered for resectional surgery. Chest. 2003;123:105S-114S.

6 Bolliger CT, Guckel C, Engel H, et al. Prediction of functional reserves after lung resection: comparison between quantitative computed tomography, scintigraphy, and anatomy. Respiration. 2002;69:482-489.

7 Ferguson MK, Little L, Rizzo L, et al. Diffusing capacity predicts morbidity and mortality after pulmonary resection. J Thorac Cardiovasc Surg. 1998;96:894-900.

8 Win T, Jackson A, Sharples L, et al. Relationship between pulmonary function and lung cancer surgical outcome. Eur Resp J. 2005;25:594-599.

9 Bolliger CT, Wyser C, Roser H, et al. Lung scanning and exercise testing for the prediction of postoperative performance in lung resection candidates at increased risk for complications. Chest. 1995;108:341-348.

10 Frank SM, Fleisher LA, Breslow MJ, et al. Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events: a randomized clinical trial. JAMA. 1997;277:1127-1134.

11 Antanavicius G, Lamb J, Papasavas P, et al. Initial chest tube management after pulmonary resection. Am Surg. 2005;71:416-419.

12 Licker M, Spiliopoulos A, Frey JG, et al. Risk factors for early mortality and major complications following pneumonectomy for non-small cell carcinoma of the lung. Chest. 2002;121:1890-1897.

13 Pennefather SH, Russell GN. Postthoracotomy analgesia: recent advances and future directions. In: Slinger PD, editor. Progress in Thoracic Anesthesia. Baltimore: Lippincott Williams & Wilkins; 2004:163-185.

14 Minzter BH, Johnson RF, Grimm BJ. The practice of thoracic epidural analgesia: a survey of academic medical centers in the United States. Anesth Analges. 2002;95:472-475.

15 Tan N, Agnew NM, Scawn ND, et al. Suprascapular nerve block for ipsilateral shoulder pain after thoracotomy with thoracic epidural analgesia: a double-blind comparison of 0.5% bupivacaine and 0.9% saline. Anesth Analges. 2002;94:199-202.

16 Lardinois D, Vogt P, Yang L, et al. Non-steroidal anti-inflammatory drugs decrease the quality of pleurodesis after mechanical pleural abrasion. Eur J Cardiothorac Surg. 2004;25:865-871.

17 Hayes JP, Williams EA, Goldstraw P, et al. Lung injury in patients following thoracotomy. Thorax. 1995;50:990-991.

18 Kutlu CA, Williams EA, Evans TW, et al. Acute lung injury and acute respiratory distress syndrome after pulmonary resection. Ann Thorac Surg. 2000;69:376-380.

19 Licker M, de Perrot M, Spiliopoulos A, et al. Risk factors for acute lung injury after thoracic surgery for lung cancer. Anesth Analg. 2003;97:1558-1565.

20 Bigatello LM, Allain R, Gaissert HA. Acute lung injury after pulmonary resection. Minerva Anestesiol. 2004;70:159-166.

21 Auriant I, Jallot A, Herve P, et al. Noninvasive ventilation reduces mortality in acute respiratory failure following lung resection. Am J Respir Crit Care Med. 2001;164:1231-1235.

22 Rena O, Papalia E, Oliaro A, et al. Supraventricular arrhythmias after resection surgery of the lung. Eur J Cardiothorac Surg. 2001;20:688-693.

23 Sekine Y, Kesler KA, Behnia M, et al. COPD may increase the incidence of refractory supraventricular arrhythmias following pulmonary resection for non-small cell lung cancer. Chest. 2001;120:1783-1790.

24 van Mieghem W, Coolen L, Malysse I, et al. Amiodarone and the development of ARDS after lung surgery. Chest. 1994;105:1642-1645.

25 Lanza LA, Visbal AI, DeValeria PA, et al. Low-dose oral amiodarone prophylaxis reduces atrial fibrillation after pulmonary resection. Ann Thorac Surg. 2003;75:223-230.

26 Ciriaco P, Mazzone P, Canneto B, et al. Supraventricular arrhythmia following lung resection for non-small cell lung cancer and its treatment with amiodarone. Eur J Cardiothorac Surg. 2000;18:12-16.

27 Ploeg AJ, Kappetein AP, van Tongeren RB, et al. Factors associated with perioperative complications and long-term results after pulmonary resection for primary carcinoma of the lung. Eur J Cardiothorac Surg. 2003;23:26-29.

28 Fabian T, Federico JA, Ponn RB. Fibrin glue in pulmonary resection: a prospective, randomized, blinded study. Ann Thorac Surg. 2003;75:1587-1592.

29 Rice TW, Okereke IC, Blackstone EH. Persistent air-leak following pulmonary resection. Chest Surg Clin North Am. 2002;12:529-539.

30 Marshall MB, Deeb ME, Bleier JI, et al. Suction vs water seal after pulmonary resection: a randomized prospective study. Chest. 2002;121:831-835.

31 Cerfolio RJ. The incidence, etiology, and prevention of postresectional bronchopleural fistula. Sem Thorac Cardiovasc Surg. 2001;13:3-7.

32 Ziomek S, Read RC, Tobler HG, et al. Thromboembolism in patients undergoing thoracotomy. Ann Thorac Surg. 1993;56:223-226.

33 McKenna RJJr, Gelb A, Brenner M. Lung volume reduction surgery for chronic obstructive pulmonary disease: where do we stand ? World J Surg. 2001;25:231-237.

34 Cordova FC, Criner GJ. Surgery for chronic obstructive pulmonary disease: the place for lung volume reduction and transplantation. Curr Opin Pulm Med. 2001;7:93-104.

35 Fishman A, Martinez F, Naunheim K, et al. A randomized trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema. New Engl J Med. 2003;348:2059-2073.

36 Bacha EA, Chapelier AR, Macchiarini P, et al. Surgery for invasive primary mediastinal tumors. Ann Thorac Surg. 1998;66:234-239.

37 Luketich JD, Alvelo-Rivera M, Buenaventura PO, et al. Minimally invasive esophagectomy: outcomes in 222 patients. Ann Surg. 2003;238:486-494.

38 Tsui SL, Law S, Fok M, et al. Postoperative analgesia reduces mortality and morbidity after esophagectomy. Am J Surg. 1997;173:472-478.

39 Flisberg P, Tornebrandt K, Walther B, et al. Pain relief after esophagectomy: thoracic epidural analgesia is better than parenteral opioids. J Cardiothorac Vasc Anesth. 2001;15:282-287.

40 Avendano CE, Flume PA, Silvestri GA, et al. Pulmonary complications after esophagectomy. Ann Thorac Surg. 2002;73:922-926.

41 Alanezi K, Urschel JD. Mortality secondary to esophageal anastomotic leak. Ann Thorac Cardiovasc Surg. 2004;10:71-75.

42 Eagle KA, Berger PB, Calkins H, et al. ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery—executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). J Am Coll Cardiol. 2002;39:542-553.