A 30-year-old patient of Asian decent was transferred to our institution following recurrent bouts of hemoptysis in which approximately 250-300 ml of blood was expectorated over a span of <3 h. Four years ago, he had been treated for pulmonary tuberculosis. Two earlier episodes, 6 and 4 years earlier, were conservatively managed with antibiotics. He gave a history of necrotizing pneumonia in infancy.
No fever or elevated white count was present upon arrival to indicate septicemia. A contrast-enhanced CT scan of the chest revealed consolidation and bronchiectasis involving the lateral segment of the right middle lobe and a larger surrounding zone of hazy airspace opacities [Figure 1] probably representing hemorrhage. A hypertrophied right internal mammary artery (IMA) was noted supplying a complex vascular malformation in the right middle lobe [Figure 2] via large pleural and phrenic collaterals draining into the right pulmonary artery. We decided to undertake angiographic evaluation and embolization of this malformation.
A pigtail oblique thoracic aortogram showed an asymmetrically enlarged right IMA with otherwise normal brachiocephalic arterial and aortic anatomy. More selective injection of the right IMA demonstrated a high-flow plexiform fistulous communication between the right internal mammary and the pulmonary arteries via a plexiform vascular malformation in the right middle lobe [Figure 3A]. Multiple feeders arising from the distal half of the right IMA supplied the malformation. A right bronchial angiogram and contralateral pulmonary and bronchial artery angiograms did not reveal any significant contributors to the malformation. The high-flow rate and large caliber of many of the fistulous communications within the malformation made particulate embolization seem inadvisable. The liquid embolic agent, Onyx, was decided upon as an effective and efficient means of achieving both distal penetration into the malformation and a relatively rapid occlusion of the long segment of the IMA which was supplying the malformation.
An Echelon-14 microcatheter (MTI, Irvine, CA, USA) was advanced coaxially through the existing 5-French diagnostic catheter. The microcatheter was positioned just below the lowest contributory side branch of the IMA and several fibered microcoils, ranging in diameter from 3 mm to 5 mm, were deployed to prevent distal escape of Onyx into the epigastric arteries. After priming of the microcatheter with dimethyl sulfoxide (DMSO) to fill the catheter dead space, Onyx-34 was slowly injected under fluoroscopy over approximately 20 min using a volume sufficient to occlude the distal half of the IMA and the contributory side branches. Due to the viscosity of the selected Onyx, the degree of distal penetration into the malformation was less than what we had anticipated or hoped for. Nevertheless, satisfactory occlusion of the IMA was achieved [Figure 3B, C] without opacification of any arterial feeders from the ipsilateral bronchial artery and contralateral intercostal artery, as demonstrated on the postembolization angiogram. We considered empiric embolization of the right bronchial artery as well, but then decided to await the results of the present embolization before undertaking any further interventions.
On follow-up, the patient has been symptom free for 21/2 years.
CT scan of the chest at two contiguous levels shows areas of bronchiectasis surrounded by air space opacities (arrow in A) representing hemorrhage within the consolidated right middle lobe, extending to the pleural surface (arrow in B).