In November 2007, a 28-year-old female patient presented at our hospital with acute onset of hemoptysis, characterized by the daily expectoration of 50 ml of fresh blood. The patient was a non-smoker with no prior history of chronic lung disease. Further, a physical examination performed upon admission revealed left lung basal crepitation with good air entry. In addition, the patient showed no signs of a fever and was hemodynamically stable. An initial investigation showed an abnormal chest radiograph with left lower zone haziness. The coagulation profile, renal, and liver function were normal. However, the patient developed another episode of massive hemoptysis, characterized by the expectoration of 100 ml of fresh blood a day later.

An urgent bronchial arteriogram and embolization (Siemens, Axiom Artis DBA, Germany) was arranged in view of the profuse hemorrhage. Next, the catheterization of the left bronchial artery was performed with a 4.1F SHK catheter (Bjaeverskov, Denmark), and demonstrated hypertrophied arteries in the lower lobe of the left lung with an arterio-venous shunt (Fig. 1A). After excluding the spinal medullary artery supply, an embolization of the left bronchial artery was performed with two vials of 500-700 µm crossed-linked tris-acryl microspheres (Embosphere) (Guerbet Biomedical; Louvres, France). Special care was taken to prevent reflux by injecting the Embospheres slowly, and under continuous fluoroscopic control. The hemoptysis subsided with a stable medical condition following the procedure.

Twenty four hours later, the patient developed a fever and generalized abdominal pain. A computerized tomography (CT) scan of the abdomen (General Electric LightSpeed VCT; Waukesha, WI) showed multiple micro-infarctions of the spleen and bilateral kidneys (Fig. 1B). The patient's renal function deteriorated with a serum creatinine level of 157 µmol/L (reference range: 60-120 µmol/L). The patient was managed conservatively by intravenous fluid replacement therapy over 10 days. The treatment resulted in the complete resolution of abdominal pain and improved renal function (serum creatinine level: 132 µmol/L). Since the patient was completely asymptomatic, she declined to undergo a follow-up CT scan of the abdomen.

A variety of embolic materials are used for BAEs. Namely, an absorbable gelatin sponge is inexpensive and simple to use. However, it has the disadvantage of causing the recanalization of the embolized artery, which may result in the recurrence of bleeding. Coils are generally not used for BAEs because they tend to occlude more proximal vessels and may preclude further embolization if hemoptysis recurs. Polyvinyl alcohol particles are a nonabsorbable embolic material with particles of 350-500 µm in diameter that are frequently used as smaller particles which can pass through the bronchopulmonary anastomosis which result in pulmonary or systemic infarctions (2).

A more recent introduction of the crossed-linked trisacryl microspheres (Embospheres), have a more uniform size and better penetration than polyvinyl alcohol particles (3). Particle sizes of 300-500 and 500-700 µm have been used for BAEs (4). However, the better penetration characteristics of the crossed-linked tris-acryl microspheres may result in a greater tendency to cross bronchial artery-pulmonary artery shunts or bronchial artery-pulmonary vein shunts, which cause pulmonary infarctions or systemic infarcts as in our patient. To the best of our knowledge, only three other previous reports of systemic infarcts following BAEs with microspheres exist in the literature. Vinaya et al. (5) reported myocardial infarcts during a BAE with 500 µm Embosphere particles. The authors suggested that the Embosphere particles had crossed the bronchiopulmonary shunt into the systemic circulation. Two other similar cases were also reported by FitztGerald et al. (6) and Sriram et al. (7).

The microinfarction of the kidneys and spleen were self-limited in our patient, which was consistent with Sriram et al. (7). Despite this, we have to be aware of this potential complication when using microspheres as the embolic material in BAEs. Since the Embosphere particles show better penetration than polyvinyl alcohol particles, choosing a size of Embosphere based on experience with polyvinyl alcohol particles could result in significant distal embolization as a result of shunting through the lesion (3). We propose that in the presence of bronchial artery-pulmonary artery shunts or bronchial artery-pulmonary vein shunts, the use of larger sized crossed-link tris-acryl microspheres (700-900 µm) may avoid this complication.