Short-term and long-term outcomes after bilateral lung volume reduction surgery : prediction by quantitative CT

Lung volume reduction surgery: from National Emphysema Treatment Trial to non-intubated awake video-assisted thoracoscopic surgery

Chronic obstructive pulmonary disease (COPD) is a major public health problem. Loss of elastic recoil, hyperinflation and obstruction of the expiratory airflow lead to an increased breathing work, which results in dyspnea during minimal physical activity of the patients. Reduction of the lung volume in these patients leads to improvement of dyspnea, physical activity and quality of life in these patients. Beside endoscopic lung volume reduction (ELVR), lung volume reduction surgery (LVRS) represents an important and valuable treatment option for patients with advanced lung emphysema. Since the National Emphysema Treatment Trial (NETT), thoracic surgery experienced a remarkable evolution of the surgical techniques enabling safe surgery and quick recovery in this critically ill patient cohort. A paradigm shift from open surgical approaches to most minimally invasive techniques accompanied by improvement of anesthesiologic management of these patients was evident. Moreover, indications for LVRS, which were originally described in the NETT, were extended to apply for further groups of patients with advanced lung emphysema, enabling significant clinical improvement in well-selected patients with a low perioperative morbidity and mortality. The current review will give an overview of the historical approaches for LVRS, highlight the indications for LVRS and discuss the development of the surgical approaches.

A Patient with GOLD Stage 3 COPD « cured » by One-Way Endobronchial Valves

Lung hyperinflation is a main determinant of dyspnoea in patients with chronic obstructive pulmonary disease (COPD). Surgical or bronchoscopic lung volume reduction are the most efficient therapeutic approaches for reducing hyperinflation in selected patients with emphysema. We here report the case of a 69-year old woman with COPD (GOLD stage 3-D) referred for lung volume reduction. She complained of persistent disabling dyspnoea despite appropriate therapy. Chest imaging showed marked emphysema heterogeneity as well as severe hyperinflation of the right lower lobe. She was deemed to be a good candidate for bronchoscopic treatment with one-way endobronchial valves. In the absence of interlobar collateral ventilation, 2 endobronchial valves were placed in the right lower lobe under general anaesthesia. The improvement observed 1 and 3 months after the procedure was such that the patient no longer met the pulmonary function criteria for COPD. The benefit persisted after 3 years.

Lung volume reduction surgery beyond the NETT selection criteria

Lung volume reduction surgery (LVRS) for symptomatic patients with advanced emphysema was proven to be successful in a large randomized multi-center trial (NETT) and in several smaller randomized single center trials. This evidence primarily concerns patients with heterogeneous, upper-lobe predominant emphysema and low exercise tolerance within certain selection criteria regarding lung function values. As the most important effect of LVRS is generated by reducing the hyperinflation, even patients with homogeneous emphysema morphology profit from the procedure. Simultaneously, by removing distended and functionless areas in heterogeneous emphysema, also patients with seriously impaired diffusion capacity, moderate pulmonary arterial hypertension, a history of previous LVRS and alpha-1-antitrypsin-deficiency (AATD) can be considered as candidates for (re-)-LVRS. This article summarizes indications for LVRS in these various subtypes of emphysema patients.

Emphysema and lung volume reduction: the role of radiology

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. One of the main findings is pulmonary emphysema in association with chronic bronchitis. Clinical signs, pulmonary function tests and imaging are the current used methods to diagnose and stage emphysema. Lung volume reduction (LVR) and endoscopic lung volume reduction (ELVR) are the current therapeutic options beside lung transplantation in cases of severe emphysema. Nowadays imaging is one of the key factors for the success of these therapies. Especially quantitative computed tomography (CT) with its increasing possibilities has become a viable tool, providing detailed information about distribution and heterogeneity of emphysema. Other imaging techniques like dual-energy CT (DECT) and functional magnetic resonance (MR) have shown to add functional information. These structural and functional information support thoracic surgeons and interventional pulmonologists in selecting patients and optimizing LVR procedures but also enables the development of new endobronchial therapies. Imaging will further improve the individual outcome by supporting the choice of optimal therapy.

Phenotyping emphysema and airways disease: Clinical value of quantitative radiological techniques

The pathophysiology of chronic obstructive pulmonary disease (COPD) and Alpha one antitrypsin deficiency is increasingly recognised as complex such that lung function alone is insufficient for early detection, clinical categorisation and dictating management. Quantitative imaging techniques can detect disease earlier and more accurately, and provide an objective tool to help phenotype patients into predominant airways disease or emphysema. Computed tomography provides detailed information relating to structural and anatomical changes seen in COPD, and magnetic resonance imaging/nuclear imaging gives functional and regional information with regards to ventilation and perfusion. It is likely imaging will become part of routine clinical practice, and an understanding of the implications of the data is essential. This review discusses technical and clinical aspects of quantitative imaging in obstructive airways disease.

Lung volume reduction of pulmonary emphysema: the radiologist task

PURPOSE OF REVIEW

Several lung volume reduction (LVR) techniques have been increasingly evaluated in patients with advanced pulmonary emphysema, especially in the last decade. Radiologist plays a pivotal role in the characterization of parenchymal damage and, thus, assessment of eligibility criteria. This review aims to discuss the most common LVR techniques, namely LVR surgery, endobronchial valves, and coils LVR, with emphasis on the role of computed tomography (CT).

RECENT FINDINGS

Several trials have recently highlighted the importance of regional quantification of emphysema by computerized CT-based segmentation of hyperlucent parenchyma, which is strongly recommended for candidates to any LVR treatment. In particular, emphysema distribution pattern and fissures integrity are evaluated to tailor the choice of the most appropriate LVR technique. Furthermore, a number of CT measures have been tested for the personalization of treatment, according to imaging detected heterogeneity of parenchymal disease.

SUMMARY

CT characterization of heterogeneous parenchymal abnormalities provides criteria for selection of the preferable treatment in each patient and improves outcome of LVR as reflected by better quality of life, higher exercise tolerance, and lower mortality.

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.

Effects of bronchoscopic lung volume reduction using transbronchial infusion of autologous blood and thrombin in patients with severe chronic obstructive pulmonary disease

BACKGROUND

Existing medical treatments have limitations in the management of very severe chronic obstructive pulmonary disease (COPD).

METHODS

We performed bronchoscopic lung volume reduction (BLVR) using transbronchial infusion of autologous blood and thrombin (BLVR with blood) in three patients with very severe COPD whose dyspnea could not be relieved by maximum medical management. Two patients underwent BLVR with blood in the left and right lungs at intervals of a half-year or a year, and one patient underwent this procedure in only the right lung. We assessed the changes in pulmonary function, exercise capacity and quality of life before and after BLVR with blood in a total of five procedures.

RESULTS

The subjects were 58- to 74-year-old males. Their forced expiratory volume in one second (FEV1) percent predicted ranged from 14.8% to 23.4%. BLVR with blood achieved significant improvements as follows (values before → after the procedure, mean ± standard deviation): FEV1 0.45r the L → 0.76r the L (P=0.004), inspiratory capacity 1.50cityo L → 2.05±.05c L (P=0.015), 3-minute walk test 46.8nuteo m → 89.6±34.5 m (P=0.004). Lung function peaked several months after BLVR with blood and returned to nearly the baseline level in 6 months, but exercise capacity was better than that at baseline for at least 12 months. St. George's Respiratory Questionnaire (SGRQ), measured in two patients before and 12 months after the procedure, showed remarkable improvements (-15.6 and -11.9 units).

CONCLUSIONS

BLVR with blood is an effective palliative treatment for very severe COPD.

Assessment of volume reduction effect after lung lobectomy for cancer

BACKGROUND

Lung lobectomy results in an unexpected improvement of the remaining lung function in some patients with moderate-to-severe emphysema. Because the lung function is the main limiting factor for therapeutic decision making in patients with lung cancer, it may be advantageous to identify patients who may benefit from the volume reduction effect, particularly those with a poor functional reserve.

METHODS

We measured the regional distribution of the emphysematous lung and normal lung using quantitative computed tomography in 84 patients undergoing lung lobectomy for cancer between January 2010 and December 2012. The volume reduction effect was diagnosed using a combination of radiologic and spirometric parameters.

RESULTS

Eight patients (10%) were favorably affected by the volume reduction effect. The forced expiratory volume in one second increased postoperatively in these eight patients, whereas the forced vital capacity was unchanged, thus resulting in an improvement of the airflow obstruction postoperatively. This improvement was not due to a compensatory expansion of the remaining lung but was associated with a relative decrease in the forced end-expiratory lung volume. According to a multivariate analysis, airflow obstruction and the forced end-expiratory lung volume were independent predictors of the volume reduction effect.

CONCLUSIONS

A combined assessment using spirometry and quantitative computed tomography helped to characterize the respiratory dynamics underlying the volume reduction effect, thus leading to the identification of novel predictors of a volume reduction effect after lobectomy for cancer. Verification of our results by a large-scale prospective study may help to extend the indications for lobectomy in patients with oncologically resectable lung cancer who have a marginal pulmonary function.

Quantitative Emphysema Distribution in Anatomic and Non-anatomic Lung Regions

PURPOSE

The change of emphysema distribution with increasing COPD severity is not yet assessed. Especially, involvement of the upper aspect of the lower lobe is unknown. The primary aim was to quantitatively determine regional distribution of emphysema in anatomically (lung lobes) and non-anatomically defined lung regions (upper/lower lung halves as well as core and rind regions) in a cohort covering equally all COPD severity stages using CT.

MATERIAL AND METHODS

Basically 100 CT data sets were quantitatively evaluated for regional distribution of emphysema. Emphysema characteristics (emphysema index, mean lung density and 15th percentile of the attenuation values of lung voxels) were compared (t-test) in: upper lobes vs. upper halves, lower lobes vs. lower halves, core vs. rind region.

RESULTS

In patients with ≤ GOLD II, a significantly higher emphysema burden was found in the upper lobes as compared to upper halves. In subjects with GOLD III/IV the differences were not significant for all emphysema characteristics. A high difference between lobes and halves in subjects with ≤ GOLD II was found, in contrast to low difference in higher GOLD stages.

CONCLUSIONS

Lobar segmentation provides improved characterization of cranio-caudal emphysema distribution compared to a non-anatomic approach in subjects up to GOLD stage II.

Outcomes in lung transplantation after previous lung volume reduction surgery in a contemporary cohort

OBJECTIVES

Lung volume reduction surgery (LVRS) provides palliation and improved quality of life in select patients with end-stage chronic obstructive pulmonary disease (COPD). The effect of previous LVRS on lung transplant outcomes has been inadequately studied. We report our experience in the largest single institution series of these combined procedures.

METHODS

The records of 472 patients with COPD undergoing lung transplantation or LVRS between 1995 and 2010 were reviewed. Outcomes of patients undergoing transplant after LVRS were compared with outcomes of patients undergoing transplant or LVRS alone. Survival was compared using log-rank tests and the Kaplan-Meier method.

RESULTS

Demographics, comorbidities, and spirometry were similar at the time of transplantation. Patients who had undergone lung transplant after LVRS had longer transplant operative times (mean 4.4 vs 5.6 hours; P = .020) and greater hospital length of stay (mean 17.6 vs 29.1 days; P = .005). Thirty-day mortality and major morbidity were similar. Posttransplant survival was reduced for transplant after LVRS (median, 49 months; 95% confidence interval [CI], 16, 85 months) compared with transplant alone (median, 96 months; 95% CI, 82, 106 months; P = .008). The composite benefit of combined procedures, defined as bridge from LVRS to transplant of 55 months and posttransplant survival of 49 months (total 104 months), was comparable with survival of patients undergoing either procedure alone.

CONCLUSIONS

Lung transplant after LVRS leads to minimal additional perioperative risk. The reduced posttransplant survival in patients undergoing combined procedures is in contradistinction to reports from other smaller series. When determining the best surgical treatment for patients with more severe disease, the benefit of LVRS before transplant should be weighed against the consequence of reduced posttransplant survival.

Phenotyping of chronic obstructive pulmonary disease using the modified Bhalla scoring system for high-resolution computed tomography

BACKGROUND

Identifying different phenotypes of chronic obstructive pulmonary disease (COPD) is important for both therapeutic options and clinical outcome of the disease.

OBJECTIVE

To characterize the phenotypes of COPD according to high-resolution computed tomography (HRCT) findings; and to correlate HRCT scores obtained using the modified Bhalla scoring system with clinical and physiological indicators of systemic inflammation.

METHODS

The present study included 80 consecutive patients with stable COPD. HRCT scans were evaluated by two independent radiologists according to the modified Bhalla scoring system.

RESULTS

Fifty-four patients exhibited morphological changes on HRCT examination while 26 had no pathological findings. Patients with HRCT findings had lower spirometric measurements and higher levels of inflammation, and reported more exacerbations in the previous year compared with patients with no findings on HRCT. Patients with morphological changes were classified into one of three groups according to their HRCT phenotype(s): emphysema (E) only, E + bronchiectasis (B)⁄peribronchial thickening (PBT) or B⁄PBT only. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1⁄FVC ratio, C-reactive protein (CRP) levels and the number of exacerbations among the groups were significantly different. Pairwise comparisons between the E only and E+B⁄PBT groups showed significantly lower FVC, FEV1 and FEV1⁄FVC values, and higher CRP levels and number of exacerbations compared with the B⁄PBT group. No significant differences were found between the E+B⁄PBT and the B⁄PBT groups. An inverse correlation was found between the total HRCT score and FVC, FEV1 and FEV1⁄FVC; the correlation was positive with CRP level, erythrocyte sedimentation rate and number of exacerbations.

CONCLUSION

The present study exposed the intimate relationship between phenotype(s) characterized by HRCT and scoring for morphological abnormalities; and clinical and functional parameters and inflammatory markers. The inclusion of HRCT among routine examinations for COPD may provide significant benefits both in the management and prognosis of COPD patients.

Racial differences in CT phenotypes in COPD

BACKGROUND

Whether African Americans (AA) are more susceptible to COPD than non-Hispanic Whites (NHW) and whether racial differences in disease phenotype exist is controversial. The objective is to determine racial differences in the extent of emphysema and airway remodeling in COPD.

METHODS

First, 2,500 subjects enrolled in the COPDGene study were used to evaluate racial differences in quantitative CT (QCT) parameters of% emphysema, air trapping and airway wall thickness. Independent variables studied included race, age, gender, education, BMI, pack-years, smoking status, age at smoking initiation, asthma, previous work in dusty job, CT scanner and center of recruitment.

RESULTS

Of the 1,063 subjects with GOLD Stage II-IV COPD, 200 self-reported as AA. AAs had a lower mean% emphysema (13.1% vs. 16.1%, p = 0.005) than NHW and proportionately less emphysema in the lower lung zones. After adjustment for covariates, there was no statistical difference by race in air trapping or airway wall thickness. Measured QCT parameters were more predictive of poor functional status in NHWs compared to AAs.

CONCLUSIONS

AAs have less emphysema than NHWs but the same degree of airway disease. Additional factors not easily assessed by current QCT techniques may account for the poor functional status in AAs.

The effect of lung volume reduction surgery on chronotropic incompetence

BACKGROUND

Chronotropic incompetence (CI) is a marker of poor prognosis in patients with COPD. Treatments that improve pulmonary function and exercise capacity may affect CI. Objectives are to evaluate CI before and after lung volume reduction surgery (LVRS) and determine if changes in CI are associated with changes in pulmonary function and exercise capacity.

METHODS

We performed a retrospective review of 75 patients who underwent LVRS and who had complete cardiopulmonary exercise testing and concurrent pulmonary function tests two months before and about 6 months after surgery. Additionally we evaluated 28 control patients that were randomized to medical treatment as part of the National Emphysema Treatment Trial at our center. We studied CI using the percent of predicted heart rate reserve=(heart rate peak-heart rate rest)/((208-0.7×age)-heart rate rest)×100, before and after surgery and compared it to the control group.

RESULTS

Mean percent of predicted heart rate reserve improved from 41% to 50% (p-value <0.001) after LVRS, while the control group did not change. The mean forced vital capacity and expiratory volume in 1s, peak oxygen consumption, carbon dioxide production, ventilation, tidal volume and maximal workload all improved in the surgery group, while the controls did not improve.

CONCLUSIONS

CI improves after LVRS in a population of patients with COPD. CI improvements are associated with the increases in pulmonary function and exercise capacity. This improvement is seen in a domain of known cardiopulmonary impairment prior to surgery that improves as a positive response to the therapy of LVRS.

Quantitative computed tomography in COPD: possibilities and limitations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by chronic airflow limitation. Unraveling of this heterogeneity is challenging but important, because it might enable more accurate diagnosis and treatment. Because spirometry cannot distinguish between the different contributing pathways of airflow limitation, and visual scoring is time-consuming and prone to observer variability, other techniques are sought to start this phenotyping process. Quantitative computed tomography (CT) is a promising technique, because current CT technology is able to quantify emphysema, air trapping, and large airway wall dimensions. This review focuses on CT quantification techniques of COPD disease components and their current status and role in phenotyping COPD.

Multidetector high-resolution computed tomography of the lungs: protocols and applications

Advances in computed tomography (CT) scanner technology have made isotropic volumetric, multiplanar high-resolution lung imaging possible in a single breath-hold, a significant advance over the incremental high-resolution CT (HRCT) technique in which noncontiguous images sampled the lung, but lacked anatomic continuity. HRCT of the lungs is an established imaging technique for the diagnosis and management of interstitial lung disease, emphysema, and small airway disease, providing a noninvasive detailed evaluation of the lung parenchyma, and providing information about the lungs as a whole and focally. In addition to having a high degree of specificity for diagnosing conditions such as emphysema, sarcoidosis, usual interstitial pneumonitis, Langerhans cell histiocytosis, and small airway disease, there is a growing body of medical evidence to support the use of HRCT findings or diagnosis to predict patient prognosis. In this article, we review the technique, advantages, and clinical applications of the current HRCT technique.

Accuracy of emphysema quantification performed with reduced numbers of CT sections

OBJECTIVE

The purpose of this study was to assess the accuracy of emphysema measurements obtained from systematic samples of evenly spaced CT images compared with measurements obtained from the entire scan.

MATERIALS AND METHODS

Evenly spaced transverse sections from the CT studies of 136 heavy smokers who underwent screening for lung cancer in the National Lung Screening Trial and of 112 subjects who underwent imaging before lung volume reduction surgery were sampled retrospectively. The samples were acquired both by selection of specific numbers of evenly spaced images and by selection of images at specific distance intervals. The percentage of lung pixels with attenuation below specific thresholds was used as an emphysema index. The image sample error was determined as the difference in emphysema index between the image samples and the entire scan.

RESULTS

The largest absolute image sample errors in the National Lung Screening Trial cohort with image sample sizes of five, 10, and 20 were 2.2, 0.8, and 0.5 index percentage points, respectively, at 1-mm section thickness (-960 HU threshold), and 2.6, 1.1, and 0.5 index percentage points at 5-mm section thickness (-930 HU threshold). The largest errors in the lung volume reduction surgery cohort for image sample sizes of five and 10 were 5.6 and 2.3 index percentage points at 8- to 10-mm section thickness (-900 HU threshold). Image sample errors were equivalent for the two sampling methods.

CONCLUSION

Systematic sampling resulted in very small errors in emphysema quantification and may be useful for decreasing radiation exposure in clinical research studies of emphysema.

Structural and functional changes of peripheral muscles in chronic obstructive pulmonary disease patients

PURPOSE OF REVIEW

The purpose of this review is to identify new advances in our understanding of skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

Recent studies have confirmed the relevance of muscle dysfunction as an independent prognosis factor in COPD. Animal studies have shed light on the molecular mechanisms governing skeletal muscle hypertrophy/atrophy. Recent evidence in patients with COPD highlighted the contribution of protein breakdown and mitochondrial dysfunction as pathogenic mechanisms leading to muscle dysfunction in these patients.

SUMMARY

COPD is a debilitating disease impacting negatively on health status and the functional capacity of patients. COPD goes beyond the lungs and incurs significant systemic effects among which muscle dysfunction/wasting is one of the most important. Muscle dysfunction is a prominent contributor to exercise limitation, healthcare utilization and an independent predictor of morbidity and mortality. Gaining more insight into the molecular mechanisms leading to muscle dysfunction/wasting is key for the development of new and tailored therapeutic strategies to tackle skeletal muscle dysfunction/wasting in COPD patients.

Cost-effectiveness of lung volume reduction surgery

Lung volume reduction surgery (LVRS) is a costly procedure that can improve quality and quantity of life. Given the prevalence of emphysema, the costs involved with its management, and resource constraints on all health care delivery systems, evaluating the cost-effectiveness of LVRS is important. In this article, we describe the purposes and principles of cost-effectiveness analysis and how those principles were applied in evaluating LVRS. We present the results of the cost-effectiveness analysis that was conducted alongside the National Emphysema Treatment Trial and other economic studies of LVRS and discuss how these should be interpreted in the context of current reimbursement guidelines.

Tiotropium bromide

Therapy with bronchodilators forms the pharmacologic foundation of the treatment of patients with COPD. Bronchodilators can significantly lessen dyspnea, increase airflow, improve quality of life, and enhance exercise performance. While bronchodilators decrease airway resistance and lessen dynamic hyperinflation in patients with COPD, they have not been shown to alter the rate of decline in FEV₁ over time, or improve patient survival. Fairly recently, a long-acting, once-daily anticholinergic medication, tiotropium bromide, has been developed which may improve symptom management in COPD patients. This paper reviews anticholinergic pharmacologic therapy for patients with COPD focusing on tiotropium bromide, and discusses treatment strategies based on disease stage. It is important to recognize that while bronchodilators improve symptoms, a multimodality treatment approach including respiratory and rehabilitative therapy, nutrition services, psychosocial counseling, and surgical care, is often necessary for the best possible care of patients with COPD.

Functional results of unilateral lung volume reduction surgery in alpha1-antitrypsin deficient patients

Lung volume reduction surgery (LVRS) has been shown to improve lung function and exercise tolerance in patients with severe emphysema. Some predictors of poor outcome have been described but the role of alpha₁-antitrypsin (α₁-AT) deficiency is still not well known. The aim of this study was to analyze the results of unilateral LVRS in our center according to the α₁-AT status. The results of LVRS in 17 deficient patients and 35 nondeficient patients were analyzed at 3–6 months and 1 year after surgery. Compared with baseline, a significant improvement of FEV₁, partial pressure in arterial blood (PaO₂), dyspnea score and walking distance was observed in the two groups at 3–6 months after surgery and the studied parameters remained significantly improved at 1 year in the nondeficient group. By contrast, PaO₂ and walking distance returned towards baseline in the deficient group at 1 year whereas improvement of FEV₁ and dyspnea score was persistent. Mean values of FEV₁ at baseline, 3–6 months, and 1 year were 22 ± 6%, 29 ± 11%, and 26 ± 9% and 28 ± 12%, 38 ± 17%, and 40 ± 17% predicted in the deficient group and in the non-deficient group, respectively. In conclusion, the functional benefit is short-lasting in α₁-AT deficient patients after unilateral LVRS.

Lessons from the National Emphysema Treatment Trial

Medicare coverage for lung volume reduction surgery has been approved recently by the Centers for Medicare and Medicaid Services for the treatment of severe emphysema. The scientific basis for this approval stems largely from findings of the National Emphysema Treatment Trial (NETT). The purpose of this article is to review the contributions of the NETT to the management of chronic obstructive pulmonary disease.

Interobserver Variability in the Determination of Upper Lobe-Predominant Emphysema

BACKGROUND

Appropriateness for lung volume reduction surgery is often determined based on the results of high-resolution CT (HRCT) scanning of the chest. At many centers, radiologists and pulmonary physicians both review the images, but the agreement between readers from these specialties is not known.

METHODS

Two thoracic radiologists and three pulmonologists retrospectively reviewed the HRCT scans of 30 patients with emphysema involved in two clinical studies at our institution. Each reader assigned an emphysema severity score and assessed upper lobe predominance, using a methodology similar to that of the National Emphysema Treatment Trial. In addition, the percentage of emphysema at -910 Hounsfield units was objectively determined by density mask analysis.

RESULTS

For the emphysema severity scores, (Spearman) correlation between readers ranged from 0.59 (p = 0.0005) to 0.87 (p < 0.0001), with generally stronger correlations among readers from the same medical specialty. Emphysema severity scores were significantly correlated with prebronchodilator and postbronchodilator spirometry findings, as well as with density mask analysis. In the assessment of upper lobe predominance, kappa statistics for agreement ranged from 0.20 (p = 0.4) to 0.60 (p = 0.0008). Examining all possible radiologist-pulmonologist pairs, the two readers agreed in their assessments of emphysema distribution in 75% of the comparisons. Readers agreed on upper lobe-predominant disease in 9 of the 10 patients in which regional density mask analysis clearly showed upper lobe predominance.

CONCLUSIONS

In a group of patients with varying emphysema severity, interobserver agreement in the determination of upper lobe-predominant disease was poor. Agreement between readers tended to be better in cases with clear upper lobe predominance as determined by densitometry.

Long-term follow-up of patients receiving lung-volume-reduction surgery versus medical therapy for severe emphysema by the National Emphysema Treatment Trial Research Group

BACKGROUND

The National Emphysema Treatment Trial defined subgroups of patients with severe emphysema in whom lung-volume-reduction surgery (LVRS) improved survival and function at 2 years. Two additional years of follow-up provide valuable information regarding durability.

METHODS

A total of 1218 patients with severe emphysema were randomized to receive LVRS or medical treatment. We present updated analyses (4.3 versus 2.4 years median follow-up), including 40% more patients with functional measures 2 years after randomization.

RESULTS

The intention-to-treat analysis of 1218 randomized patients demonstrates an overall survival advantage for LVRS, with a 5-year risk ratio (RR) for death of 0.86 (p = 0.02). Improvement was more likely in the LVRS than in the medical group for maximal exercise through 3 years and for health-related quality of life (St. George's Respiratory Questionnaire [SGRQ]) through 4 years. Updated comparisons of survival and functional improvement were consistent with initial results for four clinical subgroups of non-high-risk patients defined by upper-lobe predominance and exercise capacity. After LVRS, the upper-lobe patients with low exercise capacity demonstrated improved survival (5-year RR, 0.67; p = 0.003), exercise throughout 3 years (p < 0.001), and symptoms (SGRQ) through 5 years (p < 0.001 years 1 to 3, p = 0.01 year 5). Upper-lobe-predominant and high-exercise-capacity LVRS patients obtained no survival advantage but were likely to improve exercise capacity (p < 0.01 years 1 to 3) and SGRQ (p < 0.01 years 1 to 4).

CONCLUSIONS

Effects of LVRS are durable, and it can be recommended for upper-lobe-predominant emphysema patients with low exercise capacity and should be considered for palliation in patients with upper-lobe emphysema and high exercise capacity.

Lung volume reduction surgery for emphysema: What the radiologist needs to know

Imaging plays a pivotal role in the selection of patients for the surgical treatment of emphysema. In this article, the imaging features of emphysema are reviewed along with the surgical options for treatment. Particular emphasis is given to lung volume reduction surgery as this technique has gained wide acceptance within the thoracic surgical community in recent years. Radiologists need to have an understanding of which patients may be potentially suitable for this technique.

Quantitative computed tomography of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is described as airflow limitation that is not fully reversible. Quantitative assessment of structural changes within the lung that are responsible for this airflow limitation has relied on the examination of tissue obtained from surgical or postmortem specimens. However, in the past two decades, researchers have developed novel and robust tools to measure the structure of the lung parenchyma and airway wall by using computed tomographic (CT) scans, which do not require the removal of lung tissue. These techniques are extremely important because they allow longitudinal studies of the pathogenesis of COPD and the assessment of therapeutic interventions. Another application of this approach is that it potentially allows phenotyping of individuals who predominately have emphysema or small-airway disease, which may be important for the evaluation of pathogenesis and prescription of treatment options. This review describes some of these CT techniques for quantitative assessment of lung structure.

Perfil radiológico do candidato ideal à cirurgia redutora de volume pulmonar no enfisema: uma revisão sistemática

INTRODUÇÃO: A cirurgia redutora de volume pulmonar é uma alternativa terapêutica para o enfisema pulmonar avançado. A avaliação radiológica do tipo e distribuição do enfisema parece ser o principal critério de indicação cirúrgica, além da função pulmonar. OBJETIVO: Determinar o nível de evidência científica referente ao padrão radiológico do candidato ideal à cirurgia redutora de volume pulmonar. MÉTODO: Revisão sistemática da literatura entre janeiro de 1994 e janeiro de 2004, utilizando as bases de dados: MEDLINE, EMbase, LILACS, The Cochrane Library e EBM Reviews. RESULTADOS: Foram identificados 208 artigos e 16 deles preenchiam os critérios do estudo. Destes, dois eram randomizados (um multicêntrico, denominado National Emphysema Treatment Trial, envolvendo 1.218 pacientes; e outro que, embora randomizado, com apenas 30 pacientes). Os 14 remanescentes eram estudos observacionais. O National Emphysema Treatment Trial identificou um subgrupo de pacientes de prognóstico favorável, quando submetidos à cirurgia redutora de volume pulmonar, formado por portadores de enfisema pulmonar avançado e heterogêneo, com predomínio nos lobos superiores, na presença de hiperdistensão pulmonar difusa e baixa capacidade para exercícios físicos. O padrão dos resultados dos demais estudos foi consistente na análise individual, apesar de sua heterogeneidade. Benefício cirúrgico, taxas de mortalidade e qualidade de vida também foram mensurados nos estudos observacionais. CONCLUSÃO: O perfil radiológico caracterizado pelo tipo de enfisema, sua heterogeneidade, distribuição e presença de hiperdistensão difusa, ao lado do nível de gravidade, representa o principal fator preditor de bom resultado cirúrgico. Esta recomendação tem o nível de evidência B, pela escassez de trabalhos na literatura.

Model-based versus clinical prediction of the spirometric response to lung volume reduction surgery

BACKGROUND

Lung volume reduction surgery (LVRS) improves symptoms and lung function in selected patients with severe emphysema.

OBJECTIVES

We investigated whether models based on physiologic and radiologic predictors discriminated patients with a favorable from those with a poor spirometric response to LVRS.

METHODS

Data of a derivation cohort of 70 patients who had previously undergone LVRS served to develop two types of prediction models, lookup functions and logistic regression equations. Presence or absence of improvement in forced expiratory volume in 1 s (FEV1) > or =300 ml and forced vital capacity (FVC) > or =500 ml represented dichotomous outcomes. The residual volume/total lung capacity ratio, CT-radiological emphysema heterogeneity scores and diffusing capacity, a marker of emphysema severity, were the predictors. Models were used to predict spirometric outcomes for a validation cohort of 60 emphysema patients referred for LVRS. Furthermore, the surgeon preoperatively estimated outcomes based on all available clinical data but blinded to model predictions. Spirometric changes within 6 months following surgery were compared to predictions.

RESULTS

Median FEV1 in the validation cohort increased from 0.69 to 1.00 liters (+41%), and FVC from 2.07 to 2.78 liters (+29%; p < 0.05 for changes). Lookup functions and logistic regression equations identified patients experiencing major increases in FEV1 > or =300 ml and FVC > or =500 ml with an accuracy quantified by areas under the receiver-operating characteristic curves of 0.72 to 0.76 (all areas >0.5, p < 0.05). Predictions by the surgeon had an accuracy of 0.71 to 0.78 (p = NS vs. models).

CONCLUSIONS

The accuracy of models based on three predictors was fair and similar to assessment by an experienced surgeon based on all available clinical information. Prediction models may contribute to the consistent assessment of LVRS candidates.

[Body mass, dyspnea, and quality of life as success predictors in emphysema surgery for reduction of pulmonary volume]

OBJECTIVES

Lung volume reduction surgery has recently been proposed as a palliative treatment for advanced emphysema. Some patients improve and others remains the same, being debated at this time the factors that predict improvement. The purpose of this work is to find predictive factors for positive response in patients operated with this surgery.

MATERIAL AND METHODS

Patients with positive response (7 patients) and patients without positive response (5 patients) have been compared in our series of lung volume reduction surgery (12 patients). Positive response to surgery was defined as Delta FEV1 > or = 15%, dyspnea transitional index (Mahler scale) > or = 3, and improvement in the scoring surgery of quality of life for chronic respiratory disease questionnaire (Guyatt and Güell) > or = 1.5 3 months after the surgery. Basal values of FEV1, FEF50/FIF50%, hyperinsufflation degree, heterogeneity, PaO2, PaCO2, type of surgery, body mass index (BMI), dyspnea basal index (DBI) and quality of life questionnaire score (QLQS).

RESULTS

Patients without and with positive response were different only because their baseline BMI, DBI and QLQS were lower. Other parameters studied (although the population was rather homogeneous) did not show significant differences between the two groups.

CONCLUSIONS

Patients with higher subjective problems (dyspnea and quality of life) and more malnourished are those with less benefit from surgery for pulmonary volume reduction.

Peripheral solitary pulmonary nodule: CT findings in patients with pulmonary emphysema

PURPOSE

To analyze retrospectively the computed tomographic (CT) features of peripheral noncalcified solitary pulmonary nodules in patients with and those without emphysema.

MATERIALS AND METHODS

The authors' institutional review board required neither its approval nor patient informed consent for this retrospective study. The authors retrospectively reviewed 2-mm-thick CT images of 41 nodules (21 malignant, 20 benign) in 41 patients with emphysema (age range, 58-88 years; mean, 71.9 years) and 40 nodules (20 malignant, 20 benign) in 40 patients without emphysema (age range, 50-85 years; mean, 69.2 years). Two radiologists who were unaware of the diagnosis independently evaluated the shape and margin of the nodule, recorded the presence of ground-glass opacities and air bronchograms, and classified nodules into two diagnostic categories: malignant and benign. Final decisions were reached by consensus. For quantitative assessment of the nodules, the fractal dimensions of the nodule interfaces and circularity of the nodule shape were calculated with an image-processing program, and the percentage of the nodule surrounded by emphysema was obtained. Statistical comparisons were made with a chi(2) or Fisher exact test and the Mann-Whitney U test.

RESULTS

In patients with emphysema, there were no significant differences in fractal dimension, circularity, or frequency of lobulation or spiculation between malignant and benign nodules. Of the 41 nodules in patients with emphysema, 26 (63%) were correctly diagnosed. Thirteen benign nodules (65%) were diagnosed as malignant in patients with emphysema. Of the 40 nodules in nonemphysematous lungs, 37 (93%) were correctly diagnosed. The mean percentage of emphysema around the nodule was greater for misdiagnosed nodules than for correctly diagnosed nodules (P = .003).

CONCLUSION

Malignant and benign nodules associated with emphysema exhibited considerably more overlap in CT features than did nodules in nonemphysematous lungs.

Optimization and Standardization of Lung Densitometry in the Assessment of Pulmonary Emphysema

Currently, lung densitometry for the assessment of pulmonary emphysema has been fully validated against pathology, pulmonary function, and health status, and it is therefore being applied in pharmacotherapeutic trials. Nevertheless, its application for the early detection of emphysema has not yet been introduced in daily clinical practice. The main reason for this is the fact that it is not yet regarded a fully optimized and standardized technique. In this work, an overview is given on the current status of different standardization aspects that play an important role in this, ie, image acquisition, choice of densitometric parameter and image processing. To address these issues, solutions have been sought from the literature and from original data from previous studies. Standardization and optimization of lung densitometry has reached a more advanced stage than has been reported so far. If normal values will become available, this technique will be feasible for clinical practice. As a result, standardization for the detection and assessment of other density-related lung diseases can be achieved in a shorter period of time.

Small airway morphometry and improvement in pulmonary function after lung volume reduction surgery

We examined small airway morphometry from resected lung specimens in 25 patients with severe emphysema undergoing lung volume reduction surgery (LVRS) and correlated their pathologic findings to changes in FEV(1) 6 months after LVRS. Patients were classified into two groups: responders had a more than 12% and a more than 200-ml change in FEV(1) at 6 months, and nonresponders had 12% or less and/or 200 ml or less change in FEV(1). Epithelial height (EH) and perimeters and areas of peribronchial smooth muscle, epithelium, and subepithelial space were measured quantitatively. The degrees of interstitial fibrosis, vascular sclerosis, goblet cell hyperplasia, squamous metaplasia, chronic inflammation, peribronchial fibrosis, and bullous disease were assessed semiquantitatively. Despite similar baseline characteristics, nonresponders had a greater EH (0.045 vs. 0.035 mm, p = 0.025), greater EH adjusted for basement membrane perimeter (0.040 vs. 0.011, p = 0.016), greater epithelial area adjusted for basement membrane area (0.561 vs. 0.499, p = 0.040), and less bullous disease (1.7 vs. 2.6, p = 0.011) compared with responders. We found a linear relationship between percentage change in FEV(1) and bullous disease and inverse relationships between percentage change in FEV(1) and interstitial fibrosis, goblet cell hyperplasia, peribronchial fibrosis, and vascular sclerosis. We conclude that small airway morphometry and lung histopathology in patients with severe emphysema have an important influence on changes in FEV(1) 6 months after LVRS.

Management of severe COPD

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, and the burden of the disorder will continue to increase over the next 20 years despite medical intervention. Apart from smoking cessation, no approach or agent affects the rate of decline in lung function and progression of the disease. Especially in the later phase, COPD is a multicomponent disorder, and various integrated intervention strategies are needed as part of the optimum management programme. This seminar describes largely non-pharmacological interventions aimed at improving health status and function of disabled patients. Exacerbations become progressively more troublesome as baseline lung function declines, commonly necessitating hospital admission and associated with the development of acute respiratory failure.

[Emphysema and lung volume reduction surgery--a case report]

Lung volume reduction surgery (LVRS) has been proposed as a palliative therapy in severe emphysema, with good results in lung function improvement, exercise capacity and quality of life. The authors present a case report of a 34 years old man with severe, heterogeneous lung emphysema submit to bilateral LVRS in 2000 January. Pre-surgical conditions, clinical and radiological evolution after surgery and for a 30 months follow up were analysed. Based on a literature revision, some technical aspects of LVRS, selection criteria and comparative study of medical and surgical therapy were discussed.

Improvement after lung volume reduction surgery: a role for inspiratory muscle adaptation

In severe emphysema, lung volume reduction surgery (LVRS) can improve lung function and exercise tolerance. The maximal changes of forced expiratory volume in 1s (FEV(1)) and lung volume occur early after surgery, whereas maximal improvement of exercise tolerance occurs later. We tested the hypothesis that secondary adaptation of inspiratory muscles could explain this delayed clinical improvement. In that purpose, we evaluated nine consecutive patients before LVRS and up to 9 months post-operatively. Six weeks after LVRS, we observed an increase in FEV(1) and 6 min walk distance (6MWD). The gain in sniff nasal inspiratory pressure (SNIP) was inversely proportional to lung volume loss. Values of FEV(1) and lung volume were maintained throughout follow-up whereas SNIP values significantly increased from 6 weeks to 6 months post-LVRS. In the meantime, we observed an increase in 6MWD correlated with the SNIP increase. This suggests that in patients undergoing LVRS, early improvement of SNIP is proportional to decrease in lung volume whereas the further delayed improvement may be due, at least in part, to adaptation of the inspiratory muscles.

Lung-volume reduction surgery for severe emphysema

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States, as well as a major cause of disability. In its end stages, its inexorable progression results in profound suffering for those afflicted. Medical therapy has proven largely ineffective in improving dyspnea and functional status, and does not alter pulmonary function. Over the past decade, lung-volume reduction surgery (LVRS) has been proposed as a palliative treatment for certain subgroups of COPD patients with emphysema, but initial enthusiasm over its application had been confounded by uncertainty about the potential cost and morbidities associated with LVRS, as well as durability of its beneficial effects. Longer-term follow-up data of initial uncontrolled trials along with several landmark controlled trials have recently been published, offering insight as to the "proper" place of LVRS in the treatment of these unfortunate patients. This review will summarize and offer perspective on these recent findings, as well as offer thoughts on recent refinements in preoperative imaging assessment, and pioneering efforts in less invasive bronchoscopic lung-volume reduction that should further aid the clinician in defining who should benefit from this treatment approach.

RECENT FINDINGS

Lung-volume reduction surgery can result in demonstrable benefit in selected subgroups of COPD patients with upper-lobe disease and poor exercise capacity before surgery with improvements in six-minute walk distances, forced expiratory volume in the first second (FEV1), dyspnea scores and quality-of-life scores, and decreases in residual volume (RV) as well as the need for supplemental oxygen. Patients with FEV1 less than 20% of predicted and either homogeneous emphysema or diffusing capacities (DLCO) less than 20% of predicted do not benefit from LVRS and have unacceptable peri-operative mortalities. Costs to society are high, with a cost of $98,000 per quality-adjusted-life year gained over a 2-year period if only those with upper-lobe disease are offered the procedure.

SUMMARY

Lung-volume reduction surgery can improve both objective and subjective measures of lung performance in properly selected COPD patients. Durable effects of up to 5 years have now been demonstrated. As costs (both fiscal and emotional) of such an approach are high, refinement in patient selection remains a current goal in the surgical approach to COPD.

Redefining Treatment in COPD

COPD is a growing international health concern and it is estimated that by the year 2020 it will rank fifth as a cause of disability worldwide. In response to this problem, the World Health Organization and the US National Institutes of Health convened a panel of experts to draft a consensus strategy to treat patients with COPD. Called the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, they are designed to define and stage the severity of COPD, make recommendations for treatment, and to expand global awareness of the disease. The GOLD guidelines describe a multimodality approach to provide optimal care for the COPD patient population. This includes respiratory and rehabilitative therapy, nutrition services, psychosocial counseling, and surgical care. Bronchodilators form the cornerstone of pharmacologic treatment for COPD. These medications can significantly lessen dyspnea, enhance quality of life, increase airflow, and improve exercise performance. While bronchodilators decrease airway resistance and lessen hyperinflation in patients with COPD, they have not been shown to influence the decline in FEV1 over time or improve survival in this patient population. Recently, long-acting beta2-adrenoceptor agonists (beta2-agonists) such as formoterol and salmeterol and anticholinergic medications including tiotropium bromide have been developed which may further improve symptom management in COPD patients. This article discusses bronchodilator pharmacologic therapy for patients with COPD focusing on beta2-agonists, anticholinergics, and methylxanthines in the light of the recent GOLD consensus statements.