[Lung Volume Reduction Surgery - State of the Art 2016]

[Lung Volume Reduction Surgery - an Alternative or a Bridge to Transplantation]

Lung volume reduction surgery (LVRS) and lung transplantation (LuTX) are established therapeutic options for patients with advanced pulmonary emphysema. This review analyses both procedures with respect to indications, surgical techniques, outcomes, and complications. Special attention is given to the controversial sequential application as a bridge to transplantation. Evidence shows that both procedures can significantly improve lung function, quality of life, and survival when patients are carefully selected. Despite some overlap in indication criteria, most patients qualify for only one of the procedures as based on their specific clinical constellation. Recent research has challenged traditional contraindications such as pulmonary hypertension or homogeneous emphysema, and consequently, the indication spectrum for LVRS has been expanded. Contrary to earlier assumptions, current multicentre studies demonstrate that prior LVRS has no negative impact on subsequent transplantation outcomes, provided minimally invasive surgical techniques and modern perioperative management are employed. LVRS can delay the need for transplantation, which is a significant advantage given the shortage of donor organs. The key to success lies in interdisciplinary evaluation and personalized treatment planning. Both procedures should be understood as complementary rather than competing options. Future research should focus on predictive biomarkers, optimal timing, and combined patient-centred endpoints.

[Surgical or bronchoscopic lung volume reduction for emphysema therapy]

More than 20 years ago, surgical lung volume reduction (LVRS) was already established in patients with advanced emphysema as a palliative therapy option that reduces respiratory distress and improves lung function and quality of life. In addition, bronchoscopic procedures (BLVR) aimed at volume reduction have existed for just over 10 years. The advantages and disadvantages of LVRS and BLVR are discussed in this article.

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

BACKGROUND

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.

AIM

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?

METHODS

Retrospective evaluation of emphysema patients referred to Asklepios Fachkliniken Munich-Gauting for BLVR between January 2014 and June 2015.

RESULTS

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.

CONCLUSION

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.

Applicability of color-coded computed tomography images in lung volume reduction surgery planning

Background

Adequate patient selection is the key to successful lung volume reduction in patients with pulmonary emphysema. Computed tomography (CT) enables a reliable detection of pulmonary emphysema and allows an accurate quantification of the severity. Our goal was to investigate the usefulness and reliability of color-coded (CC) CT images in classification of emphysema and preoperative lung volume reduction planning.

Methods

Fifty patients undergoing lung volume reduction surgery at our institution between September 2015 and February 2016 were retrospectively investigated. Three readers visually assessed the amount and distribution patterns of pulmonary emphysema on axial, multi-planar and CC CT images using the Goddard scoring system and a surgically oriented grading system (bilateral markedly heterogenous, bilateral intermediately heterogenous, bilateral homogenous and unilateral heterogenous emphysema). Observer dependency was investigated by using Fleiss' kappa (κ) and the intraclass correlation coefficient (ICC). Results were compared to quantitative results from densitometry measurements and lung perfusion scintigraphy by using Spearman correlation. Recommendations for lung volume reduction sites based on emphysema amount and distribution of all readers were compared to removal sites from the surgical reports.

Results

Inter-rater agreement for emphysema distribution rating was substantial for CC images (κ=0.70; 95% CI, 0.64-0.80) and significantly better compared to axial and multiplanar images (P≤0.001). The inter-rater agreement for recommended segment removal was moderate for CC images (κ=0.56; 95% CI, 0.49-0.63) and significantly better compared to axial and multiplanar images (P<0.001). Visual emphysema rating correlated significantly with measurements from densitometry and perfusion scintigraphy in the upper and lower lung zones in all image types.

Conclusions

CC CT images allow a precise, less observer-dependent evaluation of distribution of pulmonary emphysema and resection recommendation compared to axial and multiplanar CT images and might therefore be useful in lung volume resection surgery planning.

Clinical management of lung volume reduction in end stage emphysema patients

Following the evaluation of surgical lung volume reduction (LVR) in the National Emphysema Treatment (NETT) trial, different endoscopic LVR procedures have been developed for severe emphysema. Among those, endobronchial valve placement is the best evaluated method. All these therapies aim at reducing hyperinflation and at improving respiratory mechanics. It has been shown that these procedures can improve quality of life, lung function and exercise capacity in a significant and clinically meaningful way in suitable patients. Optimal medical therapy, physical rehabilitation, smoking cessation and respiratory insufficiency assessments should been thoroughly evaluated by a multi-disciplinary team before considering any LVR procedure. Clinical experience is necessary to decide if a patient is an appropriate candidate for a surgical or an interventional LVR procedure, to choose the optimal treatment strategy and to provide a high-level of care after the intervention, particularly when complications such as pneumothorax or persistent air leak occur in this already severely ill patient population. High volume emphysema care centers, providing a broad spectrum of different LVR procedures and involving a multidisciplinary team in the diagnostic process, are best suited to provide an optimal outcome. The aim of this manuscript is to describe the structures and procedures required to achieve the best possible outcome even in patients with advanced stage of their emphysema disease, including patients who are candidates for lung transplantation.

Pulmonary hypertension in chronic obstructive pulmonary disease and emphysema patients: prevalence, therapeutic options and pulmonary circulatory effects of lung volume reduction surgery

The exact prevalence of pulmonary hypertension (PH) and cor pulmonale (CP) in chronic obstructive pulmonary disease (COPD) is unknown, and varies considerably from 20-91%. Usually, mean pulmonary artery pressure (mPAP) does not exceed 30 mmHg, and PH is not severe. However, PH and CP are important predictors of mortality in COPD and contribute to disability in this disease. Many factors contribute to the development of PH in chronic lung disease, including reduction of the pulmonary vascular cross-sectional area due to parenchymal loss and accompanying hypoxia, effects of abnormal pulmonary mechanics due to hyperinflation, but also vascular remodeling processes. So far, PH associated with chronic lung disease cannot be treated medically. Therefore, it is indicated to treat the underlying pulmonary disease. Patients with severe PH should be referred to centers experienced in the management of PH and enrollment in clinical trials should be considered. Lung volume reduction surgery (LVRS) theoretically further increases pulmonary vascular resistance (PVR) by reducing the vascular bed when resecting lung tissue, however, this might be compensated by better pulmonary mechanics through reduction of hyperinflation, which will be discussed in the present article.