A multicenter trial of an intrabronchial valve for treatment of severe emphysema

Wood, Douglas E.; McKenna, Robert J.; Yusen, Roger D.; Sterman, Daniel H.; Ost, David; Springmeyer, Steven C.; Gonzalez, H. Xavier; Mulligan, Michael S.; Gildea, Thomas R.; Houck, Ward V.; Machuzak, Michael; Mehta, Atul C.

doi:10.1016/j.jtcvs.2006.06.051

Cited by 158 publications

(110 citation statements)

References 23 publications

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“…This may be achieved with one-way (expiratory) valves placed in the airways or by introduction of tissue glues (36)(37)(38)(39). In patients in whom atelectasis is achieved, mechanisms of improved lung function or symptoms are likely identical to those after surgical LVR.…”

Section: Physiologic Basis For Improvement After Bronchoscopic Lung Vmentioning

confidence: 99%

Physiologic Basis for Improved Pulmonary Function after Lung Volume Reduction

Fessler¹,

Scharf²,

Ingenito³

et al. 2008

Proceedings of the American Thoracic Society

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It is not readily apparent how pulmonary function could be improved by resecting portions of the lung in patients with emphysema. In emphysema, elevation in residual volume relative to total lung capacity reduces forced expiratory volumes, increases inspiratory effort, and impairs inspiratory muscle mechanics. Lung volume reduction surgery (LVRS) better matches the size of the lungs to the size of the thorax containing them. This restores forced expiratory volumes and the mechanical advantage of the inspiratory muscles. In patients with heterogeneous emphysema, LVRS may also allow space occupied by cysts to be reclaimed by more normal lung. Newer, bronchoscopic methods for lung volume reduction seek to achieve similar ends by causing localized atelectasis, but may be hindered by the low collateral resistance of emphysematous lung. Understanding of the mechanisms of improved function after LVRS can help select patients more likely to benefit from this approach.Keywords: lung mechanics; emphysema surgery; lung recoil; airflow limitation; respiratory muscles PHYSIOLOGIC BASIS FOR IMPAIRMENT WITH EMPHYSEMAInflammatory changes associated with chronic obstructive pulmonary disease (COPD) initiate the changes in lung mechanical properties that characterize emphysema. Inflammation leads to destruction of elastin, which contributes to lung elasticity, and collagen, which provides tensile strength. Although recent interest has focused on the cellular and molecular mechanisms contributing to emphysema, the study of lung mechanical stresses, one of the earliest postulated causes of emphysema (1), has received less attention. Weakened lung parenchyma is more likely to fracture during respiratory stress, and coalescence of a few alveoli can increase stress on adjacent units in a way that favors formation of large, localized cysts similar to the pattern seen in patients with advanced emphysema (2-4). Effects of Emphysema on Expiratory FlowThese sequelae of inflammation ultimately decrease lung elastic recoil and small airway caliber, contributing to characteristic airflow limitation. The three classic determinants of expiratory flow limitation are lung elastic recoil, the propensity for airways to close, and airway resistance (5). Loss of elastic recoil in emphysema decreases the upstream pressure that drives expiratory flow, thereby decreasing maximal flows at any lung volume. Loss of elastic recoil also increases the unstressed volume of the lung (the volume remaining when elastic recoil is zero). Loss of radial traction on airways from lung parenchyma contributes to airway closure at higher lung volumes (increased trapped volume) because a higher transmural pressure is required to maintain airway patency. In addition, airway caliber at any lung volume is decreased (6). Coexisting small airway inflammation and fibrosis further increase airway resistance (7,8). These changes collectively reduce the rate of lung emptying.The rate of lung emptying may be expressed as its time constant, the time necessary for approximately 63% o...

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Section: Physiologic Basis For Improvement After Bronchoscopic Lung Vmentioning

confidence: 99%

Physiologic Basis for Improved Pulmonary Function after Lung Volume Reduction

Fessler¹,

Scharf²,

Ingenito³

et al. 2008

Proceedings of the American Thoracic Society

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“…In recent years, new surgical and bronchoscopic lung volume reduction techniques have been proposed in an attempt to reduce the typical shortcomings of resectional LVRS [12][13][14][15]. We have developed a nonresectional LVRS technique in awake patients that respects the basic concepts of resectional LVRS but adds some theoretic advantages and can be performed solely with thoracic epidural anesthesia.…”

mentioning

confidence: 99%

Two-Year Improvement in Multidimensional Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity Index After Nonresectional Lung Volume Reduction Surgery in Awake Patients

Pompeo

Mineo

2007

The Annals of Thoracic Surgery

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Background. This study analyzed the comprehensive 2-year outcome of nonresectional lung volume reduction surgery (LVRS) in awake patients, including calculation of the multidimensional BODE index (body mass index, degree of airflow obstruction assessed by spirometry, modified Medical Research Council dyspnea grade, and 6-minute walking distance), which has proved a useful predictor of survival in patients with chronic obstructive pulmonary disease.Methods. The study cohort included 42 patients undergoing LVRS while awake within a staged bilateral program entailing unilateral LVRS, followed by contralateral treatment performed at the reappearance of disabling symptoms. Outcome measures included hospital stay, procedure-related costs, calculation of the multidimensional BODE index, actuarial survival, and freedom from contralateral LVRS. Results were compared with those of a control group undergoing resectional LVRS under general anesthesia.Results. The groups were well matched in demographics

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“…It has the ability of obstructing the airflow selectively in the segments where it is placed and, by the same token, allows secretions to exit the segment. One study with 30 patients showed improvements in quality of life, however without significant differences in pulmonary function (Wood, McKenna et al 2007). This study has used outcome measures similar to LVRS.…”

Section: Devices and Resultsmentioning

confidence: 99%

Endoscopic Lung Volume Reduction for Emphysema

Cardoso¹

2012

Topics in Thoracic Surgery

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A multicenter trial of an intrabronchial valve for treatment of severe emphysema

Cited by 158 publications

References 23 publications

Physiologic Basis for Improved Pulmonary Function after Lung Volume Reduction

Physiologic Basis for Improved Pulmonary Function after Lung Volume Reduction

Two-Year Improvement in Multidimensional Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity Index After Nonresectional Lung Volume Reduction Surgery in Awake Patients

Endoscopic Lung Volume Reduction for Emphysema

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