Phase II Study of Pleurodesis using Sterile Graded Talc in Patients with Secondary Intractable Pneumothorax: Protocol for a Multicentre, Open-label Single-arm Trial

A pneumothorax can be primary or secondary. A high proportion of patients with secondary spontaneous pneumothorax are the elderly who are in poor general condition due to their impaired cardiac and pulmonary functions as well as due to other complications. Therefore, it may be difficult for these patients to undergo surgical procedures; in addition, the elderly may be at high risk for postoperative pulmonary fistula due to severe adhesions and emphysema complications. These non-operative and high-risk cases may be treated with pleurodesis (a procedure that involves instillation of a chemical or irritant into the thoracic cavity through an injection), bronchoscopic bronchial embolisation, or other procedures. In Japan, no device is currently approved for performing pleurodesis, but an approval of one device is expected soon. This will be an open-label, single-arm multicentre study conducted among 30 patients with secondary intractable pneumothorax who are not indicated to undergo surgery. The primary endpoint will be presence or absence of chest tube removal. The secondary endpoints will be the disappearance/decrease of air leakage, grade of dyspnoea, and duration of drainage. This study will assess the safety and efficacy of sterile graded talc pleurodesis in patients with secondary intractable pneumothorax.This research is (partially) supported by the Project Promoting Clinical Trials for Development of New Drugs and Medical Devices (Japan Medical Association) and Early/Exploratory Clinical Trial Center Development Projects from the Japan Agency for Medical Research and Development (AMED). This study is registered in the Center for Clinical Trials, Japan Medical Association (JMA-IIA00272)

Supplementary Material for: Assessment of Bronchial Obstruction Using Lateral Pressure Measurement during Bronchoscopy

<b><i>Background:</i></b> In patients with bronchial obstruction estimating the location of the maximal obstruction is crucial for guiding interventional bronchoscopy. However, flow-volume curves cannot discriminate between the right and left lungs. <b><i>Objectives:</i></b> The aim of this study was to physiologically evaluate bronchial obstruction during interventional bronchoscopy. <b><i>Methods:</i></b> We prospectively measured lateral airway pressure (P_lat) at either side of the obstruction using a double-lumen catheter (pressure-pressure [P-P] curve) simultaneously to assess the degree of bronchial obstruction in 22 patients. The shape of the P-P curve was assessed to confirm the site of maximal obstruction. <b><i>Results:</i></b> In the experimental study, P_lat was uniform between both bronchi in the normal model. For the unilateral and bilateral obstruction models, a phase shift was only seen for the more obstructed side. In healthy subjects, the angle of the P-P curve was close to 45° and linear in shape. In patients with bronchial obstruction, the angle was much smaller but approached 45° after the bronchoscopic procedure. The degree of bronchial obstruction was significantly correlated with the angle of the P-P curve (<i>r</i> = –0.51, <i>p</i> < 0.01). Dyspnea significantly increased when the airway lumen was obstructed by more than 60% (<i>p</i> < 0.0001), and when the P-P curve appeared loop-shaped (<i>p</i> < 0.01). <b><i>Conclusions:</i></b> The shape of the P-P curve could be used to detect the site of maximal obstruction for the optimal positioning of the stent and assess the need for additional procedures in real time in patients with<i></i> bronchial obstruction