Emphysema Morphology Research Articles

Imaging in alpha-1 antitrypsin deficiency: a window into the disease.

Imaging modalities such as plain chest radiograph and computed tomography (CT) are important tools in the assessment of patients with chronic obstructive pulmonary disease (COPD) of any etiology. These methods facilitate differential diagnoses and the assessment of individual lung pathologies, such as the presence of emphysema, bullae, or fibrosis. However, as emphysema is the core pathological consequence in the lungs of patients with alpha-1 antitrypsin deficiency (AATD), and because AATD is associated with the development of other lung pathologies such as bronchiectasis, there is a greater need for patients with AATD than those with non-AATD-related COPD to undergo more detailed assessment using CT. In the field of AATD, CT provides essential information regarding the presence, distribution, and morphology of emphysema. In addition, it offers the option to quantify the extent of emphysema. These data have implications for treatment decisions such as initiation of alpha-1 antitrypsin (AAT) therapy, or suitability for surgical or endoscopic interventions for reducing lung volume. Furthermore, CT has provided vital insight regarding the natural history of emphysema progression in AATD, and CT densitometry has underpinned research into the efficacy of AAT therapy. Moving forward, hyperpolarized xenon gas (129Xe) lung magnetic resonance imaging (MRI) is emerging as a promising complement to CT by adding comprehensive measures of regional lung function. It also avoids the main disadvantage of CT: the associated radiation. This chapter provides an overview of technological aspects of imaging in AATD, as well as its role in the management of patients and clinical research. In addition, perspectives on the future potential role of lung MRI in AATD are outlined.

Screening for Bronchoscopic Lung Volume Reduction: Reasons for Not Receiving Interventional Treatment.

Evidence for bronchoscopic lung volume reduction (BLVR) is based on phase 2 studies and small randomized controlled trials with in- and exclusion criteria defining a therapeutic window and contraindications. Little is known about the applicability in routine clinical practice. Which percentage of patients with severe emphysema referred to a specialized treatment center for BLVR is ultimately suitable for interventional bronchoscopic treatment? What is the relevance of the different contraindications? Retrospective evaluation of emphysema patients referred to Asklepios Fachkliniken Munich-Gauting for BLVR between January 2014 and June 2015. 138 patients were referred for evaluation of BLVR. 38 patients (27.5%) underwent BLVR procedures (valves n = 18; coils n = 18; thermal vapor ablation n = 2). 100 patients (72.5%) were deemed not eligible for BLVR based on the following contraindications: 34% emphysema morphology and emphysema-related findings (severe homogeneous emphysema, extensive pleuropulmonary adhesions, postinflammatory scaring with natural volume reduction, giant bullae), 16% active smoking; 9% pulmonary function not within indication range; 8% unexpected CT findings (nodules, cancer, interstitial disease); 8% chronic ventilatory failure; 8% patient refused BLVR; 5% relevant comorbidity; 5% frequent exacerbations, 3% preserved quality of life, 4% other. BLVR is a therapeutic option for highly selected patients. In our cohort, one in four could be treated. These data highlight the limitations of BLVR under real-life conditions.

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.

Lung Volume Reduction Surgery

Lung volume reduction surgery (LVRS) offers improvement in lung function, quality of life and even survival in well selected patients with severe emphysema. Patients with all types of emphysema morphology can profit from LVRS when certain selection criteria are present. Hyperinflation plays a key role in qualifying for the procedure. Candidate selection should be performed at high volume centers with a multidisciplinary emphysema board. Qualified thoracic surgeons together with pulmonologists and radiologists identify the suitable patient considering emphysema morphology with its target areas for resection, lung function parameters and cardiac comorbidities. This review outlines candidate selection, technique and results of LVRS to inform referring physicians how to screen und inform their patients.

Lung Volume Reduction Surgery - State of the Art 2016

In a number of large case series in the mid-1990s, lung volume reduction surgery (LVRS) was shown to reduce dyspnoea and improve pulmonary function and quality of life in patients with advanced pulmonary emphysema. The large randomised National Emphysema Treatment Trial (NETT) confirmed this in the early 2000s and also demonstrated that selected patients live longer after surgery. Patient selection is crucial to the success of the procedure and should be performed at a specialised experienced centre with a multidisciplinary team approach on emphysema treatment. The upper-lobe predominant heterogeneous type of emphysema is the best indication, but there are other types of emphysema morphology that are also eligible for surgery, if ideally chosen. Nowadays there is also growing evidence for positive effects after different types of bronchoscopic lung volume reduction (BLVR) with increasing quality. These methods add to the range of multimodal emphysema treatment.

Extended Gabor approach applied to classification of emphysematous patterns in computed tomography

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible lung condition typically related to emphysema. It hinders air from passing through airpaths and causes that alveolar sacs lose their elastic quality. Findings of COPD may be manifested in a variety of computed tomography (CT) studies. Nevertheless, visual assessment of CT images is time-consuming and depends on trained observers. Hence, a reliable computer-aided diagnosis system would be useful to reduce time and inter-evaluator variability. In this paper, we propose a new emphysema classification framework based on complex Gabor filters and local binary patterns. This approach simultaneously encodes global characteristics and local information to describe emphysema morphology in CT images. Kernel Fisher analysis was used to reduce dimensionality and to find the most discriminant nonlinear boundaries among classes. Finally, classification was performed using the k-nearest neighbor classifier. The results have shown the effectiveness of our approach for quantifying lesions due to emphysema and that the combination of descriptors yields to a better classification performance.

Fibrosis with emphysema

The concept of fibrosis with emphysema is confused by the existence of two very different clinical/pathological scenarios: first, cases in which a diffuse fibrosing interstitial pneumonia, most commonly usual interstitial pneumonia (UIP), occurs in a patient with emphysema. This combination is largely of clinical interest because of its effects on pulmonary function and pulmonary hypertension, but can produce unusual appearances in surgical lung biopsies when the fibrotic areas are wrapped around emphysematous spaces. However, the underlying morphology of emphysema and UIP or other interstitial lung disease remains unchanged. Radiological consultation is often helpful to show that the patient has both lesions; secondly, cases in which there is localized fibrosis that is part of emphysema, or related to respiratory bronchiolitis, or both. These lesions have been called 'respiratory bronchiolitis' (RB), 'respiratory bronchiolitis-interstitial lung disease' (RB-ILD), 'airspace enlargement with fibrosis', 'RB-ILD with fibrosis' and 'clinically occult interstitial fibrosis in smokers', but are probably all the same entity. Such changes are associated only rarely with the physiological or radiological features of an interstitial lung disease. Care should be taken when describing these lesions in biopsies so as not to give the impression that a diffuse interstitial lung disease is present.

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

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. 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)). 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). 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.

Lung Volume Reduction Surgery

To evaluate the activity and evolution in the field of lung volume reduction surgery (LVRS) performed at surgical centers in Europe. LVRS is a novel surgical therapy with the potential to improve lung function, exercise performance, and quality of life in selected patients suffering from severe pulmonary emphysema. Questionnaire addressed to 75 European thoracic surgical centers presumed to perform LVRS, and review of the literature. Of 45 responding centers, 42 centers in 17 countries covering a population of 423 million reported performing LVRS. Until the end of 1998, 1,120 patients were reported to have undergone LVRS, corresponding to 2.6 patients/million inhabitants. Thirty-one of 40 centers (78%) perform the operation bilaterally. Most centers (83%) evaluate their activity prospectively. The average perioperative mortality rate of 4.1% is moderate. The most commonly utilized technique is video-assisted thoracoscopy, which is most frequently performed bilaterally. Two thirds of the centers treat patients with alpha(1)-antitrypsin deficiency, and half of the centers will consider patients with homogenous morphology of emphysema on CT scan for LVRS. Half of the centers also perform lung transplantation. The five largest centers have operated on 49% of all LVRS patients assessed by this survey. LVRS is performed at few thoracic surgical centers throughout Europe, with a large variation in the operative activity between different regions. Half of the centers also perform lung transplantation. Between 1995 and 1997, the number of LVRS procedures performed per year nearly tripled but has reached a plateau since then. As five centers perform nearly half the total number of operations, an optimal exchange of knowledge with smaller centers seems important.

Patient Selection for Lung Volume Reduction Surgery: An Objective Model Based on Prior Clinical Decisions and Quantitative CT Analysis

We used whole-lung quantitative CT analysis (QCT)-an objective method of evaluating emphysema severity and distribution based on measurement of lung density-to determine whether subjective selection criteria for lung volume reduction surgery are applied consistently and to model the patient selection process, and assessed the relationship of the model to postoperative outcome. Logistic regression analysis using QCT indexes of emphysema and preoperative physiologic test results as the independent variables, and the decision to operate as the dependent variable. University hospital. Seventy patients selected for bilateral lung volume reduction surgery and 32 otherwise operable patients excluded from surgery based on subjective assessment of emphysema morphology on chest radiography, CT, and perfusion scintigraphy. Bilateral lung volume reduction surgery in the selected group. Emphysema in patients selected for surgery was more severe overall and in the upper lungs by multiple QCT indexes (p < 0.01, unpaired two-tailed t test). Physiologic abnormalities were slightly more severe in selected patients (p < 0.05, unpaired two-tailed t test). The range of many QCT and physiologic values overlapped considerably between the selected and excluded groups. The percent severe emphysema (<- 960 Hounsfield units [HU]), upper/lower lung emphysema ratio (- 900 HU threshold), and residual volume were the key variables in the model predicting selection decisions (model r(2) = 0.48; p < 0.0001). The model correctly predicted selection decisions in 87% of all cases, 91% of the selected group, and 78% of the excluded group. Surgical patients with a higher model-derived probability of selection had greater postoperative improvement in FEV(1) and 6-min walk distance. Radiologic selection criteria are applied consistently to the majority of patients. QCT features are strongly associated with selection decisions, are related to outcome, and may help improve consistency and confidence in patient selection.

Redo lung volume reduction surgery in a patient with α1-antitrypsin deficiency

Lung volume reduction surgery is a palliative procedure that improves dyspnea and pulmonary function in selected patients with advanced emphysema. Postoperative benefit is sustained for an individual period and depends on the emphysema morphology, the surgical technique, and other not yet well-defined factors. The question whether lung volume reduction surgery can be performed a second time on the same thoracic cavity is often raised but experience in this regard is lacking. We describe a patient who has undergone a successful redo operation 2 years after the initial lung volume reduction surgery.

Two years’ outcome of lung volume reduction surgery in different morphologic emphysema types

Background. Lung volume reduction surgery (LVRS) improves dyspnea, pulmonary function, and quality of life in selected patients with severe emphysema. We investigated the role of emphysema morphology in 37 patients as an outcome predictor for up to 2 years after operation.Methods. Patients selected for bilateral thoracoscopic LVRS were divided, according to a simplified emphysema morphology classification, into three groups (homogeneous, moderately heterogeneous, and markedly heterogeneous) based on a preoperative chest computed tomogram. Pulmonary function, walking distance, and dyspnea were assessed.Results. Functional improvement after LVRS was best in markedly heterogeneous emphysema with an increase from preoperative forced expiratory volume in 1 second of 31% ± 2% (mean ± standard error of the mean) to 52% ± 4% of predicted postoperatively. It was significantly higher than in homogeneous emphysema (from 26% ± 1% to 38% ± 2% predicted) and in intermediately heterogeneous emphysema (from 29% ± 2% to 44% ± 45% predicted). At 24 months postoperatively, forced expiratory volume in 1 second and dyspnea score continued to be significantly better than preoperative levels in all three morphologic groups. The survival rate was highest in patients with markedly heterogeneous emphysema.Conclusions. Functional and subjective improvements were maintained after LVRS for at least 24 months in patients with heterogeneous or homogeneous emphysema type.

Morphologic Grading of the Emphysematous Lung and Its Relation to Improvement After Lung Volume Reduction Surgery

Background. The morphologic criteria for lung volume reduction surgery, such as severity and heterogeneity of disease, differ widely between patients, and this makes any comparison of functional results between centers difficult. Here we present a morphologic scoring system and describe its possible relation to functional results after lung volume reduction operations.Methods. Between September 1994 and December 1996, 47 consecutive patients underwent bilateral lung volume reduction operations. The morphology of emphysema was quantified with standard chest roentgenograms and computed tomographic imaging, which were used to define the following four variables: degree of hyperinflation (grade 0 to 4), degree of impairment in diaphragmatic mechanics, degree of heterogeneity (grade 0 to 4), and severity of parenchymal destruction (range, 0 to 48).Results. All four variables showed good reproducibility. Degree of heterogeneity had a significant influence on functional improvement in terms of forced expiratory volume in 1 second (p = 0.0413, r2 = 0.11). Severity of parenchymal destruction was significantly associated with 30-day mortality: patients who died after operation (n = 4) had a severity of parenchymal destruction of 28.4 ± 2.1 compared with 21.3 ± 1.0 for those who survived (n = 43) (p = 0.003).Conclusions. This morphologic scoring system is easy to use, is reproducible, and allows quantification of the morphology of emphysema, thereby allowing definition of different patient subgroups. Such an exact morphologic quantification may help in the comparison of functional results between centers. Furthermore, the risk factors for certain morphologic subgroups, such as patients with a homogeneous distribution pattern, may be clarified in the future.

Radiologic emphysema morphology is associated with outcome after surgical lung volume reduction

Lung volume reduction surgery is known to alleviate dyspnea and to improve pulmonary function, performance in daily activity, and quality of life in selected patients with severe pulmonary emphysema. We investigated the role of radiologically assessed emphysema morphology on functional outcome after a lung volume reduction operation. The preoperative chest computed tomograms in 50 consecutive patients who had undergone surgical lung volume reduction were retrospectively reviewed by 6 physicians blinded to the clinical outcome. Emphysema morphology was determined according to a simplified classification (ie, homogeneous, moderately heterogeneous, and markedly heterogeneous; lobe predominance). We studied the impact of these morphologic aspects on functional outcome at 3 months. We found a fair interobserver agreement applying our classification system. Functional improvement after surgical lung volume reduction was best in markedly heterogeneous emphysema with an increase in forced expiratory volume in 1 second of 81% +/- 17% (mean +/- standard error, n = 17) compared with 44% +/- 10% (n = 16) for intermediately heterogeneous emphysema. But also in patients with homogeneous emphysema clinical relevant improvement of function could be observed (increase in forced expiratory volume in 1 second = 34% +/- 6%; n = 17). The morphologic type of emphysema, assessed by a simplified surgically oriented classification, is an important predictor of surgical outcome. Lung volume reduction surgery may also improve dyspnea and lung function in homogeneous emphysema.

The morphology of emphysema, chronic bronchitis, and bronchiectasis: definition, nomenclature, and classification.

The morphology of emphysema, chronic bronchitis, and bronchiectasis: definition, nomenclature, and classification.