{'fraction_non_alphanumeric': 0.019543973941368076, 'fraction_numerical': 0.0054288816503800215, 'mean_word_length': 5.06140350877193, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Bronchoscopic Management of Central Airway Obstruction Secondary to Rheumatoid Arthritis.

HRCT (Figs. 1A, B) revealed bullous emphysema predominantly in the right lower lobe (RLL) with secondary atelectasis of middle and upper lobes. The major fissure was considered to be radiologically complete. HRCT scans analyzed using VIDA System confirmed integrity of the right major fissure. Chartis system confirmed absence of collateral ventilation. Endobronchial valves were placed in the RLL. Three 4.0mm were placed, including 2 in the basal segments and 1 in segment VI. He was successfully weaned off noninvasive mechanical ventilation. Chest x-ray and chest computed tomographic scan revealed RLL volume reduction and reexpansion of right middle lobe and right upper lobe (Figs. 1C, D). At 36 hours following the treatment, patient developed a pneumothorax that required chest tube placement. He was discharge home after 4 days. Two weeks later, he reported coughing out one valve and an increase in dyspnea. Images revealed an increase in size of RLL bulla. A comprehensive measurement of bronchial diameter of right segment VI was obtained by tomography, and bronchial anatomy was again evaluated at a repeat flexible bronchoscopy. It appeared that the dimension of bronchial sub segment VI had significantly changed. Repeat measurement reveled that it was now 6mm in diameter and 8mm in length (Figs. 1E, F). A 5.5mm valve was successfully replaced. The patient had reduction in the volume of bulla and there was no recurrence of the pneumothorax. This case reports a change in bronchial diameter after a valve placement and the satisfactory reduction of lung volume after placing a larger diameter valve. We hypothesize that the occurrence of the observed phenomenon was caused by the change in the bronchial anatomy following the EBVR. First, the patient presented with atelectasis of the right upper lobe and right middle lobe due to extensive bullous emphysema of the RLL. Second, once valves were placed in basal segments, the segmental VI bronchus may have shifted posteriorly, increasing its diameter. Third, the development and resolution of pneumothorax can also stimulate changes in the bronchial anatomy of affected segments.4 Fourth, a relevant consideration is that a coneshaped bronchial segment could cause valve placement to be challenging and increase the possibility of valve migration. The patient described in this report developed cough that led to the expulsion of a valve that was likely too small for his new bronchial anatomy. We must consider potential postprocedure changes in the diameters and/or shapes of bronchial segments while placing endobronchial valves for bullous emphysema and resultant atelectasis of the adjacent lobes.