Bronchial artery embolization: anatomy and technique

Exacerbation of chronic pulmonary aspergillosis was associated with a high rebleeding rate after bronchial artery embolization

BACKGROUND

Hemoptysis is a common symptom associated with chronic pulmonary aspergillosis (CPA). While surgery is the primary choice to manage hemoptysis, it is often avoided because patients with CPA are more likely to have complications such as respiratory insufficiency and low pulmonary function. Bronchial artery embolization (BAE) may be considered one of the treatments of massive and persistent hemoptysis for such patients.

METHODS

We retrospectively reviewed medical records of 41 patients, admitted to National Hospital Organization Tokyo National Hospital, Tokyo, Japan with hemoptysis arising from CPA between January 2011 to December 2016, who were considered inoperable and had undergone BAE.

RESULTS

Out of the 41 cases analyzed in this study, 21 (51.2%) developed rebleeding after BAE within the mean follow-up duration of 24 months. The non-rebleeding rate of patients after BAE was 92.7% within a month and 65.8% within a year. Patients who developed rebleeding had significantly more non-bronchial systemic arteries responsible for the bleeding compared with patients who did not develop rebleeding (mean of 2.55 vs. 4.86, respectively, P = 0.011). Patients with stable or improved radiological findings demonstrated significantly lower rebleeding rates than those with radiological deterioration (P < 0.001). The non-rebleeding patients had significantly better survival than those with rebleeding (79.7% vs. 39.9% over 5 years, P = 0.046).

CONCLUSIONS

Bronchial artery embolization was effective in controlling hemoptysis in patients with CPA, especially those who could not undergo surgical resection. However, disease control of CPA was important to prevent rebleeding over the long term and to improve survival after BAE.

Lung Circulation

The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed.

Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis

INTRODUCTION

The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation.

MATERIALS AND METHODS

Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined.

RESULTS

Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA.

CONCLUSIONS

Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis.

A friend to the airways: a review of the emerging clinical importance of the bronchial arterial circulation

Lungs receive the bulk of their blood supply through the pulmonary arteries. The bronchial arteries, on the other hand, vascularize the bronchi and their surroundings. These two arteries anastomose near the alveolar ducts. Contrary to the pulmonary circulation which is fairly well studied, the bronchial arteries have been appreciated more by their absence, and in some cases, by an interruption in the pulmonary arterial flow. Therefore, a more accurate anatomical and functional knowledge of these atherosclerosis-resistant vessels is needed to help surgeons and clinicians to avoid iatrogenic injuries during pulmonary interventions. In this review, we have revisited the anatomy and pathophysiology of the bronchial arteries in humans, considering the recent advances in imaging techniques. We have also elaborated on the known clinical applications of these arteries in both the pathogenesis and management of common pulmonary conditions.

Bronchial artery embolization before interventional bronchoscopy to avoid uncontrollable bleeding: a case report of endobronchial metastasis of renal cell carcinoma

Extreme caution should be taken to avoid uncontrollable bleeding in treating hypervascular tumors via bronchoscope. We report two cases of endobronchial metastasis of renal cell carcinoma treated with bronchial artery embolization (BAE) before endoscopic treatments. The intraluminal lesions were removed swiftly and safely. Although arterial embolization is not always efficacious in cases of tracheal lesions, BAE is effective for tumors located in the carina, bilateral main bronchus or intermediate bronchus. The addition of BAE before endoscopic tumor removal should be considered a treatment option in patients suffering from airway obstructions due to hypervascular tumors such as renal cell carcinoma.