Hiroki Nishine

Assessing the Site of Maximal Obstruction in the Trachea Using Lateral Pressure Measurement during Bronchoscopy

RATIONALE Lateral airway pressure can provide valuable physiological information during bronchoscopy. OBJECTIVES To evaluate tracheal obstruction during intervention. METHODS To prospectively measure lateral airway pressure during bronchoscopy using a double-lumen catheter in 15 healthy subjects and 30 patients with tracheal obstruction. Pressure difference was used to evaluate the site of maximal obstruction. The angle between pressure recordings on either side of the stenosis was measured simultaneously (pressure-pressure curves) to assess the degree of tracheal obstruction. MEASUREMENTS AND MAIN RESULTS In the experimental study, the angle of the pressure-pressure curve was unaffected by breathing maneuvers whereas the pressure difference was affected. In healthy subjects, no pressure difference between the carina and trachea was observed during tidal breathing, and the angle was close to 45°. In patients with tracheal obstruction, the dyspnea scale, pressure difference, and angle changed significantly beyond 50% obstruction (P<0.0001). After stenting, the pressure difference disappeared and the angle was close to 45°. The degree of tracheal obstruction was significantly correlated with the pressure difference (r=0.83, P<0.0001) and angle (r=-0.84, P<0.0001). The cross-sectional area, dyspnea scale, pulmonary function tests, pressure difference, and the angle significantly improved after procedures (P<0.0001). Responder rates on the modified Medical Research Council Scale were 84.6% for obstructions above 80%, and 58.8% for obstructions between 50 and 80%. CONCLUSIONS The direct measurement of pressure difference and the angle of the pressure-pressure curve represent a new assessment modality for the success of interventional bronchoscopy. Measuring lateral airway pressure could estimate the need for additional procedures better than bronchoscopy alone.

Cell therapy with adipose tissue-derived stem/stromal cells for elastase-induced pulmonary emphysema in rats

AIMS The purpose of this study was to elucidate the mechanism underlying the effects of adipose tissue-derived stem/stromal cell (ASC) transplantation on porcine pancreatic elastase-induced emphysema. MATERIALS & METHODS ASCs (2.5 × 10(6)) were transplanted into pancreatic elastase (250 U/kg)-treated rats, after which gas exchange and growth factor/cytokine levels in lung tissue were determined. RESULTS ASC transplantation restored pulmonary function (arterial oxygen tension and alveolar-arterial oxygen tension difference) almost to that of normal animals. Enlargement of the alveolar airspaces was inhibited. HGF and CINC-1 levels were significantly higher in the ASC group even at 2 weeks after transplantation. Sponge implantation with CINC-1 induced neovascular formation with increased HGF. In vitro secretion of HGF and CINC-1 from ASCs was promoted in the presence of IL-1β. CONCLUSION Not only HGF, but also CINC-1, secreted from transplanted and viable ASCs presumably contributed to lung repair through angiogenesis.

Novel Multimodality Imaging and Physiologic Assessments Clarify Choke-Point Physiology and Airway Wall Structure in Expiratory Central Airway Collapse

Choke points and airway wall structure in expiratory central airway collapse are poorly defined. Computed tomography, white light bronchoscopy, endobronchial ultrasound, vibration response imaging, spirometry, impulse oscillometry, negative expiratory pressure, and intraluminal catheter airway pressure measurements were used in a patient with cough, dyspnea, and recurrent pulmonary infections. Computed tomography and white light bronchoscopy identified dynamic collapse of the trachea and mainstem bronchi, consistent with severe crescent tracheobronchomalacia. Spirometry showed severe obstruction. Endobronchial ultrasound revealed collapse of the airway cartilage, and vibration response imaging revealed fluttering at both lung zones. Impulse oscillometry and negative expiratory pressure suggested tidal expiratory flow limitation in the intrathoracic airways. Intraluminal catheter airway pressure measurements identified the choke point in the lower trachea. After Y-stent insertion, the choke point migrated distally. Imaging studies revealed improved airway dynamics, airway patency, and ventilatory function. Novel imaging and physiologic assessments could be used to localize choke points and airway wall structure in tracheobronchomalacia.

New technique for endobronchial ultrasound-guided transbronchial needle aspiration to improve diagnostic yield.

Background:Although the pooled sensitivity of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) using a convex scanning ultrasound bronchoscope is equivalent to the gold standard of mediastinoscopy, diagnosis cannot be obtained in a small number of patients with poor cellularity. The method described was investigated with the aim of avoiding puncturing the cartilage and enabling reliable tissue harvesting, as this can be expected to improve diagnostic yield. Methods:Outer sheath method (OSM): While pressing the outer sheath (OS) of the puncture needle gently against the bronchial wall, the hyperechoic line appeared on surface of the bronchial wall on EBUS image. Then pulling and pushing the entire bronchoscope, the tip of OS moved to the epithelium above the bronchial cartilage while detecting the best position for puncturing on the EBUS images simultaneously. The bronchoscopist could visualize the cartilage moving longitudinally on EBUS image. The movement of the cartilage was stopped when the tip of the OS was caught in a concavity between 2 rings of cartilage. Group A consisted of 169 patients who underwent EBUS-TBNA before the introduction of OSM, and group B consisted of 169 patients who underwent EBUS-TBNA after the introduction of OSM. These 2 groups were compared with to investigate the usefulness of OSM. Results:Adding this operation enabled a suitable puncture site to be identified, significantly improving diagnostic yield from 92.7% (group A) to 98.2% (group B). Conclusions:This method was regarded as useful for improving diagnostic yield by enabling the selection of a puncture site between rings of cartilage during EBUS-TBNA.

Intractable pneumothorax managed by talc pleurodesis and bronchial occlusion with spigots.

Three cases of inoperable secondary spontaneous pneumothorax were diagnosed in patients with chronic obstructive pulmonary disease. Two cases initially underwent bronchial occlusion with endobronchial Watanabe spigot (EWS), while one underwent talc poudrage with pleuroscopy. As air leaks were not stopped completely in all cases with the initial procedures, we performed additional interventional treatments: pleuroscopic talc poudrage in cases when bronchial occlusion was performed first; and bronchial occlusion with EWS for a case that initially underwent talc pleurodesis. The air leaks ceased in all cases without complication. We successfully removed chest tubes 2–10 days after secondary procedure, which was 10–23 days after the first procedure. The combination of talc pleurodesis and bronchial occlusion with EWS, when a single, initial interventional treatment fails, can be considered in cases of intractable, inoperable secondary pneumothorax.

Vibration response imaging in healthy Japanesesubjects

BACKGROUND Vibration response imaging (VRI) records the intensity and distribution of lung sounds during the respiration cycle. Our objective was to analyze VRI findings in healthy Japanese adults. METHODS VRI images of 106 healthy subjects (33.7±9.6 years, 52 male and 54 female), including 67 nonsmokers and 39 asymptomatic smokers, were recorded. The regional intensity of vibrations was assessed using quantitative lung data (QLD), and VRI dynamic images by rater assessment, left and right lung asynchrony (gap index), and regional lung asynchrony (asynchrony score). RESULTS A dominance of total left lung QLD was observed in all subjects, and this phenomenon was more prominent in female subjects. However, there was no significant difference between the total left and total right lung QLD in smokers. Rater assessments showed that 81.1% of all subjects had a normal final assessment. Male subjects had a significantly higher percentage of good or normal assessments for all image scores, except dynamic image scoring. The asynchrony score was significantly higher in female subjects. There were no significant differences in these qualitative assessments between non-smokers and smokers. CONCLUSIONS Although our QLD results were similar to those of a previous report, there were discrepancies between sexes for the qualitative assessments. A significantly higher number of female subjects had abnormal images as assessed by the raters. Furthermore, significantly higher asynchrony scores were observed in female subjects. The VRI variability in sex may be considered normal among the Japanese population. This study is registered with UMIN-CTR under registration number UMIN000002355.

The Correlation between Lung Sound Distribution and Pulmonary Function in COPD Patients

Background Regional lung sound intensity in chronic obstructive pulmonary disease (COPD) patients is influenced by the severity and distribution of emphysema, obstructed peripheral airways, and altered ribcage and diaphragm configurations and movements due to hyperinflation. Changes in the lung sound distribution accompanied by pulmonary function improvements in COPD patients were observed after bronchodilator inhalation. We investigated the association of lung sound distribution with pulmonary functions, and the effects of emphysematous lesions on this association. These studies were designed to acquire the basic knowledge necessary for the application of lung sound analysis in the physiological evaluation of COPD patients. Methods Pulmonary function tests and the percentage of upper- and lower-lung sound intensity (quantitative lung data [QLD]) were evaluated in 47 stable male COPD patients (54 - 82 years of age). In 39 patients, computed tomography taken within 6 months of the study was available and analyzed. Results The ratio of lower QLD to upper QLD showed significant positive correlations with FEV1 %predicted (%FEV1; ρ = 0.45, p<0.005) and MEF50 %predicted (%MEF50; ρ = 0.46, p<0.005). These correlations were not observed in COPD patients with dominant emphysema (% low attenuation area >40%, n = 20) and were stronger in less emphysematous patients (n = 19, %FEV1; ρ = 0.64, p<0.005, %MEF50; ρ = 0.71, p<0.001). Conclusions In COPD patients, the ratio of lower- to upper-lung sound intensities decreased according to the severity of obstructive changes, although emphysematous lesions considerably affected lung sound distribution.

Assessment of Bronchial Obstruction Using Lateral Pressure Measurement during Bronchoscopy

Background: 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. Objectives: The aim of this study was to physiologically evaluate bronchial obstruction during interventional bronchoscopy. Methods: We prospectively measured lateral airway pressure (Plat) 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. Results: In the experimental study, Plat 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 (r = –0.51, p < 0.01). Dyspnea significantly increased when the airway lumen was obstructed by more than 60% (p < 0.0001), and when the P-P curve appeared loop-shaped (p < 0.01). Conclusions: 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 bronchial obstruction.

Regional Lung Sound Asynchrony in Chronic Obstructive Pulmonary Disease Patients

Background: Regional lung sound distribution in chronic obstructive pulmonary disease (COPD) is reported to be asynchronous. Mathematical analyses using vibration response imaging (VRI), such as left and right lung asynchrony (gap index; GI) and regional lung asynchrony (asynchrony score; AS), are useful measures to evaluate lung sound asynchrony. Objectives: The aim of this study was to investigate the association of lung sound asynchrony with pulmonary functions and emphysematous lesions in COPD patients. Methods: VRI recordings and pulmonary function tests were performed in 46 stable male COPD patients and in 40 healthy male smokers. Lung sound asynchrony was evaluated using GI, AS of the left and right lung (AS L-R), and AS of the upper and lower lung (AS U-L). In 38 patients, computed tomography taken within 6 months was available and analyzed. Results: AS L-R and AS U-L were significantly higher in COPD patients than in healthy smokers, with no significant difference in GI. There were no significant correlations with either AS and pulmonary functions, excluding a negative correlation between AS U-L and diffusion capacity. Although there were no significant correlations between both AS and severity of emphysema, significant positive correlations were observed between heterogeneity of emphysematous lesions and AS L-R (ρ = 0.38, p < 0.05) or AS U-L (ρ = 0.51, p < 0.005). Conclusions: Regional lung sounds are distributed more asynchronously in COPD patients than in healthy smokers, which correlates with the heterogeneous distribution of emphysematous lesions.

Broncholithiasis Assessed by Bronchoscopic Saline Solution Injection

A 68-year-old man was admitted with hemoptysis. Bronchoscopy showed bronchial obstruction at the right B(3)bii proximal to the broncholith. The distal end of the bronchoscope was placed in a wedge position at the right B(3)bii. After repeated injection of saline solution through the working channel of the bronchoscope, we observed that the broncholith was freed from the bronchial wall. The broncholith was easily removed with forceps through the working channel of the bronchoscope. Bronchoscopic saline solution injection was safe and effective in confirming the mobility of the broncholith as bronchoscopy alone could not detect the broncholiths due to bronchial occlusion.