Differences Between Central Airway Obstruction and Chronic Obstructive Pulmonary Disease Detected with the Forced Oscillation Technique.

Background: Obstructive ventilatory disturbances occur in both chronic obstructive pulmonary disease (COPD), a typical disease representative of peripheral airway obstruction, and central airway obstruction (CAO). Pulmonary function tests (PFTs), which depend on patient effort, are traditionally used to evaluate lung function. The forced oscillation technique (FOT) is an effort-independent method for examining lung function during tidal breathing. The FOT is used universally to assess respiratory function in patients with COPD. Several studies have measured FOT to assess ventilatory disturbances in CAO. The results showed that FOT measurements in patients with CAO were similar to those reported in patients with COPD. However, no studies have compared FOT measurements directly between CAO and COPD. The aim of this study was to identify differences in ventilatory disturbances between peripheral and central airway obstructions in COPD and CAO, before patients received pharmacological therapy or bronchoscopic interventions, respectively. Patients and Methods: We retrospectively included 16 patients with CAO (10 cases of tracheal obstruction and 6 cases of bronchial obstruction) and 75 treatment-naïve patients with COPD (60 cases in Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage II and 15 cases in GOLD stage III) that were admitted from December 2013 to May 2017. Prior to treatment, patients were examined with the FOT and PFTs. Results: All parameters measured with the FOT in the inspiratory phase were significantly worse in patients with CAO than in patients with COPD. The PFTs showed that the CAO group had a significantly lower peak expiratory flow rate. In the airway wall thickening phenotype of COPD, a difference between the inspiratory and expiratory phases of the resonance frequency (ΔFres) was the best indicator for distinguishing between peripheral and central airway obstructions. Conclusion: This study compared differences between CAO and COPD (mainly GOLD stage II). We found that the FOT measurement, ΔFres, was the optimal indicator of the difference between the airway wall thickening COPD phenotype and CAO. Thus, the difference might be due to mechanical changes that occur in COPD with airway wall thickening.

Virtual bronchoscopic navigation as an aid to CT-guided transbronchial biopsy improves the diagnostic yield for small peripheral pulmonary lesions.

BACKGROUND AND OBJECTIVE: Virtual bronchoscopic navigation (VBN) entails the provision of a virtual display of the bronchial routes that lead to small peripheral pulmonary lesions (PPL). It has been predicted that a combination of computed tomography (CT)-guided transbronchial biopsy (CT-TBB) with VBN might improve the diagnostic yield for small PPL. This study sought to investigate that prediction. METHODS: A total of 100 patients with small PPL (<20 mm) were enrolled for CT-TBB and randomly allocated to either a VBN+ or VBN- group (50 subjects per group). Group results were then compared in terms of diagnostic yield, whole procedure time, times at which the first CT scan and biopsy were taken and the number of lung biopsy specimens retrieved. RESULTS: The diagnostic yield for small PPL was significantly higher in the VBN+ group versus VBN- group (84% vs 58%, respectively (P = 0.013)), with no significant difference in (whole) examination time between groups (VBN+: 32:53 (32 min and 53 s) ± 12:01 vs VBN-: 33:06 ± 10:08 (P = NS)). However, the time periods between commencing the examination and either the first CT scan or first biopsy were significantly shorter for the VBN+ group, while the net biopsy time tended to be longer for this group with a significantly higher number of specimens collected (VBN+: 3.54 ± 1.07 specimens vs VBN-: 2.98 ± 1.06 specimens (P = 0.01)). CONCLUSION: Combining VBN with CT-TBB significantly improved the diagnostic yield for small PPL.

Computed tomography-guided bronchoscopy in the diagnosis of small peripheral pulmonary lesions: A retrospective study of 240 examinations in a single academic center.

BACKGROUND: Factors that affect the diagnostic yield in computed tomography (CT)-guided bronchoscopy have not yet been fully evaluated. To improve the diagnostic yield of peripheral pulmonary lesions (PPLs) by CT-guided bronchoscopy, we quantitatively analyzed factors affecting the diagnostic yield. METHODS: The data were collected for 240 PPLs in 237 patients examined by using CT-guided bronchoscopy between October 2003 and November 2011 in our respiratory center. The association of diagnostic yield with the CT bronchus sign (CT-BS), lesion size, location, number of tissue specimens, and type of bronchoscope was retrospectively assessed. RESULTS: The diagnostic yield of PPLs with negative CT-BS was significantly lower (2.9%) than that for PPLs with positive CT-BS (52.2%; p<0.01). Among the PPLs with positive CT-BS, the yield was significantly higher in those in the left S(3) than for lesions in other bronchial segments (83.3% vs. 50.3%; p<0.05). Lesion size was not significantly associated with diagnostic yield. The yield was significantly lower in PPLs without lung tissue specimens than in lesions with biopsy specimens (p<0.01). Moreover, a thin bronchoscope produced a higher yield in comparison with other bronchoscope types (66.0% vs. 47.6%; p<0.05). Multivariate analysis revealed that the number of biopsy specimens was an independent factor affecting diagnostic yield. CONCLUSIONS: CT-guided bronchoscopy is valuable in the diagnosis of PPLs with positive CT-BS regardless of lesion size; however, PPLs with negative CT-BS are not good candidates for CT-guided bronchoscopy. Obtaining tissue specimens by biopsy is a critical factor in diagnosing PPLs.

Late-onset rejection of a unilateral donor lung with vascular C4d deposition in bilateral living-donor lobar lung transplantation: an autopsy case report.

A 37-year-old woman had undergone bilateral living-donor lobar lung transplantation 11 years previously for idiopathic pulmonary arterial hypertension. Her father donated the right lobe and her brother donated the left lobe. She subsequently developed progressively worsening respiratory dysfunction due to pneumonia. CT showed left dominant pulmonary artery dilatation, bronchial wall thickening and airway stenosis, followed by sudden death. An autopsy showed marked pathologic left dominant rejection of the pulmonary artery, small airway and large airway. Notably, only the left lung showed C4d vascular deposition, thus suggesting that antibody-mediated lung rejection may have occurred.