Bronchial arteries: anatomy, function, hypertrophy, and anomalies

Imaging in non-cystic fibrosis bronchiectasis and current limitations

Non-cystic fibrosis bronchiectasis represents a heterogenous spectrum of disorders characterised by an abnormal and permanent dilatation of the bronchial tree associated with respiratory symptoms. To date, diagnosis relies on computed tomography (CT) evidence of dilated airways. Nevertheless, definite radiological criteria and standardised CT protocols are still to be defined. Although largely used, current radiological scoring systems have shown substantial drawbacks, mostly failing to correlate morphological abnormalities with clinical and prognostic data. In limited cases, bronchiectasis morphology and distribution, along with associated CT features, enable radiologists to confidently suggest an underlying cause. Quantitative imaging analyses have shown a potential to overcome the limitations of the current radiological criteria, but their application is still limited to a research setting.

In the present review, we discuss the role of imaging and its current limitations in non-cystic fibrosis bronchiectasis. The potential of automatic quantitative approaches and artificial intelligence in such a context will be also mentioned.

A Nomogram to Predict Recurrence After Bronchial Artery Embolization for Hemoptysis Due to Bronchiectasis

OBJECTIVE

To develop and validate a nomogram for predicting recurrent hemoptysis after successful bronchial arterial embolization (BAE) in patients with bronchiectasis.

MATERIALS AND METHODS

From January 2015 to December 2019, a total of 251 patients were enrolled in this study. A nomogram was developed with the predictors of recurrent events, which were identified by univariate and multivariate Cox regression analyses. We evaluated nomogram discrimination by area under the receiver operating characteristic curve, calibration by the calibration curve, and clinical usefulness potential by decision curve analysis.

RESULTS

The one-month, 1-year, 2-year, 3-year, and 5-year cumulative recurrence-free rates of patients were 98.4%, 90.5%, 82.8%, 77.7%, and 74.4%, respectively. Three predictive factors, namely sex, lung destruction, and systemic arterial-pulmonary circulation shunts, were applied to develop the nomogram. The model maintained good discrimination (area under the curve, 0.72; 95% confidence interval, 0.62-0.81), low prediction error (integrated Brier score, 0.129), and certain net benefits in terms of clinical usefulness.

CONCLUSIONS

The proposed nomogram showed favorable predictive efficacy for hemoptysis recurrence after BAE in patients with bronchiectasis. Improved long-term outcomes are expected with close follow-up, a healthy lifestyle, and pulmonary rehabilitation for patients at risk of recurrence according to the model.

Performance evaluation of a deep learning image reconstruction (DLIR) algorithm in "double low" chest CTA in children: a feasibility study

BACKGROUND

Chest CT angiography (CTA) is a convenient clinical examination for children with an increasing need to reduce both radiation and contrast medium doses. Iterative Reconstruction algorithms are often used to reduce image noise but encounter limitations under low radiation dose and conventional 100 kVp tube voltage may not provide adequate enhancement under low contrast dose.

PURPOSE

To evaluate the performance of a deep learning image reconstruction (DLIR) algorithm in conjunction with lower tube voltage in chest CTA in children under reduced radiation and contrast medium (CM) dose.

MATERIALS AND METHODS

46 Children (age 5.9 ± 4.2 years) in the study group underwent chest CTA with 70 kVp and CM dose of 0.8-1.2 ml/kg. Images were reconstructed at 0.625 mm using a high setting DLIR (DLIR-H). The control group consisted of 46 age-matching children scanned with 100 kVp, CM dose of 1.3-1.8 ml/kg and images reconstructed with 50% and 100% adaptive statistical iterative reconstruction-V. Two radiologists evaluated images subjectively for overall image noise, vessel contrast and vessel margin clarity separately on a 5-point scale (5, excellent and 1, not acceptable). CT value and image noise of aorta and erector spinae muscle were measured.

RESULTS

Compared to the control group, the study group reduced the dose-length-product by 11.2% (p = 0.01) and CM dose by 24% (p < 0.001), improved the enhancement in aorta (416.5 ± 113.1HU vs. 342.0 ± 57.6HU, p < 0.001) and reduced noise (15.1 ± 3.5HU vs. 18.6 ± 4.4HU, p < 0.001). The DLIR-H images provided acceptable scores on all 3 aspects of the qualitative evaluation.

CONCLUSION

"Double low" chest CTA in children using 70 kVp and DLIR provides high image quality with reduced noise and improved vessel enhancement for diagnosis while further reduces radiation and CM dose.

Cardiovascular complications in cystic fibrosis: A review of the literature

Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leading to dysfunction of the CFTR protein. CFTR dysfunction leads to disease in the respiratory and gastrointestinal systems. Disorders of the cardiovascular system in individuals with CF are usually attributed to secondary effects from progressive lung disease. However, CFTR has been localized to vascular endothelium and smooth muscle, suggesting that CFTR dysfunction may directly impact cardiovascular function. As treatments for CF improve and life-expectancy increases, the risk of vascular disease may increase in prevalence related to primary and secondary CFTR dysfunction, chronic systemic inflammation, nutritional health and hyperglycemia in individuals with CF related diabetes. Here we review the available literature on CF and the cardiovascular system, examining the secondary effects and evidence for direct CFTR dysfunction in the heart, aorta, pulmonary vessels, and vasculature, as well as future directions and treatment options.

Evolution of CT findings after anticoagulant treatment for acute pulmonary embolism in patients with and without an ultimate diagnosis of chronic thromboembolic pulmonary hypertension

INTRODUCTION

The pulmonary arterial morphology of patients with pulmonary embolism (PE) is diverse and it is unclear how the different vascular lesions evolve after initiation of anticoagulant treatment. A better understanding of the evolution of computed tomography pulmonary angiography (CTPA) findings after the start of anticoagulant treatment may help to better identify those PE patients prone to develop chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to assess the evolution of various thromboembolic lesions on CTPA over time after the initiation of adequate anticoagulant treatment in individual acute PE patients with and without an ultimate diagnosis of CTEPH.

METHODS

We analysed CTPA at diagnosis of acute PE (baseline) and at follow-up in 41 patients with CTEPH and 124 patients without an ultimate diagnosis of CTEPH, all receiving anticoagulant treatment. Central and segmental pulmonary arteries were scored by expert chest radiologists as normal or affected. Lesions were further subclassified as 1) central thrombus, 2) total thrombotic occlusion, 3) mural thrombus, 4) web or 5) tapered pulmonary artery.

RESULTS

Central thrombi resolved after anticoagulant treatment, while mural thrombi and total thrombotic occlusions either resolved or evolved into webs or tapered pulmonary arteries. Only patients with an ultimate diagnosis of CTEPH exhibited webs and tapered pulmonary arteries on the baseline scan. Moreover, such lesions always persisted after follow-up.

CONCLUSIONS

Webs and tapered pulmonary arteries at the time of PE diagnosis strongly indicate a state of chronic PE and should raise awareness for possible CTEPH, particularly in patients with persistent dyspnoea after anticoagulant treatment for acute PE.

A bronchopulmonary artery fistula in a horse

A 24-year-old, Thoroughbred gelding presented with difficulty breathing for a few days and intermittent nose bleeding before dying. At necropsy, the bronchoesophageal artery and the bronchial artery that flowed into the left anterior lobe were tortuous and dilated, and it was found that dilated tortuous branches of the bronchial artery ran over the dorsal and ventral surfaces of the left anterior lobe. Histopathologically, an anastomosis between a muscular artery and an elastic artery were demonstrated, which were identified as bronchial and pulmonary arteries, respectively. Based on the gross and histopathological findings, a bronchopulmonary artery fistula was diagnosed. To the best of our knowledge, this is the first case report of a pulmonary vascular anastomosis in a horse.

Variations of bronchial artery origin in 600 patients: Systematic analysis with multidetector computed tomography and digital subtraction angiography

To identify and evaluate the spectrum and prevalence of variations in bronchial artery (BA) origin by multidetector computed tomography (MDCT) and digital subtraction angiography (DSA) in a large population with hemoptysis.From July 2008 to June 2015, data from 600 individuals with hemoptysis who underwent MDCT and DSA were retrospectively analyzed. The pattern of BA origin was investigated and classified according to distribution.A total of 1674 BAs were evaluated, 866 were right BA and 808 were left BA. Most BAs originated from the upper descending thoracic aorta, classified as orthotopic origin (n = 1464, 87.5%). Among ectopic origin BAs (n = 210, 12.5%), concavity of the aortic arch was the most common (n = 107). The most common distribution pattern was a single artery in each side (n = 262). According to our classification, Type I was most common (n = 457), including BAs originating in orthotopic fashion from the descending thoracic aorta. Type II (n = 2) was defined as BAs originating from the aortic arch or ascending aorta. Type III (not found) was defined as BAs originating from subclavian arteries, common carotid arteries, and their branch vessels. Type IV (n = 92) was Type I and II combined, Type V (n = 41) was Type I and III combined, Type VI (not found) was Type II and III combined, and Type VII (n = 8) was Type I, II, and III combined.Variations of BA origin could be systematically described in detail.

CT for Evaluation of Hemoptysis

Hemoptysis, which is defined as expectoration of blood from the alveoli or airways of the lower respiratory tract, is an alarming clinical symptom with an extensive differential diagnosis. CT has emerged as an important noninvasive tool in the evaluation of patients with hemoptysis, and the authors present a systematic but flexible approach to CT interpretation. The first step in this approach involves identifying findings of parenchymal and airway hemorrhage. The second step is aimed at determining the mechanism of hemoptysis and whether a specific vascular supply can be implicated. Hemoptysis can have primary vascular and secondary vascular causes. Primary vascular mechanisms include chronic systemic vascular hypertrophy, focally damaged vessels, a dysplastic lung parenchyma with systemic arterial supply, arteriovenous malformations and fistulas, and bleeding at the capillary level. Evaluating vascular mechanisms of hemoptysis at CT also entails determining if a specific vascular source can be implicated. Although the bronchial arteries are responsible for most cases of hemoptysis, nonbronchial systemic arteries and the pulmonary arteries are important potential sources of hemoptysis that must be recognized. Secondary vascular mechanisms of hemoptysis include processes that directly destroy the lung parenchyma and processes that directly invade the airway. Understanding and employing this approach allow the diagnostic radiologist to interpret CT examinations accurately in patients with hemoptysis and provide information that is best suited to directing subsequent treatment. ^©RSNA, 2021.

Transpleural systemic artery-to-pulmonary artery communications in the absence of chronic inflammatory lung disease. A case series and review of the literature

AIM

To describe the causes and computed tomography (CT) and angiographic appearances of transpleural systemic artery-to-pulmonary artery shunts in patients without chronic inflammatory lung disease and determine their best management.

MATERIALS AND METHODS

All patients referred to a tertiary referral unit between January 2009 and January 2020 in whom a diagnosis of a systemic-to-pulmonary artery communication without underlying chronic inflammatory lung disease was subsequently made have been included in this report. Medical records and imaging findings were reviewed retrospectively.

RESULTS

Ten patients (male: female ratio = 7:3; median age 42 years [range 22-70 years]) with systemic artery-to-pulmonary artery shunts without chronic inflammatory lung disease were identified. Five were misdiagnosed as having a pulmonary arteriovenous malformation and had been referred for embolisation. In six patients, there was either a history of accidental or iatrogenic thoracic trauma or of inflammatory disease involving the pleura, and in two patients, in whom a previous medical history could not be obtained, there were CT features suggesting previous pleural inflammatory disease. Two shunts were thought to be congenital. All individuals were asymptomatic other than one with localised thoracic discomfort that dated from the time of surgery. All patients were managed conservatively and have remained well with a median follow-up of 4.5 years (range 1-11.3 years).

CONCLUSIONS

Localised transpleural systemic artery-to-pulmonary artery shunts in the absence of chronic inflammatory lung disease are usually related to previous thoracic trauma/intervention or abdominal or pulmonary sepsis involving a pleural or diaphragmatic surface. Congenital shunts are rare. The present study and much of the literature supports conservative management.

The design and use of a simple device for the MRI assessment of changes in cardiovascular function by lower-body negative-pressure-simulated reduction of central blood volume

AIM

To use a locally designed and simple lower-body negative-pressure (LBNP) device and 1.5 T magnetic resonance imaging (MRI) to demonstrate the ability to assess changes in cardiovascular function during preload reduction. These effects were evaluated on ventricular volumes and great vessel flow in healthy volunteers, for which there are limited published data.

MATERIAL AND METHODS

After ethical review, 14 volunteers (mean age 33.9 ± 7 years, mean body mass index [BMI] 23.1 ± 2.5) underwent LBNP prospectively at 0, -5, -10, and -20 mmHg pressure, using a locally designed LBNP box. Expiratory breath-hold biventricular volumes, and free-breathing flow imaging of the ascending aorta and main pulmonary artery were acquired at each level of LBNP.

RESULTS

At -5 mmHg, there was no change in aortic flow or left ventricular volumes versus baseline. Right ventricular output (p=0.013) and pulmonary net flow (p=0.026) decreased. At -20 mmHg, aortic and pulmonary net flow (p<0.001) decreased, as were left and right ventricular end diastolic volume (p<0.001) and left and right end systolic volumes (p=0.038 and p=0.003 respectively).

CONCLUSIONS

Use of a MRI-compatible LBNP device is feasible to measure changes in ventricular volume and great arterial flow in the same experiment. This may enhance further research into the effects of preload reduction by MRI in a wide range of important cardiovascular pathologies.

Embolization of bronchial arteries and nonbronchial systemic arteries with n-butyl-cyanoacrylate in patients with hemoptysis: a retrospective single-center study

OBJECTIVES

To evaluate the safety and efficacy of the embolization of bronchial arteries and nonbronchial systemic arteries with n-butyl-cyanoacrylate (NBCA) in patients with hemoptysis.

METHODS

We analyzed a total of 55 consecutive patients with hemoptysis (14 mild, 31 moderate, and 10 massive) treated with the embolization of bronchial arteries and nonbronchial systemic arteries with n-butyl-cyanoacrylate between November 2013 and January 2020. The main variables analyzed were the rates of technical success, of clinical success, of recurrence, and of complications. Statistics included a descriptive analysis and Kaplan-Meier survival curves.

RESULTS

Embolization was a technical success in 55 (100%) and a clinical success in 54 (98.2%). During follow-up (mean, 23.8 months; interquartile range, 9.7 - 38.2 months), hemoptysis recurred in 5 (9.3%) patients. The nonrecurrence rate was 91.9% one year after the initial procedure and 88.7% two years and four years after the initial procedure. Minor complications related with the procedure occurred in 6 (10.9%); no major complications occurred.

CONCLUSIONS

The embolization of bronchial arteries and nonbronchial systemic arteries with n-butyl-cyanoacrylate is safe and efficacious for controlling hemoptysis, resulting in low recurrence rates.

Anatomical Variations of the Aortic Arch: A Computerized Tomography-Based Study

Introduction

Despite adequate preparation and meticulous pre-operative assessment, variations of the vascular anatomy of the aortic arch may lead to clinical dilemmas. In the present era, with the easy availability of imaging facilities, various anatomical variations can be found out prior to an interventional procedure. However, there are many countries including India where such facilities may still be not widely available. The purpose of this study was to assess the prevalence of these anatomical variants in patients undergoing Computerised Tomography (CT) chest with contrast.

Methods

This observational study involved patients who underwent CT chest with contrast as part of various clinical indications during a three-year period in a tertiary care centre in South India. Variations of the aortic arch and its branching pattern were studied in 4,000 chest CT images of patients referred to the radiology department. 

Results

A total of 4,000 patients underwent CT chest with contrast during the study period. Twenty-seven variations were observed in these patients. They included aberrant right subclavian artery in seven patients, bovine arch in one patient, bovine origin of left vertebral artery from arch in one patient, bronchial artery of anomalous origin from arch in one patient, double aortic arch in one patient, and right-sided aortic arch in 16 patients. 

Conclusion

The variant anatomy of the aortic arch has tremendous clinical significance, especially from the surgical standpoint. Anatomical variants can also cause difficulty during catheterization while performing endovascular interventions. Given the prevalence demonstrated in our study, imaging may be indicated prior to any procedure involving vascular access in order to prevent unwanted complications. 

Prenatal diagnosis of major aortopulmonary collateral arteries (MAPCA) in fetuses with pulmonary atresia with ventricular septal defect and agenesis of ductus arteriosus

OBJECTIVE

The aim of this study was to describe the prenatal diagnosis of Major Aortopulmonary Collateral Arteries (MAPCAs), and to present a systematic ultrasound method for evaluating lung vascularity in fetuses with pulmonary atresia with ventricular septal defect (PAVSD) and agenesis of ductus arteriosus (DA).

METHOD

This retrospective study evaluated fetuses diagnosed with PAVSD with agenesis of DA, for the presence of the MAPCAs anomaly. Fetal pulmonary vasculature was investigated by 2D and 4D Spatio Temporal Image Correlation (STIC) technology using High Definition Color Doppler.

RESULTS

Over a 10 year period, six fetuses were diagnosed with MAPCAs. Prenatal diagnosis was made between 17 w 6 d and 28 w 4 d in five fetuses, with the sixth diagnosed at 37 w 6 d. All six had PAVSD with agenesis DA, four exhibited pulmonic atresia without any arterial outflow, while two fetuses presented with absent left pulmonary artery, and a miniscule right pulmonary artery. In five cases, the parents elected to terminate the pregnancy and the last, although born alive, did not survive an attempt at restorative surgery and died at the age of 5 months. Postnatal CT angiography imaging of this case revealed the subclavian origin of the MAPCAs. Chromosomal micro array analysis of the amniotic fluid revealed that five of the six fetuses were normal and one was lost to follow up.

CONCLUSION

MAPCAs should be investigated in cases of PAVSD with agenesis DA. A meticulous ultrasound evaluation using 2D and 4D STIC can permit the prenatal diagnosis of this anomaly and provide the parents with the opportunity for prenatal consultation.

Thoracic Cardiovascular Complications of Tuberculosis

ABSTRACT

Mycobacterium infection remains a leading cause of morbidity and mortality worldwide. Although rare, thoracic cardiovascular complications are associated with devastating consequences if not promptly diagnosed using computed tomography. Intrapulmonary complications include tuberculous aortitis, Rasmussen aneurysms, involvement of bronchial and nonbronchial systemic arteries, and thromboembolic events. Extrapulmonary complications include pericarditis, myocarditis, endocarditis, involvement of coronary arteries, annular-subvalvular left ventricle aneurysms and mediastinal fibrosis. This article will review these complications and their computed tomography features.

Visibility of bronchial arteries using virtual and advanced virtual monoenergetic imaging

BACKGROUND

The utility of virtual monoenergetic imaging (VMI) for fine arteries has not been well clarified.

PURPOSE

To assess bronchial artery visualization using VMI and noise-optimized advanced VMI (VMI+).

MATERIAL AND METHODS

Eighty-seven patients with esophageal cancer underwent computed tomography (CT) using a third-generation dual-source system before surgery. Tube voltages were set to 90 kVp and 150 kVp, respectively. Images were reconstructed using VMI and VMI+ with energy levels of 40-120 keV (in 10-keV increments); composite images equivalent to CT images at 105 kVp were also generated. The CT attenuation value and contrast-to-noise ratio (CNR) of bronchial arteries using VMI and VMI+ were compared with those obtained using composite imaging. Two radiologists subjectively analyzed bronchial artery visualization with reference to the composite image.

RESULTS

CT attenuation values for bronchial arteries using VMI at 40-60 keV and VMI+ at 40 keV and 50 keV were significantly higher than those obtained using composite imaging (P < 0.05). CNR using VMI at 40-60 keV was significantly higher than that obtained using composite imaging (P < 0.05), whereas no differences were noted for values obtained using composite imaging between VMI+ at 40 keV and 50 keV. In the subjective analysis, VMI at 40 keV and 50 keV yielded significantly better visibility of bronchial arteries than VMI+ (P < 0.05).

CONCLUSION

VMI and VMI+ at low voltages (40-50 keV) may be useful for bronchial artery visualization. VMI+ may be less effective for fine vessels as bronchial artery visualization.

Clinical Outcomes of Lung Transplants From Donors With Unexpected Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) is unexpectedly detected in some donor lungs during organ procurement for lung transplantation. Anecdotally, such lungs are usually implanted; however, the impact of this finding on recipient outcomes remains unclear. We hypothesized that incidentally detected donor PE is associated with adverse short-term and long-term outcomes among lung transplant recipients.

METHODS

We analyzed a prospectively maintained database of all lung donors procured by a single surgeon and transplanted at our institution between 2009 and 2018. A standardized approach was used for all procurements and included antegrade and retrograde flush. Pulmonary embolism was defined as macroscopic thrombus seen in the pulmonary artery during the donor procurement operation.

RESULTS

A total of 501 consecutive lung procurements were performed during the study period. The incidence of donor PE was 4.4% (22 of 501). No organs were discarded owing to PE. Donors with PE were similar to donors without PE in baseline characteristics and Pao₂. Recipients in the two groups were also similar. Pulmonary embolism was associated with a higher likelihood of acute cellular rejection grade 2 or more (10 of 22 [45.5%] vs 120 of 479 [25.1%], P = .03). Multivariable Cox modeling demonstrated an association between PE and the development of chronic lung allograft dysfunction (hazard ratio 2.02; 95% confidence interval, 1.23 to 3.30; P = .005).

CONCLUSIONS

Lungs from donors with incidentally detected PE may be associated with a higher incidence of recipient acute cellular rejection as well as reduced chronic lung allograft dysfunction-free survival. Surgeons must use caution when transplanting lungs with incidentally discovered PE. These preliminary findings warrant corroboration in larger data sets.

Clinical applications of digital angiography with the harmonization function in body interventional radiology

Digital subtraction angiography (DSA) is frequently applied in interventional radiology (IR). When DSA is not useful due to misregistration, digital angiography (DA) as an alternative option is used. In DA, the harmonization function (HF) works in real time by harmonizing the distribution of gray steps or reducing the dynamic range; thus, it can compress image gradations, decrease image contrast, and suppress halation artifacts. DA with HF as a good alternative to DSA is clinically advantageous in body IR for generating DSA-like images and simultaneously reducing various motion artifacts and misregistrations caused by patient body motion, poor breath-holding, bowel and ureter peristalsis, and cardiac pulsation as well as halation artifacts often stemming from the lung field. Free-breath DA with HF can improve body IR workflow and decrease the procedure time by reducing the risk of catheter dislocation and using background structures as anatomical landmarks, demonstrating reduced radiation exposure relative to DSA. Thus, HF should be more widely and effectively utilized for appropriate purposes in body IR. This article illustrates the basic facts and principles of HF in DA, and demonstrates clinical advantages and limitations of this function in body IR.

Detection of Shunting Into Pulmonary Artery on Multidetector Row Computed Tomography Arteriography Before Bronchial Arterial Embolization: A Preliminary Study

OBJECTIVE

The aim of this study was to investigate the diagnostic performance of detecting systemic arterial pulmonary circulation shunts on multidetector row computed tomography arteriography (MDCTA).

METHODS

Thirty-five consecutive bronchial artery embolization sessions with preprocedural MDCTA were performed for 32 patients and 35 sessions. The MDCTA studies with computed tomography value of pulmonary trunk visually lower than that of ascending aorta were defined as "diagnostic MDCTA." Angiographic studies and "diagnostic MDCTA" were evaluated, respectively, for shunting into pulmonary artery. Based on the results of angiographic studies, diagnostic performance of "diagnostic MDCTA" was evaluated.

RESULTS

The rate of diagnostic MDCTA was 63% (23 of 35). On "diagnostic MDCTA," sensitivity, specificity, and positive and negative predictive values for detecting shunts were 83% 100%, 100%, 94%, respectively.

CONCLUSIONS

Systemic arterial pulmonary circulation shunts were detected on "diagnostic MDCTA" with high sensitivity and specificity.

Pleural changes in patients with pneumothoraces and Marfan syndrome

Background

Patients with Marfan syndrome (MFS) often develop pneumothorax, but the features of pneumothorax in the context of MFS have not been well described in the literature. We clarified the clinical and histopathological characteristics of this condition in these patients.

Methods

Patients with MFS were selected from among all patients who underwent surgery for pneumothorax, between December 1991 and January 2015, in our hospital. We studied the histopathological characteristics of the resected lungs as well as the clinical features of the selected patients, including surgical findings and postoperative recurrence status.

Results

There were 966 operations underwent pneumothorax-related surgeries in our hospital. A total of 16 operations (1.66%) were performed on patients with MFS in 11 cases. In this study, 9 patients (6 men, 3 women) were included. Clinically, 7 patients (77.8%) had bilateral pneumothoraces and 4 (44.4%) exhibited postoperative recurrent pneumothoraces. Pathologically, the resected pulmonary bullae exhibited blood vessel cystic medial degeneration (55.6% of cases), calcification (55.6% of cases), and demonstrated elastic fiber fragmentation and degeneration (all cases).

Conclusions

As in few previous reports, many patients with MFS develop bilateral or postoperative recurrent pneumothoraces. In many patients, characteristic changes in the pulmonary bullae, possibly caused by degenerated elastic fibers, were observed.

Massive Hemoptysis in Children

Rationale. Hemoptysis is a rare but often life-threatening condition in pediatric patients. Massive hemoptysis can easily lead to asphyxia, respiratory failure, shock, and even death. The most common causes of severe hemoptysis are lower respiratory tract infection, vascular malformation, and bronchial foreign body. We present an unusual case of massive hemoptysis caused by malformation of the bronchial artery, which includes bronchial artery hypertrophy, bronchial-pulmonary artery fistula, and ectopic bronchial artery. Patient. An 11-year-old boy was admitted to the hospital with mild hemoptysis lasting for the two preceding days. He did not report any discomfort, such as fever or chest pain. His complete blood count and coagulation function were normal. Chest X-ray documented lower right pneumonia. Massive hemoptysis occurred on the night of the admission. Diagnosis. Bronchial arteriography revealed that the right lower bronchial artery and the ectopic bronchial artery from the renal artery were the responsible vessels for hemoptysis. Interventions. The boy underwent a successful bronchial artery embolization and bronchoscopy to remove the blood clot from the airway. Outcomes. After bronchial artery embolization and bronchoscopy, the boy recovered without complications. Hemoptysis and chest pain disappeared, and chest radiographs returned to normal. Lessons. Bronchial arterial bleeding often presents as life-threatening massive hemoptysis. Patients should immediately receive hemostatic treatment and undergo chest CTA, bronchial arteriography, BAE, and bronchoscopy according to their condition. Rapid identification of the etiology and symptomatic treatment are critical to saving the lives of children.

Evaluation of the bronchial arteries: normal findings, hypertrophy and embolization in patients with hemoptysis

The enlargement of the bronchial arteries occurs in a multitude of congenital and acquired diseases and is responsible for the majority of cases of hemoptysis. In this review, we provide a simplified imaging approach to the evaluation of the bronchial arteries. We highlight the anatomy and function of the bronchial arteries, typical imaging findings, how to recognize bronchial artery dilatation, and its underlying causes. Contrast-enhanced computer tomography plays a major role in diagnosing bronchial artery enlargement and also improves treatment planning. Bronchial artery embolization has proven to be effective in controlling the potential hazardous hemoptysis.

Pulmonary complications associated with veno-arterial extra-corporeal membrane oxygenation: a comprehensive review

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a life-saving technology that provides transient respiratory and circulatory support for patients with profound cardiogenic shock or refractory cardiac arrest. Among its potential complications, VA-ECMO may adversely affect lung function through various pathophysiological mechanisms. The interaction of blood components with the biomaterials of the extracorporeal membrane elicits a systemic inflammatory response which may increase pulmonary vascular permeability and promote the sequestration of polymorphonuclear neutrophils within the lung parenchyma. Also, VA-ECMO increases the afterload of the left ventricle (LV) through reverse flow within the thoracic aorta, resulting in increased LV filling pressure and pulmonary congestion. Furthermore, VA-ECMO may result in long-standing pulmonary hypoxia, due to partial shunting of the pulmonary circulation and to reduced pulsatile blood flow within the bronchial circulation. Ultimately, these different abnormalities may result in a state of persisting lung inflammation and fibrotic changes with concomitant functional impairment, which may compromise weaning from VA-ECMO and could possibly result in long-term lung dysfunction. This review presents the mechanisms of lung damage and dysfunction under VA-ECMO and discusses potential strategies to prevent and treat such alterations.

Imaging of Chronic Thromboembolic Disease

Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.

Localized Bronchial Hyperemia in Cases of Iatrogenic Hemoptysis: Clinical Presentations and Pathophysiological Mechanisms

Hemoptysis is a frequently encountered symptom in many clinical settings, and etiologic diagnosis can sometimes prove challenging. Bronchoscopy may not promptly reveal the source or the cause of bleeding and few reports have focused so far on the abnormalities of bronchial mucosa vasculature that may unveil the underlying pathophysiology. In this special feature article, we present a series of cases presenting with hemoptysis after angiographic interventions in the thoracic vessels. Localized hyperemia and vascular dilatations in the bronchial mucosa observed during bronchoscopy as unique findings became clues enabling the correct diagnosis and management. We suggest the relevant pathophysiological mechanisms and discuss the available published experience on similar clinical entities.

Bronchial artery laceration and haemothorax complicating transbronchial needle aspiration

A 74-year-old woman presented with chest pain and dyspnoea following endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) for presumed malignancy. Computed tomography angiography revealed a left-sided pleural effusion with hypertrophied and tortuous bronchial arteries (BAs) with contrast blush into the left lung hilum. Tube thoracostomy and pleural fluid analysis confirmed the diagnosis of haemothorax. The mechanism of injury was determined to be BA laceration during EBUS-TBNA and drainage led to rapid improvement in the patient's symptoms. This is the first reported case of haemothorax due to BA injury during EBUS-TBNA.

International expert consensus on the management of bleeding during VATS lung surgery

Intraoperative bleeding is the most crucial safety concern of video-assisted thoracic surgery (VATS) for a major pulmonary resection. Despite the advances in surgical techniques and devices, intraoperative bleeding is still not rare and remains the most common and potentially fatal cause of conversion from VATS to open thoracotomy. Therefore, to guide the clinical practice of VATS lung surgery, we proposed the International Interest Group on Bleeding during VATS Lung Surgery with 65 experts from 10 countries in the field to develop this consensus document. The consensus was developed based on the literature reports and expert experience from different countries. The causes and incidence of intraoperative bleeding were summarised first. Seven situations of intraoperative bleeding were collected based on clinical practice, including the bleeding from massive vessel injuries, bronchial arteries, vessel stumps, and bronchial stumps, lung parenchyma, lymph nodes, incisions, and the chest wall. The technical consensus for the management of intraoperative bleeding was achieved on these seven surgical situations by six rounds of repeated revision. Following expert consensus statements were achieved: (I) Bleeding from major vascular injuries: direct compression with suction, retracted lung, or rolled gauze is useful for bleeding control. The size and location of the vascular laceration are evaluated to decide whether the bleeding can be stopped by direct compression or by ligation. If suturing is needed, the suction-compressing angiorrhaphy technique (SCAT) is recommended. Timely conversion to thoracotomy with direct compression is required if the operator lacks experience in thoracoscopic angiorrhaphy. (II) Bronchial artery bleeding: pre-emptive clipping of bronchial artery before bronchial dissection or lymph node dissection can reduce the incidence of bleeding. Bronchial artery bleeding can be stopped by compression with the suction tip, followed by the handling of the vascular stump with energy devices or clips. (III) Bleeding from large vessel stumps and bronchial stumps: bronchial stump bleeding mostly comes from accompanying bronchial artery, which can be clipped for hemostasis. Compression for hemostasis is usually effective for bleeding at the vascular stump. Otherwise, additional use of hemostatic materials, re-staple or a suture may be necessary. (IV) Bleeding from the lung parenchyma: coagulation hemostasis is the first choice. For wounds with visible air leakage or an insufficient hemostatic effect of coagulation, suturing may be necessary. (V) Bleeding during lymph node dissection: non-grasping en-bloc lymph node dissection is recommended for the nourishing vessels of the lymph node are addressed first with this technique. If bleeding occurs at the site of lymph node dissection, energy devices can be used for hemostasis, sometimes in combination with hemostatic materials. (VI) Bleeding from chest wall incisions: the chest wall incision(s) should always be made along the upper edge of the rib(s), with good hemostasis layer by layer. Recheck the incision for hemostasis before closing the chest is recommended. (VII) Internal chest wall bleeding: it can usually be managed with electrocoagulation. For diffuse capillary bleeding with the undefined bleeding site, compression of the wound with gauze may be helpful.

Moyamoya disease associated with fibromuscular dysplasia of intrapulmonary bronchial arteries-a case report

A case is reported of a 40-year-old woman clinically diagnosed as moyamoya disease with associated fibromuscular dysplasia of intrapulmonary bronchial arteries incidentally revealed during autoptic examination. Moyamoya disease represents an idiopathic noninflammatory and nonatherosclerotic arterio-occlusive process of intracranial arteries. Prolonged brain ischemia leads to formation of tiny and fragile collaterals. Clinically, patients with moyamoya angiopathy commonly present with severe neurological symptoms caused by brain infarction or hemorrhage. Histologically, the steno-occlusive process is based on fibrocellular thickening of intima and intimal smooth muscle cell proliferation. In the literature, extracranial arterial involvement, i.e. fibromuscular dysplasia of renal or pulmonary arteries, has been described in several cases of moyamoya disease. Our aim is to show a unique case of moyamoya disease associated with fibromuscular dysplasia affecting an uncommon site.

Fatal hemoptysis after bronchoscopic biopsy in a dog

An 8‐year‐old 24.6 kg mixed breed dog underwent bronchoscopy for evaluation of a persistent progressive cough. Bronchoscopy documented a markedly thick and irregular, cobblestone appearance of the mucosa. A bronchoscopic biopsy was obtained; immediately after the biopsy, a large amount of hemorrhage poured from the endotracheal tube. Multiple efforts to control the hemorrhage were unsuccessful and the dog suffered a cardiopulmonary arrest and could not be revived. A necropsy was performed, which was significant for pallor, evidence of prior heartworm disease, prominent bronchial arteries, and erosion of the submucosal vessels at the site of the biopsy. The cause of death was hemorrhage associated with transbronchial biopsy of an enlarged bronchial artery associated with heartworm disease. This report describes a rare complication of a routine diagnostic procedure.

Synchrotron-based phase-contrast micro-CT as a tool for understanding pulmonary vascular pathobiology and the 3-D microanatomy of alveolar capillary dysplasia

This study aimed to explore the value of synchrotron-based phase-contrast microcomputed tomography (micro-CT) in pulmonary vascular pathobiology. The microanatomy of the lung is complex with intricate branching patterns. Tissue sections are therefore difficult to interpret. Recruited intrapulmonary bronchopulmonary anastomoses (IBAs) have been described in several forms of pulmonary hypertension, including alveolar capillary dysplasia with misaligned pulmonary veins (ACD/MPV). Here, we examine paraffin-embedded tissue using this nondestructive method for high-resolution three-dimensional imaging. Blocks of healthy and ACD/MPV lung tissue were used. Pulmonary and bronchial arteries in the ACD/MPV block had been preinjected with dye. One section per block was stained, and areas of interest were marked to allow precise beam-alignment during image acquisition at the X02DA TOMCAT beamline (Swiss Light Source). A ×4 magnifying objective coupled to a 20-µm thick scintillating material and a sCMOS detector yielded the best trade-off between spatial resolution and field-of-view. A phase retrieval algorithm was applied and virtual tomographic slices and video clips of the imaged volumes were produced. Dye injections generated a distinct attenuation difference between vessels and surrounding tissue, facilitating segmentation and three-dimensional rendering. Histology and immunohistochemistry post-imaging offered complementary information. IBAs were confirmed in ACD/MPV, and the MPVs were positioned like bronchial veins/venules. We demonstrate the advantages of using synchrotron-based phase-contrast micro-CT for three-dimensional characterization of pulmonary microvascular anatomy in paraffin-embedded tissue. Vascular dye injections add additional value. We confirm intrapulmonary shunting in ACD/MPV and provide support for the hypothesis that MPVs are dilated bronchial veins/venules.

3D bioprinting for lungs and hollow organs

Three-dimensional bioprinting has been gaining attention as a potential method for creating biological tissues, supplementing the current arsenal of tissue engineering techniques. 3D bioprinting raises the possibility of reproducibly creating complex macro- and microscale architectures using multiple different cell types. This is promising for creation of multilayered hollow organs, which has been challenging using more traditional tissue engineering techniques. In this review, the state of the field in bioprinting of epithelialized hollow and tubular organs is discussed. Most of the progress for the pulmonary system has been restricted to the trachea. Due to the gross structural similarities and common engineering challenges when creating any epithelialized hollow organ, this review also covers current progress in printing within the gastrointestinal and genitourinary systems, as well as applications of traditional plastic printing in engineering these tissues.

Automatic Detection and Staging of Lung Tumors using Locational Features and Double-Staged Classifications

Lung cancer is a life-threatening disease with the highest morbidity and mortality rates of any cancer worldwide. Clinical staging of lung cancer can significantly reduce the mortality rate, because effective treatment options strongly depend on the specific stage of cancer. Unfortunately, manual staging remains a challenge due to the intensive effort required. This paper presents a computer-aided diagnosis (CAD) method for detecting and staging lung cancer from computed tomography (CT) images. This CAD works in three fundamental phases: segmentation, detection, and staging. In the first phase, lung anatomical structures from the input tomography scans are segmented using gray-level thresholding. In the second, the tumor nodules inside the lungs are detected using some extracted features from the segmented tumor candidates. In the last phase, the clinical stages of the detected tumors are defined by extracting locational features. For accurate and robust predictions, our CAD applies a double-staged classification: the first is for the detection of tumors and the second is for staging. In both classification stages, five alternative classifiers, namely the Decision Tree (DT), K-nearest neighbor (KNN), Support Vector Machine (SVM), Ensemble Tree (ET), and Back Propagation Neural Network (BPNN), are applied and compared to ensure high classification performance. The average accuracy levels of 92.8% for detection and 90.6% for staging are achieved using BPNN. Experimental findings reveal that the proposed CAD method provides preferable results compared to previous methods; thus, it is applicable as a clinical diagnostic tool for lung cancer.

The Bronchial Arterial Circulation in Lung Transplantation: Bedside to Bench to Bedside, and Beyond

Chronic allograft dysfunction (CLAD) remains a major complication, causing the poor survival after lung transplantation (Tx). Although strenuous efforts have been made at preventing CLAD, surgical approaches for lung Tx have not been updated over the last 2 decades. The bronchial artery (BA), which supplies oxygenated blood to the airways and constitutes a functional microvasculature, has occasionally been revascularized during transplants, but this technique did not gain popularity and is not standard in current lung Tx protocols, despite the fact that a small number of studies have shown beneficial effects of BA revascularization on limiting CLAD. Also, recent basic and clinical evidence has demonstrated the relationship between microvasculature damage and CLAD. Thus, the protection of the bronchial circulation and microvasculature in lung grafts may be a key factor to overcome CLAD. This review revisits the history of BA revascularization, discusses the role of the bronchial circulation in lung Tx, and advocates for novel bronchial-arterial-circulation sparing approaches as a future direction for overcoming CLAD. Although there are some already published review articles summarizing the surgical techniques and their possible contribution to outcomes in lung Tx, to the best of our knowledge, this review is the first to elaborate on bronchial circulation that will contribute to prevent CLAD from both scientific and clinical perspectives: from bedside to bench to bedside, and beyond.

Safety and efficacy of transcatheter embolization in patients with massive hemoptysis due to intercostal pulmonary venous shunts

PURPOSE

Bronchial hemoptysis induced by intercostal pulmonary venous shunt (IPVS) is clinically rare. Pulmonary lesions on pleural surface may facilitate opening of vascular network. This retrospective study investigated safety and efficacy of embolization agents with small-particle embolization treating patients with massive hemoptysis due to IPVS.

METHODS

Patients with massive hemoptysis (n = 207) underwent computed tomography angiography of bronchial artery. Depending on results, selective or superselective digital subtraction angiography and embolization were performed. Polyvinyl alcohol (300-500 μm), or microcoils combined with polyvinyl alcohol, was utilized according to IPVS volume. Vital signs of each patient were closely monitored.

RESULTS

Of 207 patients with massive hemoptysis, 24 (11.6%) had IPVS syndrome. Patients with IPVS had concomitant bronchiectasis (54.2%), followed by tuberculosis (25.0%). Embolizations were performed in 39 culprit intercostal arteries; 37 (94.9%) of these were successfully embolized. Of the latter, 30 and 7 arteries were embolized, respectively, by polyvinyl alcohol alone or polyvinyl alcohol particles combined with microcoils. Embolization failed in one case because the agents could not enter the intercostal artery. If artery dissection occurred during procedure, microcoils were utilized to embolize the main artery. No skin necrosis, spinal artery embolization, or death occurred. Immediate clinical success was achieved in 22 patients (91.7%) after embolization. Two patients (8.3%) experienced recurrence of hemoptysis. Only four patients experienced mild hemoptysis during the 24-month follow-up with the efficiency of 75.0%.

CONCLUSIONS

Intercostal artery embolization with 300-500 μm alone or combined with microcoils is a safe and effective procedure in patients with IPVS-induced bronchial hemoptysis.

Pictorial review of the pulmonary vasculature: from arteries to veins

Pathology of the pulmonary vasculature involves an impressive array of both congenital and acquired conditions. While some of these disorders are benign, disruption of the pulmonary vasculature is often incompatible with life, making these conditions critical to identify on imaging. Many reviews of pulmonary vascular pathology approach the pulmonary arteries, pulmonary veins and bronchial arteries as individual topics. The goal of this review is to provide an integrated overview of the high-yield features of all major disorders of the pulmonary vasculature. This approach provides a more cohesive and comprehensive conceptualisation of respiratory pathology. In this review, we present both the salient clinical and imaging features of congenital and acquired disorders of the pulmonary vasculature, to assist the radiologist in identifying pathology and forming a robust differential diagnosis tailored to the presenting patient. TEACHING POINTS: • Abnormalities of the pulmonary vasculature are both congenital and acquired. • Pathology of a single pulmonary vascular territory often affects the entire pulmonary vasculature. • Anomalous pulmonary venous flow is named as a function of its location and severity. • Bronchial arteries often undergo dilatation secondary to cardio-respiratory pathology.

[Clinical effect of endovascular embolization in treatment of hemoptysis of systemic arterial origin in children]

OBJECTIVE

To investigate the clinical effect of endovascular embolization (EVE) in the treatment of hemoptysis of systemic arterial origin in children.

METHODS

A total of 20 children with hemoptysis of systemic arterial origin who underwent EVE from January 2016 to November 2017 were enrolled. The method for embolization was analyzed and the clinical outcome was evaluated.

RESULTS

Offending vessels were bronchial artery (BA) in 14 children, non-bronchial systemic artery (NBSA) in 1 child, and BA and NBSA in 5 children. Of all the children, 13 underwent EVE with peripheral embolization agents and 7 underwent EVE with mechanical coils. A total of 41 offending vessels were embolized (34 BAs and 7 NBSAs) and all the children achieved immediate arrest of hemoptysis. Two children experienced recurrence within 6 months after EVE and 2 experienced recurrence with 6-24 months after EVE. The peripheral embolization agent group had a lower overall recurrence rate than the mechanical coil group [8%(1/13) vs 43%(3/7); P=0.10]. One child experienced intracranial ectopic embolism after surgery and had good quality of life during 20 months of follow-up after treatment. No other complications were observed.

CONCLUSIONS

EVE is a safe and effective method for the treatment of hemoptysis of systemic arterial origin in children and thus holds promise for clinical application.

Management of severe hemoptysis

INTRODUCTION

Though rare, severe hemoptysis (SH) is associated with a mortality rate exceeding 50% when not managed properly. Areas covered: This paper reviews the recent epidemiological data regarding SH, the role of multidetector computed tomography angiography (MDCTA), and fiberoptic bronchoscopy (FOB) in its management, as well as the value of current treatments. Expert commentary: MDCTA is becoming an essential modality, since it allows determining the location, etiology, and mechanism of the bleeding. FOB can be delayed, except when local control of bleeding is required. Emergency treatment relies on interventional radiology. Both bronchial and non-bronchial arteries should be explored during bronchial arteriography. Surgery must be considered in all operable patients if the cause of hemoptysis persists.

An Interventionalist's Guide to Hemoptysis in Cystic Fibrosis

Massive hemoptysis occurs in a minority of patients with cystic fibrosis, with an annual incidence of 1%. Although rare, massive hemoptysis can be a severe and potentially fatal complication of this disease. Beyond the acute life-threatening event, hemoptysis in patients with cystic fibrosis has been associated with faster decline in lung function, accelerated need for lung transplant, and increased mortality. The bronchial arteries are the culprit vessels in over 90% of cases of hemoptysis. This normally quiescent vascular system undergoes remarkable hypertrophy, collateralization, and angiogenesis before the onset of hemoptysis, introducing numerous pitfalls for the interventionalist. However, in experienced hands, bronchial artery embolization is a safe and potentially lifesaving therapy. Preprocedural noninvasive imaging, specifically computed tomographic angiography, has been repeatedly validated for helping to localize the likely site of bleeding, characterizing pertinent arterial anatomy, and promoting efficient and effective intervention; it has been recommended for all stable patients with hemoptysis. Success in the angiographic suite requires a thorough understanding of normal and variant bronchial arterial anatomy, appropriate patient selection, and a meticulous embolization technique. A meticulous approach to imaging and intervention, conscientious of both visualized and nonvisualized collateral pathways and nontarget vessels, can minimize potentially devastating complications. This review summarizes the current literature, modern procedural techniques, and emerging controversies, serving to guide an evolving approach to management of patients with cystic fibrosis and hemoptysis. ^©RSNA, 2018.

Congenital anomalies of the pulmonary arteries: an imaging overview

Congenital pulmonary artery anomalies represent a diverse group of abnormalities, ranging from asymptomatic incidental findings to causes of sudden cardiac death. While some may be recognized in childhood, others may be found incidentally in adulthood. We review the clinical and imaging findings in patients with congenital anomalies of the pulmonary arteries, including valvular and perivavular anomalies as well as abnormal narrowing, course and communications of the pulmonary arteries. We also discuss the role of various imaging modalities in the evaluation of these patients. It is vital to be aware of the key radiologic manifestations and associated haemodynamic consequences in these conditions in order to facilitate accurate diagnosis and prognostic stratification.

Mediastinoscopic view of the bronchial arteries in a series of surgical cases evaluated with three-dimensional computed tomography

BACKGROUND

We have routinely performed three-dimensional computed tomography (3-D CT) prior to video-assisted transmediastinal esophagectomy to evaluate the small arteries in the mediastinal operative field. This evaluation would be helpful in performing mediastinoscopic esophagectomy.

METHODS

Thirty-one patients who underwent transmediastinal esophagectomy with preoperative evaluations by 3-D CT were the study subject. The bronchial arteries depicted by the 3-D CT were classified by their origin and laterality. In 18 of the 31 cases, the surgical video was available and the identification rate in the video was reviewed for each of the categorized bronchial arteries.

RESULTS

The detection rates of each classified artery were as follows (abbreviations, detection rate); the intercostal-bronchial trunk (IBT, 22/31), the direct left bronchial artery (LBA, 17/31), the common trunk of bronchial arteries (CTB, 7/31), the direct right bronchial artery (RBA, 2/31), and the ectopic arteries (16/31). The ectopic arteries arose from the aortic arch (11 cases), the right subclavian artery (6 cases) or the left subclavian artery (1 case). The identification rates of IBT, LBA, CTB, RBA and any of the ectopic arteries in the video review were 12/13, 4/8, 3/4, 1/1 and 2/10, respectively.

CONCLUSIONS

Preoperative 3-D CT was a highly sensitive evaluation for the bronchial arteries encountered during transmediastinal esophagectomy. Orthotopic arteries except for LBA were frequently identified at the predicted sites. Although RBA and CTB were present infrequently, they often flowed into regional nodes at the bilateral bronchi or the tracheal bifurcation and, therefore, should be preoperatively evaluated.

Lung Ischaemia-Reperfusion Injury: The Role of Reactive Oxygen Species

Lung ischaemia-reperfusion injury (LIRI) occurs in many lung diseases and during surgical procedures such as lung transplantation. The re-establishment of blood flow and oxygen delivery into the previously ischaemic lung exacerbates the ischaemic injury and leads to increased microvascular permeability and pulmonary vascular resistance as well as to vigorous activation of the immune response. These events initiate the irreversible damage of the lung with subsequent oedema formation that can result in systemic hypoxaemia and multi-organ failure. Alterations in the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been suggested as crucial mediators of such responses during ischaemia-reperfusion in the lung. Among numerous potential sources of ROS/RNS within cells, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, nitric oxide synthases and mitochondria have been investigated during LIRI. Against this background, we aim to review here the extensive literature about the ROS-mediated cellular signalling during LIRI, as well as the effectiveness of antioxidants as treatment option for LIRI.

Palliative Embolization for Refractory Bleeding

Bleeding is a common and often challenging complication of malignancy. Etiologies of hemorrhage in this patient population vary, and bleeding may present as an acute, life-threatening emergency or a chronic, low-volume blood loss. For patients with advanced malignancies, interventions to manage bleeding must be balanced by the patient's life expectancy and quality of life. As such, minimally invasive procedures such as transarterial embolization are useful therapeutic options in appropriately selected patients. There is a rich history of palliative transarterial embolization for refractory bleeding in cancer patients. This technique was first applied in the 1970s and has since become an established treatment tool for malignancy-related bleeding throughout the body. While the preponderance of published data comprised case reports and small retrospective studies, the use of embolization continues to expand as experience grows and techniques are refined. In this review, we summarize the literature and provide our perspective on embolization for refractory bleeding in cancer patients.