Management of Refractory Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a common condition with an estimated prevalence of 12% in adults over the age of 30 years worldwide. COPD is a leading cause of morbidity and mortality globally, with a substantial economic and social burden. There are an estimated 3 million deaths annually due to COPD. However, most of the patients with COPD respond to routine interventions like bronchodilator therapy, assessing supplemental oxygen needs, smoking cessation, vaccinations, and pulmonary rehabilitation. There is a significant number of patients who unfortunately progress to have persistent symptoms despite these interventions. Refractory COPD is not yet formally defined. Patients with severe persistent symptoms or exacerbations despite appropriate care can be considered to have refractory COPD. Managing refractory COPD needs a multidimensional approach. In this review article, we will discuss essential interventions like ensuring adequate inhaler techniques, exploring the need for non-invasive ventilatory support, use of chronic antibiotics and phosphodiesterase inhibitors to advanced therapies like bronchoscopic lung volume reduction surgery, and the upcoming role of anti-IL5 agents in managing patients with refractory COPD. We will also discuss non-pharmacologic interventions like psycho-social support and nutritional support. We will conclude by discussing the palliative care aspect of managing patients with refractory COPD. Through this review article, we aim to better the approach to managing patients with refractory COPD and discuss new upcoming therapies.

Surgical and bronchoscopic pulmonary function-improving procedures in lung emphysema

COPD is a highly prevalent, chronic and irreversible obstructive airway disease without curative treatment. Standard therapeutic strategies, both non-pharmacological and pharmacological, have only limited effects on lung function parameters of patients with severe disease. Despite optimal pharmacological treatment, many patients with severe COPD still have a high burden of dyspnoea and a poor quality of life. If these patients have severe lung emphysema, with hyperinflation as the driver of symptoms and exercise intolerance, lung volume reduction may be an effective treatment with a significant impact on lung function, exercise capacity and quality of life. Currently, different lung volume reduction approaches, both surgical and bronchoscopic, have shown encouraging results and have been implemented in COPD treatment recommendations. Nevertheless, choosing the optimal lung volume reduction strategy for an individual patient remains challenging. Moreover, there is still room for improving durability of effect and safety in all available procedures. Ongoing and innovative research is essential to push this field forwards. This review provides an overview of results and limitations of the current lung volume reduction options for patients with severe lung emphysema and hyperinflation.

[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.

Indications for Lung Transplantation and Patient Selection

Globally, thousands of patients undergo lung transplantation owing to end-stage lung disease each year. As lung transplantation evolves, recommendations and indications are constantly being updated. In 2021, the International Society for Heart and Lung Transplantation published a new consensus document for selecting candidates for lung transplantation. However, it is still difficult to determine appropriate candidates for lung transplantation among patients with complex medical conditions and various diseases. Therefore, it is necessary to analyze each patient’s overall situation and medical condition from various perspectives, and ongoing efforts to optimize the analysis will be necessary. The purpose of this study is to review the extant literature and discuss recent updates.

Lung Volume Reduction Followed by Lung Transplantation in Emphysema-A Multicenter Matched Analysis

Objective: The impact of previous lung volume reduction surgery (LVRS) or endoscopic lung volume reduction (ELVR) on lung transplantation (LuTX) remains unclear. This study assesses the risk of previous lung volume reduction on the outcome of a later LuTX.

Methods: Patients suffering from emphysema who underwent bilateral LuTX were included in this multicenter analysis. Study groups were defined as: previous LVRS, previous ELVR, controls. Imbalances were corrected by coarsened exact matching for center, gender, age, diagnosis, and BMI. A comparative analysis of intraoperative characteristics, perioperative outcome and long-term survival was performed.

Results: 615 patients were included (LVRS = 26; ELVR = 60). Compared to controls, LVRS patients had a higher rate of postoperative ECMO (15.4 vs. 3.9%; p = 0.006), whereas ELVR patients suffered more often from wound infections (8.9% vs. 2.5%; p = 0.018). Perioperative outcome, duration of ventilation, ICU stay, and hospital stay were comparable between groups. Bacterial colonization of the airway differed significantly between both LVR groups and controls in pre- and post-LuTX cultures. Survival was not impacted (1-/3-/5-year survival for LVRS: 92.3%/85.7%/77.1%; controls: 91.3%/82.4%/76.3%; p = 0.58 | ELVR: 93.1%/91%/91%; controls 91.2%/81.7%/75.3%; p = 0.17).

Conclusion: Lung volume reduction does not impact short and long-time survival after bilateral LuTX. Due to differences in airway colonization after LVR, caution to prevent infectious complications is warranted.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Analysis of Recent Literature on Lung Volume Reduction Surgery

Publication of the National Emphysema Treatment Trial (NETT) in 2003 established lung volume reduction surgery (LVRS) as a viable treatment of select patients with moderate to severe emphysema, and the only intervention since the availability of ambulatory supplemental oxygen to improve survival. Despite these findings, surgical treatment has been underused in part because of concern for high morbidity and mortality. This article reviews recent literature generated since the original NETT publication, focusing on physiologic implications of LVRS, recent data regarding the safety and durability of LVRS, and patient selection and extension of NETT criteria to other patient populations.

Analytic Morphomics Are Related to Outcomes After Lung Volume Reduction Surgery

:Lung volume reduction surgery continues to have a high morbidity despite National Emphysema Treatment Trial selection criteria. This study evaluated the association between analytic morphomics on chest computed tomography scans and outcomes after lung volume reduction surgery. In a retrospective review of 85 lung volume reduction surgery patients from 1998-2013, dorsal muscle group area, subcutaneous and visceral fat area, and bone mineral density were assessed using analytic morphomics. Lung density was divided into five levels of increasing density (Lung density 1, emphysema; 2, normal lung; 4-5, scarring). Outcomes including survival, hospital length of stay, readmission at 30 days, and pulmonary complications were analyzed using univariate and multivariable techniques. Pulmonary complications developed in 27.1% (23/85). Mortality at 90 days was 9.4% (8/85). On multivariable analysis, lower bone mineral density (Odds ratio 0.61; 95% confidence interval 0.39-0.95) was associated with decreased survival, longer length of stay (0.83; 0.77-0.89), and readmissions (0.39; 0.15-1.00). Higher lung density 5:lung density 2 volume (1.84; 1.05-3.23), possibly due to scarring, was associated with pulmonary complications and longer length of stay (1.32; 1.23-1.41) while lower subcutaneous fat area:height was associated with readmissions which may reflect decreased metabolic reserve (0.35; 0.13-0.93). Patients with signs of frailty including lower bone mineral density may be at increased risk of adverse outcomes including decreased survival after lung volume reduction surgery. The results of this hypothesis-generating study will need to be confirmed in larger, multicenter trials to determine whether analytic morphomics can improve risk stratification and patient selection.

Lung Transplant Recipients With Prior Coronary Artery Bypass Grafting Are at Increased Risk of Death and Early Perioperative Hemorrhage

Prior coronary artery bypass grafting (CABG) has been considered a relative contraindication to lung transplantation due to the atherosclerotic disease burden and technical challenges. We hypothesized that lung transplant recipients with prior CABG have increased mortality compared to recipients without prior CABG. Further, the causes of death are different for lung transplant recipients with prior CABG vs without CABG. The Scientific Registry of Transplant Recipients database was queried to define the survival and causes of death of lung transplant recipients with or without CABG during the Lung Allocation Score era from May 5, 2005 to December 31, 2015. The primary end-points were all-cause mortality at 1 year and 5 years, as well as mortality due to major causes of death. This retrospective study cohort included a total of 13,064 lung transplant recipients, of whom 319 patients had previously undergone CABG, representing 2.4% of all transplants. Patients without prior CABG were more likely to have undergone bilateral lung transplantation compared to those with prior CABG (61.2 % vs 15.7%, P < 0.001). Among patients with prior CABG, single right lung transplant was most common. Overall patient survival at 1 year was 76.8% for lung transplant recipients with prior CABG and 85.4% for patients without prior CABG. Freedom from death due to graft failure at 1 and 5 years in patients with a prior CABG was 93.1% and 76.2% respectively, cardiac and/or cerebrovascular disease 96.2% and 88.5% respectively, and hemorrhage 97.9% and 97.5% respectively. In a multivariate Cox regression model utilizing time-dependent coefficients for recipient age, prior CABG, among several other risk factors, was associated with increased mortality within 1 year. Prior CABG is associated with short- and long-term mortality in lung transplant recipients with history of CABG despite the majority of these patients undergoing single lung transplantation vs bilateral lung transplantation. Graft failure and/or pulmonary causes are the most common cause of death regardless of whether or not the lung transplant recipient had prior CABG, but patients with prior CABG are at increased risk of death due to graft failure, cardiac or cerebrovascular disease, and hemorrhage.

Lung Volume Reduction Surgery Before Lung Transplantation: A Propensity-Matched Analysis

BACKGROUND

Lung volume reduction surgery (LVRS) is treatment option for chronic obstructive pulmonary disease, the second most common indication for lung transplantation (LTx) in the United States. Lung volume reduction surgery before LTx is controversial. Single-institution studies report contradicting results, and the impact of undergoing LVRS before LTx on outcomes after LTx is unclear.

METHODS

We reviewed the United Network for Organ Sharing database for all adults (aged more than 18 years) who underwent first-time LTx for chronic obstructive pulmonary disease in the lung allocation score era. We used patient demographic and clinical characteristics and lung allocation score to propensity match patients who did and patients who did not undergo LVRS before LTx. The primary exposure was prior LVRS. The primary outcome was graft failure after LTx. Unadjusted Kaplan-Meier and adjusted Cox proportional hazards models were used to assess outcomes.

RESULTS

A total of 4905 patients with chronic obstructive pulmonary disease underwent LTx between May 2005 and March 2017. Of them, 107 patients (2.2%) underwent LVRS before LTx. Propensity matching generated 212 matches (106 LVRS+LTx, and 106 LTx only). Median survival was significantly longer in the LTx only cohort (6.5 vs 3.4 years, P = .034). Lung volume reduction surgery before lung transplantation was associated with significantly increased risk of graft failure after lung transplant (hazard ratio 1.72; 95% confidence interval, 1.13 to 2.60; P = .01).

CONCLUSIONS

In this national, propensity-matched analysis of LVRS before LTx, we show that LVRS is associated with a significantly increased risk of graft failure. Patients who undergo LVRS and remain in need of LTx should be carefully assessed and followed postoperatively.

Lung transplantation for emphysema

Lung transplantation (LT) is proved to be effective in patients with end-stage lung disease who are failing optimal therapy. Chronic obstructive pulmonary disease (emphysema) is the most common indication for adult lung transplantation. As most patients with emphysema (EMP) can survive long term, it could be difficult to decide which patient should be listed for LT. LT is a complex surgery. Therefore, it is extremely important to choose a recipient in whom expected survival is at less equal or comparable to the survival without surgery. This paper reviews patient selection, bridging strategies until lung transplantation, surgical approach and choice of the procedure, and functional outcome in emphysema recipients.

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.

Lung volume reduction followed by lung transplantation-considerations on selection criteria and outcome

Lung transplantation (LuTX) and lung volume reduction (LVR), either surgical (LVRS: lung volume reduction surgery) or endoscopic (ELVR: endoscopic lung volume reduction), are established therapies in the treatment of end-stage chronic obstructive pulmonary disease (COPD) patients. Careful patient selection is crucial for each intervention. If these techniques are sequentially applied there is a paucity of available data and individual center experiences vary depending on details in selection criteria and operative technique. This review aims to summarize the published data with a focus on LuTX after LVRS. This review covers patient selection for LuTX and LVR, technical considerations, limitations and outcomes. Published literature was identified by systematic search on Medline and appropriate papers were reviewed. Seven case reports/series, 7 comparative observational studies and one multicenter database analysis incorporating a total of 284 patients with LuTX and LVR were evaluated. Prior LVR can significantly affect intraoperative and postoperative risks after subsequent LuTX. Careful patient selection and timing and the choice of appropriate techniques such as minimal invasive LVRS and using ECMO as extracorporeal support during LuTX if required can minimize those risks, ultimately leading to very good postoperative outcomes in terms of lung function and survival. LVRS has the potential to delay listing and to bridge patients to LuTX by improving their physical condition while on the waiting list. After single lung transplantation (SLuTX) contralateral LVRS can counteract the deleterious effects of native lung hyperinflation (NLH). LVR and LuTX are adjunct therapies in the treatment of end-stage COPD. The combination of both can safely be considered in selected patients.

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.

The role of the multidisciplinary emphysema team meeting in the provision of lung volume reduction

Despite a positive result in favour of lung volume reduction surgery (LVRS), from one of the largest randomized controlled trial in thoracic surgery, the identification of poor outcome in certain high-risk groups has resulted in a worldwide decrease in its utilization. Patient selection is the key to successful lung volume reduction which, with the advent of a range of less invasive techniques, has become more complex. The greater variety of potential therapeutic options will inevitably lead to debate amongst treating clinicians. Therefore, to be able to make an informed decision on the best treatment for an individual patient, discussion between clinicians in a multidisciplinary team (MDT) meeting is advisable. The membership of this MDT must include all specialists involved in assessment and subsequent treatment of the patient including non-medical input. There must be robust administrative organization and record of decisions together with inter-disciplinary communication of decisions. Whilst ultimately it is the patient who will benefit from the MDT, individual participants will enhance their continued professional development. The referral pathway into the MDT must be clearly defined and disseminated. Which investigations are to be performed by referrers and which by the specialist centre need to be in an agreed protocol. Specialist input may be required to interpret the results of the latest assessment tools. The decision-making process of the MDT begins with confirmation of basic selection criteria but addresses three main areas of discussion: the definition of target areas of lung for reduction; the presence of collateral, interlobar ventilation and an assessment of individualized risk and benefit. The emphysema or lung volume reduction MDT has been established in several specialist units and its benefits include an increase in referrals overall for LVR. The establishment of an MDT approach to lung volume reduction has now been incorporated into several national guidelines.