Attitudes and access to lung volume reduction surgery for COPD: a survey by the British Thoracic Society

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of disability and mortality in the UK and is now the third most frequent cause of death worldwide1 ,2 as a consequence of the ongoing epidemic of tobacco addiction.3 The pathological processes involved, destruction of small airways and lung parenchyma as well as narrowing of larger airways, are poorly responsive to medical therapies and many patients remain severely disabled despite optimum medical therapy.4 Only a handful of treatments including smoking cessation, long-term oxygen therapy in selected patients and lung volume reduction surgery (LVRS) have been shown to improve prognosis.5–8

LVRS was described as a palliative treatment for emphysema by Brantigan and Muller in 1957.9 The aim of LVRS is to resect the most emphysematous portion of the lung. This allows healthier, less compliant areas to be ventilated more effectively, reduces operating lung volumes and thus improves chest wall and respiratory muscle mechanics. In the US National Emphysema Treatment Trial (NETT),5 ,6 patients with an upper lobe predominant pattern of emphysema and a low preoperative exercise capacity gained the maximum benefit and had increased survival, which long-term economic analysis suggests is achieved at an acceptable cost per quality-adjusted life year.10 The NETT study also identified a group of patients with an excess risk of surgical mortality: those with a forced expiratory volume 1 s (FEV₁) <20% predicted and either homogeneous disease or a carbon monoxide transfer factor <20% predicted. The mortality rate for patients excluding this high-risk group was 5.2% at 90 days. In the NETT trial, complications included major respiratory or cardiac complication in 29.8% and 20% of patients, respectively. At 1 month, 28.1% of patients were still hospitalised or in a long-term care facility. However, audit of current practice suggests that mortality and morbidity are significantly lower.11

Data from the UK Society of Cardiothoracic Surgery (SCTS) register, http://www.scts.org/professionals/audit_outcomes.aspx show that only 96 procedures in 2009–2010 and 90 in 2010–2011 were recorded. The likely pool of eligible patients is significantly larger than this12 and there is therefore concern that patients who may benefit are not being considered for treatment. Some authors have suggested that physicians are deterred from referral as LVRS is perceived as too complicated with limited patient benefit and a substantial risk of complications.5 To improve understanding of the obstacles limiting provision of LVRS to suitable patients with COPD, we undertook a survey of members of the British Thoracic Society (BTS).

Methods

A survey including questions about clinicians’ attitudes to and knowledge of LVRS was designed in collaboration with the British Thoracic Society Professional and Organisational Standards of Care Committee of the BTS. The survey is available in the online supplementary material. The survey was completed electronically and a link to complete it sent out to 2498 BTS members in the monthly e-newsletter on two occasions.

Results

There were 65 respondents to the questionnaire with replies from all UK nations and 13 different regions in total. A total of 82% were consultant physicians and 11% specialist trainees in respiratory medicine (table 1). The remainder comprised two respiratory nurses, one thoracic surgeon, one physiotherapist and one clinical physiologist. Twenty two (34%) identified themselves as the COPD lead for their organisation.

Discussion

The main findings from the present survey are, first, that there are significant information needs around the indications for LVRS and the accompanying risks of morbidity and mortality. Second, there is a lack of systematic structures to evaluate patients and, third, there is a lack of consensus about the best approach for screening individuals to identify potential candidates for LVRS.

LVRS for selected patients is recommended in national and international guidelines for the management of COPD.13 ,14 This survey suggests that the majority of those surveyed know how to refer patients for LVRS and had done so within the last year. A significant proportion of respondents were clinical leads for COPD in their organisation and the majority had referred a patient for potential LVRS in the last year, suggesting that the respondents were likely to represent the more engaged clinicians in this area. However, survey responses suggest that published historical data from the late 1990s and early 21st century inform many individuals’ assessment of risk. In current surgical practice with largely unilateral, thoracoscopic approaches for LVRS, the morbidity and mortality are significantly lower than reported in the NETT trial5 with no deaths within 90 days and only 6% of patients in hospital at 30 days reported in one recent series.11

Most hospitals appear to have easy access to appropriate investigations, but there was no consensus on when a CT of the thorax is indicated. It has been proposed that a routine assessment of the pattern of emphysema by CT scan, as well as gas transfer measurement, should be considered in all patients with COPD with Medical Research Council dyspnoea scores of 4 or 5 and an FEV₁<50%, unless there are obvious comorbidities precluding surgery, with review by an MDT including chest physicians, surgeons and radiologists, as is already the case for the management of lung cancer.15 Clearly, this requires decisions about the appropriate allocation of resources to ensure best value. The cost per quality-adjusted life year of LVRS in the NETT study in upper lobe predominant emphysema was estimated to be $48 000 for low exercise capacity and $40 000 for high exercise capacity patients at 10 years.10 The true cost in current practice is likely to be considerably lower than this as the costs are driven by early surgical morbidity and mortality, which are lower now.11 ,16

The response rate to the survey was low, which impacts on the precision of the findings. We have no data as to the reasons for non-response, and can therefore only speculate. However, as a self-selecting group, respondents may be expected to have been more interested in LVRS, so it is unlikely that responses from a larger sample would have produced ‘better’ results. Clearly, people may have been too busy to respond, but non-response itself may also represent a general lack of engagement with lung volume reduction strategies in COPD. The overestimation of mortality risk by half of the respondents and the overestimation of hospital stay by 60% of the respondents may contribute to this disengagement. A further consequence of this is that low referral rates have made the development of bronchoscopic approaches,17–20 intended to deliver lung volume reduction either more safely or in different emphysema phenotypes,21 ,22 more difficult.

Lung volume reduction has a strong evidence base in appropriately selected patients with COPD where, unlike current pharmacotherapy, it can modify the natural history of the disease.5 ,19 ,23 The survey confirms that work is needed to ensure that clinicians are aware of the risks and benefits associated with the technique in modern practice and that structures are put in place to ensure systematic evaluation of patients.