Bronchoscopic lung volume reduction (BLVR) may be considered in Chronic Obstructive Pulmonary Disease (COPD) patients with advance emphysema who are symptomatic and have refractory hyperinflation despite optimal medical therapy and pulmonary rehabilitation (PR) [1]. The 2016 Expert Panel Report on Endoscopic Lung Volume Reduction focused on the patient selection and discussed available endoscopic techniques [1]. In 2017, researchers indicated that patients should receive optimal medical therapy as defined by the Global Initiative for Chronic Obstructive Lung Disease [2] and they have completed PR or a structured physical therapy program and quit smoking definitively [3].

Different techniques are used in BLVR and it basically shows treatment efficiency with four main mechanisms. These mechanisms include nonsurgical volume reduction effect, restoration of lung elasticity, rearrangement of airflow by creating new airways, and reduction of bronchoconstriction by ablation of the parasympathetic nerve [4]. The endoscopic methods used are summarized in Table 1. There are studies showing that exercise capacity increases after the application of the valve and coil technique [5,6]. Most of the studies on this subject are related to valve cases [6] and there is a need to present the results of coil case series. In addition, there are studies showing that exercise capacity increases in patients who undergo PR after the bronchoscopic procedure [7]. The effect of PR before the procedure on the post-procedure clinical status is not fully known.

The content of PR that should be applied in BLVR is not a clear. The COPD PR program content applied to patients with bronchoscopic intervention. This program includes chest hygiene techniques, breathing exercises, aerobic and strengthening training. In the guide published by European Respiratory Society and American Thoracic Society, the effectiveness of PR in Lung Volume Reduction Surgery (LVRS) is emphasized [8]. It should not be forgotten that complications such as COPD exacerbation, chest pain, mild bleeding, pneumonia, pneumothorax (px), and respiratory failure may develop after BLVR [9]. In a study, it was reported that in emphysema cases with an FEV1 of less than 20%, px developed in 20% of the cases who underwent BLVR [10]. Possible complications should be taken into consideration especially in the application of respiratory exercises and chest hygiene techniques.

The necessity of applying PR or structured physical therapy program before BLVR procedure has caused rehabilitation strategies to be included in the treatment routines of these cases. In contrast, there are very few clinical studies on PR efficacy before BLVR. On the other hand, the small number of PR centers is insufficient to compensate for the need for existing hospital-based PR programs. This situation brings up different types of PR organizations.

 In the Bronchoscopic expert panel [11] published in 2019, attention was drawn to the existence of only 2 PR clinical studies on this subject. Of these, SOLVE trial (NCT03474471) is still in recruiting status. The other study is ours, completed and published [12].

The mentioned study is a prospective randomized controlled study. Sixty-seven cases with emphysema and found to be suitable for BLVR were included in the study. Most of the patients were men. The subjects were in the middle age group and their COPD Assessment Test (CAT) score averages 25 and above. In other words, the patients were very symptomatic. We randomly divided the cases into 2 groups and applied hospital-based PR to one group and home-based PR to the other group. The program included aerobic training, resistance training and breathing exercises.  Hospital-based program involved 8 weeks of twice-weekly supervised sessions; it included education, breathing exercises, treadmill walking, cycle ergometer, arm ergometer training and strengthening training. Exercise intensity was predetermined to be 80% of the maximum heart rate, and it was gradually increased taking the severity of dyspnea perception and fatigue ratio as the basis. Strengthening training was recommended over resistance targets which were set at loads equivalent to 40% of a 1-repetition maximum (1RM). Home program included education, breathing exercises, upper and lower extremity strengthening exercise with free weights and free walking for at least four days weekly during the eight weeks. It was recommended that resistance targets were set at loads equivalent to 40% of a 1RM. We recommended daily free walking for all patients. The method of the calculating number of free walking laps based on the six-minute walk test.

Study outcome measures were 6-minute walking distance (6MWD), modified Medical Research Council (mMRC) dyspnea score, CAT and pulmonary function test parameters. After 8 weeks of exercise, both groups had a significant improvement in dyspnea and the CAT score, which is a symptomatic follow-up material. The parameter that different between the groups was the walking distance.

The important result here was the greater increase in exercise capacity in the hospital-based PR group. One of the factors that we think may affect the achievement of this result may be the differences in success rates in achieving targeted exercise intensities in home and hospital-based PR organization types. The success of reaching the target workload in unattended programs and performing all exercises within the discipline is a matter of patient initiative. In a clinical study we previously conducted with a similar methodology in COPD patients, exercise capacity was increased only in the hospital-based group [13]. In another study with online support and using face-to-face PR, the online-supported PR was noninferior to conventional model delivered in face-to-face sessions in terms of effects on 6MWD [14].

Based on the foregoing we can draw the following conclusions:

• It is a necessity for patients before BLVR to be included in the PR program.

• Symptomatic improvement and increase in exercise capacity are achieved with PR before BLVR.

• Different PR organization models can be applied to these patients, but according to the available data, hospital-based PR programs seem to be more effective in these cases.

The work has not been published before in any language, is not being considered for publication elsewhere, and has been read and approved by all authors. There are no conflicts of interest around this study.