Unilateral thoracoscopic surgical approach for diffuse emphysema

Surgical and bronchoscopic pulmonary function-improving procedures in lung emphysema

COPD is a highly prevalent, chronic and irreversible obstructive airway disease without curative treatment. Standard therapeutic strategies, both non-pharmacological and pharmacological, have only limited effects on lung function parameters of patients with severe disease. Despite optimal pharmacological treatment, many patients with severe COPD still have a high burden of dyspnoea and a poor quality of life. If these patients have severe lung emphysema, with hyperinflation as the driver of symptoms and exercise intolerance, lung volume reduction may be an effective treatment with a significant impact on lung function, exercise capacity and quality of life. Currently, different lung volume reduction approaches, both surgical and bronchoscopic, have shown encouraging results and have been implemented in COPD treatment recommendations. Nevertheless, choosing the optimal lung volume reduction strategy for an individual patient remains challenging. Moreover, there is still room for improving durability of effect and safety in all available procedures. Ongoing and innovative research is essential to push this field forwards. This review provides an overview of results and limitations of the current lung volume reduction options for patients with severe lung emphysema and hyperinflation.

Postoperative complications and management after lung volume reduction surgery

The aim of lung volume reduction surgery (LVRS) for patients suffering from severe emphysema is to improve lung function and palliate dyspnea. Careful patient selection in a multidisciplinary approach in a high-volume center is mandatory for a successful outcome. Pulmonary complications including air leak and pneumonia as well as cardiac complications are the most common complications after LVRS. The following article will focus on most common complications observed after LVRS and review the management strategies to improve surgical outcome.

Staged unilateral lung volume reduction surgery: from mini-invasive to minimalist treatment strategies

Lung volume reduction surgery (LVRS) entailing unilateral or bilateral non-anatomical resection of severely damaged emphysematous tissue carried out by thoracoscopic or open surgical approaches, under general anesthesia with single-lung ventilation, has resulted in significant and long-lasting clinical and functional benefit. Unfortunately, the morbidity rates reported by simultaneous bilateral resectional LVRS has led to raise criticism regarding its cost-effectiveness and has stimulated in recent years the development of less invasive bronchoscopic and surgical non-resectional methods of treatment that are preferentially performed in a staged unilateral fashion. We had previously proposed an innovative LVRS modality, which did not entail any resection of lung tissue and was electively carried out according to a staged unilateral strategy by a multiport thoracoscopic access, through thoracic epidural anesthesia in conscious, spontaneously ventilating patients (awake LVRS). The awake LVRS resulted in significant clinical benefit paralleling that achieved by the resectional method with lower morbidity rates and shorter hospital stay. Moreover, the awake LVRS proved also suitable to be employed in stringently selected patients to perform redo procedures following previous successful bilateral LVRS. More recently, in order to minimize the global surgery- and anesthesia-related traumas, we have modified our original non-resectional method by adopting a single thoracoscopic access as well as an anesthesia protocol entailing use of a simple intercostal block with target control sedation, to realize an ultra-minimally invasive or minimalist LVRS. Hence, a deeper investigation of the pros and cons of staged unilateral LVRS strategies as well as of the novel surgical non-resectional and redo LVRS is warranted in order to verify, the optimal strategies of treatment, which will prove to reduce the typical LVRS-related morbidity while assuring the most durable benefit in patients with advanced emphysema.

Is preoperative hypercapnia a justified exclusion criterion for lung volume reduction surgery?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether potential surgical candidates for lung volume reduction surgery (LVRS), who have preoperative hypercapnia, should be excluded on this basis. Using the reported search, 45 papers were found, of which 14 represented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses were tabulated. Of these, seven papers showed a significant (P < 0.05) improvement in postoperative forced expiratory volume in 1 second (FEV1) at up to 6 months in hypercapnic patients. There were six papers which found significant decreases in postoperative arterial carbon dioxide partial pressures (PaCO2) levels following LVRS up to 6 months. There were three papers which showed significant (P < 0.05) improvements in the 6-min walk test in hypercapnic patients following LVRS. Only two papers showed an increased operative mortality in the hypercapnic group compared to the normocapnic group, while nine papers did not find a difference in perioperative mortality. The only randomized controlled study, the landmark NETT study, excluded patients with severe hypercapnia (PaCO2 >55 mmHg and >60 mmHg) and the mean PaCO2 in the surgical and medical group were 43.3 ± 5.9 and 43.0 ± 5.8, respectively. We conclude that the evidence is not strong enough to consider hypercapnia in isolation as high risk or unsuitable for LVRS.

Lung volume reduction surgery for diffuse emphysema

BACKGROUND

Lung volume reduction surgery (LVRS) performed to treat patients with severe diffuse emphysema was reintroduced in the nineties. Lung volume reduction surgery aims to resect damaged emphysematous lung tissue, thereby increasing elastic properties of the lung. This treatment is hypothesised to improve long-term daily functioning and quality of life, although it may be costly and may be associated with risks of morbidity and mortality. Ten years have passed since the last version of this review was prepared, prompting us to perform an update.

OBJECTIVES

The objective of this review was to gather all available evidence from randomised controlled trials comparing the effectiveness of lung volume reduction surgery (LVRS) versus non-surgical standard therapy in improving health outcomes for patients with severe diffuse emphysema. Secondary objectives included determining which subgroup of patients benefit from LVRS and for which patients LVRS is contraindicated, to establish the postoperative complications of LVRS and its morbidity and mortality, to determine which surgical approaches for LVRS are most effective and to calculate the cost-effectiveness of LVRS.

SEARCH METHODS

We identified RCTs by using the Cochrane Airways Group Chronic Obstructive Pulmonary Disease (COPD) register, in addition to the online clinical trials registers. Searches are current to April 2016.

SELECTION CRITERIA

We included RCTs that studied the safety and efficacy of LVRS in participants with diffuse emphysema. We excluded studies that investigated giant or bullous emphysema.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed trials for inclusion and extracted data. When possible, we combined data from more than one study in a meta-analysis using RevMan 5 software.

MAIN RESULTS

We identified two new studies (89 participants) in this updated review. A total of 11 studies (1760 participants) met the entry criteria of the review, one of which accounted for 68% of recruited participants. The quality of evidence ranged from low to moderate owing to an unclear risk of bias across many studies, lack of blinding and low participant numbers for some outcomes. Eight of the studies compared LVRS versus standard medical care, one compared two closure techniques (stapling vs laser ablation), one looked at the effect of buttressing the staple line on the effectiveness of LVRS and one compared traditional 'resectional' LVRS with a non-resectional surgical approach. Participants completed a mandatory course of pulmonary rehabilitation/physical training before the procedure commenced. Short-term mortality was higher for LVRS (odds ratio (OR) 6.16, 95% confidence interval (CI) 3.22 to 11.79; 1489 participants; five studies; moderate-quality evidence) than for control, but long-term mortality favoured LVRS (OR 0.76, 95% CI 0.61 to 0.95; 1280 participants; two studies; moderate-quality evidence). Participants identified post hoc as being at high risk of death from surgery were those with particularly impaired lung function, poor diffusing capacity and/or homogenous emphysema. Participants with upper lobe-predominant emphysema and low baseline exercise capacity showed the most favourable outcomes related to mortality, as investigators reported no significant differences in early mortality between participants treated with LVRS and those in the control group (OR 0.87, 95% CI 0.23 to 3.29; 290 participants; one study), as well as significantly lower mortality at the end of follow-up for LVRS compared with control (OR 0.45, 95% CI 0.26 to 0.78; 290 participants; one study). Trials in this review furthermore provided evidence of low to moderate quality showing that improvements in lung function parameters other than forced expiratory volume in one second (FEV1), quality of life and exercise capacity were more likely with LVRS than with usual follow-up. Adverse events were more common with LVRS than with control, specifically the occurrence of (persistent) air leaks, pulmonary morbidity (e.g. pneumonia) and cardiovascular morbidity. Although LVRS leads to an increase in quality-adjusted life-years (QALYs), the procedure is relatively costly overall.

AUTHORS' CONCLUSIONS

Lung volume reduction surgery, an effective treatment for selected patients with severe emphysema, may lead to better health status and lung function outcomes, specifically for patients who have upper lobe-predominant emphysema with low exercise capacity, but the procedure is associated with risks of early mortality and adverse events.

Predicting the Response to Lung Volume Reduction Surgery Using Scintigraphy

This study was conducted to evaluate the use of quantitative scintigraphy with a newly designed marker to assess and predict the efficacy of lung volume reduction surgery in treating emphysema. In a series of 50 patients with severe emphysema who underwent the operation, ventilation/perfusion scintigraphy was performed and 2 markers of area ratio and lung uniformity were measured before and 6 months after surgery. The markers were correlated with the results of pulmonary function tests. The histopathological subtype of emphysema was also determined in the resected specimen and related to improvement in the markers. The markers were closely related to improvement in forced expiratory volume in 1 second, with the highest correlation being the marker lung uniformity measured by perfusion scintigraphy. Improvement in this marker was significantly greater in centrilobular than in panlobular emphysema. This quantitative method of scintigraphy could provide an excellent reflection of surgical efficacy as well as predict the surgical outcome. Additionally, it provides a mechanistic explanation for the differential improvement between the histopathological subtypes of emphysema following surgery.

The complex care of severe emphysema: role of awake lung volume reduction surgery

The resectional lung volume reduction surgery (LVRS) procedure entailing nonanatomic resection of destroyed lung regions through general anesthesia with single-lung ventilation has shown to offer significant and long-lasting improvements in respiratory function, exercise capacity, quality of life and survival, particularly in patients with upper-lobe predominant emphysema and low exercise capacity. However mortality and morbidity rates as high as 5% and 59%, respectively, have led to a progressive underuse and have stimulated investigation towards less invasive surgical and bronchoscopic nonresectional methods that could assure equivalent clinical results with less morbidity. We have developed an original nonresectional LVRS method, which entails plication of the most severely emphysematous target areas performed in awake patients through thoracic epidural anesthesia (TEA). Clinical results of this ultra-minimally invasive procedure have been highly encouraging and in a uni-center randomized study, intermediate-term outcomes paralleled those of resectional LVRS with shorter hospital stay and fewer side-effects. In this review article we analyze indications, technical details and results of awake LVRS taking into consideration the available data from the literature.

[Lung volume reduction surgery for emphysema and bullous pulmonary emphysema]

The improvement of respiratory symptoms for emphysematous patients by surgery is a concept that has evolved over time. Initially used for giant bullae, this surgery was then applied to patients with diffuse microbullous emphysema. The physiological and pathological concepts underlying these surgical procedures are the same in both cases: improve respiratory performance by reducing the high intrapleural pressure. The functional benefit of lung volume reduction surgery (LVRS) in the severe diffuse emphysema has been validated by the National Emphysema Treatment Trial (NETT) and the later studies which allowed to identify prognostic factors. The quality of the clinical, morphological and functional data made it possible to develop recommendations now widely used in current practice. Surgery for giant bullae occurring on little or moderately emphysematous lung is often a simpler approach but also requires specialised support to optimize its results.

Randomized comparison of awake nonresectional versus nonawake resectional lung volume reduction surgery

OBJECTIVE

The study objective was to assess in a randomized controlled study (NCT00566839) the comparative results of awake nonresectional or nonawake resectional lung volume reduction surgery.

METHOD

Sixty-three patients were randomly assigned by computer to receive unilateral video-assisted thoracic surgery lung volume reduction surgery by a nonresectional technique performed through epidural anesthesia in 32 awake patients (awake group) or the standard resectional technique performed through general anesthesia in 31 patients (control group). Primary outcomes were hospital stay and changes in forced expiratory volume in 1 second. During follow-up, the need of contralateral treatment because of loss of postoperative benefit was considered a failure event as death.

RESULTS

Intergroup comparisons (awake vs control) showed no difference in gender, age, and body mass index. Hospital stay was shorter in the awake group (6 vs 7.5 days, P = .04) with 21 versus 10 patients discharged within 6 days (P = .01). At 6 months, forced expiratory volume in 1 second improved significantly in both study groups (0.28 vs 0.29 L) with no intergroup difference (P = .79). In both groups, forced expiratory volume in 1 second improvements lasted more than 24 months. At 36 months, freedom from contralateral treatment was 55% versus 50% (P = .5) and survival was 81% versus 87% (P = .5).

CONCLUSIONS

In this randomized study, awake nonresectional lung volume reduction surgery resulted in significantly shorter hospital stay than the nonawake procedure. There were no differences between study groups in physiologic improvements, freedom from contralateral treatment, and survival. We speculate that compared with the nonawake procedure, awake lung volume reduction surgery can offer similar clinical benefit but a faster postoperative recovery.

Lung transplantation and lung volume reduction surgery

Since the publication of the last edition of the Handbook of Physiology, lung transplantation has become widely available, via specialized centers, for a variety of end-stage lung diseases. Lung volume reduction surgery, a procedure for emphysema first conceptualized in the 1950s, electrified the pulmonary medicine community when it was rediscovered in the 1990s. In parallel with their technical and clinical refinement, extensive investigation has explored the unique physiology of these procedures. In the case of lung transplantation, relevant issues include the discrepant mechanical function of the donor lungs and recipient thorax, the effects of surgical denervation, acute and chronic rejection, respiratory, chest wall, and limb muscle function, and response to exercise. For lung volume reduction surgery, there have been new insights into the counterintuitive observation that lung function in severe emphysema can be improved by resecting the most diseased portions of the lungs. For both procedures, insights from physiology have fed back to clinicians to refine patient selection and to scientists to design clinical trials. This section will first provide an overview of the clinical aspects of these procedures, including patient selection, surgical techniques, complications, and outcomes. It then reviews the extensive data on lung and muscle function following transplantation and its complications. Finally, it reviews the insights from the last 15 years on the mechanisms whereby removal of lung from an emphysema patient can improve the function of the lung left behind.

Treatment of advanced emphysema with emphysematous lung sealant (AeriSeal®)

BACKGROUND

This report summarizes initial tests of an emphysematous lung synthetic polymer sealant (ELS) designed to reduce lung volume in patients with advanced emphysema.

OBJECTIVES

The primary study objective was to define a therapeutic strategy to optimize treatment safety and effectiveness.

METHODS

ELS therapy was administered bronchoscopically to 25 patients with heterogeneous emphysema in an open-label, noncontrolled study at 6 centers in Germany. Treatment was performed initially at 2-4 subsegments. After 12 weeks, patients were eligible for repeat therapy to a total of 6 sites. Safety and efficacy were assessed after 6 months. Responses were evaluated in terms of changes from baseline in lung physiology, functional capacity, and health-related quality of life. Follow-up is available for 21 of 25 patients.

RESULTS

Treatment was well tolerated. There were no treatment-related deaths (i.e., within 90 days of treatment), and an acceptable short- and long-term safety profile. Physiological and clinical benefits were observed at 24 weeks. Efficacy responses were better among Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III patients [n = 14; change in residual volume/total lung capacity (ΔRV/TLC) = -7.4 ± 10.3%; Δ forced expiratory volume in 1 s (ΔFEV(1)) = +15.9 ± 22.6%; change in forced vital capacity (ΔFVC) = +24.1 ± 22.7%; change in carbon monoxide lung diffusion capacity (ΔDLCO) = +19.3 ± 34.8%; change in 6-min walk test (Δ6MWD) = +28.7 ± 59.6 m; change in Medical Research Council Dyspnea (ΔMRCD) score = -1.0 ± 1.04 units; change in St. George's Respiratory Questionnaire (ΔSGRQ) score = -9.9 ± 15.3 units] than for GOLD stage IV patients (n = 7; ΔRV/TLC = -0.5 ± 6.4%; ΔFEV(1) = +2.3 ± 12.3%; ΔFVC = +2.6 ± 21.1%; ΔDLCO = -2.8 ± 17.2%; Δ6MWD = +28.3 ± 58.4 m; ΔMRCD = 0.3 ± 0.81 units; ΔSGRQ = -6.7 ± 7.0 units).

CONCLUSIONS

ELS therapy shows promise for treating patients with advanced heterogeneous emphysema. Additional studies to assess responses in a larger cohort with a longer follow-up are warranted.

Anesthetic considerations in candidates for lung volume reduction surgery

The administration of anesthesia to patients undergoing lung volume reduction surgery (LVRS) requires a complete understanding of the pathophysiology of severe chronic obstructive pulmonary disease, the planned surgical procedure, and the anticipated postoperative course for this group of patients. Risk factors and associated morbidity and mortality are discussed within the context of patients with obstructive pulmonary disease in the National Emphysema Treatment Trial having surgical procedures. Preoperative evaluation and the anesthetic techniques used for patients undergoing LVRS are reviewed, as are monitoring requirements. Intraoperative events, including induction of anesthesia, lung isolation, management of fluid requirements, and options for ventilatory support are discussed. Possible intraanesthetic complications are also reviewed, as is the optimal management of such problems, should they occur. To minimize the potential for a surgical air leak in the postoperative period, positive-pressure ventilation must cease at the conclusion of the procedure. An awake, comfortable, extubated patient, capable of spontaneous ventilation, is only possible if there is careful attention to pain control. The thoracic epidural is the most common pain control method used with patients undergoing LVRS procedures; however, other alternative methods are reviewed and discussed.

Lung volume reduction surgery: technique, operative mortality, and morbidity

The objective of lung volume reduction surgery (LVRS) is the safe, effective, and durable palliation of dyspnea in appropriately selected patients with moderate to severe emphysema. Appropriate patient selection and preoperative preparation are prerequisites for successful LVRS. An effective LVRS program requires participation by and communication between experts from pulmonary medicine, thoracic surgery, thoracic anesthesiology, critical care medicine, rehabilitation medicine, respiratory therapy, chest radiology, and nursing. The critical analysis of perioperative outcomes has influenced details of the conduct of the procedure and has established a bilateral, stapled approach as the standard of care for LVRS. The National Emphysema Treatment Trial (NETT) remains the world's largest multi-center, randomized trial comparing LVRS to maximal medical therapy. NETT purposely enrolled a broad spectrum of anatomic patterns of emphysema. This, along with the prospective, audited collection of extensive demographic, physiologic, radiographic, surgical and quality-of-life data, has positioned NETT as the most robust repository of evidence to guide the refinement of patient selection criteria for LVRS, to assist surgeons in providing optimal intraoperative and postoperative care, and to establish benchmarks for survival, complication rates, return to independent living, and durability of response. This article reviews the evolution of current LVRS practice with a particular emphasis on technical aspects of the operation, including the predictors and consequences of its most common complications.

Hyperinflation and its management in COPD

Chronic obstructive pulmonary disease (COPD) is characterized by poorly reversible airflow limitation. The pathological hallmarks of COPD are inflammation of the peripheral airways and destruction of lung parenchyma or emphysema. The functional consequences of these abnormalities are expiratory airflow limitation and dynamic hyperinflation, which then increase the elastic load of the respiratory system and decrease the performance of the respiratory muscles. These pathophysiologic features contribute significantly to the development of dyspnea, exercise intolerance and ventilatory failure. Several treatments may palliate flow limitation, including interventions that modify the respiratory pattern (deeper, slower) such as pursed lip breathing, exercise training, oxygen, and some drugs. Other therapies are aimed at its amelioration, such as bronchodilators, lung volume reduction surgery or breathing mixtures of helium and oxygen. Finally some interventions, such as inspiratory pressure support, alleviate the threshold load associated to flow limitation. The degree of flow limitation can be assessed by certain spirometry indexes, such as vital capacity and inspiratory capacity, or by other more complexes indexes such as residual volume/total lung capacity or functional residual capacity/total lung capacity. Two of the best methods to measure flow limitation are to superimpose a flow–volume loop of a tidal breath within a maximum flow–volume curve, or to use negative expiratory pressure technique. Likely this method is more accurate and can be used during spontaneous breathing. A definitive definition of dynamic hyperinflation is lacking in the literature, but serial measurements of inspiratory capacity during exercise will document the trend of end-expiratory lung volume and allow establishing relationships with other measurements such as dyspnea, respiratory pattern, exercise tolerance, and gas exchange.

Computerized estimation of the lung volume removed during lung volume reduction surgery

RATIONALE AND OBJECTIVES

This study was designed to develop an automated method for estimating lung volume removed during lung volume reduction surgery (LVRS) using computed tomography (CT).

MATERIALS AND METHODS

The CT examinations of six patients who underwent bilateral LVRS were analyzed in this study. The resected lung tissue (right and left) was weighed during pathologic examination. An automated computer scheme was developed to estimate the lung volume removed using the CT voxel values and lung specimen weight. The computed fraction of lung volume removed was evaluated across a range of simulated surgical planes (ie, other than parallel to the CT image plane) and CT reconstruction kernels, and it was compared with the surgeons' postsurgical estimates.

RESULTS

The computed fraction of the lung volume removed during LVRS was linearly correlated with the resected lung tissue weight (Pearson correlation = 0.697, P = .012). The computed fraction of lung volume removed ranged from 12.9% to 51.7% of the total lung volume. The surgeons' postsurgical estimates of lung volume removed ranged from 30% to 33%. The percent difference between the surgeons' estimates and the computed lung volume removed as a percentage of the surgeons' estimates ranged from -72.3% to 57.0% with mean absolute difference of 29.7% (+/-20.7).

CONCLUSION

The preliminary findings of this study suggest that the proposed quantitative model should provide an objective measure of lung volume removed during LVRS that may be used to investigate the relationship between lung volume removed and outcome.

Lung volume reduction surgery for diffuse emphysema

BACKGROUND

Lung volume reduction surgery (LVRS) has been re-introduced for treating patients with severe diffuse emphysema. It is a procedure that aims to improve long-term daily functioning, although it is costly and may also be associated with a high risk of mortality.

OBJECTIVES

To assemble evidence from randomised controlled trials for the effectiveness of LVRS, and identify optimal surgical techniques.

SEARCH STRATEGY

Randomised controlled trials were identified using the Cochrane Airways Group Chronic Obstructive Pulmonary Disease (COPD) register. Searches are current to September 2005.

SELECTION CRITERIA

Randomised controlled trials that studied the safety and efficacy of LVRS in patients with diffuse emphysema were included. Studies were excluded if they investigated giant or bullous emphysema.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed trials for inclusion and extracted data. Where possible, data from more than one study were combined using RevMan 4.2 software.

MAIN RESULTS

Eight studies (1663 participants) met the entry criteria of the review. One study accounted for 73% of the participants recruited. Study quality was high, although blinding in studies was not possible. Ninety day mortality was significantly greater in all those who underwent LVRS (odds ratio 6.57 (95% CI 3.34 to 12.95), four studies, N = 1415). A subgroup analysis by risk status suggested that there was a subgroup of participants who were consistently at a significant risk of death, although this was only measured in one large study. The ninety day mortality data indicated that death was more likely with LVRS irrespective of risk status identified in one large study. Improvements in lung function, quality of life and exercise capacity were more likely with LVRS than with usual follow-up.

AUTHORS' CONCLUSIONS

The evidence summarised in this review is drawn from one large study, and several smaller trials. The findings from the large study indicated that in patients who survive up to three months post-surgery, there were significantly better health status and lung function outcomes in favour of surgery compared with usual medical care. Patients identified post hoc as being of high risk of death from surgery were those with particularly impaired lung function and poor diffusing capacity and/or homogenous emphysema. Further research should address the effect of this intervention on exacerbations and rate of decline in lung function and health status.

Anaesthesia for lung volume reduction surgery

To date, only a few published studies have been concerned with the anaesthesiological aspects of lung volume reduction surgery. This review summarizes the different anaesthetic concepts and offers a general strategy to meet specific requirements. Limitation of peak inspiratory pressure, tolerance of hypercapnia and avoidance of hypoxia during one-lung ventilation, and the immediate postoperative tracheal extubation of these patients, are considered to be crucial. However, many aspects of the procedure and of anaesthesiological management remain to be elucidated.

Predictors of operative mortality and cardiopulmonary morbidity in the National Emphysema Treatment Trial

OBJECTIVE

We sought to identify predictors of operative mortality, pulmonary morbidity, and cardiovascular morbidity after lung volume reduction surgery.

METHODS

Univariate and multivariate logistic regression analyses were performed. Candidate predictors included demographic characteristics, physical condition characteristics, pulmonary function measures, measures of the distribution of emphysema as determined by radiologists and by means of computerized analysis of chest computed tomographic scans, and measures of exercise capacity, dyspnea, and quality of life. End points analyzed were operative mortality (death within 90 days of the operation), major pulmonary morbidities (tracheostomy, failure to wean, reintubation, pneumonia, and ventilator for > or =3 days), and cardiovascular morbidities (infarction, pulmonary embolus, or arrhythmia requiring treatment).

RESULTS

Five hundred eleven patients in the non-high-risk group of the National Emphysema Treatment Trial underwent lung volume reduction. The incidence of operative mortality was 5.5%, major pulmonary morbidity occurred in 29.8% of patients, and cardiovascular morbidity occurred in 20.0% of patients. Predictors for these end points are as follows: [table: see text].

CONCLUSIONS

Although lung volume reduction can be performed in selected patients with acceptable mortality, the incidence of major cardiopulmonary morbidity remains high. The lone predictor for operative mortality of lung volume reduction was the presence of non-upper-lobe-predominant emphysema, as assessed by the radiologist. Pulmonary morbidity can be expected in elderly patients who have a low diffusing capacity for carbon monoxide and forced expiratory volume in 1 second. When assessing morbidity, the computer-assisted chest computed tomographic analysis proved useful only in predicting cardiovascular complications.

Lung volume reduction surgery as a bridge to lung transplantation

Lung volume reduction surgery (LVRS) improves lung function, exercise capacity, and quality of life in patients with advanced emphysema. In some patients with emphysema who are candidates for lung transplantation, LVRS is an alternative treatment option to lung transplantation, or may be used as a bridge to lung transplantation. Generally accepted criteria for LVRS include severe non-reversible airflow obstruction due to emphysema associated with significant evidence of lung hyperinflation and air trapping. Both high resolution computed tomography (CT) scan of the chest and quantitative ventilation/perfusion scan are used to identify lung regions with severe emphysema which would be used as targets for lung resection. Bilateral LVRS is the preferred surgical approach compared with the unilateral procedure because of better functional outcome. Lung transplantation is the preferred surgical treatment in patients with emphysema with alpha1 antitrypsin deficiency and in patients with very severe disease who have homogeneous emphysema pattern on CT scan of the chest or very low diffusion capacity.

Results of unilateral lung volume reduction surgery in patients with distinct heterogeneity of emphysema between lungs

OBJECTIVE

This study was undertaken to analyze the comprehensive outcome of unilateral lung volume reduction in patients with distinct heterogeneity of emphysema between lungs assessed by a visual radiologic scoring system.

METHODS

Ninety-seven patients who underwent intentional unilateral lung volume reduction because of distinct heterogeneity of emphysema between lungs (asymmetric ratio of emphysema >/=1.1) between 1995 and 2003 were evaluated. Baseline median measures were 0.83 L for forced expiratory volume in 1 second, 5.0 L for residual volume, 380 m for 6-minute walking test distance, 0.50 for maximal incremental treadmill test score, and 25 for physical functioning domain score assessed by the Short Form-36 Quality of Life questionnaire.

RESULTS

Median follow-up was 34 months. Significant improvements occurred for as long as 36 months in forced expiratory volume in 1 second (+24%), residual volume (-12%), Short Form-36 Quality of Life questionnaire physical functioning domain score (+100%), 6-minute walking test distance (+18%), and maximal incremental treadmill test score (+200%). A direct correlation was found between asymmetric ratio of emphysema and change in forced expiratory volume in 1 second ( r = 0.65, P < .00001). At 60 months, residual volume (-6.2%), maximal incremental treadmill test score (+100%), and Short Form-36 Quality of Life questionnaire physical functioning domain score (+70%) were still significantly improved. Five-year survival was 82%; 5-year freedom from contralateral lung volume reduction was 70%.

CONCLUSIONS

In this series, significant, long-lasting improvements and satisfactory survival were seen after intentional unilateral lung volume reduction. Heterogeneity of emphysema between lungs was directly correlated with improvement at 36 months in forced expiratory volume in 1 second. Our results suggest that unilateral lung volume reduction is a suitable option for patients with distinct heterogeneity of emphysema between lungs.

[Lung volume reduction surgery for emphysema: a unilateral or bilateral approach?]

INTRODUCTION

Lung Volume reduction surgery (LVRS) is a recognized therapeutic option for patients presenting with severe and disabling pulmonary emphysema. Case selection is based upon clinical, morphological and functional criteria.

STATE OF THE ART

LVRS has shown promising results, with improvements in exercise capacity, pulmonary function and quality of life, in selected patients with severe and disabling emphysema. A variety of surgical techniques have been described. The procedure may be unilateral or bilateral, through a sternotomy or by a video-assisted thoracoscopic (VATS) technique. The controversial aspects of the surgical technique will be analysed and discussed in the following review.

PERSPECTIVES

A bilateral approach clearly offers a better functional improvement when compared to a unilateral procedure, however, the postoperative functional decline appears greater and more rapid after a bilateral procedure. A unilateral approach, with often less postoperative morbidity, allows the option to perform a future contra-lateral procedure in the event of further clinical or functional deterioration.

CONCLUSIONS

In selected cases LVRS is an effective treatment for severe pulmonary emphysema. Different surgical techniques have been described. Nowadays VATS is considered to be the technique of choice, with the option to carry out a future unilateral or bilateral procedure.

Complications after lung volume reduction surgery

LVRS has greater morbidity than most general thoracic surgical procedures. Proper care of patients after LVRS is a labor-intensive activity, but it is worthwhile because LVRS can be performed with acceptable risk. Patient selection, postoperative care, and an understanding of the potential complications are the keys to successful LVRS.

Results of lung volume reduction surgery for emphysema

LVRS provides an exciting opportunity for palliation of symptoms and improvement in quality of life for patients who have severe end-stage emphysema. Because no medical therapy has been able to improve pulmonary function or reverse the inexorable decline of breathless patients who have emphysema, this opportunity to improve lung function and quality of life is one of the most innovative additions to thoracic surgery since the first successful lung transplant procedure 20 years ago. Although initial short-term, case-controlled surgeries were criticized because of incomplete and short follow-up care, substantial long-term data now exist to support the use of LVRS for select patients who have severe emphysema. Patients who have upper lobe predominant disease or low exercise capacity are more likely to have a benefit in exercise capacity and quality of life after LVRS. Selected patients who have upper lobe emphysema and poor exercise capacity are also more likely to have improved survival after LVRS. The individual contributions by the large number of investigators pioneering LVRS development, along with the collective contributions of the NETT investigators, have propelled the knowledge surrounding LVRS far beyond that of any similar new technology or procedure in its adolescence.

Operative techniques for lung volume reduction surgery

Recently, LVRS has received renewed public interest. Various surgical approaches and techniques exist, and each has challenges, advantages, and disadvantages. Stapled techniques have been used more commonly than plication techniques or lasers. The choice of staple buttressing material has not been shown to affect outcome. For most patients who are suitable for LVRS, a bilateral procedure is appropriate. Minimally invasive techniques are gaining in popularity and have demonstrated good results. Of the approaches discussed above, bilateral thoracoscopy in the supine position is likely to be the most expeditious with the lowest incision-related morbidity and dysfunction.

Patient selection for lung volume reduction surgery

LVRS represents a valid surgical option for a limited number of patients who have symptomatic emphysema. The results of recent controlled studies have provided a realistic view of LVRS outcomes and yielded a validated algorithm for selection of optimal candidates for surgery. Furthermore, the NETT has provided simultaneously collected cost data that have provided a unique view of the costs and benefits of LVRS in patients who have advanced emphysema. Additional data collection will better define the long-term benefits of such surgical intervention in patients who have COPD.

Lung Volume Reduction Surgery in Australia and New Zealand

BACKGROUND

Lung volume reduction surgery (LVRS) has been shown to improve lung function, exercise performance, and quality of life in highly selected individuals with severe emphysema; however, major questions regarding the efficacy and long-term outcomes of LVRS still remain unanswered. Pending the results of large randomized controlled trials (RCTs), the Australian and New Zealand LVRS Database was created to audit local clinical practice and patient outcomes.

AIMS

To review patient selection, surgical activity, and patient outcomes related to LVRS in Australia and New Zealand.

METHODS

Prospective data were voluntarily submitted by hospitals performing LVRS in Australia and New Zealand. Preoperative, surgical, perioperative, and follow-up variables were analyzed.

RESULTS

Data were collected from 15 hospitals regarding 529 patients. Mean age (+/- SD) at surgery was 63 +/- 7 years. Preoperatively, FEV(1) was 29 +/- 9% predicted, total lung capacity (TLC) was 138 +/- 20% predicted, residual volume (RV) was 250 +/- 64% predicted, and 6-min walk (6MW) distance was 327 +/- 111 m. There has been a reduction in the overall number of cases and hospitals performing LVRS since 1999. Improvements in lung function following LVRS (ie, FEV(1) increase of 38%, RV decrease of 27%, TLC decrease of 17%) and exercise capacity (ie, 6MW distance increase of 24%) appear to be maintained for approximately 3 years.

CONCLUSIONS

LVRS continues to be performed in Australia and New Zealand, predominantly in large tertiary teaching hospitals with similar outcomes to those described in the literature. It remains difficult to capture long-term lung function and survival outcomes in this population. Ongoing audit and RCTs are both required to resolve the confusion that still shrouds this procedure.

A prospective evaluation of lung volume reduction surgery in 200 consecutive patients

OBJECTIVES

Though numerous studies have demonstrated the short-term efficacy of lung volume reduction surgery (LVRS) in select patients with emphysema, the longer-term follow-up studies are just being reported. The primary objectives of this study were to assess long-term health-related quality of life, satisfaction, physiologic status, and survival of patients following LVRS.

DESIGN

We used a prospective cohort study design to assess the first 200 patients undergoing bilateral LVRS (from 1993 to 1998), with follow-up through the year 2000. Each patient served as his own control, initially receiving optimal medical management including exercise rehabilitation before undergoing surgery. Preoperative postrehabilitation data were used as the baseline for comparisons with postoperative data. The primary end points were the effects of LVRS on dyspnea (modified Medical Research Council dyspnea sale), general health-related quality of life (Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]), patient satisfaction, and survival. The secondary end points were the effects of LVRS on pulmonary function, exercise capacity, and supplemental oxygen requirements.

SETTING

A tertiary care urban university-based referral center.

PATIENTS

Eligibility requirements for LVRS included disabling dyspnea due to marked airflow obstruction, thoracic hyperinflation, and heterogeneously distributed emphysema that provided target areas for resection. Patients were assessed at 6 months, 3 years, and 5 years after surgery.

INTERVENTIONS

Preoperative pulmonary rehabilitation and bilateral stapling LVRS.

MEASUREMENTS AND RESULTS

The 200 patients accrued 735 person-years (mean +/- SD, 3.7 +/- 1.6 years; median, 4.0 years) of follow-up. Over the three follow-up periods, an average of > 90% of evaluable patients completed testing. Six months, 3 years, and 5 years after surgery, dyspnea scores were improved in 81%, 52%, and 40% of patients, respectively. Dyspnea scores were the same or improved in 96% (6 months), 82% (3 years), and 74% (5 years) of patients. Improvements in SF-36 physical functioning were demonstrated in 93% (6 months), 78% (3 years), and 69% (5 years) of patients. Good-to-excellent satisfaction with the outcomes was reported by 96% (6 months), 89% (3 years), and 77% (5 years) of patients. The FEV(1) was improved in 92% (6 months), 72% (3 years), and 58% (5 years) of patients. Changes in dyspnea and general health-related quality-of-life scores, and patient satisfaction scores were all significantly correlated with changes in FEV(1). Following surgery, the median length of hospital stay in survivors was 9 days. The 90-day postoperative mortality was 4.5%. Annual Kaplan-Meier survival through 5 years after surgery was 93%, 88%, 83%, 74%, and 63%, respectively. During follow-up, 15 patients underwent subsequent lung transplantation.

CONCLUSIONS

In stringently selected patients, LVRS resulted in substantial beneficial effects over and above those achieved with optimized medical therapy. The duration of improvement was at least 5 years in the majority of survivors.

Treatment of patients with lung cancer and severe emphysema: lessons from lung volume reduction surgery

Lung volume reduction surgery (LVRS) is effective therapy for selected patients with end-stage emphysema. Surgery produces improved pulmonary function, increased exercise tolerance and enhanced quality of life. It has been shown to be superior to medical management over the short-term in randomized controlled trials. The experience gained by dealing with this select group of patients has had a substantial impact on management of lung cancer in some patients with advanced lung disease. Numerous surgical, anaesthetic, and nursing advances gained in dealing with lung volume reduction surgery (LVRS) procedures now allow surgery to be considered as the optimal cancer management technique. For some carefully selected candidates, cancer resection and LVRS can be performed simultaneously, with dual benefits. The physiologic principles underlying LVRS and selection guidelines will be reviewed. The impact on cancer management and the current strategy at Toronto General Hospital will also be presented.

Technical issues and controversies in lung volume reduction surgery

The goal of lung volume reduction surgery (LVRS) is to safely palliate dyspnea in patients suffering from emphysema. Successful LVRS demands attention to the details of patient selection, preoperative preparation, intraoperative anesthetic and surgical technique and multidisciplinary postoperative care. Expertise in and effective communication between pulmonary medicine, thoracic surgery, thoracic anesthesia, pain management services, critical care medicine, respiratory therapy and rehabilitation medicine are vital components to any LVRS program. In experienced centers, bilateral approaches yield nearly twice the physiologic benefit to unilateral LVRS without adversely affecting operative morbidity or mortality. Current practice favors stapled resection over laser ablation to achieve volume reduction. Controversy persists regarding open versus video-assisted operations. The cost-effective need for and choice of materials to buttress staple-lines to reduce the incidence of postoperative air leak have yet to be defined. Ongoing multi-center, randomized, controlled trials should define the utility and durability of LVRS for appropriately selected patients and resolve some of the residual technical controversies. Therapeutic innovations may further reduce the invasiveness of lung volume reduction strategies and allow a more tailored approach to palliate patients with moderate to severe emphysema.

Lung volume reduction: where do we stand?

The concept of lung volume resection (LVR) was introduced in 1995 for the treatment of end-stage emphysema patients utilizing stapled resection through a median stenotomy approach. This article discusses this procedure and the trials that have been instituted. LVR might prove to be a viable alternative treatment modality for selected, end-stage emphysema patients in the future.

Thoracoscopy and transplantation: a new attractive tool

BACKGROUND

Transplanted patients on immunosuppressive treatment have an increased risk of infections or neoplasms. Transplantation candidates with infection or a suspected malignancy are excluded from transplantation. In patients already transplanted, thoracoscopy can resolve complications or treat the pulmonary pathology without compromising the precarious existing reactive equilibrium. These patients require an approach that is as least traumatic as possible.

METHODS

From September 1991 to December 2000, of 2068 videothoracoscopic procedures carried out at our hospital, 2 were in patients who had undergone transplantation and 3 in candidates for kidney, liver, and bone marrow transplantation. Starting from our personal experience in videothoracoscopy as a diagnostic and therapeutic approach, the possibilities of the method in the field of transplantation are reported by a review of the literature carried out by consulting the reference systems of the most important data banks.

CONCLUSIONS

In our experience, videothoracoscopy had a major impact on the management of candidates for transplant, because it allowed us to rule out or treat conditions that would have determined exclusion from a transplant program. In transplanted patients, videothoracoscopy allows a correct diagnosis and treatment with minimal trauma.

Improvement in spirometry following lung volume reduction surgery: application of a physiologic model

According to a previously published theoretical model of emphysema, the ratio of RV to TLC (RV/TLC) reflects the size mismatch between the hyperinflated lungs in the disease and the surrounding chest. The model suggests that RV/TLC is an important predictor of improvement in FVC and that increased FVC is an important determinant of increased FEV(1) after lung volume reduction surgery (LVRS). We tested these predictions in 13 patients undergoing LVRS, in whom we made detailed measurements of lung mechanics. Using stepwise regression, we found that RV/TLC was the only preoperative independent predictor of the increase in FVC. Seventy percent of the increase in FEV(1) was attributable to increased FVC, with the remainder due to increased FEV(1)/FVC. In a separate group of 78 LVRS patients evaluated with standard preoperative pulmonary function tests, RV/TLC again was found to correlate with the increase in FVC, and changes in FEV(1) were also due largely to changes in FVC. However, RV/TLC was not predictive of the increase in FEV(1) among the group of 78 patients, because FEV(1)/FVC in patients with a low preoperative RV/TLC often increased despite little change in FVC. These findings support the proposed mechanism for increased FVC following LVRS. They also illustrate the limitations of the model, and suggest further hypotheses for selecting patients who may benefit from surgery.

Patients at high risk of death after lung-volume-reduction surgery

BACKGROUND

Lung-volume-reduction surgery is a proposed treatment for emphysema, but optimal selection criteria have not been defined. The National Emphysema Treatment Trial is a randomized, multicenter clinical trial comparing lung-volume-reduction surgery with medical treatment.

METHODS

After evaluation and pulmonary rehabilitation, we randomly assigned patients to undergo lung-volume-reduction surgery or receive medical treatment. Outcomes were monitored by an independent data and safety monitoring board.

RESULTS

A total of 1033 patients had been randomized by June 2001. For 69 patients who had a forced expiratory volume in one second (FEV1) that was no more than 20 percent of their predicted value and either a homogeneous distribution of emphysema on computed tomography or a carbon monoxide diffusing capacity that was no more than 20 percent of their predicted value, the 30-day mortality rate after surgery was 16 percent (95 percent confidence interval, 8.2 to 26.7 percent), as compared with a rate of 0 percent among 70 medically treated patients (P<0.001). Among these high-risk patients, the overall mortality rate was higher in surgical patients than medical patients (0.43 deaths per person-year vs. 0.11 deaths per person-year; relative risk, 3.9; 95 percent confidence interval, 1.9 to 9.0). As compared with medically treated patients, survivors of surgery had small improvements at six months in the maximal workload (P= 0.06), the distance walked in six minutes (P=0.03), and FEV1 (P<0.001), but a similar health-related quality of life. The results of the analysis of functional outcomes for all patients, which accounted for deaths and missing data, did not favor either treatment.

CONCLUSIONS

Caution is warranted in the use of lung-volume-reduction surgery in patients with emphysema who have a low FEV1 and either homogeneous emphysema or a very low carbon monoxide diffusing capacity. These patients are at high risk for death after surgery and also are unlikely to benefit from the surgery.

Lung volume reduction surgery and nutritional status in patients with severe emphysema

OBJECTIVE

We studied the short-term effect of lung volume reduction surgery on nutritional status including body composition and the relationship between preoperative nutritional status and postoperative morbidity.

METHODS

Subjects were 28 patients with emphysema who underwent bilateral thoracoscopic lung volume reduction surgery (23 simultaneously, 5 staged). Functional tests, body weight, and body composition were measured before and 6 months after surgery. Fat-free mass and fat mass were assessed by bioelectrical impedance analysis.

RESULTS

FEV1.0 improved 35.2% following surgery and maximal oxygen uptake 23.8%. Body weight and fat-free mass increased significantly after surgery, while fat mass was unchanged. Of the 23 undergoing simultaneous bilateral lung volume reduction surgery, 8 had major complications-3 required additional surgery to close air leaks, 3 required mechanical ventilation (> 72 hrs), and 2 developed postoperative infection. The preoperative percentage of ideal body weight and fat-free mass was significantly higher among patients without major complications.

CONCLUSIONS

Bilateral lung volume reduction surgery increases fat-free mass and provides functional improvement for underweight patients with severe emphysema. We found fat-free mass and body weight to be good predictors of unacceptable postoperative complications following bilateral lung volume reduction surgery.

Thoracoscopic lung volume reduction surgery for pulmonary emphysema patients with severe hypercapnia

OBJECTIVES

We assessed whether hypercapnia patients with an extremely high level of PaCO2 > or = 60 mmHg were suitable candidates for lung volume reduction in the treatment of severe pulmonary emphysema.

METHODS

Of 65 patients undergoing lung volume reduction surgery between May 1993 and August 1997, 6 (9.23%) who had a preoperative rest room air blood gas level of PaCO2 > or = 60 mmHg were selected for study. All patients underwent video-assisted thoracoscopic surgery. Of the 6 with severe hypercapnia, 5 underwent the unilateral procedure and 1 the bilateral procedure.

RESULTS

All severe hypercapnia patients showed significant clinical improvement. When assessed at 3 to 6 months after lung volume reduction surgery, significant improvements were seen in mean forced expiratory volume in 1 second (preop: 0.44 +/- 0.04 L; postop: 0.74 +/- 0.20 L; p < 0.01), for a magnitude improvement of 69.8%, and in trapped gas volume (preop: 3.28 +/- 1.11 L; postop: 1.61 +/- 1.02 L; p < 0.05). Arterial blood gas analysis showed significant improvement in PaO2 from 51.1 +/- 6.68 mmHg to 69.8 +/- 7.87 mmHg (p < 0.001) with a decrease in PaCO2 from 70.4 +/- 9.41 mmHg to 46.9 +/- 3.44 mmHg (p < 0.01). Postoperative follow-up averaged 55 months (43-69 months). All but 1 patient remain alive and well.

CONCLUSION

Patients with severe pulmonary emphysema accompanied by hypercapnia can gain relief and a better quality of life through volume reduction surgery and should not be excluded from surgical treatment simply based on this condition. Selection should involve a comprehensive view of the patient's condition that includes criteria such as the results of radiographic diagnosis and detailed pulmonary function tests.

Lung volume reduction surgery in emphysema: a systematic review

The aim of this study was to systematically review the literature regarding the safety and efficacy of lung volume reduction surgery (LVRS) in patients with emphysema. Studies on LVRS to August 2000 were identified using MEDLINE, Embase, Current Contents, and the Cochrane Library. Human studies of patients with upper, lower or diffuse distributions of emphysema were included. All types of bullous emphysema were excluded. A surgeon and researcher independently assessed the retrieved articles for their inclusion in the review. When LVRS was compared with medical management, at 2 years LVRS was associated with a higher FEV1 and at least equivalent survival. The use of staple excision of selected areas of lung appeared to be more efficacious than laser ablation. There is insufficient evidence to show preference for median sternotomy or videoscopically assisted thoracotomy, as the more safe and efficacious procedure. In highly selected patients with emphysema LVRS is deemed an acceptable treatment. To fully evaluate the safety and efficacy of LVRS, outcomes beyond 2 years must be included. The results of prospective randomized trials between medical management and LVRS, now in progress, are essential before a final assessment can be made.

Underestimation of mortality following lung volume reduction surgery resulting from incomplete follow-up

STUDY OBJECTIVES

Incomplete follow-up can bias interpretation of data that are collected in longitudinal studies. We noted that many patients failed to return for follow-up in a study of effect of lung volume reduction surgery (LVRS) on quality of life (QOL). Accordingly, we designed this investigation to determine the reasons patients dropped out, and to assess differences between those who continued in the study (attendees) and those who did not (nonattendees).

DESIGN

Telephone survey.

SUBJECTS

Patients with advanced emphysema who had undergone LVRS and had previously agreed to participate in a longitudinal QOL study.

RESULTS

No differences were found with regard to age, gender, preoperative pulmonary function, or oxygen use between attendees and nonattendees. Long-term mortality in nonattendees (27%) was considerably greater than that seen in attendees (3%, p < 0.05). Distance from the hospital, financial burden, and living out of the region were the most common reasons cited by surviving nonattendees for their failure to return for follow-up.

CONCLUSIONS

Studies reporting the long-term mortality after LVRS can be biased in the direction of underestimating the true value if they are compromised by incomplete follow-up.

The efficacy and side effects of gelatin-resorcinol formaldehyde-glutaraldehyde (GRFG) glue for preventing and sealing pulmonary air leakage

This study was conducted to examine the efficacy and side effects of gelatin-resorcinol formaldehyde-glutaraldehyde (GRFG) glue, when used for preventing or sealing pulmonary air leakage during lung surgery. Formaldehyde-glutaraldehyde (FG) jelly was prepared by mixing FG fluid with 2.5% carboxymethyl cellulose to increase its viscosity. A GRFG glue-spreading stapler was employed to prevent air leakage from the staple line when cutting emphysematous lung tissue in 26 patients, 25 of whom underwent video-assisted thoracoscopic surgery (VATS) and 1, open thoracotomy. A glue-sealing procedure was employed to stop existing pulmonary air leakage in a further 36 patients, 28 of whom underwent VATS and 8, open thoracotomy. The glue-spreading stapler technique prevented air leakage in all 26 patients (100%), while the glue-sealing procedure for pulmonary air leakage stopped air leakage in 31 of the 36 patients (86%). Two patients who underwent glue sealing for air leakage from a deeply cut lung surface suffered massive pulmonary air leakage on postoperative day (POD) 1 and 6, respectively, and required repeat surgery to suture the lung fistula. A transient fever of 38 degrees-39 degrees developed on POD 7 in 6 of the 62 patients (9.7%), but no other complications were observed. These results demonstrated that GRFG is safe and effective in preventing or stopping pulmonary air leakage in the peripheral lung, but not for stopping air leakage from a deeply cut lung.

Lung volume reduction surgery for emphysema

Over the past decades, extensive literature has been published regarding surgical therapies for advanced COPD. Lung-volume reduction surgery would be an option for a significantly larger number of patients than classic bullectomy or lung transplantation. Unfortunately, the initial enthusiasm has been tempered by major questions regarding the optimal surgical approach, safety, firm selection criteria, and confirmation of long-term benefits. In fact, the long-term follow-up reported in patients undergoing classical bullectomy should serve to caution against unbridled enthusiasm for the indiscriminate application of LVRS. Those with the worst long-term outcome despite favourable short-term improvements after bullectomy have consistently been those with the lowest pulmonary function and significant emphysema in the remaining lung who appear remarkably similar to those being evaluated for LVRS. With this in mind, the National Heart, Lung and Blood Institute partnered with the Health Care Finance Administration to establish a multicenter, prospective, randomized study of intensive medical management, including pulmonary rehabilitation versus the same plus bilateral (by MS or VATS), known as the National Emphysema Treatment Trial. The primary objectives are to determine whether LVRS improves survival and exercise capacity. The secondary objectives will examine effects on pulmonary function and HRQL, compare surgical techniques, examine selection criteria for optimal response, identify criteria to determine those who are at prohibitive surgical risk, and examine long-term cost effectiveness. It is hoped that data collected from this novel, multicenter collaboration will place the role of LVRS in a clearer perspective for the physician caring for patients with advanced emphysema.

Preoperative severity of emphysema predictive of improvement after lung volume reduction surgery: use of CT morphometry

STUDY OBJECTIVE

To determine how the volume and severity of emphysema measured by CT morphometry (CTM) before and after lung volume reduction surgery (LVRS) relates to the functional status of patients after LVRS.

DESIGN

A histologically validated CT algorithm was used to quantify the volume and severity of emphysema in 35 patients before and after LVRS: total lung volume (TLV), normal lung volume (< 6.0 mL gas per gram of tissue), volume of mild/moderate emphysema (ME; 6.0 to 10.2 mL gas per gram of tissue), volume of severe emphysema (> 10.2 mL gas per gram of tissue), surface area/volume (SA/V; meters squared per milliliter), and surface area (SA; meters squared). Outcome parameters included maximal cardiopulmonary exercise (CPX) performance in 21 patients and routine pulmonary function in all patients. We hypothesized that baseline CTM parameters predict response to LVRS and that the change in these parameters may offer insight into mechanisms of improvement.

PATIENTS AND INTERVENTION

Thirty-five patients with severe emphysema who had successful LVRS.

RESULTS

The significant decrease in TLV following LVRS was entirely accounted for by a decrease in severe emphysema. The SA/V and the SA both increased significantly following LVRS. The change in maximal CPX in watts following surgery correlated significantly with baseline values of severe emphysema (r = 0.60), which was collinear with TLV, and SA/V. The change in diffusing capacity of the lung for carbon monoxide revealed a significant positive linear relationship with preoperative severe emphysema (r = 0.37) and a negative relationship with ME (r = -0.37). Change in watts revealed a strong relationship with changes in severe emphysema (r = -0.75) and weaker but significant relationships with change in TLV, ME, SA/V, and SA. Other measures of pulmonary function revealed significant albeit less dominant relationships with baseline CTM and change in these indexes.

CONCLUSION

Using CTM, we have identified a close relationship between baseline severe emphysema, or change in severe emphysema, and the improvement in CPX after LVRS. These observations support a potential role of CTM in future clinical trials for predicting responders to LVRS and identifying mechanisms of improvement.

Acute respiratory failure after lung volume reduction surgery

In this study, we characterized patients who developed respiratory failure postoperatively after lung volume reduction surgery (LVRS). We retrospectively reviewed the records of 72 patients who underwent LVRS from February 1995 to February 1998, examining perioperative variables and complications. Twenty-one patients (29%) developed postoperative respiratory failure, five due to hypoxemia, nine due to hypercapnia, and seven secondary to hemodynamic instability. The hospital mortality was 33% among patients who developed respiratory failure. No preoperative clinical or physiologic variable (including percent ideal body weight, serum albumin, prednisone use, lung function, maximal O(2) uptake on exercise testing, 6-min walk distance, and hemodynamic parameters) was predictive of postoperative respiratory failure. Patients who developed respiratory failure were older (63 +/- 7 versus 57 +/- 8 yr, p = 0.01), had longer anesthesia time (188 +/- 96 versus 127 +/- 56 min, p = 0.001), had a higher incidence of coronary artery disease (40% versus 10%, p = 0.001) and performance of concomitant surgical procedures during the LVRS operation (40% versus 2%, p < 0.001) compared with those without respiratory failure. All patients who underwent simultaneous surgery, which were mostly for cardiac disease, developed respiratory failure. Risk factor analysis confirmed that older patients and those undergoing cardiac surgery combined with LVRS are at increased risk for postoperative respiratory failure.

Clinical evaluation of 99mTc-Technegas SPECT in thoracoscopic lung volume reduction surgery in patients with pulmonary emphysema

99mTc-Technegas (Tcgas) SPECT is useful for evaluating the patency of the airway and highly sensitive in detecting regional pulmonary function in pulmonary emphysema. The aim of this study is to evaluate regional ventilation impairment by this method pre and post thoracoscopic lung volume reduction surgery (LVRS) in patients with pulmonary emphysema.

METHODS

There were 11 patients with pulmonary emphysema. The mean age of patients was 64.1 years. All patients were males. LVRS was performed bilaterally in 8 patients and unilaterally in 3 patients. Post inhalation of Tcgas in the sitting position, the subjects were placed in the supine position and SPECT was performed. Distribution of Tcgas on axial images was classified into 4 types, A: homogeneous, B: inhomogeneous, C: hot spot, D: defect. Three slices of axial SPECT images, the upper, middle and lower fields were selected, and changes in deposition patterns post LVRS were scored (Tcgas score).

RESULTS

Post LVRS, dyspnea on exertion and pulmonary function tests were improved. Pre LVRS, inhomogeneous distribution, hot spots and defects were observed in all patients. Post LVRS, improvement in distribution was obtained not only in the surgical field and other fields, but also in the contralateral lung of unilaterally operated patients. In 5 patients some fields showed deterioration. The Tcgas score correlated with improvements in FEV1.0, FEV1.0% and %FEV1.0.

CONCLUSION

Tcgas SPECT is useful for evaluating changes in regional pulmonary function post LVRS.

Effects of Nd:YAG laser irradiation on morphometry and lung function in elastase-induced emphysema in rats

BACKGROUND & OBJECTIVE

Although thoracoscopic laser ablation therapy has been hailed as an effective surgical treatment for diffuse emphysema, no one has as yet made an in-depth study of the efficacy of this treatment. This investigation was undertaken to research the effects of laser pneumoplasty on an animal model of emphysema.

STUDY DESIGN/MATERIALS AND METHODS

Eight weeks after elastase treatment, the rats' left lungs were irradiated using contact Nd:YAG laser. Pulmonary function tests were performed 4 weeks after irradiation and the lungs were prepared for histologic examination.

RESULTS

Dense fibrous scars beneath the pleura were observed at 4 weeks after irradiation. Although mean linear intercept values of irradiated lungs were not much lower than those in the non-irradiated elastase-treated group, laser irradiation caused a significant decrease in lung volume. While there was no significant difference in quasistatic compliance, elastic recoil pressure of the lung increased to control levels at total lung capacity volume.

CONCLUSION

We conclude that laser therapy does not cause normalization of compliance, or improvement in the deeper part of the emphysematous lung, but rather a peripheral volume reduction and "encasement effect" on the lungs as a result of fibrotic scars.

Morphologic grading of emphysema is useful in the selection of candidates for unilateral or bilateral reduction pneumoplasty

OBJECTIVE

Radiologic morphology of emphysema proves useful in the selection of candidates for bilateral reduction pneumoplasty. We developed a simple morphologic grading system capable of identifying subsets of patients who had maximal functional improvement after unilateral or bilateral operation.

METHODS

Fifty-two patients who underwent unilateral (n=34) or bilateral (n=18) reduction pneumoplasty were evaluated. Emphysema morphology was visually scored by digital roentgenograms and high-resolution computed tomography. In each lung, severity of emphysema (ES), heterogeneity (DHT) and hyperinflation (DHF) degrees, were assessed. Asymmetric ratio of emphysema (ARE) between the lungs was expressed as: higher ES/lower ES scores. Morphometric data were correlated with absolute preoperative-postoperative FEV(1) change (DeltaFEV(1)).

RESULTS

No difference was found between the unilateral and the bilateral group for ES and DHT. DHF was greater in the bilateral group (3.1 vs. 2.7, P=0.02) whereas ARE was greater in the unilateral group (1.29 vs. 1. 05, P=0.0001). Stepwise logistic regression extracted as best predictors of maximal DeltaFEV(1), ARE (odds ratio=238, Wald test P=0.04) in the unilateral group, and DHT (odds ratio=24, P=0.03) in the bilateral group. Unilateral group DeltaFEV(1) was greater in patients with ARE>/=1.3 (0.44 vs. 0.24 l, P=0.02). Bilateral group DeltaFEV(1) was greater in patients with DHT>1 (0.50 vs. 0.31 l, P=0. 03). No difference was found when comparing DeltaFEV(1) resulting from unilateral RP and ARE>/=1.3, and bilateral RP (0.44 vs. 0.41 l, not significant).

CONCLUSIONS

This morphologic grading system identified subsets of patients who had maximal functional benefit from unilateral or bilateral reduction pneumoplasty and might be useful in the preoperative screening of candidates for either approach.

Interactions of regional respiratory mechanics and pulmonary ventilatory impairment in pulmonary emphysema: assessment with dynamic MRI and xenon-133 single-photon emission CT

STUDY OBJECTIVES

Dynamic MRI and (133)Xe single-photon emission CT (SPECT) were used to directly evaluate the interaction of regional respiratory mechanics and lung ventilatory function in pulmonary emphysema.

METHODS

Respiratory diaphragmatic and chest wall (D/CW) motions were analyzed by sequential MRI of fast-gradient echo pulse sequences during two to three respiratory cycles in 28 patients with pulmonary emphysema, including 9 patients undergoing lung volume reduction surgery (LVRS). The extent of air trapping in the regional lung was quantified by the (133)Xe retention index (RI) on three-dimensional (133)Xe SPECT displays.

RESULTS

By contrast to healthy subjects (n = 6) with regular, synchronous D/CW motions, pulmonary emphysema patients showed reduced, irregular, or asynchronous motions in the hemithorax or location with greater (133)Xe retention, with significant decreases in the maximal amplitude of D/CW motions (MADM and MACWM; p < 0.0001 and p < 0.05, respectively). The removal of (133)Xe retention sites by LVRS effectively and regionally improved D/CW motions in nine patients, with significant increases in MADM and MACWM (p < 0.01 and p < 0.001, respectively). In a total of 40 studies of the 28 patients including post-LVRS studies, normalized MADM and MACWM correlated with percent predicted FEV(1) (r = 0.881, p < 0.0001; and r = 0.906, p < 0.0001, respectively), and also with (133)Xe RI in each hemithorax (r = -0.871, p < 0 0.0001; and r = -0.901, p < 0 0.0001, respectively.)

CONCLUSIONS

This direct comparison of regional respiratory mechanics with lung ventilation demonstrated a close interaction between these impairments in pulmonary emphysema. The present techniques provide additional sensitivity for evaluating pathophysiologic compromises in pulmonary emphysema, and may also be useful for selecting resection targets for LVRS and for monitoring the effects.

Risk analysis for thoracoscopic lung volume reduction: a multi-institutional experience

OBJECTIVE

Most reports of thoracoscopic lung volume reduction (TLVR) are relatively small and early experiences from a single institution, factors which limit both the statistical validity and the applicability to the population at large. In order to address these shortcomings we undertook an analysis of the TLVR experience at five separate institutions to assess operative morbidity and identify predictors of mortality.

METHODS

Questionnaires were sent to four groups of surgical investigators at five institutions actively performing TLVR. Data was requested regarding preoperative, operative and postoperative parameters. Twenty-five potential predictors of mortality were analyzed and seven proved to be at least marginally significant (P<0.10). These parameters were entered into a stepwise logistic regression analysis to identify independent predictors.

RESULTS

The 682 patients (415 males, 267 females, mean age 64.0 years) underwent unilateral (410) or bilateral (272) TLVRs. Overall, operative mortality was 6% with half of the deaths resulting from respiratory causes. The remaining patients were discharged to home (88%), a rehabilitation facility (4%) or a ventilator facility (2%). There were 25 perioperative factors chosen representing clinically important indices such as spirometry, oxygenation, functional status, clinical and demographic variables. Univariate analysis identified seven variables as predictors of mortality (P<0.10) and these were entered into a stepwise logistic regression analysis. Only age, 6-min walk, gender (male 8%, female 3% mortality) and the procedure performed (unilateral 4.6%, bilateral 8%) were independent predictors while preoperative steroid therapy, preoperative oxygen administration, and time since smoking cessation dropped out of the model. The specific institution, learning curve (early vs. late experience), type of lung disease, spirometric indices and predicted maximum VO(2) were not significant predictors.

CONCLUSION

This experience suggests that unilateral and bilateral lung volume reduction procedure can be performed with acceptable morbidity and mortality. Although age, gender, exercise capacity and the procedure performed are all independent predictors of mortality, the risk of operative death did not appear excessive in this fragile patient subset.