Longterm histopathologic follow-up of bronchial arteries after therapeutic embolization with polyvinyl alcohol (Ivalon) in patients with cystic fibrosis.

We used light microscopy to examine, at autopsy, bronchial arteries in three patients with cystic fibrosis who died, respectively, 10, 16, and 28 months after bronchial artery embolization with barium sulfate-impregnated polyvinyl alcohol (PVA) to control hemoptysis. PVA was not identified beyond the midsegmental bronchus in any patient. Persistent focal fibrovascular occlusion was noted in two patients, and recanalized and/or partially obstructed vessels were associated with PVA in all. The histologic reaction to PVA included fibrosis, mild chronic inflammation, localized foreign body reaction, and, in two patients, focal calcification of PVA spicules. Within the inflammatory milieu were numerous macrophages containing BaSO4. Extensive vascular mural destruction and fibrosis associated with PVA were also observed. Both PVA and BaSO4 were also frequently present in the perivascular connective tissue. These findings indicate that, although longterm occlusion persists after therapeutic arterial embolization with PVA, focal recanalization also occurs. The extent of vascular mural injury following PVA embolization in humans has been previously underestimated by animal experiments. Finally, perivascular deposition of PVA represents a common reaction to diverse foreign body emboli in both systemic and pulmonary arteries.