Lung volume reduction surgery for chronic obstructive pulmonary disease: where do we stand?

Preoperative pulmonary rehabilitation in patients with non-small cell lung cancer and chronic obstructive pulmonary disease

INTRODUCTION

The aim of this study was to assess the effects of preoperative pulmonary rehabilitation (PPR) on preoperative clinical status changes in patients with chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC), and net effects of PPR and cancer resection on residual pulmonary function and functional capacity.

MATERIAL AND METHODS

This prospective single group study included 83 COPD patients (62 ±8 years, 85% males, FEV1 = 1844 ±618 ml, Tiffeneau index = 54 ±9%) with NSCLC, on 2-4-week PPR, before resection. Pulmonary function, and functional and symptom status were evaluated by spirometry, 6-minute walking distance (6MWD) and Borg scale, on admission, after PPR and after surgery.

RESULTS

Following PPR significant improvement was registered in the majority of spirometry parameters (FEV1 by 374 ml, p < 0.001; VLC by 407 ml, p < 0.001; FEF50 by 3%, p = 0.003), 6MWD (for 56 m, p < 0.001) and dyspnoeal symptoms (by 1.0 Borg unit, p < 0.001). A positive correlation was identified between preoperative increments of FEV1 and 6MWD (r s = 0.503, p = 0.001). Negative correlations were found between basal FEV1 and its percentage increment (r s = -0.479, p = 0.001) and between basal 6MWD and its percentage change (r s = -0.603, p < 0.001) during PPR. Compared to basal values, after resection a significant reduction of most spirometry parameters and 6MWD were recorded, while Tiffeneau index, FEF25 and dyspnoea severity remained stable (p = NS).

CONCLUSIONS

Preoperative pulmonary rehabilitation significantly enhances clinical status of COPD patients before NSCLC resection. Preoperative increase of exercise tolerance was the result of pulmonary function improvement during PPR. The beneficial effects of PPR were most emphasized in patients with initially the worst pulmonary function and the weakest functional capacity.

Assessment of a novel lung sealant for performing endoscopic volume reduction therapy in patients with advanced emphysema

AeriSeal Emphysematous Lung Sealant is a novel endoscopic lung-volume reduction therapy designed to reduce hyperinflation and improve pulmonary function and quality of life in patients with advanced emphysema. The device is administered to the subsegmental bronchus via a catheter as a 20 ml volume of liquid-foam. It flows into the peripheral airways and alveoli where it polymerizes and functions as a tissue glue, forming a film of material on the lung surface that seals the target region to cause durable absorption atelectasis. The AeriSeal System received CE mark approval for the treatment of patients with advanced upper lobe predominant and homogeneous emphysema based upon favorable results from clinical studies, and is commercially available in Europe. Patient and treatment site selection algorithms have been developed to simplify product use and optimize outcomes. This manuscript summarizes how the device is used, its mechanism of action and clinical trial results supporting its safety and efficacy.

Quantitative analysis of emphysema in 3D using MDCT: influence of different reconstruction algorithms

PURPOSE

The aim of the study was to compare the influence of different reconstruction algorithms on quantitative emphysema analysis in patients with severe emphysema.

MATERIAL AND METHODS

Twenty-five patients suffering from severe emphysema were included in the study. All patients underwent inspiratory MDCT (Aquilion-16, slice thickness 1/0.8mm). The raw data were reconstructed using six different algorithms: bone kernel with beam hardening correction (BHC), soft tissue kernel with BHC; standard soft tissue kernel, smooth soft tissue kernel (internal reference standard), standard lung kernel, and high-convolution kernel. The only difference between image data sets was the algorithm employed to reconstruct the raw data, no additional radiation was required. CT data were analysed using self-written emphysema detection and quantification software providing lung volume, emphysema volume (EV), emphysema index (EI) and mean lung density (MLD).

RESULTS

The use of kernels with BHC led to a significant decrease in MLD (5%) and EI (61-79%) in comparison with kernels without BHC. The absolute difference (from smooth soft tissue kernel) in MLD ranged from -0.6 to -6.1 HU and were significant different for all kernels. The EV showed absolute differences between -0.05 and -0.4 L and was significantly different for all kernels. The EI showed absolute differences between -0.8 and -5.1 and was significantly different for all kernels.

CONCLUSION

The use of kernels with BHC led to a significant decrease in MLD and EI. The absolute differences between different kernels without BHC were small but they were larger than the known interscan variation in patients. Thus, for follow-up examinations the same reconstruction algorithm has to be used and use of BHC has to be avoided.

Multi-detector CT of the chest: influence of dose onto quantitative evaluation of severe emphysema: a simulation study

PURPOSE

Quantitative evaluation of the lung parenchyma might be impaired or unreliable by use of reduced-dose CT protocols. Aim of the study was to define the threshold where reduced dose has significant impact on quantitative emphysema parameters.

MATERIALS AND METHODS

Thirty patients with severe centrilobular emphysema underwent multidetector computed tomography (120 kV, 150 mAs). Original CT raw data were simulated using 10 mAs settings (10-100 SIMmAs). Quantitative analysis provided lung volume, emphysema volume, emphysema index, mean lung density, and 4 emphysema volume classes. Simulated low-dose results were compared with original acquisition.

RESULTS

Emphysema index showed no clinical relevant variation down to 30 SIMmAs. The large emphysema volume class was significantly different below 50 SIMmAs. The intermediate and small classes showed an overproportional variation below 50 SIMmAs.

CONCLUSIONS

Dose reduction down to 30 SIMmAs is possible for clinical routine. Settings below 50 SIMmAs significantly alter the in-detailed 3-dimensional emphysema quantification.

Innovative approaches to lung volume reduction for emphysema

The 10 years of resurgent interest in lung volume reduction surgery (LVRS) and recent National Emphysema Treatment Trial findings for emphysema have stimulated a range of innovative alternative ideas aimed at improving outcomes and reducing complications associated with current LVRS techniques. Concepts being actively investigated at this time include surgical resection with compression/banding devices, endobronchial blockers, sealants, obstructing devices and valves, and bronchial bypass methods. These novel approaches are reaching the stage of clinical trials at this time. Theory, design issues, methods, potential advantages and limitations, and available results are presented. Extensive research in the near future will help to determine the potential clinical applicability of these new approaches to the treatment of emphysema symptoms.

Chronic respiratory failure after lung resection: the role of pulmonary rehabilitation

Pulmonary rehabilitation gradually has become the gold standard treatment for patients with severe lung disease, especially COPD. By definition, rehabilitation services are provided to patients with symptoms, most of whom have moderate-to-advanced lung disease. Because new therapeutic strategies, such as lung volume-reduction surgery and lung transplantation, require well-conditioned patients, pulmonary rehabilitation is becoming a crucial component of the overall treating strategy of many patients who heretofore were deemed untreatable. The positive results in several randomized trials have documented the effectiveness of pulmonary rehabilitation. Currently, pulmonary rehabilitation should be made available to all patients with symptomatic respiratory disease and be an integral part of any program considering high-risk surgery.

Regional ventilation and distribution of emphysema - a quantitative comparison

The distribution of ventilation and emphysema throughout the lung was compared in 20 emphysematous patients who were candidates for lung volume reduction surgery. Ventilation distribution among 1.6-cm-high stripe regions was obtained in supine position by planar gamma camera scintigraphy after inhalation of technegas. Results from nine healthy subjects provided normal stripe count rates. Patient count rates were expressed as the difference from predicted normal stripe count rate (DeltaSVI). Thus, DeltaSVI is a relative index of abnormal ventilation. Emphysema was assessed quantitatively by a density mask method on corresponding slices of high resolution computed tomography (HRCT). The results show that in the majority of patients, there is a highly significant relationship between the degree of stripe hypoventilation and the amount of distribution of emphysema, but in some patients no such relationship is found. We speculate that the distribution of airway obstruction not necessarily follows the distribution of emphysema, which could explain the lack of concordance between ventilation and emphysema distribution in some patients. We conclude that ventilation scintigraphy contains complementary information to lung HRCT.