Distribution of bronchial arteries in the human lung

Ultrathin Bronchoscopy Without Virtual Navigation for Diagnosis of Peripheral Lung Lesions

BACKGROUND

The increasing incidence of encountering lung nodules necessitates an ongoing search for improved diagnostic procedures. Various bronchoscopic technologies have been introduced or are in development, but further studies are needed to define a method that fits best in clinical practice and health care systems.

RESEARCH QUESTION

How do basic bronchoscopic tools including a combination of thin (outer diameter 4.2 mm) and ultrathin bronchoscopes (outer diameter 3.0 mm), radial endobronchial ultrasound (rEBUS) and fluoroscopy perform in peripheral pulmonary lesion diagnosis?

STUDY DESIGN AND METHODS

This is a retrospective review of the performance of peripheral bronchoscopy using thin and ultrathin bronchoscopy with rEBUS and 2D fluoroscopy without a navigational system for evaluating peripheral lung lesions in a single academic medical center from 11/2015 to 1/2021. We used a strict definition for diagnostic yield and assessed the impact of different variables on diagnostic yield, specifically after employment of the ultrathin bronchoscope. Logistic regression models were employed to assess the independent associations of the most impactful variables.

RESULTS

A total of 322 patients were included in this study. The median of the long axis diameter was 2.2 cm and the median distance of the center of the lesion from the visceral pleural surface was 1.9 cm. Overall diagnostic yield was 81.3% after employment of the ultrathin bronchoscope, with more detection of concentric rEBUS views (93% vs. 78%, p < 0.001). Sensitivity for detecting malignancy also increased from 60.5% to 74.7% (p = 0.033) after incorporating the ultrathin scope into practice, while bronchus sign and peripheral location of the lesion were not found to affect diagnostic yield. Concentric rEBUS view, solid appearance, upper/middle lobe location and larger size of the nodules were found to be independent predictors of successful achievement of diagnosis at bronchoscopy.

INTERPRETATION

This study demonstrates a high diagnostic yield of biopsy of lung lesions achieved by utilization of thin and ultrathin bronchoscopes. Direct visualization of small peripheral airways with simultaneous rEBUS confirmation increased localization rate of small lesions in a conventional bronchoscopy setting without virtual navigational planning.

Efficacy and safety of particle embolization in bronchial arteries of hemoptysis patients with shunts

AIM

This study assesses the safety and efficacy of particle embolization during bronchial artery embolization (BAE) in patients with shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery.

METHODS

In this retrospective, single-center study, we analyzed 312 BAE procedures performed from June 2020 to April 2023. The patient cohort had shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery. We meticulously collected and examined comprehensive data, including clinical characteristics, computed tomography (CT) imaging, and embolization procedural details.

RESULTS

Vascular shunts were identified in 49 patients. The etiologies of hemoptysis included post-TB sequelae (42.8%), bronchiectasis (26.5%), active TB (12.2%), aspergilloma (8.1%), bacterial pneumonia (4.1%), lung cancer (4.1%), and non-tuberculous mycobacterial infection (2%). The technical success rate of the procedures was 98%, with 149 out of 152 identified vessels successfully embolized. All patients experienced cessation or significant reduction of hemoptysis within 24 hours following the procedure. The clinical success rates were 97.9% at one month, 93.9% at six months, and 89.8% at one year. No shunt-related complications were detected.

CONCLUSION

BAE with particle embolization is a safe and effective treatment for hemoptysis, particularly in cases with complex shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery.

A Deep Dive Into Retroesophageal Major Aortopulmonary Collateral Arteries

Background: The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. The purpose of this paper was to review the anatomy, physiology, and surgical characteristics of retroesophageal MAPCAs. Methods: This manuscript summarizes the data from a series of three papers that have focused on the subject of retroesophageal MAPCAs from our institution over the past ten years. Results: Two-thirds of patients evaluated had a retroesophageal MAPCA identified at surgery. Retroesophageal major aortopulmonary collateral arteries (REMs) were more common with a left arch (77%) compared with a right arch (53%). Of all REMs evaluated, 83% were single supply, 13% were dual supply with an inadequate connection, and 4% were dual supply with an adequate connection. Based on these findings, 96% of retroesophageal MAPCAs were unifocalized. Follow-up catheterization was performed at a median of 17 months after surgery; 75% of unifocalized MAPCAs were widely patent, 20% were patent but stenotic, and 5% were occluded. Conclusions: The data demonstrate that retroesophageal MAPCAs are relatively common and almost always require unifocalization. At mid-term follow-up, 95% of unifocalized MAPCAs were found to be patent.

Efficacy and safety of CalliSpheres drug-eluting beads for bronchial arterial chemoembolization for refractory non-small-cell lung cancer and its impact on quality of life: A multicenter prospective study

Objective

This study aimed to prospectively observe the efficacy and safety of CalliSpheres drug-eluting beads bronchial arterial chemoembolization (DEB-BACE) for refractory non-small-cell lung cancer (NSCLC).

Methods

The interventional therapy plan was as follows: 300-500 μm CalliSpheres drug-loaded microspheres were loaded with epirubicin, and then slow embolization of tumor supplying artery was performed after microcatheter superselection. Chest enhanced computed tomography and related hematological examination were reviewed after 2 months of DEB-BACE, and the tumor response after the first interventional therapy was evaluated using modified response evaluation criteria in solid tumors. The overall survival (OS) of patients was determined, and the quality of life and the incidence rate of adverse reactions were observed.

Results

From January 2019 to January 2021, 43 patients with refractory NSCLC were enrolled. The patients were followed up until June 2022. All 43 patients underwent DEB-BACE 1.79 ± 0.69 times on average. The 3-, 6-, 12-, and 24-month survival rates were 100%, 86.0%, 41.9%, and 11.8%, respectively. The median OS was 11.5 months. After the first interventional treatment, cough and wheezing significantly improved in 31 patients, hemoptysis was effectively controlled in 12 patients, and superior vena cava compression disappeared in 2 patients after 2 times of treatment. The general health status of the patients after treatment significantly improved compared with that before treatment, including the improvement in physical and emotional functions. Fatigue, nausea and vomiting, dyspnea, and insomnia improved significantly after treatment. No serious adverse events, such as spinal cord injury and cerebral embolism, were observed during the perioperative period. The main adverse reaction after DEB-BACE was chest pain (13/43, grade 1) followed by fever (10/43, grade 1-2), which was significantly relieved within 3-5 days after symptomatic treatment. Other adverse reactions included irritating cough, nausea and vomiting, and bone marrow suppression, and the incidence was less than 20%.

Conclusions

DEB-BACE was effective and safe in treating refractory NSCLC, which could significantly improve patients' quality of life and was worthy of clinical promotion and application.

The Vasculature in Pulmonary Fibrosis

Purpose of Review

The current paradigm of idiopathic pulmonary fibrosis (IPF) pathogenesis involves recurrent injury to a sensitive alveolar epithelium followed by impaired repair responses marked by fibroblast activation and deposition of extracellular matrix. Multiple cell types are involved in this response with potential roles suggested by advances in single-cell RNA sequencing and lung developmental biology. Notably, recent work has better characterized the cell types present in the pulmonary endothelium and identified vascular changes in patients with IPF.

Recent Findings

Lung tissue from patients with IPF has been examined at single-cell resolution, revealing reductions in lung capillary cells and expansion of a population of vascular cells expressing markers associated with bronchial endothelium. In addition, pre-clinical models have demonstrated a fundamental role for aging and vascular permeability in the development of pulmonary fibrosis.

Summary

Mounting evidence suggests that the endothelium undergoes changes in the context of fibrosis, and these changes may contribute to the development and/or progression of pulmonary fibrosis. Additional studies will be needed to further define the functional role of these vascular changes.

Bronchial Artery Chemoembolization for Hemoptysis in Advanced Primary Lung Cancer

BACKGROUND

To evaluate the safety and effectiveness of bronchial arterial infusion chemoembolization (BAICE) for lung cancer with hemoptysis.

PATIENTS AND METHODS

Retrospectively analyze clinical data of patients undergoing BAICE for the treatment of lung cancer with hemoptysis, evaluate the clinical efficacy of this approach, observe postoperative adverse reactions, and analyze hemoptysis-free survival (HFS) and overall survival (OS).

RESULTS

All 187 patients underwent BAICE with technical success rate of 100%, clinical success rate of 86.6%, clinical failure rate of 13.4%. After BAICE, the tumor curative effect was evaluated as complete remission in 56 cases, partial remission in 82 cases, stable disease in 26 cases, and progressive disease in 6 cases. The objective response rate was 73.8%, and the disease control rate was 87.7%. Median HFS of the 154 clinically successful cases was 10.5 months (95% confidence interval [CI]: 8.11-11.89). The degree of hemoptysis (massive hemoptysis hazard ratio [HR] = 5.9, 95% CI: 3.43-10.16, P = .00) and cavitary lung mass (HR = 2.39, 95% CI: 1.44-3.99, P = .001), were significantly related to a reduction in HFS after BAICE. The 6-month and 12-month survival rates were 66.5% and 45.6%, respectively. The median OS of clinically successful cases was 13.0 months (95% CI: 11.22-14.77). The median OS of 16 clinically failed cases was 2.0 months (95% CI: 0.41-2.45) (P < .001). All adverse events were grade 1.

CONCLUSION

BAICE for advanced lung cancer with hemoptysis is safe, effective, and tolerable.

Hypervascularized bronchial arteries as a risk factor for intraoperative bleeding and prolonged surgery

Background

The present study investigated whether highly vascularized bronchial arteries affect the intraoperative blood loss and the operative time of video-assisted thoracic surgery (VATS) lobectomy for patients with non-small cell lung cancer.

Results

Among the 175 patients enrolled, risk factors for intraoperative blood loss >50 mL were being male (P=0.005), a history of smoking (P=0.01), percent forced expiratory volume in 1 s (FEV1.0%) <70% (P=0.012), squamous cell carcinoma (P=0.049), and a bronchial artery diameter >2.0 mm (P<0.001) in the unadjusted analysis, and a bronchial artery diameter >2.0 mm (P<0.001) in the multivariable analysis. Risk factors for an operative time >200 min were being male (P<0.001), a history of smoking (P=0.007), FEV1.0% <70% (P=0.011), squamous cell carcinoma (P=0.046), a bronchial artery diameter >2.0 mm (P<0.001), and experience of surgeon <10 years (P=0.011) in the unadjusted analysis, and being male (P=0.047), a bronchial artery diameter >2.0 mm (P=0.024), and experience of surgeon <10 years (P=0.047) in the multivariable analysis.

Conclusions

Bronchial artery diameter was the most important risk factor of intraoperative bleeding and prolonged operative time during VATS lobectomy.

Coil embolisation for massive haemoptysis in cystic fibrosis

Introduction

Massive haemoptysis is a life-threatening event in advanced cystic fibrosis (CF) lung disease with bronchial artery embolisation (BAE) as standard of care treatment. The aim of our study was to scrutinise short-term and long-term outcomes of patients with CF and haemoptysis after BAE using coils.

Methods

We carried out a retrospective cohort study of 34 adult patients treated for massive haemoptysis with super selective bronchial artery coil embolisation (ssBACE) between January 2008 and February 2015. Embolisation protocol was restricted to the culprit vessel(s) and three lobes maximum. Demographic data, functional end-expiratory volume in 1 s in % predicted (FEV1% pred.) and body mass index before and after ssBACE, sputum colonisation, procedural data, time to transplant and time to death were documented.

Results

Patients treated with ssBACE showed significant improvement of FEV₁% pred. after embolisation (p=0.004) with 72.8% alive 5 years post-ssBACE. Mean age of the patients was 29.9 years (±7.7). Mean FEV₁% pred. was 45.7% (±20.1). Median survival to follow-up was 75 months (0–125). Severe complication rate was 0%, recanalisation rate 8.8% and 5-year-reintervention rate 58.8%. Chronic infection with Pseudomonas aeruginosa was found in 79.4%, Staphylococcus areus in 50% and Aspergillus fumigatus in 47.1%.

Discussion

ssBACE is a safe and effective treatment for massive haemoptysis in patients with CF with good results for controlling haemostasis and excellent short-term and long-term survival, especially in severely affected patients with FEV<40% pred. We think the data of our study support the use of coils and a protocol of careful and prudent embolisation.

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.

To Unifocalize or Not to Unifocalize?: A Comparison of Retroesophageal Versus Anterior Collaterals

BACKGROUND

The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. This study compared the physiologic and surgical characteristics of retroesophageal vs anterior located MAPCAs.

METHODS

This was a retrospective review of 42 patients who had 1 (n = 36) or 2 (n = 6) retroesophageal MAPCAs. These MAPCAs were then characterized as (1) single supply, meaning no connection to the pulmonary arteries; (2) dual supply, but inadequate connection to the distal pulmonary vascular bed; and (3) dual supply with adequate connection.

RESULTS

The 42 patients presented with 187 MAPCAs, or 4.5 MAPCAs per patient. Of these, 48 MAPCAs were retroesophageal, including 40 that were single supply, 6 were dual supply with inadequate connection, and 2 had dual supply with adequate connection. On the basis of this anatomy and physiology, 96% of retroesophageal MAPCAs were unifocalized. For the 139 anterior MAPCAs, 89 were single supply, 15 were dual supply with inadequate connection, and 35 were dual supply with adequate connection; thus, 75% of anterior MAPCAs were unifocalized (P < .01 compared with retroesophageal MAPCAs).

CONCLUSIONS

The data demonstrate that retroesophageal MAPCAs had very different anatomy and physiology compared with anterior MAPCAs. These results suggest that nearly every retroesophageal MAPCA should be unifocalized to incorporate the lung segments supplied.

The extent of enlarged bronchial arteries is not correlated with the development of reperfusion pulmonary edema after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension

This study investigated whether dilated bronchial arteries are associated with reperfusion pulmonary edema in patients with chronic thromboembolic pulmonary hypertension. Results showed that the extent of enlarged bronchial arteries was not associated with the development of reperfusion pulmonary edema, whereas the residual pulmonary hypertension had a significant association.

Combination of Bronchial Arterial Infusion Chemotherapy plus Drug-Eluting Embolic Transarterial Chemoembolization for Treatment of Advanced Lung Cancer-A Retrospective Analysis of 23 Patients

PURPOSE

To determine the efficacy and safety of the combination of bronchial arterial infusion (BAI) chemotherapy and transarterial chemoembolization with the use of drug-eluting embolic (DEE) particles in the treatment of unresectable advanced lung cancer.

MATERIALS AND METHODS

A retrospective review was performed of 23 patients with unresectable lung cancer (stage III/IV) who received BAI chemotherapy and DEE chemoembolization. Treatment response was assessed by enhanced CT and evaluated on the basis of Response Evaluation Criteria In Solid Tumors at 30 d after the last combination treatment. Patients were followed up until death or March 15, 2020, whichever was first. Overall survival (OS) was estimated by Kaplan-Meier analysis, and factors associated with OS were evaluated by Cox proportional-hazards test.

RESULTS

Complete response, partial response, stable disease, and progressive disease were seen in 2, 16, 5, and 0 patients at 30 d after the last combination treatment, respectively; therefore, the overall response rate was 78.3% and the disease control rate was 100%. Preprocedure symptoms (hemoptysis in 7 patients and dyspnea in 10) resolved in all cases after combination therapy. Nineteen patients died during follow-up, and 4 survived. Median OS was 15.6 mo (95% confidence interval, 10.1-21.1 mo). On univariate analysis and multivariate analysis, tumor/node/metastasis staging was an independent risk factor for prognosis. There were no serious adverse events during the procedures.

CONCLUSIONS

The combination of BAI chemotherapy plus DEE chemoembolization appears to be a promising method for treatment of advanced lung cancer.

Bronchial Artery Embolization, an Increasingly Used Method for Hemoptysis; Treatment and Avoidance

Objectives

Hemoptysis is an alarming symptom. It may cause some severe life-threatening complications. Hypertrophic and fragile bronchial artery causes hemoptysis and occurs mostly in bronchiectasis, sarcoidosis, active or sequelae tuberculosis, aspergilloma, lung cancer or cystic fibrosis. Bronchial artery embolization is one of the angiographic methods used in diagnosis and treatment for years performed by radiologists. Hemoptysis is used mostly in patients with hemoptysis. Using this method, surgical management with high mortality and morbidity rates can be avoided or better conditions for surgery can be provided via stopping hemorrhage before surgery. We aim to share the experiences of our hospital about patients who underwent bronchial artery embolization and compare our results with the literature.

Methods

Thirty-nine patients (29 male, 10 female) underwent angiography-aiming embolization. Pathologies were hemoptysis in 37 patients, Castleman disease in two patients. Embolization was performed in 33 patients; 31 for hemoptysis, two for Castleman disease. Bilateral embolization was performed in six patients.

Results

Computed tomography (CT) was helpful in diagnosing the side of bleeding in 91.8% of the patients with hemoptysis. Bronchoscopy was diagnostic in 53% of patients. Polyvinyl alcohol (n=27) was mostly used for embolization. Hemoptysis recurred in six patients (19.3%). All were managed successfully, of four with re-embolization. One major complication, transient blindness, was observed.

Conclusion

Bronchial artery embolization is minimally invasive, more tolerable compared to surgery can be managed with high success and lower complication rates, especially hemoptysis and in some other situations. It provides time for evaluating the underlying disease and delaying surgery for elective conditions. That is why this method has been used increasingly.

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.

Ectopic origin of bronchial arteries: still a potential pitfall in embolization

PURPOSE

To evaluate the influence of ectopic origin of bronchial arteries (BAs) on bronchial artery embolization (BAE) for hemoptysis.

METHODS

CT and angiography images of 50 consecutive sessions in 39 patients (aged 26-93 years; mean, 70.6 years) who underwent BAE for hemoptysis from April 2010 to December 2019 were reviewed. We defined ectopic BA as a systemic artery originating from other than the T5-T6 vertebral level of the descending aorta with course along the major bronchi. The background of patients, number of BAs, culprit arteries, and treatment outcomes were compared between the cases with and without ectopic BAs.

RESULTS

Seventeen patients (43.6%) demonstrated 19 ectopic BAs, originating from the subclavian artery (n = 7), aortic arch above the T5-T6 level (n = 6), internal mammary artery (n = 3), brachiocephalic trunk (n = 2) or lower descending thoracic aorta (n = 1). Total number of BAs in the cases with ectopic BA was significantly greater than those in cases without ectopic BA (p = 0.0062). Required sessions of embolization were similar in the two groups. No procedure-related significant complications were noted; however, four ectopic BAs caused unexpected filling of contrast media or migration of the embolic material from the orthotopic BA to ectopic BA originating from the arch vessels via tiny communication.

CONCLUSION

Although BAE under the presence of ectopic BA is feasible and safe, detection of BAs with ectopic origin, even of small diameter, is needed to avoid risk of non-target coursing of embolic materials.

A Novel Smart Assistance System for Blood Vessel Approaching: A Technical Report Based on Oximetry

In clinical practice, the catheter has to be placed at an accurate position during anesthesia administration. However, effectively guiding the catheter to the accurate position in deeper tissues can be difficult for an inexperienced practitioner. We aimed to address the current issues associated with catheter placement using a novel smart assistance system for blood vessel catheter placement. We used a hollow introducer needle embedded with dual wavelength (690 and 850 nm) optical fibers to advance the tip into the subclavian vessels in anesthetized piglets. The results showed average optical density changes, and the difference between the absorption spectra and hemoglobin concentrations of different tissue components effectively identified different tissues (p < 0.05). The radial basis function neural network (RBFNN) technique was applied to distinguish tissue components (the F-measure value and accuracy were 93.02% and 94%, respectively). Finally, animal experiments were designed to validate the performance of the proposed system. Using this system based on oximetry, we easily navigated the needle tip to the target vessel. Based on the experimental results, the proposed system could effectively distinguish different tissue layers of the animals.

Non-aortic vascular findings on chest CT angiogram: including arch vessels and bronchial arteries

CT angiogram (CTA) has become the modality of choice for imaging of thoracic vascular pathologies, involving the aorta and the pulmonary arteries. Apart from showing exquisite details of these large arteries, pathologies and anatomic variants of their branches can also be studied to a great extent. The major branches of aortic arch can be affected by a wide variety of pathologies ranging from atherosclerosis to trauma and vasculitis. Bronchial arteries in spite of supplying only 1% of lung parenchyma can become hypertrophied in various congenital and acquired conditions, becoming an important source of collateral circulation as well as a source for life threatening hemoptysis. CT also plays an important role in diagnosis of vascular compression at the thoracic outlet. With advances in CT technology, the acquisition, interpretation and clinical applications of CT angiography will continue to grow in the years to come.

Bronchial arterial embolization using a gelatin sponge for hemoptysis from pulmonary aspergilloma: comparison with other pulmonary diseases

PURPOSE

To evaluate the clinical outcomes of bronchial artery embolization (BAE) using a gelatin sponge for hemoptysis from pulmonary aspergilloma and compare them with treatment outcomes for hemoptysis from other diseases.

METHODS

Fifty-two patients underwent BAE using a gelatin sponge. The etiology of hemoptysis was pulmonary aspergilloma in 8 (PA group) and other diseases in 44 (control group). The technical success rate, clinical success rate, hemoptysis-free rate, and complication rate were compared between the PA group and control group. Technical success was defined as the complete cessation of the targeted feeding artery as confirmed by digital subtraction angiography, and clinical success as the cessation of hemoptysis within 24 h of BAE. Recurrent hemoptysis was defined as a single or multiple episodes of hemoptysis causing > 30 ml of bleeding per day.

RESULTS

Technical and clinical success rates were 100% in both groups. Hemoptysis-free rates were 85% at 6 months and 72% at 12-60 months in the control group, and 38% at 6-12 months and 25% thereafter in the PA group (P = 0.0009). No complications were observed following BAE in any case in the two groups.

CONCLUSION

BAE using a gelatin sponge may not be effective for hemoptysis from pulmonary aspergilloma.

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.

The Diagnosis and Treatment of Hemoptysis

BACKGROUND

Hemoptysis, i.e., the expectoration of blood from the lower airways, has an annual incidence of approximately 0.1% in ambulatory patients and 0.2% in inpatients. It is a potentially life-threatening medical emergency and carries a high mortality.

METHODS

This review article is based on pertinent publications retrieved by a selective search in PubMed.

RESULTS

Hemoptysis can be a sign of many different diseases. Its cause remains unknown in about half of all cases. Its more common recognized causes include infectious and inflammatory airway diseases (25.8%) and cancer (17.4%). Mild hemoptysis is self-limited in 90% of cases; massive hemoptysis carries a worse prognosis. In patients whose life is threatened by massive hemoptysis, adequate oxygenation must be achieved through the administration of oxygen, positioning of the patient with the bleeding side down (if known), and temporary intubation if necessary. A thorough diagnostic evaluation is needed to identify the underlying pathology, site of bleeding, and vascular anatomy, so that the appropriate treatment can be planned. The evaluation should include conventional chest x-rays in two planes, contrastenhanced multislice computerized tomography, and bronchoscopy. Hemostasis can be achieved at bronchoscopically accessible bleeding sites with interventionalbronchoscopic local treatment. Bronchial artery embolization is the first line of treatment for hemorrhage from the pulmonary periphery; it is performed to treat massive or recurrent hemoptysis or as a presurgical measure and provides successful hemostasis in 75-98% of cases. Surgery is indicated if bronchial artery embolization alone is not successful, or for special indications (traumatic or iatrogenic pulmonary/vascular injury, refractory asper gilloma).

CONCLUSION

The successful treatment of hemoptysis requires thorough diagnostic evaluation and close interdisciplinary collaboration among pulmonologists, radiologists, and thoracic surgeons.

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.

The Rationale and Evidence for Use of Inhaled Antibiotics to Control Pseudomonas aeruginosa Infection in Non-cystic Fibrosis Bronchiectasis

Non-cystic fibrosis bronchiectasis (NCFBE) is a chronic inflammatory lung disease characterized by irreversible dilation of the bronchi, symptoms of persistent cough and expectoration, and recurrent infective exacerbations. The prevalence of NCFBE is on the increase in the United States and Europe, but no licensed therapies are currently available for its treatment. Although there are many similarities between NCFBE and cystic fibrosis (CF) in terms of respiratory symptoms, airway microbiology, and disease progression, there are key differences, for example, in response to treatment, suggesting differences in pathogenesis. This review discusses possible reasons underlying differences in response to inhaled antibiotics in people with CF and NCFBE. Pseudomonas aeruginosa infections are associated with the most severe forms of bronchiectasis. Suboptimal levels of antibiotics in the lung increase the mutation frequency of P. aeruginosa and lead to the development of mucoid strains characterized by formation of a protective polysaccharide biofilm. Mucoid strains of P. aeruginosa are associated with a chronic infection stage, requiring long-term antibiotic therapy. Inhaled antibiotics provide targeted delivery to the lung with minimal systemic toxicity and adverse events compared with oral/intravenous routes of administration, and they could be alternative treatment options to help address some of the treatment challenges in the management of severe cases of NCFBE. This review provides an overview of completed and ongoing trials that evaluated inhaled antibiotic therapy for NCFBE. Recently, several investigators conducted phase 3 randomized controlled trials with inhaled aztreonam and ciprofloxacin in patients with NCFBE. While the aztreonam trial results were not associated with significant clinical benefit in NCFBE, initial results reported from the inhaled ciprofloxacin (dry powder for inhalation and liposome-encapsulated/dual-release formulations) trials hold promise. A more targeted approach could identify specific populations of NCFBE patients who benefit from inhaled antibiotics.

Massive Hemoptysis: Pathogenesis and Management

Massive hemoptysis is a life-threatening complication of many pulmonary disorders, and it occurs most com monly in association with longstanding inactive tuber culosis, bronchiectasis, lung abscess, bronchogenic car cinoma, and fungal disease. It is generally a neovascular change or local erosive effect of chronic pulmonary dis ease and may originate from either bronchial or pulmo nary circulation. Recurrent bleeding is unpredictable; therefore, diagnostic and therapeutic intervention must be undertaken with urgency. The immediate priorities must be protection of the airway to the nonbleeding lung and localization of the site of hemorrhage prefera bly by bronchoscopy, which has a high yield when per formed during active hemorrhage. Immediate control of bleeding may be obtained by local tamponade with a balloon-tipped Fogarty catheter, use of a double-lumen endotracheal tube, or angiographically guided emboliza tion. Surgical resection is the preferred definitive treat ment for those who meet operative criteria; those who lack adequate pulmonary reserve are candidates for em bolization of sites with persistent bleeding. The high mortality of conservatively treated massive hemoptysis and the current inability to predict which patients will have fatal hemorrhage mandate rapid assessment and intervention.

Bronchial arteries: anatomy, function, hypertrophy, and anomalies

The two main sources of blood supply to the lungs and their supporting structures are the pulmonary and bronchial arteries. The bronchial arteries account for 1% of the cardiac output but can be recruited to provide additional systemic circulation to the lungs in various acquired and congenital thoracic disorders. An understanding of bronchial artery anatomy and function is important in the identification of bronchial artery dilatation and anomalies and the formulation of an appropriate differential diagnosis. Visualization of dilated bronchial arteries at imaging should alert the radiologist to obstructive disorders that affect the pulmonary circulation and prompt the exclusion of diseases that produce or are associated with pulmonary artery obstruction, including chronic infectious and/or inflammatory processes, chronic thromboembolic disease, and congenital anomalies of the thorax (eg, proximal interruption of the pulmonary artery). Conotruncal abnormalities, such as pulmonary atresia with ventricular septal defect, are associated with systemic pulmonary supply provided by aortic branches known as major aortopulmonary collaterals, which originate in the region of the bronchial arteries. Bronchial artery malformation is a rare left-to-right or left-to-left shunt characterized by an anomalous connection between a bronchial artery and a pulmonary artery or a pulmonary vein, respectively. Bronchial artery interventions can be used successfully in the treatment of hemoptysis, with a low risk of adverse events. Multidetector computed tomography helps provide a vascular road map for the interventional radiologist before bronchial artery embolization.

Histologic Evidence of Intrapulmonary Bronchopulmonary Anastomotic Pathways in Neonates with Meconium Aspiration Syndrome

We examined lung histology from 8 infants who died with meconium aspiration syndrome in order to determine the presence of intrapulmonary bronchopulmonary anastomotic pathways. Each infant required mechanical ventilation to treat hypoxemic respiratory distress. Lung histology from each infant shows evidence of prominent bronchopulmonary vascular connections.

Intravascular Placement of Metallic Coils as Lung Tumor Markers for CyberKnife Stereotactic Radiation Therapy

Objective

To present our experience with placing endovascular coils in pulmonary arteries used as a fiducial marker for CyberKnife therapy and to describe the technical details and complications of the procedure.

Materials and Methods

Between June 2005 and September 2013, 163 patients with primary or secondary lung malignancies, referred for fiducial placement for stereotactic radiosurgery, were retrospectively reviewed. Fourteen patients (9 men, 5 women; mean age, 70 years) with a history of pneumonectomy (n = 3), lobectomy (n = 3) or with severe cardiopulmonary co-morbidity (n = 8) underwent coil (fiducial marker) placement. Pushable or detachable platinum micro coils (n = 49) 2-3 mm in size were inserted through coaxial microcatheters into a small distal pulmonary artery in the vicinity of the tumor under biplane angiography/fluoroscopy guidance.

Results

Forty nine coils with a median number of 3 coils per tumor were placed with a mean tumor-coil distance of 2.7 cm. Forty three (87.7%) of 49 coils were successfully used as fiducial markers. Two coils could not be used due to a larger tumor-coil distance (> 50 mm). Four coils were in an acceptable position but their non-coiling shape precluded tumor tracking for CyberKnife treatment. No major complications needing further medication other than nominal therapy, hospitalization more than one night or permanent adverse sequale were observed.

Conclusion

Endovascular placement of coil as a fiducial marker is safe and feasible during CyberKnife therapy, and might be an option for the patients in which percutaneous transthoracic fiducial placement might be risky.

A novel dual ex vivo lung perfusion technique improves immediate outcomes in an experimental model of lung transplantation

The lungs are dually perfused by the pulmonary artery and the bronchial arteries. This study aimed to test the feasibility of dual-perfusion techniques with the bronchial artery circulation and pulmonary artery circulation synchronously perfused using ex vivo lung perfusion (EVLP) and evaluate the effects of dual-perfusion on posttransplant lung graft function. Using rat heart-lung blocks, we developed a dual-perfusion EVLP circuit (dual-EVLP), and compared cellular metabolism, expression of inflammatory mediators, and posttransplant graft function in lung allografts maintained with dual-EVLP, standard-EVLP, or cold static preservation. The microvasculature in lung grafts after transplant was objectively evaluated using microcomputed tomography angiography. Lung grafts subjected to dual-EVLP exhibited significantly better lung graft function with reduced proinflammatory profiles and more mitochondrial biogenesis, leading to better posttransplant function and compliance, as compared with standard-EVLP or static cold preservation. Interestingly, lung grafts maintained on dual-EVLP exhibited remarkably increased microvasculature and perfusion as compared with lungs maintained on standard-EVLP. Our results suggest that lung grafts can be perfused and preserved using dual-perfusion EVLP techniques that contribute to better graft function by reducing proinflammatory profiles and activating mitochondrial respiration. Dual-EVLP also yields better posttransplant graft function through increased microvasculature and better perfusion of the lung grafts after transplantation.

Percutaneous embolization for ruptured ectopic bronchial artery aneurysm: a case report

Bronchial artery aneurysm (BAA) is an uncommon disease, and spontaneous rupture of an ectopic BAA can be difficult for diagnosis and life-threatening. This case study describes a 52-year-old man who presented with acute onset of right chest pain, mild tachycardia, and hypertension. The initial diagnosis of acute myocardial infarction was made, and the patient was given nitroglycerin prior to admission to our hospital. However, the patient's symptoms deteriorated. An enhanced computed tomography scan revealed a ruptured 25-mm diameter mediastinal aneurysm under the tracheal bifurcation when he was admitted to our hospital. Bronchial arteriography further demonstrated a ruptured mediastinal BAA of a bronchial artery originated from the left subclavian artery, supplying the right lobe. Transcatheter artery embolization with polyvinyl alcohol particles and microcoils was performed successfully. The patient's symptoms were gradually relieved, and without recurrence on 1 year follow-up.This case highlights the rare variation of mediastinal BAA and the role of interventional radiology in diagnosing and treating this critical condition.

Experimental studies in the bronchial circulation. Which is the ideal animal model?

BACKGROUND

The importance of the role of bronchial arteries is notable in modern days thoracic surgery. The significance of their anastomoses with adjusted structures has not yet been sufficiently rated, especially in cases of haemoptysis, heart-lung transplantations and treatment of aneurysms of the thoracic aorta. The need of a thorough study is more relevant than ever and appropriate laboratory animals are required.

METHODS

We review the literature in order to highlight the ideal experimental animal for the implementation of pilot programs relative to the bronchial circulation. A comparative analysis of the anatomy of the bronchial arterial system in humans along with these of pigs, dogs, rats, and birds, as being the most commonly used laboratory animals, is presented in details.

RESULTS

The pig has the advantage that the broncho-oesophageal artery usually originates from the aorta as a single vessel, which makes the recognition and dissection of the artery easy to perform. In dogs, there is significant anatomical variation of the origin of the bronchial arteries. In rats, bronchial artery coming from the aorta is a rare event while in birds the pattern of the bronchial artery tree is clearly different from the human analog.

CONCLUSIONS

The pig is anatomically and physiologically suited for experimental studies on the bronchial circulation. The suitable bronchial anatomy and physiology along with the undeniable usefulness of the pig in experimental research and the low maintenance cost make the pig the ideal model for experiments in bronchial circulation.

Bronchopulmonary lymph nodes and large airway cell trafficking in patients with fatal asthma

BACKGROUND

Immune responses in asthmatic patients involve coordinated cellular responses in the airways and lymph nodes (LNs). However, no studies have described the composition of different cell populations in the bronchopulmonary LNs of asthmatic patients.

OBJECTIVE

We sought to investigate the expression of dendritic cells (DCs) and costimulatory molecules, B cells, T cells, TH2-related cytokines, eosinophils, and vascular cell adhesion molecule in the bronchopulmonary LNs and large airways of asthmatic patients.

METHODS

Using histochemistry, immunohistochemistry, and image analysis, we investigated the expression of Factor XIIIa(+), CD1a(+), CD83(+), and CD207(+) DCs; CD4(+) and CD8(+) T cells; CD20(+) B cells; CD23(+) (FcεRII) cells; IL-4; IL-5; eosinophils, and vascular cell adhesion molecule 1 in the large airways and bronchopulmonary LNs of 11 nonsmokers who died from an asthma exacerbation (fatal asthma [FA]) in comparison with 8 nonasthmatic control subjects. In selected cases of FA, we analyzed the coexpression of HLA-DR, CD40, and CD80 in lung and LN eosinophils.

RESULTS

The LNs of asthmatic patients exhibited increased density of eosinophils. No other cells were expressed differently in the LNs of patients with FA. The large airways of patients with FA had increased expression of eosinophils in all layers and increased expression of Factor XIIIa(+) cells, CD4(+) and CD8(+) T cells, CD20(+) B cells, and CD23(+) cells in the outer layer. There was colocalization of HLA-DR, CD40, and CD80 in the eosinophils at both sites.

CONCLUSIONS

FA is associated with the increased presence of eosinophils in the LNs and large airways, which express HLA-DR and costimulatory molecules. The expression of Factor XIIIa(+) monocyte-derived DCs, CD4(+) and CD8(+) T cells, CD20(+) B cells, and CD23(+) cells was increased in the large airways without a corresponding increase in the expression of these cells in the bronchopulmonary LNs. These findings support the concept that eosinophils might act as antigen-presenting cells in patients with FA.

Multidetector computed tomography in life-threatening hemoptysis

Life-threatening hemoptysis is a severe condition that requires rapid diagnosis and treatment. One of the treatments of choice is embolization. The initial assessment aims to locate the origin and cause of bleeding. The technological advance of the development of multidetector computed tomography (MDCT) has changed the management of patients with life-threatening hemoptysis. MDCT angiography makes it possible to evaluate the cause of bleeding and locate the vessels involved both rapidly and noninvasively; it is particularly useful for detecting ectopic bronchial arteries, nonbronchial systemic arteries, and pulmonary pseudoaneurysms. Performing MDCT angiography systematically before embolization enables better treatment planning. In this article, we review the pathophysiology and causes of life-threatening hemoptysis (including cryptogenic hemoptysis) and the MDCT angiography technique, and we review how to systematically evaluate the images (lung parenchyma, airways, and vascular structures).

Safety of bronchial arterial embolization with n-butyl cyanoacrylate in a swine model

AIM: To compare the efficacy and safety of bronchial artery embolization (BAE) with n-butyl cyanoacrylate (NBCA) and gelatin sponge particles (GSPs).

METHODS: Six healthy female swine were divided into two groups to be treated with BAE using NBCA-lipiodol (NBCA-Lp) and using GSPs. The occlusive durability, the presence of embolic materials, the response of the vessel wall, and damage to the bronchial wall and pulmonary parenchyma were compared.

RESULTS: No animals experienced any major complication. Two days later, no recanalization of the bronchial artery was observed in the NBCA-Lp group, while partial recanalization was seen in the GSP group. Embolic materials were not found in the pulmonary artery or pulmonary vein. NBCA-Lp was present as a bubble-like space in bronchial branch arteries of 127-1240 μm, and GSPs as reticular amorphous substance of 107-853 μm. These arteries were in the adventitia outside the bronchial cartilage but not in the fine vessels inside the bronchial cartilage. No damage to the bronchial wall and pulmonary parenchyma was found in either group. Red cell thrombus, stripping of endothelial cells, and infiltration of inflammatory cells was observed in vessels embolized with NBCA-Lp or GSP.

CONCLUSION: NBCA embolization is more potent than GSP with regard to bronchial artery occlusion, and both materials were present in bronchial branch arteries ≥ 100 μm diameter.

Unresectable lung malignancy: combination therapy with segmental pulmonary arterial chemoembolization with drug-eluting microspheres and radiofrequency ablation in 17 patients

PURPOSE

To evaluate the feasibility, safety, and effectiveness of combining segmental pulmonary arterial chemoembolization (SPACE) and percutaneous radiofrequency (RF) ablation in patients with unresectable lung neoplasms or patients with resectable neoplasms who refused surgery and to compare the local tumor progression (LTP) rate with that in previous studies of RF ablation alone.

MATERIALS AND METHODS

After institutional review board approval and informed consent, 17 patients with primary and metastatic lung cancer were enrolled in this prospective study. Between January 2008 and February 2011, 20 nodules (median diameter, 3.0 cm; range, 2.0-5.0 cm) were treated during 19 sessions. Antineoplastic agents loaded on 50-100-µm microspheres were selectively infused into specific pulmonary arteries. Percutaneous computed tomography (CT)-guided RF ablation of lung nodules was performed 48 hours after SPACE. Follow-up consisted of enhanced CT 48 hours after combination treatment was completed, after 30 days, and every 3 months thereafter. Fluorine 18 fluorodeoxyglucose positron emission tomography was performed 3 months after combination therapy and then every 6 months. The t test was used to compare groups.

RESULTS

Technical success was achieved in 100% of cases. Ventilation-lung single photon emission computed tomography showed a wide area without ventilation in the lung parenchyma treated with SPACE. The LTP rate was 21% (three of 14 nodules) in 3-5-cm-diameter tumors and 0% (zero of six nodules) in tumors of 3 cm or smaller in diameter. Complete response was achieved in 65% (11 of 17) of patients at minimum follow-up of 6 months. Overall, treatment was well tolerated. Major complications were pneumothorax in five of 19 sessions (26%) and one bronchopleural fistula (one of 19, 5%). No treatment-related changes in general lung function were noted.

CONCLUSION

Combination therapy with RF ablation after SPACE to treat unresectable lung tumors is technically feasible, safe, and effective and may represent an advantage over RF ablation alone.

Bronchial artery embolization for hemoptysis

Bronchial artery angiography with embolization has become a mainstay in the treatment of hemoptysis. Major complications are rare and immediate clinical success defined as cessation of hemorrhage ranges in most series from 85% to 100%, although recurrence of hemorrhage ranges from 10% to 33%. Bronchial artery embolization offers a minimally invasive procedure for even the most compromised patient serving as first-line treatment for hemorrhage as well as providing a bridge to more definitive medical or surgical intervention focused upon the etiology of the hemorrhage. The aim of this article is to summarize the etiologies, pathophysiology, and the diagnostic and management strategies of hemoptysis as related to bronchial artery embolization. In addition, the techniques of arteriography and embolization as well as associated procedural outcomes and complications are delineated.

[Bronchial and nonbronchial systemic artery embolization in managing haemoptysis: 31 years of experience]

PURPOSE

The authors report on 31 years of experience with bronchial (BAE) and/or nonbronchial (NBAE) systemic artery embolisation for managing haemoptysis.

MATERIALS AND METHODS

A total of 534 patients who underwent bronchial artery angiography for haemoptysis between 1979 and 2010 were retrospectively evaluated. Of these patients, 477 (89%) had active bleeding and underwent BAE and/or NBAE (295 males and 182 females, aged between 12 and 71 years). Embolisation techniques, materials, major and minor complications and relapses were recorded.

RESULTS

Complete resolution of haemoptysis was achieved within 24 h in 458/477 (96%) cases and within 48 h in 2% of cases. The aetiology of haemoptysis was as follows: cystic fibrosis (23%), bronchiectasis (13%), tuberculosis sequelae (8%), chronic obstructive pulmonary disease (COPD) (6%) and no apparent cause (21%). Major complications were recorded in 3/477 (0.6%): stroke (n=1), transient ischaemic attack (TIA) (n=1) and transient quadriplegia (n=1). Minor complications were recorded in 143/477 (30%): chest pain 86/143 (60%) and dysphagia 29/143 (20%). During a mean follow-up period of 14 (8-36) months, haemoptysis recurrence was observed in 42/110 cases (38%) of cystic fibrosis and in 77/367 cases of other diseases (21%).

CONCLUSIONS

BAE and NBAE are effective and safe for acute treatment of haemoptysis, with low recurrence and complication rates. Interventional radiologist experience is crucial to the successful haemoptysis control and preventing complications.

[Management of massive hemoptysis]

Massive hemoptyses are serious clinical conditions that can quickly jeopardize the vital prognosis. The major risk is asphyxiation, due to the bleeding into the tracheobronchial tree. The clinician should provide in parallel support for diagnosis and treatment, locating the bleeding but also finding its cause. Such patients should be cared for by a multidisciplinary team, having quick access to an important technical support. The association fiberoptic bronchoscopy-chest CT scan seems to be the most effective to locate and identify the cause of the bleeding. The development of bronchial artery embolization has revolutionized the management of these patients, replacing surgery in many of its indications. The latter still keeps a place in the management of these patients. Indeed, it is the main etiological treatment, preventing the vast majority of recidivism. It is absolutely indicated in the treatment of bleeding from the pulmonary vessels, and in case of failure of other techniques. It should be performed whenever possible away from the episode of hemoptysis, in order to minimize the operative risk.

Which Arteries Are Expendable? The Practice and Pitfalls of Embolization throughout the Body

This article outlines general concepts of, and strategies for, therapeutic embolization throughout the body, touching on all major arterial distributions. Clinical scenarios that allow or prevent safe embolization of vessels are presented. Specific agents are recommended where appropriate, as are alternate approaches when embolization is not an option. Pre-embolization precautions and adjunctive measures are described in high-risk areas.

Bronchial artery embolization for hemoptysis

Bronchial artery bleeding is the most common cause of life-threatening hemoptysis. The most common underlying etiologies include tuberculosis, bronchiectasis, aspergillosis, and cystic fibrosis. Bronchial artery embolization is an important treatment for significant hemoptysis, given its high early success rate and relatively low risk compared with alternative medical and surgical treatments. In this article, the relevant anatomy and pathophysiology leading to bronchial artery bleeding is discussed, including the roles of parenchymal lung diseases and of collateral and aberrant vessels. The indications for treatment, success rate, and complication rate for bronchial artery embolization are reviewed. Preprocedure clinical stabilization and evaluation, including the roles of radiographs, bronchoscopy, and computed tomography examination are evaluated. Details of technique, including the published variety of approaches, and an emphasis on avoidance of nontarget embolization of important mediastinal structures and of the anterior spinal artery are discussed.

Complications of embolization

Embolization is a remarkably versatile procedure used in nearly all vascular and nonvascular systems to treat a wide range of pathology. The published literature is rich with studies demonstrating the enormous therapeutic potential offered by embolization procedures, and the possibilities continue to expand with the advent of new embolization agents and techniques. Unfortunately, with this variety and innovation comes a wide spectrum of potential complications, not always easy to classify and summarize, associated with embolization. This article reviews the procedures and associated complications of arterial and venous embolization procedures, organized by vascular distribution.

Bronchial artery embolization for treatment of life-threatening hemoptysis

Massive hemoptysis is an emergent and life-threatening condition with a broad range of underlying causes. Fortunately, massive hemoptysis accounts for a minority of cases of hemoptysis, ~5%. Unlike hemorrhage in other areas of the body, the primary cause of death from pulmonary hemorrhage is most commonly asphyxiation rather than exsanguination. Given the limited capacity for the lung to preserve oxygen transfer in the setting of massive hemoptysis, a rapid and effective method for controlling hemorrhage is essential to minimize death in patients demonstrating respiratory compromise. Since its introduction in 1973, bronchial artery embolization has proven to be a safe and effective tool for the treatment of massive hemoptysis and is now considered the treatment of choice, with initial success rates ranging from 77 to 94%. The long-term control rate of hemoptysis ranges from 70 to 85% and is largely a function of the degree of inflammation and the natural progression of the underlying disease. This article reviews the current literature on bronchial artery embolization for the treatment of massive hemoptysis.