Methodological Aspects of Bronchoscopic Lung Volume Reduction with a Proprietary System

Clinical evaluation of endoscopic bronchial occlusion with silicone spigots for the management of persistent pulmonary air leaks

OBJECTIVE

The aim of this study was to evaluate the clinical effectiveness of endoscopic bronchial occlusion (EBO) with endobronchial Watanabe spigots (EWSs), a type of silicone bronchial blocker, for managing prolonged pulmonary air leaks.

PATIENTS AND METHODS

Between October 2002 and April 2010, 24 patients with surgically incurable pulmonary air leaks underwent EBO with EWSs. The spigot was grasped with forceps and inserted into the affected bronchus by using a flexible bronchoscope through an endotracheal or a tracheostomy tube.

RESULTS

In each patient, at least one EWS (mean=2.8) was placed for air leaks due to pneumothorax (n=15), empyema (n=8), or postsurgical complications (n=1). Twelve patients (50%) had complete resolution of the air leaks and seven (29.2%) had a reduction in air leaks, but five (20.8%) showed no improvement. Twenty-three patients required thoracic drainage tubes, which were successfully removed after EBO in 15 patients (65.2%). Of the 24 patients, four experienced severe respiratory failure requiring mechanical ventilation but were successfully treated. Complications were spigot migration, atelectasis, pneumonia, and lung abscess, but none caused significant mortality.

CONCLUSION

EBO with EWSs seems to be a reasonable and manageable treatment option for patients with prolonged pulmonary air leaks, including those with severe respiratory failure requiring mechanical ventilation.

Reduction of persistent air leak with endoscopic valve implants

The standard management of air leaks due to persistent bronchopleural fistula involves chest drainage and occasionally pleurodesis, with intractable cases requiring surgical decortication or surgical repair. However, some of these patients may be at high risk for surgery, particularly if they have already had thoracic surgery or have other medical problems; for this group there is a need for less invasive methods of stopping or reducing air leaks. Emphasys endobronchial valves (EBV) are occlusive devices designed primarily for endoscopic lung volume reduction in emphysema. Because the device is a one-way inspiratory airway blocker, it is possible that it could be used in controlling persistent air leaks while maintaining the drainage of secretions. Two cases are reported of persistent air leaks that were managed by endoscopic occlusion with EBV. In one case complete stoppage of the air leak was achieved with immediate clinical benefits. The second patient died 5 days after treatment from additional complications apparently not related to the procedure. Endobronchial blockage may be a useful salvage procedure for patients with persistent air leak for whom there is no other treatment available.

Bronchoscopic lung volume reduction: indications, effects and prospects

PURPOSE OF REVIEW

Despite optimal pharmacological treatment, many patients with chronic obstructive pulmonary disease remain very disabled. Bronchoscopic lung volume reduction involves the insertion of valves into the airways supplying emphysematous areas of lung with the intention of causing atelectasis and thus improving operating lung volumes. Bronchoscopic techniques are less hazardous than lung volume reduction surgery.

RECENT FINDINGS

Case series in the literature are reviewed. The presence of extensive pathological collateral ventilation, particularly in patients with homogeneous disease, means that atelectasis occurs relatively infrequently even with complete lobar occlusion. Benefit is greatest in the presence of atelectasis but does not occur only in this group of patients. Endobronchial valves have also been used to treat persistent air leaks in a number of clinical contexts.

SUMMARY

A number of case series have been published which show promise and the results of a large multicentre randomized controlled study are anticipated in 2007. A number of other bronchoscopic treatments for emphysema are also under development, including airway bypass techniques and tissue glues.

Transbronchoscopic Pulmonary Emphysema Treatment

OBJECTIVE

Describe the results of a 1- to 24-month follow-up of individuals undergoing transbronchoscopic placement of one-way valves.

DESIGN

Longitudinal, noncomparative study.

SETTING

University hospital.

PATIENTS

Nineteen heterogeneous emphysema patients.

MEASUREMENTS AND RESULTS

Pulmonary function testing, imaging examination, and videobronchoscopy were performed at 1, 3, 6, 12, and 24 months after the insertion of one-way valves. Mean age was 67.63 +/- 8.71 years, mean body mass index (BMI) was 24.02 +/- 2.65, and mean exposure to smoking was 65.32 +/- 27.46 pack-years (+/- SD). Baseline BODE index (BMI, degree of airflow obstruction and dyspnea, exercise capacity as measured by the 6-min walk test [6MWT]) was 7 to 10 in 10 patients (estimated 4-year mortality, 80%) and 5 to 6 in 9 patients (estimated 4-year mortality, 40%). Sixty-four valves were inserted. There was no procedure-related mortality. Nonsustained atelectasis was observed within 48 h in 2 of 12 patients with right upper lobe occlusion. Fifty-six bronchoscopic examinations were performed in 24 months. Granulomas not requiring treatment were the main complication. Mucus clogging the valve, mainly at 1 month, was easily cleaned. Eighteen patients completed the 1- and 3-month follow-ups, 14 patients completed the 6-month follow-up, 11 patients completed the 12-month follow-up, and 5 patients completed the 24-month follow-up. Improvement was observed in the 6MWT after 1 month (p = 0.028) and in the BODE index at 3 months (p = 0.002). FEV1 or FVC improvement > or = 12% or > or = 150 mL was observed, respectively, in 4 of 18 patients and 8 of 18 patients at 1 month, 4 of 18 patients and 7 of 18 patients at 3 months, and in 3 of 14 patients and 5 of 14 patients at 6 months. After 24 months, one of five patients and three of five patients, respectively, retained an FEV1 and FVC change > or = 12% or > or = 150 mL. Significant improvement (decrease > or = 4%) in the St. George Respiratory Questionnaire was observed at 3 months and 6 months in three of four domains.

CONCLUSION

Endobronchial valves are safe, but the criteria to measure improvement and to select patients should be refined. Atelectasis should be reconsidered as primary treatment goal.

Bronchoscopic Lung Volume Reduction for End-Stage Emphysema

OBJECTIVES

To report the first multicenter experience on the treatment of end-stage emphysema using an endobronchial valve (EBV) [Emphasys EBV; Emphasys Medical; Redwood City, CA].

DESIGN

Retrospective analysis from prospective multicenter registry.

PATIENTS AND INTERVENTIONS

This is a study of the use of EBVs in the treatment of end-stage emphysema at nine centers in seven countries. Ninety-eight patients with mean FEV(1) of 0.9 +/- 0.3 L (30.1 +/- 10.7% of predicted) [+/- SD] and residual volume (RV) of 5.1 +/- 1.3 L (244.3 +/- 0.3% of predicted) were treated over a period of 20 months. Spirometry, plethysmography, and diffusing capacity of the lung for carbon monoxide (Dlco) and exercise tolerance testing were performed at 30 days and 90 days after the procedure.

RESULTS

RV decreased by 4.9 +/- 17.4% (p = 0.025), FEV(1) increased by 10.7 +/- 26.2% (p = 0.007), FVC increased by 9.0 +/- 23.9% (p = 0.024), and 6-min walk distance increased by 23.0 + 55.3% (p = 0.001). There was a trend toward improvement in Dlco, but this did not reach statistical significance (17.2 +/- 52.0%, p = 0.063). Patients treated unilaterally showed a trend toward greater improvement than those treated bilaterally. A similar trend toward improvement was observed in patients who had one entire lobe treated compared to those with just one or two bronchopulmonary segments treated. Eight patients (8.2%) had serious complications in the first 90 days, including one death (1.0%).

CONCLUSION

This multicenter analysis confirms that improvement in pulmonary function and exercise tolerance can be achieved in emphysematous patients using EBVs. Future efforts should be directed to determining how to select those patients who would benefit most from this procedure and the best endobronchial treatment strategy.

Respiratory impedance following bronchoscopic or surgical lung volume reduction for emphysema

BACKGROUND

Bronchoscopic methods for achieving lung volume reduction (BLVR) are presently undergoing clinical trials, and will soon be clinically available. Understanding the differential effects of surgical volume reduction therapy (LVRS) and BLVR on lung and chest wall physiology will assist physicians in selecting an optimal approach for patients.

OBJECTIVES

Determine whether LVRS adversely affects lung or chest wall physiology at 3-month follow-up relative to BLVR in an experimental model of sheep emphysema.

METHODS

Twelve mixed-breed sheep were treated with papain to produce experimental emphysema, and were divided into control, LVRS, and BLVR treatment groups. Lung and chest wall impedance was measured at 0, 5, and 10 cm H2O positive end-expiratory pressure at baseline and 3-month follow-up.

RESULTS

Emphysema was associated with increased airway resistance, decreased lung tissue resistance and elastance, and increased chest wall tissue resistance. Following treatment, equivalent increases in lung elastance occurred in the LVRS and BLVR groups compared to controls. LVRS did not adversely affect chest wall impedance despite causing extensive pleural scarring.

CONCLUSIONS

(1) Experimental emphysema following prolonged papain exposure progresses after cessation of treatment. (2) BLVR and LVRS produced equivalent lung and chest wall impedance responses at 3-month follow-up. (3) LVRS did not adversely affect chest wall impedance despite being associated with extensive pleural scarring.

[VENT: International study of bronchoscopic lung volume reduction as a palliative treatment for emphysema]

BACKGROUND

Therapeutic options for patients with severe emphysema remain limited. In selected patients, lung volume reduction surgery has been shown to improve pulmonary function, exercise capacity, quality of life and also survival. The technique of inserting one-way valves endoscopically into the airways supplying the most affected areas of lung provides the possibility of achieving similar results to surgery (i.e. volume reduction) in a less invasive way, which is also reversible, since the valves can be removed at any time. This technique has been shown to be safe. The aim of this study is to evaluate the efficacy of this technique compared to optimal medical therapy in patients with heterogeneous emphysema defined according to radiological criteria.

METHODS

A prospective, international, multicentre (20 centres) randomised trial is underway to establish the efficacy and safety of endobronchial valve placement in this patient group. This study will enrol 270 patients and be analysed on an intention to treat basis. Patients are randomised either to valve insertion or optimal medical treatment alone in a ratio of 2 to 1. Follow up will be ensured for at least one year.

EXPECTED RESULTS

The two principal outcome measures will be improvement at six months in FEV1 and in six minute walk distance. The safety of the technique will be evaluated over the same period. Details of the study are available online for patients and their physicians at www.euroemphysema.com.

Effect of bronchoscopic lung volume reduction on dynamic hyperinflation and exercise in emphysema

Endobronchial valve placement improves pulmonary function in some patients with chronic obstructive pulmonary disease, but its effects on exercise physiology have not been investigated. In 19 patients with a mean (SD) FEV(1) of 28.4 (11.9)% predicted, studied before and 4 weeks after unilateral valve insertion, functional residual capacity decreased from 7.1 (1.5) to 6.6 (1.7) L (p = 0.03) and diffusing capacity rose from 3.3 (1.1) to 3.7 (1.2) mmol . minute(-1) . kPa(-1) (p = 0.03). Cycle endurance time at 80% of peak workload increased from 227 (129) to 315 (195) seconds (p = 0.03). This was associated with a reduction in end-expiratory lung volume at peak exercise from 7.6 (1.6) to 7.2 (1.7) L (p = 0.03). Using stepwise logistic regression analysis, a model containing changes in transfer factor and resting inspiratory capacity explained 81% of the variation in change in exercise time (p < 0.0001). The same variables were retained if the five patients with radiologic atelectasis were excluded from analysis. In a subgroup of patients in whom invasive measurements were performed, improvement in exercise capacity was associated with a reduction in lung compliance (r(2) = 0.43; p = 0.03) and isotime esophageal pressure-time product (r(2) = 0.47; p = 0.03). Endobronchial valve placement can improve lung volumes and gas transfer in patients with chronic obstructive pulmonary disease and prolong exercise time by reducing dynamic hyperinflation.