Pulmonary arteries in coelacanths shed light on the vasculature evolution of air-breathing organs in vertebrates.

To date, the presence of pulmonary organs in the fossil record is extremely rare. Among extant vertebrates, lungs are described in actinopterygian polypterids and in all sarcopterygians, including coelacanths and lungfish. However, vasculature of pulmonary arteries has never been accurately identified neither in fossil nor extant coelacanths due to the paucity of fossil preservation of pulmonary organs and limitations of invasive studies in extant specimens. Here we present the first description of the pulmonary vasculature in both fossil and extant actinistian, a non-tetrapod sarcopterygian clade, contributing to a more in-depth discussion on the morphology of these structures and on the possible homology between vertebrate air-filled organs (lungs of sarcopterygians, lungs of actinopterygians, and gas bladders of actinopterygians).

Assessment of pulmonary vascular anatomy: comparing augmented reality by holograms versus standard CT images/reconstructions using surgical findings as reference standard.

BACKGROUND: We compared computed tomography (CT) images and holograms (HG) to assess the number of arteries of the lung lobes undergoing lobectomy and assessed easiness in interpretation by radiologists and thoracic surgeons with both techniques. METHODS: Patients scheduled for lobectomy for lung cancer were prospectively included and underwent CT for staging. A patient-specific three-dimensional model was generated and visualized in an augmented reality setting. One radiologist and one thoracic surgeon evaluated CT images and holograms to count lobar arteries, having as reference standard the number of arteries recorded at surgery. The easiness of vessel identification was graded according to a Likert scale. Wilcoxon signed-rank test and κ statistics were used. RESULTS: Fifty-two patients were prospectively included. The two doctors detected the same number of arteries in 44/52 images (85%) and in 51/52 holograms (98%). The mean difference between the number of artery branches detected by surgery and CT images was 0.31 ± 0.98, whereas it was 0.09 ± 0.37 between surgery and HGs (p = 0.433). In particular, the mean difference in the number of arteries detected in the upper lobes was 0.67 ± 1.08 between surgery and CT images and 0.17 ± 0.46 between surgery and holograms (p = 0.029). Both radiologist and surgeon showed a higher agreement for holograms (κ = 0.99) than for CT (κ = 0.81) and found holograms easier to evaluate than CTs (p < 0.001). CONCLUSIONS: Augmented reality by holograms is an effective tool for preoperative vascular anatomy assessment of lungs, especially when evaluating the upper lobes, more prone to anatomical variations. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04227444 RELEVANCE STATEMENT: Preoperative evaluation of the lung lobe arteries through augmented reality may help the thoracic surgeons to carefully plan a lobectomy, thus contributing to optimize patients' outcomes. KEY POINTS: • Preoperative assessment of the lung arteries may help surgical planning. • Lung artery detection by augmented reality was more accurate than that by CT images, particularly for the upper lobes. • The assessment of the lung arterial vessels was easier by using holograms than CT images.

Different anatomical variations in the anterior segment of the right upper lung.

During a routine physical examination three years ago, a 47-year-old woman received a diagnosis of a nodule in her right upper lung. Since then, she has been regularly attending outpatient clinic appointments for follow-up. Over time, the nodule has shown gradual growth, leading to a suspicion of lung cancer. Through the use of enhanced CT imaging, a three-dimensional reconstruction was performed to examine the bronchi and blood vessels in the patient's chest. This reconstruction revealed several variations in the anatomy of the anterior segment of the right upper lobe. Specifically, the anterior segmental bronchus (B3) was found to have originated from the right middle lung bronchus. Additionally, the medial subsegmental artery of the anterior segmental artery (A3b) and the medial segmental artery (A5) were observed to share a common trunk. As for the lateral subsegmental artery of the anterior segmental artery (A3a), it was found to have originated from the right inferior pulmonary trunk. Furthermore, the apical subsegmental artery of the apical segmental artery (A1a) and the posterior segmental artery (A2) were found to have a shared trunk.

CT-based comparison of porcine, ovine, and human pulmonary arterial morphometry.

To facilitate pre-clinical animal and in-silico clinical trials for implantable pulmonary artery pressure sensors, understanding the respective species pulmonary arteries (PA) anatomy is important. Thus, morphological parameters describing PA of pigs and sheep, which are common animal models, were compared with humans. Retrospective computed tomography data of 41 domestic pigs (82.6 ± 18.8 kg), 14 sheep (49.1 ± 6.9 kg), and 49 patients (76.8 ± 18.2 kg) were used for reconstruction of the subject-specific PA anatomy. 3D surface geometries including main, left, and right PA as well as LPA and RPA side branches were manually reconstructed. Then, specific geometric parameters (length, diameters, taper, bifurcation angle, curvature, and cross-section enlargement) affecting device implantation and post-interventional device effect and efficacy were automatically calculated. For both animal models, significant differences to the human anatomy for most geometric parameters were found, even though the respective parameters' distributions also featured relevant overlap. Out of the two animal models, sheep seem to be better suitable for a preclinical study when considering only PA morphology. Reconstructed geometries are provided as open data for future studies. These findings support planning of preclinical studies and will help to evaluate the results of animal trials.

Pulmonary vessels and bronchus anatomy of the left upper lobe.

PURPOSES: The bronchopulmonary vascular bifurcation patterns in the upper lobe of the left lung are diverse. Therefore, it is important for general thoracic surgeons to understand the detailed anatomy of the pulmonary segments when performing thoracoscopic anatomical pulmonary resection. This study aimed to analyze the bronchovascular patterns of the left upper lobe and summarize the anatomical information associated with pulmonary anatomical pulmonary resection. METHODS: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus of 539 patients using computed tomography imaging data including those obtained using three-dimensional computed tomography. We herein report the anatomic structure in the left upper lobe. RESULTS: Regarding the superior division bronchi, a pattern of trifurcation into B1+2, B3, lingular division bronchus was observed in nine patients (1.7%). A pattern of proximal bifurcation of B4 was found in eight patients (1.5%). Regarding the lingular veins (LV), patterns of LV drainage into the left lower pulmonary vein were observed in 22 patients (4.1%). Regarding the pulmonary artery, mediastinal lingular arteries (MLA) were found in 161 patients (29.9%). CONCLUSION: The bifurcation patterns of the bronchovascular region in the upper lobe of the left lung were clarified. These results should be carefully noted when performing anatomical pulmonary resection.

Anatomic Risk Factors for Reintervention After Arterial Switch Operation for Taussig-Bing Anomaly.

BACKGROUND: This study aimed to determine the factors related to reintervention, especially for pulmonary stenosis (PS), in patients with Taussig-Bing anomaly (TBA) after the arterial switch operation. METHODS: This retrospective study included 34 patients with TBA who underwent the arterial switch operation between 1993 and 2018. Preoperative anatomic and physiologic differences and long-term outcomes were determined using a case-matched control with transposition of the great arteries with ventricular septal defect and TBA with an anterior and rightward aorta. RESULTS: At arterial switch operation, median age was 43 days (range, 16 to 102) and median body weight was 3.6 kg (range, 2.8 to 3.8 kg). Aortic arch obstruction and coronary anomalies were present in 64% and 41% of patients, respectively. The hospital mortality rate was 11%, including one cardiac death, and the late mortality rate was 2.9%. Furthermore, 41% patients underwent 26 reinterventions for PS. Patients undergoing PS-related reintervention had a significantly larger native pulmonary artery to aortic annulus size ratio than patients not receiving reintervention (1.69 vs 1.41, P = .02). This ratio was the only predictor of PS-related reintervention; it was significantly higher in the TBA group than in the transposition of great arteries/ventricular septal defect group. The PS-related reintervention was required more in the TBA group than in the transposition of great arteries/ventricular septal defect group. CONCLUSIONS: Regardless of complex coronary anatomy and associated anomalies, early and late survival were acceptable. Postoperative PS was strongly associated with having a larger native pulmonary valve, suggesting that an optimal surgical reconstruction was required for achieving an appropriate aortopulmonary anatomic relationship during the arterial switch operation.

CT-Derived Pulmonary Artery Diameters to Preselect for Echocardiography in COPD Patients Eligible for Bronchoscopic Treatments.

BACKGROUND: Currently, patients with COPD who are evaluated for bronchoscopic treatments are routinely screened for pulmonary hypertension (PH) and systolic left ventricle dysfunction by echocardiography. OBJECTIVES: We evaluated the prevalence of PH and systolic left ventricle dysfunction in this patient group and investigated if the previously proposed CT-derived pulmonary artery to aorta (PA:A) ratio >1 and PA diameter measurements can be used as alternative screening tools for PH. METHODS: Two hundred fifty-five patients were included in this retrospective analysis (FEV1 25%pred, RV 237%pred). All patients received transthoracic echocardiography and chest CT scans on which diameters of the aorta and pulmonary artery were measured at the bifurcation and proximal to the bifurcation. RESULTS: Following echocardiography, 3 patients (1.2%) had PH and 1 (0.4%) had systolic left ventricle dysfunction. Using a PA:A ratio >1, only 10.3% of the patients with a right ventricular systolic pressure (RVSP) ≥35 mm Hg were detected and none of the patients with an RVSP >50 mm Hg were detected. Patients with an RVSP ≥35 mm Hg had significantly higher PA diameters (29.5 vs. 27.5 mm; p = 0.02) but no significantly different PA:A ratios. All patients with an RVSP >50 mm Hg had PA diameters >30 mm. CONCLUSIONS: The prevalence of PH and systolic left ventricle dysfunction is low in this preselected cohort of patients with severe COPD. In this population, a PA:A ratio >1 is not a useful cardiac screening tool for PH. A PA diameter >30 mm could substitute for routinely performed echocardiography in the screening for PH in this patient group.

Anatomical analysis of the left upper lobe of lung on three-dimensional images with focusing the branching pattern of the subsegmental veins.

BACKGROUND: A clear understanding of the anatomical characteristics of the pulmonary veins (PVs) is essential for the successful performance of segmentectomy and important to avoid intraoperative pulmonary vessels injury. However, there is no report showing the relations between the branching patterns of PVs and pulmonary arteries (PAs). Moreover, internationally accepted symbols for describing PVs remain unavailable. For anatomically assessing the branches and courses of the subsegmental veins in the left upper lobe (LUL), the diverse branching patterns of blood vessels and bronchi should be investigated. METHODS: The branching patterns and intersegmental courses of PVs were assessed by performing three-dimensional image analysis of the bronchi, and PAs and PVs in the LUL in 103 patients who were scheduled to receive segmentectomy in LUL from January 2008 through August 2012. RESULTS: Branching types of the bronchi and pulmonary vessels failed to be independent each other. Although the combinations of anterior extension type of bronchus with the inter-lobar type (IL-type) of arterial branching pattern were often observed, but those with the mediastinal type (M-type) were rarely observed. The combinations of apical vein dominant type with the IL-type of arteries, and intermediate and central vein types with the M-type were often observed. Since LUL was adjoined by various subsegments, and the intersegmental pulmonary veins showed diverse patterns. CONCLUSIONS: This study found the relationship among PA, PV, and bronchus patterns, in the subsegment where the branching patterns were fixed in 103 cases. This study discovered PVs that was difficult to be named by the conventional naming systems because of the diversity of the locations in the subsegment.

Characteristics of Acute Pulmonary Embolism in Patients With COVID-19 Associated Pneumonia From the City of Wuhan.

The aim of this study was to describe clinical, imaging, and laboratory features of acute pulmonary embolism (APE) in patients with COVID-19 associated pneumonia. Patients with COVID-19 associated pneumonia who underwent a computed tomography pulmonary artery (CTPA) scan for suspected APE were retrospectively studied. Laboratory data and CTPA images were collected. Imaging characteristics were analyzed descriptively. Laboratory data were analyzed and compared between patients with and without APE. A series of 25 COVID-19 patients who underwent CTPA between January 2020 and February 2020 were enrolled. The median D-dimer level founded in these 25 patients was 6.06 µg/mL (interquartile range [IQR] 1.90-14.31 µg/mL). Ten (40%) patients with APE had a significantly higher level of D-dimer (median, 11.07 µg/mL; IQR, 7.12-21.66 vs median, 2.44 µg/mL; IQR, 1.68-8.34, respectively, P = .003), compared with the 15 (60%) patients without APE. No significant differences in other laboratory data were found between patients with and without APE. Among the 10 patients with APE, 6 (60%) had a bilateral pulmonary embolism, while 4 had a unilateral embolism. The thrombus-prone sites were the right lower lobe (70%), the left upper lobe (60%), both upper lobe (40%) and the right middle lobe (20%). The thrombus was partially or completely absorbed after anticoagulant therapy in 3 patients who underwent a follow-up CTPA. Patients with COVID-19 associated pneumonia have a risk of developing APE during the disease. When the D-dimer level abnormally increases in patients with COVID-19 pneumonia, CTPA should be performed to detect and assess the severity of APE.

An analysis of anatomical variations of the left pulmonary artery of the interlobar portion for lung resection by three-dimensional CT pulmonary angiography and thin-section images.

PURPOSE: The purpose of the present study was to analyze the left pulmonary artery (LPA) branching pattern of the interlobar portion using three-dimensional CT pulmonary angiography (3D-CTPA) and thin-section CT images, and to attempt to diagrammatize these patterns. MATERIALS AND METHODS: The study included 320 patients suspected of having lung cancer of the left upper/lower lobe who underwent CTPA. The number and origin of the LPA branches of the interlobar portion, A1 + 2c, A6, and lingular artery from pars interlobaris (PI), were identified meticulously using 3D-CTPA and thin-section images. We then diagrammatized the identified LPA branching patterns of the interlobar portion. RESULTS: The diagrammatized LPA branching patterns of the interlobar portion were broadly classified into seven types in the order of bifurcation from proximal to distal. Type 1 was the most frequent (120/320, 37.5%). PI originated from the lower portion, that is, from A8 or the common trunk of A8 and A9 in 95 cases (29.7%). We could also precisely diagrammatize the LPA branching patterns of the interlobar portion into 85 types in all 320 patients. CONCLUSION: 3D-CTPA and thin-section images provided precise preoperative information regarding the LPA branching patterns of the interlobar portion.

Axial pulmonary trunk diameter variations during the cardiac cycle.

PURPOSE: Previous studies have shown a correlation between axial pulmonary trunk diameter (PTD) on chest computed tomography (CT) and pulmonary artery pressure. However, it is not known whether the PTD slices measured on chest CT have been recorded during the systolic or diastolic phase. The aim of this study was to demonstrate the variations in PTD during the cardiac cycle by measuring coronary CT angiography (CCTA) images. METHODS: A retrospective analysis was made of 101 patients who underwent CCTA for coronary artery disease assessment. CCTA images were reconstructed during a full cardiac cycle and measurements were taken of the systolic and diastolic PTD and ascending aorta diameter (AAD) from the same slice by two independent observers. RESULTS: Inter-observer agreement was excellent (intraclass correlation coefficient = 0.99) for all CT measurements. The mean systolic PTD of all patients was 26.3 ± 3.6 mm and the mean diastolic PTD was 22.8 ± 3.2 mm (p < 0.001). The mean difference between systole and diastole was found to be 3.5 ± 1.2 mm for PTD, 1.2 ± 0.7 mm for AAD, and 0.1 ± 0.04 for the PTD/AAD ratio (p values < 0.001). There was no statistical significance of PTD variations according to gender, age, height, weight, body mass index, and body surface area. CONCLUSION: When an increased PTD is detected in a chest CT compared to normal limits or a previous CT scan, this may be the result of the variation in PTD due to the cardiac cycle.

Increased main pulmonary artery diameter and main pulmonary artery to ascending aortic diameter ratio in smokers undergoing lung cancer screening.

OBJECTIVES: Pulmonary hypertension (PH) is a progressive, potentially fatal disease, difficult to diagnose early due to non-specific nature of symptoms. PH is associated with increased morbidity and death in many respiratory and cardiac disorders, and with all-cause mortality, independent of age and cardiopulmonary disease. The main pulmonary artery diameter (MPA), and ratio of MPA to adjacent ascending aorta (AA), MPA:AA, on Chest CT are strong indicators of suspected PH. Our goal was to determine the prevalence of abnormally high values of these indicators of PH in asymptomatic low-dose CT (LDCT) screening participants at risk of lung cancer, and determine the associated risk factors. METHODS: We reviewed consecutive baseline LDCT scans of 1949 smokers in an IRB-approved study. We measured the MPA and AA diameter and calculated MPA:AA ratio. We defined abnormally high values as being more than two standard deviations above the average (MPA ≥ 34 mm and MPA:AA ≥ 1.0). Regression analyses were used to identify risk factors and CT findings of participants associated with high values. RESULTS: The prevalence of MPA ≥ 34 mm and MPA:AA ≥ 1.0 was 4.2% and 6.9%, respectively. Multivariable regression demonstrated that BMI was a significant risk factor, both for MPA ≥ 34 mm (OR = 1.07, p < 0.0001) and MPA:AA ≥ 1.0 (OR = 1.04, p = 0.003). Emphysema was significant in the univariate but not in the multivariate analysis. CONCLUSIONS: We determined that the possible prevalence of PH as defined by abnormally high values of MPA and of MPA:AA was greater than previously described in the general population and that pulmonary consultation be recommended for these participants, in view of the significance of PH.

Pulmonary vessels and bronchial anatomy of the left lower lobe.

PURPOSE: To identify and clarify the comprehensive anatomic patterns in the left lower lobe (LLL). METHODS: Using computed tomography (CT) imaging data, including that obtained using three-dimensional CT, we reviewed the anatomic patterns of the pulmonary vessels and bronchi in the left lungs of 539 patients, focusing on the LLL. RESULTS: The two-stem type in A6 was observed in 131 (24.7%) patients and the three-stem type in A6 was observed in 11 (2.1%) patients. The independent two-stem type in B6 was observed in four (0.75%) patients. The B7 with independent branching from the basal bronchi was observed in 42 (7.9%) patients. B* was observed in 129 (24.0%) patients and B* was accompanied by A* in all patients. An extrapericardial common trunk of the left pulmonary veins was identified in five patients (0.93%). CONCLUSION: We identified various bronchovascular patterns in the LLL of a large number of patients. Our results provide useful information for anatomic pulmonary resection, especially segmentectomy.

Introduction of a CMR-conditional cardiac phantom simulating cardiac anatomy and function and enabling training of interventional CMR procedures.

Interventional magnetic resonance imaging (MRI) procedures promise to open-up new vistas regarding clinically relevant diagnostic and/or therapeutic procedures in the field of cardiology. However, a number of major limitations and challenges regarding interventional cardiovascular magnetic resonance (CMR) procedures still delay their translation from pre-clinical studies to human application. A CMR-conditional cardiac phantom was constructed using MR-safe or -conditional materials only that is based on a unique modular composition allowing quick replacement of individual components. A maximal flow of 76 ml/sec in the aorta and 111 ml/sec in the pulmonary artery were measured, whereas the maximal flow velocity was 56 cm/sec and 89 cm/sec, respectively. A conventional wedge-pressure catheter was advanced over a MRI-conditional guidewire into the right ventricle and thereafter positioned in the pulmonary artery. Pulmonary artery pressure was measured, obtaining the following values for our cardiac phantom: max/min/mean = 16/10/12 mmHg. The presented CMR-conditional cardiac phantom is the first of its kind that does not only mimic cardiac mechanics with adjustable fluid pressure in a four chamber setup that is closely adapted to that of the human heart, but also enables introduction and testing of interventional tools such as guidewires and catheters.

Multimodal noninvasive prediction of pulmonary hypertension in IPF.

INTRODUCTION AND OBJECTIVE: Pulmonary hypertension (PH) complicating idiopathic pulmonary fibrosis (IPF) is challenging to diagnose given inaccuracy of transthoracic echocardiogram (TTE) measurements. However, it has significant prognostic implications and is therefore important to accurately identify. METHODS: We conducted a cross-sectional study of patients with IPF who underwent RHC as part of their evaluation. A variety of commonly available noninvasive variables were evaluated for their ability to predict pulmonary arterial pressure in a linear regression model, including the traditionally used right ventricular systolic pressure (RVSP) estimated from TTE. RESULTS: There were 105 eligible patients identified from January 2006 to July 2016. The average age was 62.7 ± 7.7 years, 35 had RHC proven PH and 43% ultimately underwent lung transplantation. A linear model including three terms: RVSP (ANOVA P < .01), the ratio of FVC/DLCO from PFTs (P = .05) and pulmonary artery to aorta diameter ratio from CT (P < .01) was found to predict the mean pulmonary artery pressure more reliably than RVSP alone (R2 .39 vs .29, P < .05), with a lower rate of incorrect classification of PH status in these individuals (27.6 vs 35.2%, P = .05) and high negative predictive value (87.2%). CONCLUSION: If used in conjunction with RVSP from TTE, parameters from PFTs and the CT scan more accurately predict the presence or absence of PH than any of the variables in isolation. Using these in concert may allow greater discrimination in deciding which patients to subject to diagnostic right heart catheterization.

Increased pulmonary artery diameter is associated with reduced FEV1 in former World Trade Center workers.

RATIONALE: Occupational exposures at the WTC site after September 11, 2001 have been associated with several presumably inflammatory lower airway diseases. Pulmonary arterial enlargement, as suggested by an increased ratio of the diameter of the pulmonary artery to the diameter of the aorta (PAAr) has been reported as a computed tomographic (CT) scan marker of adverse respiratory health outcomes, including WTC-related disease. In this study, we sought to utilize a novel quantitative CT (QCT) measurement of PAAr to test the hypothesis that an increased ratio is associated with FEV1 below each subject's statistically determined lower limit of normal (FEV1  < LLN). METHODS: In a group of 1,180 WTC workers and volunteers, we examined whether FEV1  < LLN was associated with an increased QCT-measured PAAr, adjusting for previously identified important covariates. RESULTS: Unadjusted analyses showed a statistically significant association of FEV1  < LLN with PAAr (35.3% vs 24.7%, P = 0.0001), as well as with height, body mass index, early arrival at the WTC disaster site, shorter WTC exposure duration, post-traumatic stress disorder checklist (PCL) score, wall area percent and evidence of bronchodilator response. The multivariate logistic regression model confirmed the association of FEV1  < LLN with PAAr (OR 1.63, 95% CI 1.21, 2.20, P = 0.0015) and all the unadjusted associations, except for PCL score. CONCLUSIONS: In WTC workers, FEV1  < LLN is associated with elevated PAAr which, although likely multifactorial, may be related to distal vasculopathy, as has been hypothesized for chronic obstructive pulmonary disease.

Pulmonary Vascular Dynamics.

The pulmonary circulation carries deoxygenated blood from the systemic veins through the pulmonary arteries to be oxygenated in the capillaries that line the walls of the pulmonary alveoli. The pulmonary circulation carries the cardiac output with a relatively low driving pressure, and so differs considerably in structure and function from the systemic circulation to maintain a low-resistance vascular system. The pulmonary circulation is often considered to be a quasi-static system in both experimental and computational studies of pulmonary perfusion and its matching to ventilation (air flow) for exchange. However, the system is highly dynamic, with cardiac output and regional perfusion changing with posture, exercise, and over time. Here we review this dynamic system, with a focus on understanding the physiology of pulmonary vascular dynamics across spatial and temporal scales, and the changes to these dynamics that are reflective of disease. © 2019 American Physiological Society. Compr Physiol 9:1081-1100, 2019.