Postintubation Tracheal Stenosis Evaluated by Endobronchial Optical Coherence Tomography: A Canine Model Study.

BACKGROUND: The predictors and airway morphological changes during the development of postintubation tracheal stenosis (PITS) have not been well elucidated. OBJECTIVES: To elucidate the validation of endobronchial optical coherence tomography (EB-OCT) in assessing the airway morphological changes in PITS. METHODS: We performed oral endotracheal intubation in 12 beagles to establish the PITS model. EB-OCT was performed respectively before modeling and on the 1st, 7th, and 12th day after extubation in 9 canines, and was conducted consecutively in 3 canines during the development of PITS. Histological findings and the thickness and gray-scale value of the tracheal wall assessed by EB-OCT measurements were analyzed and compared. RESULTS: The tracheal wall edema, granulation tissue proliferation, cartilage destruction in PITS, and airway wall thickening detected by EB-OCT were in concordance with the histopathological measurements. The consecutive EB-OCT observation of the airway structure demonstrated the tracheal wall thickness significantly increased from 344.41 ± 44.19 µm before modeling to 796.67 ± 49.75 µm on the 9th day after modeling (p < 0.05). The airway wall gray-scale values assessed by EB-OCT decreased from 111.19 ± 14.71 before modeling to 74.96 ± 4.08 on the 9th day after modeling (p < 0.05). The gray-scale value was negatively correlated with the airway wall thickness (r = -0.945, p = 0.001). CONCLUSION: The EB-OCT imaging, in concordance with the histopathological finding, was validated for assessing the airway morphological changes during the development of PITS. The EB-OCT evaluation of cartilage damage and gray-scale value measurement might help predict the development and prognosis of PITS.

Airway morphological abnormalities of bronchiolitis assessed by endobronchial optical coherence tomography.

BACKGROUND: A few studies have reported the medium-sized and small airway morphological abnormalities of bronchiolitis. Whether spirometry or impulse oscillometry (IOS) is correlated with airway remodeling of bronchiolitis remains unclear. OBJECTIVES: Aiming to demonstrate the airway morphological abnormalities of bronchiolitis obliterans (BO) and diffuse panbronchiolitis (DPB) assessed by endobronchial optical coherence tomography (EB-OCT), and elucidate whether spirometric and IOS parameters have correlation with the airway remodeling of bronchiolitis. METHODS: We recruited 18 patients with bronchiolitis (BO, n = 9; DPB, n = 9) and 17 control subjects. Assessments of clinical features, St. George's respiratory questionnaire (SGRQ), chest computed tomography (CT), spirometry, IOS, and EB-OCT were performed in all enrolled subjects. The correlation between EB-OCT and lung function parameters was studied and analyzed. RESULTS: The magnitude of abnormalities of spirometric and IOS parameters was significantly greater in patients with bronchiolitis than that in control subjects (p < 0.05). Patients with BO had notably lower forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, maximal mid-expiratory flow (MMEF)% pred and higher resonant frequency (Fres), and area of reactance (AX) than those with DPB (p < 0.05). The EB-OCT measurement among patients with bronchiolitis and between the bronchus in the left and the right lung demonstrated a heterogeneous distribution of airway calibers, presenting a high intra- and inter-individual variability. Patients with bronchiolitis had notably greater airway wall area (p < 0.05) compared with control, while BO presented greater magnitude of airway abnormalities than DPB. Fres and the difference in airway resistance at 5 and 20 Hz (R5-R20) correlated negatively with medium-sized and small airway inner area, and correlated positively with airway wall area (p < 0.05), whose correlation coefficients were higher than those of spirometric parameters. CONCLUSION: Bronchiolitis, BO and DPB, manifested a heterogeneous distribution of airway calibers with significant intra- and inter-individual variability. IOS parameters, rather than spirometry, correlated better with medium-sized and small airway remodeling in bronchiolitis assessed by EB-OCT measurement.

[Clinical Application of Preoperative Autologous Blood Donation in Selective General Surgery].

OBJECTIVE: To study the clinical effects of preoperative autologous blood donation (PABD) in selective general surgery. METHODS: Paired study was performed in PABD group with 70 PABD cases screened from selective general surgery during the period from November 2017 to August 2018 in our hospital, and the control group included 70 cases without preoperative autologous blood donation, the baseline data before surgery were not significantly different. The transfusion quantities of allogeneic RBC and plasma, the levels of perioperative hemoglobin and platelets, the time and expense of hospitalization were compared between two groups. RESULTS: The levels of Hb and Plt in PABD group before and after blood collection were determined as follows: 138.26±14.73 g/L vs 127.52±13.36 g/L (P＜0.05) and (221.67±52.86)×109/L vs (198.35±52.65)×109/L (P＞0.05) respectively. The analysis of allo-RBC and allo-plasma transfusion in PABD group and control group showed that: the quantity of allogeneic RBC transfusion was 0.20±0.71 U and 0.89±0.97 U, and the quantity of allogeneic plasma transfusion was 30.43±100.81 ml and 106.52±152.61 ml (P＜0.05) respectirdy during perioperation. The comparison results of preoperative Hb and plt in PABD group and control group were 135.65±14.16 g/L vs 134.15±11.98 g/L and (270.36±58.28)×109/L vs (271.67±65.02) ×109/L respectively. The levels of postoperative Hb and plt in PABD group and control group were 120.24±14.40 g/L vs 121.20±14.30 g/L at 1 d after operation, and (241.80±63.58)×109/L vs (241.30±69.11)×109/L at 1 d after operation respectively; 123.15±13.80 g/L vs 121.65±14.33 g/L at 3 d after operation and (251.26±72.94)×109/L vs (255.54±73.85)×109/L at 3 d after operation; 122.78±13.92 g/L and 122.00±13.82 g/L (before discharge) and (262.50±80.96)×109/L and (264.56±71.08)×109/L (before discharge, platelet). These data were not statistically different (P＞0.05). The hospitalization time was 14.84±3.37 days and 14.84±2.24 days, respectively, without statistical difference (P＞0.05) in two groups. The expenses of hospitalization and the blood transfusion in two groups were 50627.27±9889.45 RMB and 50979.43±8195.00 RMB; 354.39±362.57 RMB and 684.02±425.53 RMB (P＜0.05). CONCLUSION: The application of PABD reduces the use of allogeneic blood and costs for patients undergoing selective surgery with blood losts of 1000 ml.

Evaluation of the Normal Airway Morphology Using Optical Coherence Tomography.

BACKGROUND: The anatomic location of small airways, the distribution of airway cartilage, and their correlation with ageing have not been well elucidated. The objective of this article was to explore the morphologic characteristics of small airways in vivo, and how airway structural changes correlate with age using endobronchial optical coherence tomography (EB-OCT). METHODS: We recruited 112 subjects with peripheral pulmonary nodules. Participants underwent CT scan, spirometry, and EB-OCT measurements. We measured the airway internal diameter, the inner area (Ai), the airway wall area percentage (Aw%), and the thickness of airway cartilage. EB-OCT airway structural characteristics at different age intervals were analyzed, and the association between airway morphology and age was evaluated. RESULTS: Of the small airways, 47.3% originated from the seventh generation of bronchi. Cartilage was uniformly present in the third to sixth generation of bronchi, despite a decreasing proportion of cartilage from the seventh to ninth generation of bronchi (92.4%, 54.5%, and 26.8%, respectively). The thickness of airway cartilage progressively decreased with older age. In subjects 40 to 54 years of age, Ai from the third to sixth generation correlated positively with age (r = 0.577, P < .001). Both Ai from the third to sixth generation and Ai from the seventh to ninth generation correlated negatively with age in subjects 55 to 69 years of age (r = -0.374, P = .021 and r = -0.410, P = .011). Aw% from the third to sixth generation and Aw% from the seventh to ninth generation did not correlate significantly with age. CONCLUSIONS: Small airways are mainly located at the seventh generation, where cartilaginous structures are present despite reduced distribution in more distal airways, and the thickness decreased in older age. Reduction in luminal area of medium-to-small airways might be the morphologic changes associated with ageing (ie, > 55 years of age).