ISSN: 0277-0903 (print), 1532-4303 (electronic) J Asthma, Early Online: 1–3 ! 2015 Informa Healthcare USA, Inc. DOI: 10.3109/02770903.2015.1005844


Lung abscess as a complication of bronchial thermoplasty Anandh Balu, Dorothy Ryan, and Robert Niven

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Department of Respiratory Medicine, University Hospital South Manchester, Manchester, UK



Background: Bronchial thermoplasty (BT) is an emerging treatment modality for patients with difficult to treat asthma. It has been shown to be beneficial for symptom control and improves quality of life and reduces frequency of hospitalization. Safety data from the two major trials of BT indicate that patients who undergo these procedures are most likely to experience adverse respiratory events in the first six weeks post treatment. Lung abscess has never been reported as a direct complication of BT. In this case; we report a lung abscess as an immediate complication of BT, which we believe may be the first case. Case presentation: We describe a forty three year old Caucasian female presented three days post-bronchial thermoplasty with left sided chest pain radiating to the back associated with shortness of breath, wheeze and dry cough. She had also started to feel hot and cold and generally unwell. Conclusion: It remains unclear why this patient developed a lung abscess so acutely post BT treatment. It is important that safety data continues to be collated and published as the procedure becomes more widely available with further long term follow-up in particular.

Abscess, bronchial thermoplasty, safety, severe asthma

Background Asthma is a complex inflammatory disorder affecting the airways with growing global burden. A significant subgroup of asthma patients, estimated to be between 5 and 10% [1] have disease resistant to conventional treatments and have poor quality of life and suffer severe exacerbations of asthma requiring recurrent hospitalization [2]. Bronchial thermoplasty (BT) is the only treatment modality for severe asthma patients that targets smooth muscle directly [3]. Over a series of three bronchoscopies, controlled doses of thermal energy are applied to segments of airway smooth muscle through radiofrequency ablation. This is thought to reduce airway hyperresponsiveness and bronchoconstriction in asthma attacks [4]. It has been shown to improve quality of life, reduce severe exacerbation and hospital admissions [5]. The European Respiratory Society and American Thoracic Society guidelines (2014) recommend BT for adult patients with severe asthma if institutionally approved or in the context of a clinical study [6]. In this case, we report a lung abscess as an immediate complication of BT, which we believe may be the first such early complication of BT.

Case report The patient was a forty-three year old Caucasian female with a background of poorly controlled severe asthma and bipolar Correspondence: Dr Robert Niven, Department of Respiratory Medicine, University Hospital South Manchester, Southmoor Road, Wythenshawe, Manchester M23 9LT, UK. E-mail: [email protected]

History Received 28 October 2014 Revised 29 December 2014 Accepted 5 January 2015 Published online 13 March 2015

disorder. She had previously failed treatment with Xolair (Omalizumab) and had previously been admitted to High Dependency Unit (HDU) on one occasion. Despite step 5 British Thoracic Society treatment (maintenance oral corticosteroids) for her asthma, she had recurrent admissions to hospital for asthma exacerbations requiring emergency rescue medication. Having previously had bronchial thermoplasty (BT) to her right lower lobe and a good response, she had her second treatment to the left lower lobe with 48 complete tissue activations in an uncomplicated procedure using sterile technique and equipment. During the procedure, the airways were noted to be clear and normal in appearance. She was admitted three days post bronchial thermoplasty with a three day history of left sided chest pain radiating round to the back – worse on inspiration associated with increased shortness of breath, wheeze and a dry cough. She had felt hot and cold and generally unwell over this period. On examination she was tachypneic (RR – 29) with bilateral wheeze throughout. A chest X-ray showed minimal inflammatory shadowing in the left lower zone with no collapse/atelectasis or organized local lesion. CRP was 44 mg/L with mildly raised white blood cells (WBC – 11.1), neutrophilia (neutrophils – 12.47). Peripheral blood eosinophils were 0.34  109/L as compared to 0.24  109/L pre-procedure. She was treated initially as an acute exacerbation of asthma and given steroids, IV aminophylline and empiric oral amoxicillin-clavulanate. Despite five days of oral antibiotics and high dose steroids, her symptoms of pleuritic pain and wheeze continued to worsen and her inflammatory markers remained raised.

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A. Balu et al.

Peripheral blood eosinophils peaked at 0.66 day 5 post procedure although she remained apyrexial. She was escalated to IV Tazocin. Repeat chest X-ray showed linear atelectasis at the left base. High-resolution CT-chest (HRCT) was performed on day 11 to further evaluate (Figure 1). This demonstrated an area of pulmonary necrosis in the posterior segment of the left lower lobe with associated bronchial narrowing medially and surrounding consolidation. The case was discussed at chest radiology MDT and the consensus was a diagnosis of lung abscess with associated asthma exacerbation post bronchial thermoplasty. Pulmonary infarction was considered as a differential diagnosis, however the radiological findings were considered consistent with abscess rather than infarction. She was continued on IV Tazocin and went on to have a follow-up bronchoscopy with bronchoalveolar lavage (BAL) on day 19. This demonstrated minimal secretions in the left lower lobe. All airways were patent and clear with no evidence of obstruction. BAL cultures were negative for acidfast bacilli, fungi and bacteria although fungal elements were seen on one of the cultures. Thoracentesis was not performed as there was an insufficient amount of pleural fluid. Post bronchoscopy, the patient was started on a six week course of oral clindamycin to treat her lung abscess. The patient was reviewed six weeks later in clinic. Her inflammatory markers had returned to normal ranges, including CRP and eosinophils and a repeat chest X-ray showed some residual atelectasis. A repeat HRCT chest was done at four months post abscess which showed complete resolution of the abscess and atelectasis with a small residual bronchocele within subsegmental branches of the posterior segment of the left lower lobe. Her symptoms of chest pain are now completely resolved, however her asthma is not yet well controlled and she has been steroid dependent (40 mg prednisolone once daily) since discharge from hospital post abscess. Accordingly, a decision regarding her third and final BT treatment has been deferred until her asthma is better controlled.

J Asthma, Early Online: 1–3

Discussion A study followed up 69 patients from the Asthma Intervention Research (AIR) trial for five years and published their longterm safety findings [7]. Of the 45 BT-treated patients, one patient went onto develop a lung abscess in previously treated left upper lobe at 14 months post treatment [7]. This was considered secondary to infection and any obstruction or potential treatment-related contribution was ruled out in histological analysis of the dissected tissue when treated with surgical resection. The AIR-2 trial [5] acknowledged that BT subjects were more likely to suffer respiratory adverse events compared to subjects from the sham group in the initial six weeks post treatment (85% vs 76%). BT subjects were also significantly more likely to be hospitalized within the first six weeks (19 vs 2) compared to sham subjects [5]. This is offset during the post-treatment period (more than six weeks post BT) where BT patients realized the benefits of treatment with fewer exacerbations and hospital admissions. This six week window post treatment has been highlighted as a window of vulnerability for BT patients and underlines the need for close monitoring in this period. A further study [8] which evaluated the long-term safety data from AIR-2 after five-year follow-up with 162 patients showed no change in respiratory adverse events or hospital admissions in years two to five compared to year one. Interestingly, the patients in this study had annual high-resolution CT (HRCT) chest from baseline to five years which demonstrated no structural changes related to BT. The patient had a pre-BT CT which showed widespread bronchial wall thickening with very minimal right upper lobe bronchial dilatation and multifocal air trapping. This was felt to be stable in comparison to a previous CT scan two years prior with no overt features of bronchiectasis or fungal disease. In particular, there was no pre-existing abnormality in the left lower lobe that would account for increased susceptibility to abscess formation. We are uncertain why the patient in this case developed a lung abscess and specifically so immediately post treatment. The most likely explanation is transient localised airway obstruction although the medial bronchial narrowing on CT-chest points to a longer period of obstruction. The patient had no previous history of recurrent lower respiratory tract infections and had normal functional antibodies to haemophilus influenza and pneumococcus. Allergic bronchopulmonary aspergillosis (ABPA) had previously been screened for and excluded. One of the difficulties of this case was that there was no feature before, during or after her bronchoscopy that could have predicted the development of her abscess. In particular, she had no significant difference in pain symptoms, she tolerated the procedure well.


Figure 1. HRCT chest (lung abscess).

BT has been validated in a robust randomized sham-control study and has also been found to be safe after five years follow-up. We report an acute lung abscess post BT, possibly the first reported such complication of BT. There is a need for further long-term follow-up data with larger numbers of patients as the procedure becomes more available. The only two long-term follow-up studies (from AIR and AIR-2) thus far used 69 and 162, patients respectively. Both studies monitored pulmonary function tests. Patients from AIR-2 also

DOI: 10.3109/02770903.2015.1005844

Lung abscess as a complication of bronchial thermoplasty

had HRCT monitoring, however no studies have repeated biopsies so far to evaluate the actual effect on airway smooth muscle and remodeling. Another challenge in the future will be characterizing responders and non-responders by phenotype and perhaps even genotype.

2. Moore W, Bleecker E, Curran-Everett D, Erzurum S, Ameredes B, Bacharier L, Calhoun W, et al. Characterization of the severe asthma phenotype by the national heart, lung, and blood institute’s severe asthma research program. J Allergy Clin Immunol 2007;119: 405–413. 3. Cox P, Miller J, Mitzner W, Leff A. Radiofrequency ablation of airway smooth muscle for sustained treatment of asthma: preliminary investigations. Eur Respir J 2004;24:659–663. 4. Mitzner W. Bronchial thermoplasty in asthma. Allergol Int 2006; 55:225–234. 5. Castro M, Rubin A, Laviolette M, Fiterman J, De Andrade Lima M, Shah P, Fiss E, et al: Effectiveness and safety of bronchial thermoplasty in the treatment of severe asthma: a multicenter, randomized, double-blind, sham-controlled clinical trial. Am J Respir Crit Care Med 2010;181:116–124. 6. Chung K, Wenzel S, Brozek J, et al. International ERS/ATS guidelines on definition, evaluation and treatment of severe asthma. Eur Respir J 2013;43:343–373. 7. Thomson N, Rubin A, Niven R, Corris P, Siersted H, Olivenstein R, Pavord I, et al. Long-term (5 year) safety of bronchial thermoplasty: asthma Intervention Research (AIR) trial. BMC Pulmonary Med 2011;11:8. 8. Wechsler M, Laviolette M, Rubin A, Fiterman J, Lapa E Silva J, Shah P, Fiss E, et al: Bronchial thermoplasty: long-term safety and effectiveness in patients with severe persistent asthma. J Allergy Clin Immunol 2013;132:1295–1302.

Declaration of Interest The authors report no conflict of interest.


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Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.

References 1. Barnes P, Woolcock A. Difficult asthma. Eur Respir J 1998;12: 1209–1218.


Lung abscess as a complication of bronchial thermoplasty.

Bronchial thermoplasty (BT) is an emerging treatment modality for patients with difficult to treat asthma. It has been shown to be beneficial for symp...
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