Alveolar Microdynamics during Tidal Ventilation in Live Animals Imaged by SPring-8 Synchrotron.

It is self-evident that our chests expand and contract during breathing but, surprisingly, exactly how individual alveoli change shape over the respiratory cycle is still a matter of debate. Some argue that all the alveoli expand and contract rhythmically. Others claim that the lung volume change is due to groups of alveoli collapsing and reopening during ventilation. Although this question might seem to be an insignificant detail for healthy individuals, it might be a matter of life and death for patients with compromised lungs. Past analyses were based on static post-mortem preparations primarily due to technological limitations, and therefore, by definition, incapable of providing dynamic information. In contrast, this study provides the first comprehensive dynamic data on how the shape of the alveoli changes, and, further, provides valuable insights into the optimal lung volume for efficient gas exchange. It is concluded that alveolar micro-dynamics is nonlinear; and at medium lung volume, alveoli expand more than the ducts.

Lung volume recruitment and airway clearance for children at home in France.

BACKGROUND: Airway clearance (ACT) and lung volume recruitment (LVR) techniques are used to manage bronchial secretions, increase cough efficiency and lung/chest wall recruitment, to prevent and treat respiratory tract infections. The aim of the study was to review the prescription of ACT/LVR techniques for home use in children in France. METHODS: All the centers of the national pediatric noninvasive ventilation (NIV) network were invited to fill in an anonymous questionnaire for every child aged ≤20 years who started a treatment with an ACT/LVR device between 2022 and 2023. The devices comprised mechanical in-exsufflation (MI-E), intermittent positive pressure breathing (IPPB), intrapulmonary percussive ventilation (IPV), and/or invasive mechanical ventilation (IMV)/NIV for ACT/LVR. RESULTS: One hundred and thirty-nine patients were included by 13 centers. IPPB was started in 83 (60 %) patients, MI-E in 43 (31 %) and IPV in 30 (22 %). No patient used IMV/NIV for ACT/LVR. The devices were prescribed mainly by pediatric pulmonologists (103, 74 %). Mean age at initiation was 8.9 ± 5.6 (0.4-18.5) years old. The ACT/LVR devices were prescribed mainly in patients with neuromuscular disorders (n = 66, 47 %) and neurodisability (n = 37, 27 %). The main initiation criteria were cough assistance (81 %) and airway clearance (60 %) for MI-E, thoracic mobilization (63 %) and vital capacity (47 %) for IPPB, and airway clearance (73 %) and repeated respiratory exacerbations (57 %) for IPV. The parents were the main carers performing the treatment at home. CONCLUSIONS: IPPB was the most prescribed technique. Diseases and initiation criteria are heterogeneous, underlining the need for studies validating the indications and settings of these techniques.

Physiological and clinical effects of trunk inclination adjustment in patients with respiratory failure: a scoping review and narrative synthesis.

BACKGROUND: Adjusting trunk inclination from a semi-recumbent position to a supine-flat position or vice versa in patients with respiratory failure significantly affects numerous aspects of respiratory physiology including respiratory mechanics, oxygenation, end-expiratory lung volume, and ventilatory efficiency. Despite these observed effects, the current clinical evidence regarding this positioning manoeuvre is limited. This study undertakes a scoping review of patients with respiratory failure undergoing mechanical ventilation to assess the effect of trunk inclination on physiological lung parameters. METHODS: The PubMed, Cochrane, and Scopus databases were systematically searched from 2003 to 2023. INTERVENTIONS: Changes in trunk inclination. MEASUREMENTS: Four domains were evaluated in this study: 1) respiratory mechanics, 2) ventilation distribution, 3) oxygenation, and 4) ventilatory efficiency. RESULTS: After searching the three databases and removing duplicates, 220 studies were screened. Of these, 37 were assessed in detail, and 13 were included in the final analysis, comprising 274 patients. All selected studies were experimental, and assessed respiratory mechanics, ventilation distribution, oxygenation, and ventilatory efficiency, primarily within 60 min post postural change. CONCLUSION: In patients with acute respiratory failure, transitioning from a supine to a semi-recumbent position leads to decreased respiratory system compliance and increased airway driving pressure. Additionally, C-ARDS patients experienced an improvement in ventilatory efficiency, which resulted in lower PaCO2 levels. Improvements in oxygenation were observed in a few patients and only in those who exhibited an increase in EELV upon moving to a semi-recumbent position. Therefore, the trunk inclination angle must be accurately reported in patients with respiratory failure under mechanical ventilation.

An analysis of residual lung volume changes after segmentectomy based on three-dimensional computed tomography.

Background: Based on the results of JCOG0802 and CALGB studies, segmentectomy has considered to be a standard procedure for early-stage non-small cell lung cancer (NSCLC). After lobectomy, the residual cavity is filled with mediastinal and diaphragmatic deviations, and compensatory volume changes are present in the residual lungs. In this study, we examined the efficacy of segmentectomy, a surgical procedure, by focusing on its impact on postoperative lung volume and function. Methods: We enrolled 77 patients who underwent segmentectomy as their initial surgical procedure, excluding those with additional lung resections and those who lacked postoperative computed tomography imaging. The predicted residual volume (mL) was defined as the total lung volume before surgery minus the volume of the resected area. Using the predicted residual volume (mL) and postoperative total lung volume (mL), we calculated the rate of postoperative lung volume increase [(postoperative total lung volume/predicted residual volume) × 100] (%). We also classified 52 cases with a rate of postoperative lung volume increase of ≥100% into a compensatory group, while those with a rate of <100% were classified into a non-compensatory group. Results: The average postoperative lung volume increase was 104.6% among 77 cases. Age ≥65 years, pack year index ≥27.5, ≥3 resected segments, and use of electrocautery for intersegmental plane division were significantly associated with compensatory group classification. In 20 compensatory cases with preoperative and postoperative pulmonary function tests, postoperative vital capacity and forced expiratory volume in one second values exceeded the preoperative predictions. This study further examined the areas responsible for postoperative compensatory lung volume increase. In the compensatory group, significant expansion was observed in the ipsilateral lobes, excluding the resected segment and contralateral lung, while no significant changes were noted in the volume of the lobe, including the resected segment. Conversely, the non-compensatory group showed a significant volume decrease in the resected lobe, but no significant increase in other areas. Conclusions: This study emphasizes the importance of preserving lung segments in segmentectomy. The study demonstrates extensive compensatory volume changes in the ipsilateral lung and contralateral lung. There was no significant volume decrease in any residual segment. This underlines the potential of segmentectomy to maintain lung function and expand treatment options post-surgery. In addition, the compensated group included patients with a lower pack-year index and younger patients. These results suggest that postoperative compensatory lung expansion includes not only hyperinflation of the remaining lung, but also an increase in the functional lung parenchyma.

First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. METHODS: Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. RESULTS: Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2. CONCLUSIONS: EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. TRIAL REGISTRATION: Not applicable.

Multiethnic growth standards for fetal body composition and organ volumes derived from 3D ultrasonography.

BACKGROUND: A major goal of contemporary obstetrical practice is to optimize fetal growth and development throughout pregnancy. To date, fetal growth during prenatal care is assessed by performing ultrasonographic measurement of 2-dimensional fetal biometry to calculate an estimated fetal weight. Our group previously established 2-dimensional fetal growth standards using sonographic data from a large cohort with multiple sonograms. A separate objective of that investigation involved the collection of fetal volumes from the same cohort. OBJECTIVE: The Fetal 3D Study was designed to establish standards for fetal soft tissue and organ volume measurements by 3-dimensional ultrasonography and compare growth trajectories with conventional 2-dimensional measures where applicable. STUDY DESIGN: The National Institute of Child Health and Human Development Fetal 3D Study included research-quality images of singletons collected in a prospective, racially and ethnically diverse, low-risk cohort of pregnant individuals at 12 U.S. sites, with up to 5 scans per fetus (N=1730 fetuses). Abdominal subcutaneous tissue thickness was measured from 2-dimensional images and fetal limb soft tissue parameters extracted from 3-dimensional multiplanar views. Cerebellar, lung, liver, and kidney volumes were measured using virtual organ computer aided analysis. Fractional arm and thigh total volumes, and fractional lean limb volumes were measured, with fractional limb fat volume calculated by subtracting lean from total. For each measure, weighted curves (fifth, 50th, 95th percentiles) were derived from 15 to 41 weeks' using linear mixed models for repeated measures with cubic splines. RESULTS: Subcutaneous thickness of the abdomen, arm, and thigh increased linearly, with slight acceleration around 27 to 29 weeks. Fractional volumes of the arm, thigh, and lean limb volumes increased along a quadratic curvature, with acceleration around 29 to 30 weeks. In contrast, growth patterns for 2-dimensional humerus and femur lengths demonstrated a logarithmic shape, with fastest growth in the second trimester. The mid-arm area curve was similar in shape to fractional arm volume, with an acceleration around 30 weeks, whereas the curve for the lean arm area was more gradual. The abdominal area curve was similar to the mid-arm area curve with an acceleration around 29 weeks. The mid-thigh and lean area curves differed from the arm areas by exhibiting a deceleration at 39 weeks. The growth curves for the mid-arm and thigh circumferences were more linear. Cerebellar 2-dimensional diameter increased linearly, whereas cerebellar 3-dimensional volume growth gradually accelerated until 32 weeks followed by a more linear growth. Lung, kidney, and liver volumes all demonstrated gradual early growth followed by a linear acceleration beginning at 25 weeks for lungs, 26 to 27 weeks for kidneys, and 29 weeks for liver. CONCLUSION: Growth patterns and timing of maximal growth for 3-dimensional lean and fat measures, limb and organ volumes differed from patterns revealed by traditional 2-dimensional growth measures, suggesting these parameters reflect unique facets of fetal growth. Growth in these three-dimensional measures may be altered by genetic, nutritional, metabolic, or environmental influences and pregnancy complications, in ways not identifiable using corresponding 2-dimensional measures. Further investigation into the relationships of these 3-dimensional standards to abnormal fetal growth, adverse perinatal outcomes, and health status in postnatal life is warranted.

Tidal volume selection in volume-controlled ventilation guided by driving pressure versus actual body weight in healthy anesthetized and mechanically ventilated dogs: A randomized crossover trial.

OBJECTIVE: To compare static compliance of the respiratory system (CstRS) and the ratio of partial pressure of end-tidal to arterial carbon dioxide (Pe'CO2/PaCO2), in healthy dogs using two approaches for tidal volume (VT) selection during volume-controlled ventilation: body mass based and driving pressure (ΔPaw) guided. STUDY DESIGN: Randomized, nonblinded, crossover, clinical trial. ANIMALS: A total of 19 client-owned dogs anesthetized for castration and ovariohysterectomy. METHODS: After a stable 10 minute baseline, each dog was mechanically ventilated with a VT selection strategy, randomized to a constant VT of 15 mL kg-1 of actual body mass (VTBW) or ΔPaw-guided VT (VTΔP) of 7-8 cmH2O. Both strategies used an inspiratory time of 1 second, 20% end-inspiratory pause, 4 cmH2O positive end-expiratory pressure and fraction of inspired oxygen of 0.4. Respiratory frequency was adjusted to maintain Pe'CO2 between 35 and 40 mmHg. Respiratory mechanics, arterial blood gases and Pe'CO2/PaCO2 were assessed. Continuous variables are presented as mean ± SD or median (interquartile range; quartiles 1-3), depending on distribution, and compared with Wilcoxon signed-rank tests. RESULTS: The VT was significantly higher in dogs ventilated with VTΔP than with VTBW strategy (17.20 ± 4.04 versus 15.03 ± 0.60 mL kg-1, p = 0.036). CstRS was significantly higher with VTΔP than with VTBW strategy [2.47 (1.86-2.86) versus 2.25 (1.79-2.58) mL cmH2O-1 kg-1, p = 0.011]. There were no differences in Pe'CO2/PaCO2 between VTΔP and VTBW strategies (0.94 ± 0.06 versus 0.92 ± 0.06, p = 0.094). No discernible difference in ΔPaw was noted between the strategies. CONCLUSIONS AND CLINICAL RELEVANCE: While no apparent difference was observed in the Pe'CO2/PaCO2 between the VT selection strategies employed, CstRS significantly increased during the VTΔP approach. A future trial should explore if VTΔP improves perioperative gas exchange and prevents lung damage.

End-expiratory lung volumes as a potential indicator for COVID-19 associated acute respiratory distress syndrome: a retrospective study.

BACKGROUND: End-expiratory lung volume (EELV) has been observed to decrease in acute respiratory distress syndrome (ARDS). Yet, research investigating EELV in patients with COVID-19 associated ARDS (CARDS) remains limited. It is unclear whether EELV could serve as a potential metric for monitoring disease progression and identifying patients with ARDS at increased risk of adverse outcomes. STUDY DESIGN AND METHODS: This retrospective study included mechanically ventilated patients diagnosed with CARDS during the initial phase of epidemic control in Shanghai. EELV was measured using the nitrogen washout-washin technique within 48 h post-intubation, followed by regular assessments every 3-4 days. Chest CT scans, performed within a 24-hour window around each EELV measurement, were analyzed using AI software. Differences in patient demographics, clinical data, respiratory mechanics, EELV, and chest CT findings were assessed using linear mixed models (LMM). RESULTS: Out of the 38 patients enrolled, 26.3% survived until discharge from the ICU. In the survivor group, EELV, EELV/predicted body weight (EELV/PBW) and EELV/predicted functional residual capacity (EELV/preFRC) were significantly higher than those in the non-survivor group (survivor group vs. non-survivor group: EELV: 1455 vs. 1162 ml, P = 0.049; EELV/PBW: 24.1 vs. 18.5 ml/kg, P = 0.011; EELV/preFRC: 0.45 vs. 0.34, P = 0.005). Follow-up assessments showed a sustained elevation of EELV/PBW and EELV/preFRC among the survivors. Additionally, EELV exhibited a positive correlation with total lung volume and residual lung volume, while demonstrating a negative correlation with lesion volume determined through chest CT scans analyzed using AI software. CONCLUSION: EELV is a useful indicator for assessing disease severity and monitoring the prognosis of patients with CARDS.

Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy: A Retrospective Study.

PURPOSE: We elucidated the effects of planned resection volume on postoperative pulmonary function and changes in residual lung volume during segmentectomy. METHODS: This study included patients who underwent thoracoscopic segmentectomy between January 2017 and December 2022 and met eligibility criteria. Pre- and post-resection spirometry and computed tomography were performed. Three-dimensional reconstructions were performed by using computed tomography images to calculate the volumes of the resected, remaining, and nonoperative side regions. Based on the resected region volume, patients were divided into the higher and lower volume segmentectomy groups. Changes in lung volume and pulmonary function before and after the surgery were comparatively analyzed. RESULTS: The median percentage of resected lung volume was 10.9%, forming the basis for categorizing patients into the two groups. Postoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) ratios to preoperative measurements in both groups did not differ significantly (FEV1, p = 0.254; FVC, p = 0.777). Postoperative FEV1 and FVC ratios to their predicted postoperative values were significantly higher in the higher volume segmentectomy group than in the lower volume segmentectomy group (FEV1, p = 0003; FVC, p < 0.001). The higher volume segmentectomy group showed significantly greater post-to-preoperative lung volume ratio in overall, contralateral, ipsilateral, residual lobe and residual segment than the lower volume segmentectomy group. CONCLUSIONS: Postoperative respiratory function did not differ significantly between the higher- and lower-volume segmentectomy groups, indicating improved respiratory function because of substantial postoperative residual lung expansion. Our findings would aid in determining the extent of resection during segmentectomy.

Impact of rapid iodine contrast agent infusion on tracheal diameter and lung volume in CT pulmonary angiography measured with deep learning-based algorithm.

PURPOSE: To compare computed tomography (CT) pulmonary angiography and unenhanced CT to determine the effect of rapid iodine contrast agent infusion on tracheal diameter and lung volume. MATERIAL AND METHODS: This retrospective study included 101 patients who underwent CT pulmonary angiography and unenhanced CT, for which the time interval between them was within 365 days. CT pulmonary angiography was scanned 20 s after starting the contrast agent injection at the end-inspiratory level. Commercial software, which was developed based on deep learning technique, was used to segment the lung, and its volume was automatically evaluated. The tracheal diameter at the thoracic inlet level was also measured. Then, the ratios for the CT pulmonary angiography to unenhanced CT of the tracheal diameter (TDPAU) and both lung volumes (BLVPAU) were calculated. RESULTS: Tracheal diameter and both lung volumes were significantly smaller in CT pulmonary angiography (17.2 ± 2.6 mm and 3668 ± 1068 ml, respectively) than those in unenhanced CT (17.7 ± 2.5 mm and 3887 ± 1086 ml, respectively) (p < 0.001 for both). A statistically significant correlation was found between TDPAU and BLVPAU with a correlation coefficient of 0.451 (95% confidence interval, 0.280-0.594) (p < 0.001). No factor showed a significant association with TDPAU. The type of contrast agent had a significant association for BLVPAU (p = 0.042). CONCLUSIONS: Rapid infusion of iodine contrast agent reduced the tracheal diameter and both lung volumes in CT pulmonary angiography, which was scanned at end-inspiratory level, compared with those in unenhanced CT.

Age, sex, and lung volume dependence of dissolved xenon-129 MRI gas exchange metrics.

PURPOSE: To characterize the dependence of Xe-MRI gas transfer metrics upon age, sex, and lung volume in a group of healthy volunteers. METHODS: Sixty-five subjects with no history of chronic lung disease were assessed with 129Xe-MRI using a four-echo 3D radial spectroscopic imaging sequence and a dose of xenon titrated according to subject height that was inhaled from a lung volume of functional residual capacity (FRC). Imaging was repeated in 34 subjects at total lung capacity (TLC). Regional maps of the fractions of dissolved xenon in red blood cells (RBC), membrane (M), and airspace (Gas) were acquired at an isotropic resolution of 2 cm, from which global averages of the ratios RBC:M, RBC:Gas, and M:Gas were computed. RESULTS: Data from 26 males and 36 females with a median age of 43 y (range: 20-69 y) were of sufficient quality to analyze. Age (p = 0.0006) and sex (p < 0.0001) were significant predictors for RBC:M, and a linear regression showed higher values and steeper decline in males: RBC:M(Males) = -0.00362 × Age + 0.60 (p = 0.01, R2 = 0.25); RBC:M(Females) = -0.00170 × Age + 0.44 (p = 0.02, R2 = 0.15). Similarly, age and sex were significant predictors for RBC:Gas but not for M:Gas. RBC:M, M:Gas and RBC:Gas were significantly lower at TLC than at FRC (plus inhaled volume), with an average 9%, 30% and 35% decrease, respectively. CONCLUSION: Expected age and sex dependence of pulmonary function concurs with 129Xe RBC:M imaging results, demonstrating that these variables must be considered when reporting Xe-MRI metrics. Xenon doses and breathing maneuvers should be controlled due to the strong dependence of Xe-MRI metrics upon lung volume.

Bronchoscopic Lung Volume Reduction as the Treatment of Choice versus Robotic-Assisted Lung Volume Reduction Surgery in Similar Patients with Emphysema - An Initial Experience of the Benefits and Complications.

Objective: There is an assumption that because EBLVR requires less use of hospital resources, offsetting the higher cost of endobronchial valves, it should therefore be the treatment of choice wherever possible. We have tested this hypothesis in a retrospective analysis of the two in similar groups of patients. Methods: In a 4-year experience, we performed 177 consecutive LVR procedures: 83 patients underwent Robot Assisted Thoracoscopic (RATS) LVRS and 94 EBLVR. EBLVR was intentionally precluded by evidence of incomplete fissure integrity or intra-operative assessment of collateral ventilation. Unilateral RATS LVRS was performed in these cases together with those with unsuitable targets for EBLVR. Results: EBLVR was uncomplicated in 37 (39%) cases; complicated by post-procedure spontaneous pneumothorax (SP) in 28(30%) and required revision in 29 (31%). In the LVRS group, 7 (8%) patients were readmitted with treatment-related complications, but no revisional procedure was needed. When compared with uncomplicated EBLVR, LVRS had a significantly longer operating time: 85 (14-82) vs 40 (15-151) minutes (p<0.001) and hospital stay: 7.5 (2-80) vs 2 (1-14) days (p<0.01). However, LVRS had a similar total operating time to both EBLVR requiring revision: 78 (38-292) minutes and hospital stay to EBLVR complicated by pneumothorax of 11.5 (6.5-24.25) days. Use of critical care was significantly longer in RATS group, and it was also significantly longer in EBV with SP group than in uncomplicated EBV group. Conclusion: Endobronchial LVR does use less hospital resources than RATS LVRS in comparable groups if the recovery is uncomplicated. However, this advantage is lost if one includes the resources needed for the treatment of complications and revisional procedures. Any decision to favour EBLVR over LVRS should not be based on the assumption of a smoother, faster perioperative course.

Management of Refractory Chronic Obstructive Pulmonary Disease: A Review.

Chronic obstructive pulmonary disease (COPD) is a common condition with an estimated prevalence of 12% in adults over the age of 30 years worldwide. COPD is a leading cause of morbidity and mortality globally, with a substantial economic and social burden. There are an estimated 3 million deaths annually due to COPD. However, most of the patients with COPD respond to routine interventions like bronchodilator therapy, assessing supplemental oxygen needs, smoking cessation, vaccinations, and pulmonary rehabilitation. There is a significant number of patients who unfortunately progress to have persistent symptoms despite these interventions. Refractory COPD is not yet formally defined. Patients with severe persistent symptoms or exacerbations despite appropriate care can be considered to have refractory COPD. Managing refractory COPD needs a multidimensional approach. In this review article, we will discuss essential interventions like ensuring adequate inhaler techniques, exploring the need for non-invasive ventilatory support, use of chronic antibiotics and phosphodiesterase inhibitors to advanced therapies like bronchoscopic lung volume reduction surgery, and the upcoming role of anti-IL5 agents in managing patients with refractory COPD. We will also discuss non-pharmacologic interventions like psycho-social support and nutritional support. We will conclude by discussing the palliative care aspect of managing patients with refractory COPD. Through this review article, we aim to better the approach to managing patients with refractory COPD and discuss new upcoming therapies.

Lung volume reduction surgery is safe and feasible after initial endobronchial valve treatment for emphysema patients.

OBJECTIVES: Bronchoscopic lung volume reduction with endobronchial valves is a guideline treatment leading to improved pulmonary function, exercise tolerance and quality of life, in patients with advanced emphysema, severe hyperinflation and no collateral ventilation. After valve treatment, loss of the initial lung volume reduction effect can occur, as well as local valve-induced complications such as persistent haemoptysis. In these cases, a surgical lobectomy can be considered to achieve similar efficacy outcomes. We evaluated the safety and feasibility of a video-assisted thoracoscopic surgery lobectomy after valve treatment. METHODS: This single-centre retrospective study included patients who underwent an elective lobectomy after previous valve treatment. Data were evaluated for safety and efficacy for the additional surgical procedure. RESULTS: Twenty-one patients [73% female, median age 67 (7) years, forced expiratory volume in 1 s 29 (7) %pred, and residual volume 223 (58) %pred] were included. There was no 90-day mortality and there were no postoperative intensive care admissions. Pulmonary infections (14%) and prolonged air leak (14%) were the most common complications. In patients who underwent surgery due to loss or lack of effect of valve treatment, a lobectomy led to a significant improvement in pulmonary function; median forced expiratory volume in 1 s +75 (193) ml (P < 0.013), forced vital capacity +450 (572) ml (P = 0.001), residual volume -665 (715) ml (P = 0.005). In patients who underwent a lobectomy because of complications of valve treatment, all complications were resolved after surgery. CONCLUSIONS: We demonstrate that an elective lobectomy after an initial valve treatment is safe and feasible and restores the lung volume reduction effect.

A preclinical animal study to evaluate the operability and safety of domestic one-way endobronchial valves.

Purpose: To evaluate the operability and safety of bronchoscopic domestic one-way endobronchial valves (EBV) on animals. Methods: Nine pigs were randomly assigned (2:1) to receive domestic one-way EBV (the experimental group, n = 6) and Zephyr® EBV (the control group, n = 3). Routine blood tests, arterial blood gases, and CT scans of the lungs were performed 1 day pre-procedure in addition to 1 week and 1 month post-procedure to assess changes in blood markers and lung volumes. At 1 month post-procedure, the animals were sacrificed, followed by removal of all valves via bronchoscopy. Pathological examinations of critical organs were subsequently performed. Results: A total of 15 valves were placed in the experimental group and 6 valves were placed in the control group, without serious complications. Routine blood tests and arterial blood gas examinations at 1 day pre-procedure, 1 week post-procedure, and 1 month post-procedure did not differ significantly in both groups. No EBV displacement was noted under bronchoscopy, and the valve was smoothly removable by bronchoscope at 1 month post-procedure. At 1 week post-procedure, varying degrees of target lung lobe volume reduction were observed on lung CT in both groups. Lung volume reduction was achieved at 1 month post-procedure in both groups, without significant statistical difference. Although 3 cases in the experimental group and 1 case in the control group developed varying degrees of pneumonia, the inflammatory response did not increase over time during the experimental period. Pathological examination revealed no significant abnormal changes in the critical organs for both groups. Conclusion: Our results demonstrate that domestic EBV is safe and reliable for endobronchial application in general-grade laboratory white pigs. The safety of domestic EBV is similar to that of Zephyr® EBV, with good ease of use and operability. This kind of domestic EBV can meet the safety evaluation requirements for animal testing.

Longitudinal changes in the volume of residual lung lobes after lobectomy for lung cancer: a retrospective cohort study.

It is unclear how the residual lobe volume changes over time after lobectomy. This study aims to clarify the temporal patterns of volume changes in each remaining lung lobe post-lobectomy. A retrospective review was conducted on patients who underwent lobectomy for lung cancer at Yueyang Central Hospital from January to December 2021. Lung CT images were reconstructed in three dimensions to calculate the volumes of each lung lobe preoperatively and at 1, 6, and 12 months postoperatively. A total of 182 patients were included. Postoperatively, the median total lung volume change rates relative to preoperative values were -20.1%, -9.3%, and -5.9% at 1, 6, and 12 months, respectively. Except for the right middle lobe in patients who underwent right upper lobectomy, the volumes of individual lung lobes exceeded preoperative values. The volume growth of the lung on the side of the resection was significantly more than that of the lung on the opposite side. For left lobectomy patients, the right lower lobe's volume change rate exceeded that of the right upper and middle lobes. Among right lobectomy patients, the left lower lobe and the relatively inferior lobe of right lung had higher volume change rates than the superior one. Right middle lobe change rate was more in patients with right lower lobectomy than right upper lobectomy. Six months postoperatively, FEV1% and right middle lobectomy were positively correlated with the overall volume change rate. One year postoperatively, only age was negatively correlated with the overall volume change rate. 75 patients had pulmonary function tests. Postoperative FEV1 change linearly correlated with 1-year lung volume change rate, but not with theoretical total lung volume change rate or segmental method calculated FEV1 change. Time-dependent compensatory volume changes occur in remaining lung lobe post-lobectomy, with stronger compensation observed in the relatively inferior lobe compared to the superior one(s). Preoperative lung function and age may affect compensation level.

Twenty four-month follow-up after bullectomy, unilateral and bilateral lung volume reduction surgery: a single-center retrospective analysis of consecutive cases.

PURPOSE: While pharmacologic therapy remains the cornerstone of lung emphysema treatment, surgery is an additional therapeutic option in selected patient groups with advanced emphysema. The aim of lung volume reduction surgery (LVRS) is to improve lung function, exercise capacity, quality of life and survival. We sought to determine the therapeutic value of surgical resection in specific patients with lung emphysema. PATIENTS AND METHODS: A retrospective study was performed consisting of 58 patients with lung emphysema who underwent surgical intervention over a 10-year period and were followed for 2 years postoperatively. The clinical characteristics recorded were FEV1 (forced expiratory volume in 1 s), the 6-min walk test (6-MWT), the Modified Medical Research Council (mMRC), body mass index (BMI) and quality of life prior to and 6, 12 and 24 months after surgical intervention. Moreover, all peri- and post-operative complications were noted. RESULTS: Out of 58 emphysema patients (72% male, FEV1 (L) 2.21 ± 0.17, RV (L) 3.39 ± 0.55), 19 underwent surgical bullectomy, 31 unilateral LVRS and 8 sequential bilateral LVRS. Six months after surgery, there was a statistically significant improvement in FEV1, RV, TLC, 6-MWT and mMRC. Over a period of 12 to 24 months postoperatively, clinical benefit gradually declines most likely due to COPD progression but patients still experienced a significant improvement in FEV1. The most common postoperative complications were persistent air leakage (> 7 days), arrhythmia and subcutaneous emphysema in 60%, 51.6% and 22.4%, respectively. No deaths were observed after surgical intervention. CONCLUSION: In a selected patient population, surgery led to significant improvement of lung function parameters, exercise capacity and quality of life. Over a period of 12 to 24 months postoperatively, clinical benefit gradually decreased most likely due to COPD progression.

Timing of magnetic resonance imaging in pregnancy for outcome prediction in congenital diaphragmatic hernia.

PURPOSE: To evaluate the impact of the timing of MRI on the prediction of survival and morbidity in patients with CDH, and whether serial measurements have a beneficial value. METHODS: This retrospective cohort study was conducted in two perinatal centers, in Germany and Italy. It included 354 patients with isolated CDH having at least one fetal MRI. The severity was assessed with the observed-to-expected total fetal lung volume (o/e TFLV) measured by two experienced double-blinded operators. The cohort was divided into three groups according to the gestational age (GA) at which the MRI was performed (< 27, 27-32, and > 32 weeks' gestation [WG]). The accuracy for the prediction of survival at discharge and morbidity was analyzed with receiver operating characteristic (ROC) curves. Multiple logistic regression analyses and propensity score matching examined the population for balance. The effect of repeated MRI was evaluated in ninety-seven cases. RESULTS: There were no significant differences in the prediction of survival when the o/e TFLV was measured before 27, between 27 and 32, and after 32 WG (area under the curve [AUC]: 0.77, 0.79, and 0.77, respectively). After adjustment for confounding factors, it was seen, that GA at MRI was not associated with survival at discharge, but the risk of mortality was higher with an intrathoracic liver position (adjusted odds ratio [aOR]: 0.30, 95% confidence interval [95%CI] 0.12-0.78), lower GA at birth (aOR 1.48, 95%CI 1.24-1.78) and lower o/e TFLV (aOR 1.13, 95%CI 1.06-1.20). ROC curves showed comparable prediction accuracy for the different timepoints in pregnancy for pulmonary hypertension, the need of extracorporeal membrane oxygenation, and feeding aids. Serial measurements revealed no difference in change rate of the o/e TFLV according to survival. CONCLUSION: The timing of MRI does not affect the prediction of survival rate or morbidity as the o/e TFLV does not change during pregnancy. Clinicians could choose any gestational age starting mid second trimester for the assessment of severity and counseling.

Lung volume reduction surgery is safe and leads to functional improvement in patients who fail or cannot undergo bronchoscopic lung volume reduction.

Background: Bronchoscopic lung volume reduction (BLVR) has supplanted surgery in the treatment of patients with advanced emphysema, but not all patients qualify for it. Our study aimed to investigate the outcomes of lung volume reduction surgery (LVRS) among patients who either failed BLVR or were not candidates for it. Methods: We conducted a retrospective analysis of patients who underwent LVRS for upper lobe-predominant emphysema at a single tertiary center between March 2018 and December 2022. The main outcomes measures were preoperative and postoperative respiratory parameters, perioperative morbidity, and mortality. Results: A total of 67 LVRS recipients were evaluated, including 10 who had failed prior valve placement. The median patient age was 69 years, and 35 (52%) were male. All procedures were performed thoracoscopically, with 36 patients (53.7%) undergoing bilateral LVRS. The median hospital length of stay was 7 days (interquartile range, 6-11 days). Prolonged air leak (>7 days) occurred in 20 patients. There was one 90-day mortality from a nosocomial pneumonia (non-COVID-related) and no further deaths at 12 months. There were mean improvements of 10.07% in forced expiratory volume in 1 second and 4.74% in diffusing capacity of the lung for carbon monoxide, along with a mean decrease 49.2% in residual volume (P < .001 for all). The modified Medical Research Council dyspnea scale was improved by 1.84 points (P < .001). Conclusions: LVRS can be performed safely in patients who are not candidates for BLVR and those who fail BLVR and leads to significant functional improvement. Long-term follow-up is necessary to ensure the sustainability of LVRS benefits in this patient population.

Impact and timing of pulmonary rehabilitation in patients undergoing bronchoscopic lung volume reduction with endobronchial valves: A multicentre randomized controlled trial in patients with severe emphysema.

BACKGROUND AND OBJECTIVE: Both bronchoscopic lung volume reduction with endobronchial valves (BLVR-EBV) and pulmonary rehabilitation (PR) are effective treatments for improving exercise capacity and patient-reported outcomes in patients with severe Chronic Obstructive Pulmonary Disease (COPD). According to current recommendations, all BLVR-EBV patients should have undergone PR first. Our aim was to study the effects of PR both before and after BLVR-EBV compared to BLVR-EBV alone. METHODS: We included patients with severe COPD who were eligible for BLVR-EBV and PR. Participants were randomized into three groups: PR before BLVR-EBV, PR after BLVR-EBV or BLVR-EBV without PR. The primary outcome was change in constant work rate cycle test (CWRT) endurance time at 6-month follow-up of the PR groups compared to BLVR-EBV alone. Secondary endpoints included changes in 6-minute walking test, daily step count, dyspnoea and health-related quality of life. RESULTS: Ninety-seven participants were included. At 6-month follow-up, there was no difference in change in CWRT endurance time between the PR before BLVR-EBV and BLVR-EBV alone groups (median: 421 [IQR: 44; 1304] vs. 787 [123; 1024] seconds, p = 0.82) or in any of the secondary endpoints, but the PR after BLVR-EBV group exhibited a smaller improvement in CWRT endurance time (median: 107 [IQR: 2; 573], p = 0.04) and health-related quality of life compared to BLVR-EBV alone. CONCLUSION: The addition of PR to BLVR-EBV did not result in increased exercise capacity, daily step count or improved patient-reported outcomes compared to BLVR-EBV alone, neither when PR was administered before BLVR-EBV nor when PR was administered after BLVR-EBV.