Since the initial description by Remy et al.,1 arterial embolization (AE) has become a widely used procedure in the treatment of life-threatening and recurrent hemoptysis. Several studies have examined its effectiveness, safety and usefulness.2–10 However, hemoptysis relapse may occur even after embolization in 9.25%–50% of cases.11–24 When this occurs, it is associated with increased risk of mortality.20,22

Recurrence of bleeding after AE has been reported as possibly due to incomplete embolization of vessels, recanalization of previously embolized vessels, revascularization of collateral circulation or progression of the underlying lung disease.12,17,19,23 No studies have examined the relationship between the technical characteristics of the procedure and the risk of recurrence due to recanalization.

The aim of this paper is to describe the experience of our center with AE in the treatment of life-threatening hemoptysis, to analyze the technical characteristics of AE, and to identify factors associated with recurrence due to recanalization.

This article describes the experience of a tertiary university hospital treating life-threatening hemoptysis with AE. Our data demonstrate that hemoptysis recurrence due to recanalization is associated with the time to recurrence, and not with the use of coils or the number of embolized arteries. According to this model, the cause of recurrence of hemoptysis within the first 80 weeks after AE would be incomplete embolization, while recurrence after 80 weeks would be secondary to recanalization in most cases.

The described causes of recurrence include progression of the underlying disease, revascularization or recanalization, incomplete embolization, and the occurrence of new blood flow from systemic collaterals. Early re-bleeds have been associated with an incomplete embolization, whereas later hemorrhage is usually due to disease progression.2,12,14,17,19,20 Thus, our study confirms the findings of other groups who included fewer cases of relapse, and adds the 80-week threshold. This 80-week time point could be an important guide for the angioradiology specialist when performing an AE in a patient with recurrence. While the inspection of all vascular territories likely to bleed is strongly recommended, we believe that this information could guide the specialist to initially explore a specific vascular territory. This information would be particularly useful in patients in a life-threatening situation due to hemoptysis, as it would help prioritize which arteries should be studied first. Secondly, a better indication of the bleeding site could help reduce the radiation dose, operative time, and the volume of contrast agent needed for the procedure.27

The etiology of hemoptysis has been associated with the recurrence rate after arterial embolization.13,14,20 Thus, hemoptysis due to tumor disease has higher short- and long-term recurrence rates.14,20 However, one group has reported reasonably good immediate results in patients with malignancy.23

Several studies have explored the likelihood of recurrence in relation to the procedure. Kim et al.21 compared to the results of embolization according to the material used, and found no statistically significant differences in the use of gelfoam, coils, or both, comparing patients with and without recurrence. Mal et al.17 analyzed the results of AE in relation to the interventional radiologist, or the material used for embolization. Brinson et al.16 reported that, in the case of recurrence, the incidence of bleeding from non-bronchial systemic collateral vessels was higher than in the first embolization (75% vs 8%). This is also true in our study, although the difference was not so marked (42% vs 29%). Other authors have analyzed the relationship between the angiographic findings (degree of vascularization) during embolization, and the outcome, and have not found significant differences.13,18,19

Overall, 17.6% of our patients experienced recurrence. The most frequent cause of hemoptysis was bronchiectasis, followed by COPD, active tuberculosis and mycetoma. The recurrence of hemoptysis was due to bronchiectasis in 37.5% of the cases, tumor disease in 25%, and COPD in 18.8%. Differences are detected when our findings are compared with previous series in Spain.9,10 Firstly, our recurrence rate (17.6%) is higher than that reported by Orriols et al.,10 but similar to that found by De Gregorio et al.9 The etiologies most frequently associated with recurrent bleeding, according to Orriols et al.,10 were malignancy and mycetoma, which coincides with the findings in our series. The findings are similar in other series.11–18 These groups agree that the likelihood of recurrence is high, ranging between 9.2511 and 50%.18 Aspergilloma is associated with poor prognosis with respect to both the likelihood of recurrence21–23 and mortality.23

In our study, 75% of recurrences occurred within 80 weeks of surgery, and 61.4% of the arteries embolized in the second procedure were different from those initially embolized. Recurrence occurred when embolization of the vessels involved was not complete, either due to the infiltrative nature of the disease, or because all the arteries involved were not located. If the bleeding site is known, all the anomalous bronchial arteries in the region should be embolized. If the bleeding site is unknown, all the bronchial arteries should be treated. If no abnormal bronchial arteries are detected, an exhaustive search of aberrant bronchial arteries and non-bronchial systemic arteries must be carried out. Failure to treat all the arteries involved increases the number of procedures required to resolve the bleeding,7 as found in our series. When recurrence occurs, mortality increases.22 Therefore, complete embolization and treatment of the causes are crucial to prevent recurrence secondary to the progression of disease.

The mortality rate in our series was 12.5%. Of the patients who died, the etiology of bleeding in 59.1% was malignancy. The mortality rate reported by Orriols et al.10 was 12.3%, similar to our data, and De Gregorio et al.9 reported a mortality at 3 days of 1.7%, well below the rate in the other two reports.

The main limitation of our study is that we performed a retrospective analysis of patients from a single center, which makes it difficult to generalize the results. Furthermore, data on the volume and duration of bleeding could not be recovered from all patients, so this important piece of information has not been included in the analysis. However, one of the strengths of the study is that all patients were clinically followed up in our center after the embolization episode, which means that all further episodes of bleeding or AE have been included in this study.

In summary, AE is an effective technique in the treatment of life-threatening hemoptysis, but recurrences are not uncommon. Hemoptysis recurrence due to recanalization of an embolized artery is related to the period of time until recurrence, but not with the use of coils or the number of embolized arteries.

IGO and JRM contributed to the study design. CC, JSS, FA and ZS contributed to the clinical data collection. JS, JM and JMM contributed to the angiography review. IGO and JR contributed to the statistical analysis. IGO, JSS, CC, JR, FA, JS, JM, JMM, ZS and JRM contributed to the critical reading of the manuscript.

The authors declare that they have no financial or personal relationships with people or organizations that could inappropriately influence their work in this article.