Adult Chest Surgery

Chapter 87. Lung Volume-Reduction Surgery 

Lung volume-reduction surgery (LVRS) is one of the most interesting and controversial areas in thoracic surgery. The purpose of the operation is to palliate dyspnea and improve functional status and quality of life for a highly select group of patients with emphysema. It is estimated that 12 million people in the United States have chronic obstructive pulmonary disease (COPD).Nearly 2 million of these people develop severe dyspnea with a reduction in their quality of life, and emphysema accounts for more than 90,000 deaths annually.2,3 Most patients with COPD are managed with medical therapy consisting of smoking cessation, pulmonary rehabilitation, bronchodilator therapy, and oxygen. Unfortunately, there is no medical therapy capable of improving pulmonary function or reversing the inexorable decline of breathless patients with emphysema.

The goal of LVRS is to lessen the severity of some of the distressing symptoms and limitations imposed by end-stage emphysema. The controversy has focused on the procedure, interpretation of the results, and the manner in which new surgical procedures should be introduced, scientifically evaluated, and funded by health care providers. Ideal candidates for LVRS have marked hyperinflation and significant regions of severe destruction juxtaposed with other more healthy areas of lung parenchyma. The areas to be removed, frequently referred to as target areas, are usually located in the upper lobes and have little, if any, perfusion. Excision of these areas improves both respiratory mechanics and function of the remaining lung. Clinically, the anticipated benefits are a reduction in dyspnea and improved exercise tolerance. A subset of highly selected patients may experience a survival benefit as well.

HISTORY

The debilitating symptoms of pulmonary emphysema have attracted the interest of surgeons for decades. Many innovative and creative operations have been devised to treat the dyspnea caused by this disease. Costochondrectomy, phrenic crush, pneumoperitoneum, pleural abrasion, lung denervation, and thoracoplasty all have been proposed as surgical treatments for the hyperexpanded and poorly perfused emphysematous lung.As Laforet cogently explained, "The alleged benefits of these maneuvers were frequently lost on patients whose worsening dyspnea left them with little energy to debate with their surgeons."5

LVRS was proposed by Brantigan in conjunction with lung denervation.Among 33 patients having the operation, there were 6 operative deaths (18% mortality) and no objective data to support the claim that patients who survived were helped subjectively. LVRS was discarded after this initial experience revealed the operation to be too risky. Over the subsequent four decades, different groups attempted variations on Brantigan's procedure with limited success. Observations about the physiologic behavior of emphysema patients during and after lung transplantation led to the reconsideration of volume reduction by Cooper and colleagues.Similar to Brantigan's procedure, Cooper's group removed approximately 30% of the patient's lung volume by performing peripheral resection of the most emphysematous portions. However, the new approach used linear cutting/stapling devices and was performed as a bilateral procedure via median sternotomy. The procedure was designed to reduce dyspnea, increase exercise tolerance and performance in activities of daily living, and improve quality of life. LVRS has undergone substantial growth over the past decade with refinements in patient selection criteria, operative technique, and perioperative care.

PATHOPHYSIOLOGY OF EMPHYSEMA

Emphysema is a condition of the lung characterized by abnormal permanent enlargement of airspaces distal to the terminal bronchiole, accompanied by destruction of the airspace walls in the absence of obvious fibrosis.7The destruction of pulmonary parenchyma decreases the overall mass of functioning lung tissue, thus reducing the amount of gas exchange that can take place. As the lung tissue is destroyed, it loses elastic recoil and expands in volume. This leads to the typical hyperexpanded chest seen in emphysema patients with flattened diaphragms, widened intercostal spaces, and horizontal ribs. The increased distensibility of emphysematous lung yields a lung that is easily inflated but tends to remain pathologically inflated throughout the breathing cycle. Portions of severely emphysematous lung act as nonfunctional volume-occupying areas. These anatomic changes result in the loss of the mechanical advantages exploited during normal breathing and thus lead to dyspnea and increased work during breathing.When the destruction and expansion occur in a nonuniform manner, the most affected lung tissue expands, crowding the relatively spared lung tissue and further impairing ventilation of the functioning lung. Finally, there is obstruction in the small airways, likely caused by a combination of reversible bronchospasm and irreversible loss of elastic recoil by adjacent lung parenchyma. The suitability of a given patient for surgical treatment of emphysema depends in part on the relative contributions of lung destruction, lung compression, and small airways obstruction to the overall physiologic impairment of that patient.

Rationale for LVRS

The removal of severely diseased, slowly ventilating and expanded lung may decrease hyperinflation and improve the mechanical function of the diaphragm and thoracic cage. If the most severely diseased lung can be identified and resected, hyperinflation is reduced, and overall breathing function will improve by restoring elastic recoil of the remaining lung. This will result in increased expiratory flow rates and allow the more normal lung to function without compression. LVRS also may improve alveolar gas exchange and ventilation/perfusion mismatch. These potential improvements in respiratory mechanics and decreased work of breathing help patients to function more normally and decrease the sensation of dyspnea. It is interesting to note that the true etiology or etiologies for dyspnea remain poorly understood. Although dyspnea is associated with severe airflow limitation, it is also linked to hyperinflation, respiratory muscle dysfunction, increases in respiratory drive, and abnormalities in alveolar gas exchange. Unfortunately, the correlation between the symptom of breathlessness and routinely measured physiologic parameters of pulmonary function are imprecise.9

EVALUATION OF CANDIDATES/DIAGNOSTIC TECHNIQUES

History and Physical Examination

The evaluation of candidates for LVRS should be aimed at identifying patients with a physiologic profile that is most likely to respond to LVRS. This includes patients with severe hyperinflation and reduced elastic recoil but less pronounced airway disease, relatively well-preserved gas exchange, and no major comorbidities that carry an unacceptable perioperative risk.10 The patient profile used for evaluation of patients with emphysema at Washington University Medical Center is outlined in Table 87-1. Because LVRS is a palliative procedure, the first step is to assess the symptoms and the degree of quality-of-life impairment related to the patient's emphysema. The medical history must be very thorough and include questions about daily activities and limitations caused by symptoms. The Medical Research Council (MRC) Dyspnea Score allows standardized grading of symptoms. Patients considered for LVRS typically have severe, incapacitating emphysema. They have stopped smoking for at least 6 months and have received optimal medical management for their COPD, which includes pulmonary rehabilitation and nutritional support, if necessary. Patients must be highly motivated to undergo surgical treatment and be willing to accept the risk associated with LVRS. The evaluation should differentiate COPD with predominant airways disease (e.g., chronic bronchitis and bronchiectasis) from COPD with predominant features of emphysema. Because the mean age of candidates is in the mid-60s, medical comorbidities are common. Hence cardiovascular disease, cerebrovascular disease, obesity, and cachexia deserve particular attention. Patients with cardiovascular disease may be difficult to evaluate by elicited symptoms or signs because the emphysema limits their ability to induce anginal symptoms. Exercise testing is often not useful because of the patient's inability to exercise to heart rate limits. Echocardiography may be limited by chest hyperinflation, resulting in poor visualization of the heart. The use of dipyridamole or adenosine during cardiac testing is limited out of concern for inducing bronchoconstriction. Ultimately, many candidates for LVRS undergo cardiac catheterization to obtain a definitive answer regarding cardiovascular risk.

Table 87-1. Patient Profile Eligible for LVRS

Criteria

Method

Disabling COPD

History, QOL survey, MRC dyspnea index, intensive pulmonary rehabilitation

Severe airflow obstruction

PFTs with FEV1 and lung volumes

Emphysema

CT scan

Hyperinflation

Chest radiograph, plethysmography

Surgically accessible "target areas"

CT scan, ventilation/perfusion scan

Prediction of adequate remaining lung after LVRS

Resting PaO2, supplemental oxygen with exercise, DLCO

Preserved respiratory muscle function

Normal or minimally elevated PaCO2

 

COPD = chronic obstructive pulmonary disease; QOL = quality of life; MRC = maximal respiratory capacity; PFT = pulmonary function tests; FEV1 = forced expiratory volume in 1 second; DLCO = diffusing capacity of the lung for carbon monoxide.

With permission from ref 31.

Pulmonary Function

The cornerstone of pulmonary function testing is spirometry. It is used to quantify the degree of airflow obstruction as well as its reversibility with bronchodilator drugs. Airflow obstruction is the most significant abnormality with emphysema, and it can be estimated accurately by forced expiratory maneuvers. Lung volumes are measured by plethysmography rather than by dilution techniques because the latter measurements tend to underestimate the degree of trapped gas and residual volume. Additional parameters of pulmonary function that are assessed include resting and formal exercise arterial blood gas analyses. These are indicative of the patient's pulmonary reserve and reflect the patient's potential for recovery after surgery. In addition, diffusing capacity, as measured by the diffusing capacity of the lung for carbon monoxide (DLCO), estimates the severity of disease in the pulmonary capillary bed.

Exercise Capacity

The distance walked in 6 minutes is used frequently to assess exercise capacity. This test evaluates cardiopulmonary function and documents the amount of supplemental oxygen necessary to maintain oxygen saturation above 90%. It is also a useful parameter for the objective documentation of functional improvement after LVRS. Other approaches have used formal cardiopulmonary testing, which yields the maximal exercise capacity expressed in watts, to provide an objective measure of functional capacity.

Imaging

The purpose of imaging in patient selection is to identify findings favorable for LVRS. Presence of hyperinflation, severity of emphysema, and distribution of emphysema are the main features to assess. These features are important to establish the rationale for performing LVRS as well as to understand the relationship of preoperative radiographic findings with postoperative outcomes.11

The presence of hyperinflation is assessed accurately from inspiratory posteroanterior and lateral chest radiographs (Fig. 87-1). Paired inspiratory and expiratory views show the maximum achievable diaphragm excursion and subjectively estimate the potential for improvement in diaphragm function if lung volume is reduced by LVRS. The main indicators of hyperinflation are a low, flat diaphragm, increased anteroposterior diameter, and increased width of the intercostal spaces. Hyperinflated upper lobes may expand anterior to the upper mediastinum and increase the retrosternal space. Hyperinflation, which does not occur until emphysema is moderately severe, is a relatively specific sign for emphysema. Although hyperinflation should be present in any patient being considered for LVRS, there is no convincing evidence that the degree of hyperinflation predicts surgical outcome.

Figure 87-1.

 
 

Hyperinflation in emphysema. These preoperative posteroanterior (A) and lateral (B) inspiratory radiographs reveal severe hyperinflation. In A, the dome of the diaphragm is flattened, and the costal diaphragmatic insertions are visible. In B, the diaphragm appears flat, and the upper lobes have expanded anterior to the mediastinum, widening the retrosternal space.

The severity and distribution of emphysema on imaging studies correlate with clinical outcomes after surgery. The best outcomes, as demonstrated by improvements in forced expiratory volume in 1 second (FEV1) and exercise capacity, are usually observed in patients with more severe, heterogeneous disease that predominates in the upper lobes.12 CT scanning is the most accurate means of evaluating emphysema and is the modality most studied in LVRS. Quantitation of emphysema by CT scan is possible because the decreased tissue density of emphysematous regions is reflected in lower CT attenuation values. In quantitative studies, patients with the greatest overall severity of emphysema, distributed predominantly in the upper lobes, are selected more frequently for LVRS and show more physiologic improvement postoperatively.13 CT scanning is also an effective means of screening for potential exclusionary findings. Lung cancer has been discovered in 2–8% of candidates for LVRS, and some patients are candidates for combined cancer resection and volume reduction.14,15 Pleural thickening and calcification raise concern for adhesions. In addition, bronchiectasis, inflammatory disease or asymptomatic infiltrates, and pulmonary hypertension also may be identified or suggested by CT scan and require additional investigation.

Nuclear medicine ventilation/perfusion lung scans depicting regional blood flow patterns provide a valuable roadmap for surgery. Although the absolute severity of emphysema is not assessed accurately by this means, the presence of diffuse or upper or lower lobe predominant disease can be identified. For instance, a right- or left-sided predominance of lung function may direct surgery toward a unilateral approach if corroborated by CT scan.

PREDICTORS OF OUTCOME/CONTRAINDICATIONS

Review of the surgical results of LVRS has identified risk factors for surgical mortality (Table 87-2). These predictors appear to reflect the function of different parts of the respiratory system. A markedly reduced DLCOreflects a poor distribution of ventilation surface area to perfusion of the lung. This severity of disease usually is associated with a significant supplemental oxygen requirement and may indicate that the lung is too impaired to support the patient postoperatively. An elevated PaCO2 indicates excessive work of breathing and chronic muscle fatigue and is a significant risk factor for general anesthesia alone. It is not clear why upper lobe predominance has a better outcome than lower lobe resection. This is independent of the etiology for emphysema (e.g., smoking versus 1-antitrypsin deficiency) and may be explained by the fact that the lower lobes comprise a larger volume of lung parenchyma than the upper lobes. Other markers of increased risk or poor outcome include male gender, increasing age, and markedly reduced lung function with an FEV1 of less than 20% of predicted values.

Table 87-2. Predictors of Outcome Following LVRS

Parameter

Favorable Result

Poorer Result

Age (years)

<70

>70

FEV1 (% predicted)

>20

<15

PaCO2

<45

>60

PaO2

>50

<40

Target area

Upper lobes

Lower lobes, diffuse

Ideal body weight

70–120%

<60%, >130%

DLCO (% predicted)

>20

<15

 

THERAPEUTIC OPTIONS

Median Sternotomy

At Washington University, our preferred approach for bilateral LVRS is via median sternotomy. It provides excellent exposure and increased flexibility with a minimum of morbidity. Median sternotomy avoids injury to chest wall muscles and intercostal nerves both from the operative approach and from the chest tubes, which are brought out below the costal arch. However, other groups have obtained similar results using a bilateral video-assisted thoracic surgery (VATS) approach.

Many patients with severe emphysema have a significant element of chronic bronchitis with increased sputum production. After induction of anesthesia, a single-lumen tube is placed, and flexible bronchoscopy is carried out to suction secretions and obtain a specimen for culture and for STAT Gram stain. If thick, tenacious secretions are encountered, a minitracheostomy may be inserted at the end of the operative procedure to facilitate postoperative pulmonary toilet. After bronchoscopy, the endotracheal tube is replaced with a left-sided double-lumen tube.

Ventilation to both lungs is briefly suspended just before sternal division. A rolled sponge is advanced upward behind the sternum from the subxiphoid position and used to sweep the pleura away from the retrosternal area (Fig. 87-2). This keeps the mediastinal pleura intact on both sides as the sternum is divided. While ventilation is suspended, the sternum is divided with a sternal saw. The right mediastinal pleura is incised sharply, taking care to visualize and avoid injury to the phrenic nerve near the apex of the chest. Ventilation is maintained to the right lung until just prior to entrance into the pleural space because this facilitates assessment of the degree of emphysematous damage in various portions of the lung. Demarcation of the fissures or lack thereof is best seen when the lung is fully inflated. Ventilation to the right lung then is suspended while ventilation to the left lung is continued. Care is taken by the anesthesiologist to avoid overinflating the left lung, and airway pressures generally are restricted to 15–20 cm H2O pressure. Hypercapnia occasionally occurs, but this is usually well tolerated.

Figure 87-2.

 

The pleura is swept off the underside of the sternum before median sternotomy to prevent injury to the emphysematous lungs.

 

Most candidates for LVRS have upper lobe predominant disease. Several minutes after ventilation is suspended to the right lung, the right middle and lower lobes are usually well deflated and become progressively atelectatic. The pulmonary ligament is divided, and adhesions are taken down under direct vision (Fig. 87-3). Dense adhesions are not common but may be encountered if there have been prior episodes of pneumonia. We occasionally use an extrapleural dissection adjacent to adhesions to avoid injuring the fragile lung parenchyma.

Figure 87-3.

 

As a consequence of the asymmetric emphysema, the right upper lobe remains hyperinflated despite single-lung ventilation to the left lung.

 

For upper lobe disease, 70–80% of the right upper lobe is excised with multiple applications of a linear stapler buttressed with strips of bovine pericardium. It is often easier to apply the stapler to the deflated lung, and this can be accomplished rapidly by using the cautery to fenestrate the apex of the right upper lobe (Fig. 87-4). The marked collateral ventilation leads to prompt collapse. A long, straight intestinal clamp can be applied to the lung to create a linear "crush" mark prior to application of the linear stapler (Fig. 87-5). We currently staple straight across the upper lobe beginning medially above the hilum and ending up just above the upper extent of the oblique fissure. Care should be taken to avoid crossing the fissure because this may damage the superior segment of the lower lobe (Fig. 87-6). In addition, stapling across the fissure may tether the superior segment of the lower lobe to the remaining upper lobe and prevent the superior segment from fully expanding and filling the apex of the chest. After the first two applications of the linear stapler, it may be awkward to insert the stapler into the chest again to complete the excision. An endoscopic stapler fitted with pericardial strips is well suited to reach deeply into the chest to complete the excision. We prefer to use a single line of excision to remove most of the right upper lobe rather than multiple excisions. It is important to remember that the goal is to adequately reduce volume, not to remove all areas of diseased lung.

Figure 87-4.

 

A cautery can be used to facilitate deflation of the upper lobe. This is performed on an area that will be excised and makes it easier to apply the mechanical staplers.

 

Figure 87-5.

 

The lung is marked with an atraumatic clamp to guide the generous wedge resection.

 

Figure 87-6.

 

The wedge is performed with a buttressed stapler with all due care to avoid injury of the superior segment of the lower lobe.

 

Occasionally, the apex of the upper lobe will be densely adherent to the apex of the chest and to the superior mediastinum. In such cases, it may be easier to first transect the upper lobe as described earlier before attempting to dissect the apical and mediastinal adhesions (Fig. 87-7). Once the transection has been accomplished, the specimen can be detached more easily from the chest wall and mediastinum using blunt or sharp dissection, cautery, or even a linear stapler, leaving a small remnant of the lung attached to the mediastinum, if necessary. It is imperative to avoid injury to the phrenic nerves, a complication that will severely compromise postoperative recovery.

Figure 87-7.

 

It is sometimes easier to perform the wedge resection before separating the pleural adhesions. If there are dense mediastinal adhesions, the phrenic nerve must be identified and protected. A paralyzed diaphragm is catastrophic in these patients. If the adhesions are so dense that the phrenic nerve is not well identified, it is better to leave a little lung parenchyma attached to the mediastinal pleura.

 

After the upper lobe resection, the chest is partially filled with warm saline, and the lung is gently inflated. Air leaks at this time are unusual, but the reexpanded remaining lung often does not completely fill the apex of the chest. We have explored the use of a pleural tent in this situation but now reserve it for rare instances, in particular when the remaining lung is still tethered in the chest by virtue of adhesions to the chest wall or diaphragm. It has not been our practice to perform mechanical or talc pleurodesis, even if the patient is not a potential candidate for subsequent lung transplantation.

Two chest tubes are placed in the pleural space and brought out near the midline through small subcostal stab wounds. The posterior tube is brought across the dome of the diaphragm and halfway up the posterior chest. The anterior tube is brought to the apex of the chest near the mediastinum.

Ventilation is shifted from the left lung to the right lung, and the mediastinal pleura is then opened on the left side. Particular care should be taken to visualize the phrenic nerve and avoid injury to it when opening the upper portion of the mediastinal pleura because the anatomic location of the left phrenic nerve makes it vulnerable to injury. With upper lobe predominant disease, the goal is to excise the superior subdivision of the left upper lobe, leaving the lingula intact, because this is usually much less diseased (Fig. 87-8). The left pulmonary ligament usually is divided, but this requires displacement of the heart. If exposure is limited, the ligament is left intact, and adhesions between the left lower lobe and the diaphragm are taken down. Unlike the anatomic situation on the right side, the superior segment of the left lower lobe usually easily reaches to the apex of the chest, even without division of the pulmonary ligament.

Figure 87-8.

 

A generous left upper lobe wedge is shown. Most of the lingula is left in place.

The upper half to two-thirds of the left upper lobe is excised with multiple applications of the linear GIA stapler. This is facilitated by deflating the apex of the upper lobe with cautery puncture. The long, straight intestinal clamp is often useful in helping to identify and demarcate the proposed line of excision. The line of excision usually is parallel to the oblique fissure separating the upper and lower lobes. Similar to the right side, care is taken to avoid stapling across the fissure into the superior segment of the left upper lobe.

After left upper lobe excision, the lung is reinflated and inspected for air leaks. Two chest tubes are placed, and the mediastinal pleuras are closed on both sides. A small window of pleura is left open inferiorly to allow drainage of any mediastinal fluid collection into the pleural spaces. Mediastinal chest tubes are not necessary. Many volume-reduction patients are on steroids before surgery. To prevent wound dehiscence, we use an overlapping figure-of-eight stainless steel wire closure of the sternum. Virtually all patients are extubated in the OR. If excessive secretions are present after the procedure or during the initial bronchoscopy, a 4-mm-diameter minitracheostomy is inserted at the time of extubation to facilitate aggressive pulmonary toilet.

Anesthesia

Pain control is essential to ensure adequate postoperative respiratory function. An epidural catheter is placed, and it is imperative to confirm that a bilateral block has been established before beginning the procedure. Although this is not absolutely necessary, we use fluoroscopy to allow placement of the catheter at the tip of T4. During induction, hypotension can result from air trapping as well as pneumothorax. Air trapping leading to "pulmonary tamponade" is treated by removing the patient from the ventilator and allowing him or her to exhale to the atmosphere. Bronchodilators and prolonged exhalation times are also helpful, but it is often necessary to remove the patient from the ventilator during exhalation.

During the procedure, our anesthesiologists avoid narcotics and limit the use of benzodiazepines to limit long-term respiratory depression. The inspiratory pressures are limited to 15–20 cm H2O during one-lung ventilation to avoid excessive pressure on the fresh staple lines. Most of these patients have an element of CO2 retention, and permissive hypercapnia is tolerated. During emergence, patients may be drowsy, and it is not unusual to have initial PaCO2 values as high as 90 mm Hg. This is transient and will come down as the patient receives nebulizers and chest physical therapy in the recovery room.

PERIOPERATIVE MANAGEMENT

Contrary to the management of most patients after pulmonary resection, the chest tubes for patients after LVRS are placed to water seal without the application of suction. The loss of elastic recoil, the obstructive physiology of the remaining lung, and the fragile nature of the tissue make the lungs more susceptible to hyperinflation caused by chest tube suction. Our group has prospectively demonstrated a related phenomenon after bilateral lung transplantation.16 The keys to postoperative management are adequate pain relief, aggressive chest physiotherapy, early ambulation, and management of secretions. Inhaled bronchodilators and systemic steroids during the perioperative period can be very beneficial in reducing airway reactivity.

COMPLICATIONS

The value of LVRS as a palliative procedure clearly depends on the surgeon's ability to minimize the frequency and severity of postoperative complications.17 The true mortality is difficult to assess owing to bias in published case series with favorable results. Furthermore, individual case series often have an unintentional positive bias because patients who experience good outcomes are more likely to return for follow-up. Despite this, most of the published reports on the outcomes of LVRS describe a perioperative mortality under 8%.

The key to reducing morbidity is applying strict criteria at the time of evaluation. The risk factors for poor outcomes have been summarized in Table 87-2, and adhering to these criteria makes the ratio of patients selected for surgery to patients evaluated quite small. In the prospective trial reported by Pompeo and colleagues, only 60 patients were randomized to surgery or medical treatment from the 237 patients who were evaluated initially.18 Similarly, at Washington University, 3000 patients were evaluated to select the first 250 bilateral LVRS candidates. Less than a third of patients referred for LVRS will be invited for on-site evaluation, and only a fraction of these will be offered surgery. The National Emphysema Treatment Trial (NETT) demonstrated that performing LVRS on two high-risk subgroups, namely, patients with a very low FEV1 and homogeneous emphysema and patients with a very low FEV1 and a low DLCO, resulted in an unacceptably high mortality.19 These patients have been viewed by many to be of too high risk for LVRS, and these findings highlight the importance of prudent patient selection to maximize the benefit of this palliative procedure.

The most common complication of LVRS is a parenchymal air leak. Most patients have an initial air leak, and it prolongs hospitalization in up to 15% of patients. Prevention strategies focus on using buttressed staple lines with pericardium or polytetrafluoroethylene strips and ensuring pleural symphysis with a pleural tent when necessary.20 In the absence of a large air leak, most patients will improve with time. Although chest tubes after LVRS are placed initially to water seal, suction is used for larger and symptomatic air leaks. If the air leak continues and prevents hospital discharge, the chest tube can be shortened and connected to a Heimlich valve as long as the remaining lung is still expanded off suction. Pleurodesis and reoperation are rarely indicated but are performed occasionally for persistent large air leaks to revise the staple line or excise the leaking site.

Infections are the second major class of complications associated with LVRS. Pneumonia is the most serious of these and is avoided by aggressive management of secretions and early ambulation. Sputum is submitted routinely for culture at the time of surgery to provide objective data if infiltrates progress postoperatively. Empyema is rare but may be severe because patients can have an air leak and a pleural space problem. However, low-grade pleural contamination may help to promote pleural fusion. Finally, mediastinitis is a potential problem associated with sternotomy but has not occurred despite more than 250 sternotomies for bilateral LVRS at Washington University.

Respiratory decompensation and mucus plugging are a major problem after LVRS. Prevention measures focus on early ambulation and good respiratory therapy. High-risk patients with copious, thick sputum are scrutinized carefully during their evaluation. If history and preoperative bronchoscopy are of concern in this regard, a minitracheostomy is placed after the patient is extubated in the OR. If preoperative bronchoscopy reveals heavy, purulent sputum, the procedure should be canceled with a plan to reschedule after a course of antibiotics and reassessment.

Gastrointestinal complications are notable in patients who have undergone LVRS.21 The link between emphysema and gastrointestinal complications is uncertain, but many reports have noted a higher rate of intestinal ischemia, perforation, and ileus. We favor early colonoscopy to treat pseudoobstruction and rule out mucosal ischemia. Despite the fact that cigarette smoking predisposes to both emphysema and cardiovascular disease, perioperative cardiac complications are relatively rare. The reason for this is the careful preoperative screening for coronary artery disease and pulmonary hypertension. Our routine is to perform a radionuclide ventriculogram on all patients and to follow up abnormal results with cardiac catheterization.

RESULTS

Many groups have reported preliminary results for LVRS, and these results have consistently shown benefit to the recipient with acceptable mortality and varying morbidity.4,22–25 It is remarkable that fairly uniform results have been obtained using a wide array of surgical strategies, including bilateral and unilateral approaches, open and thoracoscopic operations, and buttressed or unbuttressed staplers. The consistent theme among reports of successful LVRS programs has been meticulous patient selection, methodical patient preparation with reduction of risk factors, and attentive postoperative care. Most groups have reported operating on patients with a mean age of 65 years and a preoperative FEV1 of 600–800 mL. The typical postoperative length of stay is 8–14 days, with almost half the patients being detained because of persistent air leaks. Mortality ranges from 0% to 7% for the initial hospitalization. The expected benefits of the operation vary according to whether a unilateral or bilateral approach has been used, but gains of 20–35% in the FEV1 have been reported for unilateral operations and gains of 40–80% are seen with bilateral operations. Most authors also report substantial gains in exercise tolerance, freedom from oxygen use, freedom from steroid use, and subjective quality of life.

Ciccone and colleagues reported long-term results in 250 bilateral LVRS recipients at Washington University.26 After a median follow-up of 4.4 years, the 5-year survival was estimated to be 68%. Eighteen of the two hundred and fifty-eight patients in this report proceeded to lung transplantation after a median interval of 4.3 years. Five years after surgery, the mean FEV1 was 7% higher than that prior to surgery, and half the individual patients continued to demonstrate improvement over their preoperative FEV1 values. This finding is very important when one considers the relentless progression in functional impairment seen in the medical arms of the randomized trials described below.

After the initial wave of single-institution case series, several prospective, randomized trials have compared LVRS with maximal medical care.19,27–29 The results of these trials have been controversial because they failed to duplicate the physiologic and functional gains reported in many case series. Furthermore, the mortality and morbidity in the prospective, randomized trials exceeded those seen in most retrospective case series. Much of the discordance between the reported case series and the controlled trials is a consequence of the more liberal selection criteria of the randomized trials compared with individual case series. Unfortunately, as a result of low accrual, the NETT ultimately eliminated many eligibility criteria and based eligibility on physician judgment. The inclusion of patients with severe, diffuse emphysema has altered the clinical significance of these results by including patients previously felt by many to be contraindicated for the procedure.

In 2003, the NETT reported the main results of a 5-year effort. This trial included 1218 patients randomized between LVRS and medical therapy between January 1998 and July 2002.30 This multicenter trial reported a 90-day surgical mortality of 7.9%, which did not differ according to surgical approach (sternotomy versus video-assisted thoracoscopy) or specific center. A survival benefit was seen in the surgical arm for upper lobe predominant emphysema patients with low baseline exercise capacity, whereas a survival benefit was seen in the medical arm for non-upper lobe predominant emphysema patients with high baseline exercise capacity (Fig. 87-9). An interim report by this study group identified a subset of patients at high risk for death after surgery, specifically those with either a very low FEV1 and homogeneous emphysema or those with a very low FEV1 and a very low diffusing capacity for carbon monoxide.19 Our own group has refrained from offering LVRS to patients with homogeneous emphysema from the outset of our experience, but our results in the latter high-risk group are different from those suggested by the NETT report. Our patients with an FEV1 and DLCO of less than 20% of predicted experienced a perioperative mortality of 5%, and the durability of their improvement from LVRS was the same as the rest of the cohort.31 The survival curves from this study are shown in Fig. 87-10.

Figure 87-9.

 

Kaplan-Meier estimates of the probability of death from the NETT. P values were derived by Fisher's exact test for the comparison between groups over a mean follow-up period of 29.2 months. High-risk patients were defined as those with an FEV1 that was 20% or less of the predicted value and either homogeneous emphysema or a carbon monoxide diffusing capacity that was 20% or less of the predicted value. A low baseline exercise capacity was defined as a maximal workload at or below the sex-specific 40th percentile; a high exercise capacity was defined as a workload above this threshold. This was an intention-to-treat analysis. With permission from ref 30.

 

Figure 87-10.

 

Kaplan-Meier survival graph after LVRS. Kaplan-Meier survival estimates for high-risk and all other patients undergoing LVRS at Washington University Medical Center. The median follow-up was 4.6 years. With permission from ref 31.

EDITOR'S COMMENT

A commonly misunderstood result of the NETT is illustrated in Figure 87-9D; namely, that patients with apical predominant emphysema and low exercise tolerance do better with surgery than medical therapy alone. Whereas there is a highly significant difference between these groups, the reason for the difference is not an improvement in surgical survival (e.g., compare 87-9D and 87-9E), but rather the high probability of death in the medical therapy arm. Until the NETT, the mortality of emphysema patients with low exercise tolerance was generally underestimated. This result also highlights the importance of control groups in evaluating new therapies.

–SJM

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2. Association AL: Lung Disease Data—1993. New York, American Lung Association, 1993.

3. Espey DK, Wu XC, Swan J, et al: Annual report to the nation on the status of cancer, 1975-2004, featuring cancer in American Indians and Alaska Natives. Cancer 110:2119–52, 2007. [PubMed: 17939129]

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