Background: Hydrophilic coatings on arterial introducer sheaths reduce the frequency of spasm during cardiac catheterization. Moreover, during treatment of cerebral artery aneurysms, hydrophilic coatings on microcatheters ease their maneuverability, and polymers within embolization coils enhance neointimal fibrosis at the aneurysm neck. Foreign-body giant cell reactions can result when a polymer is stripped from its source. CASES 1 AND 2: A 51-year-old man and a 66-year-old woman underwent coronary angiography via the radial artery, using hydrophilic-coated sheaths. They both developed tender lesions at the access site 2 weeks later. Microscopy of resected lesions showed pieces of hydrophilic coating and granulomatous inflammation, as has been reported by others. CASE 3: A 58-year-old woman underwent embolization of a ruptured distal right internal carotid artery aneurysm using polymer-containing coils. Nine months later, she began developing multiple right-sided cerebral ring-enhancing lesions. Biopsy revealed granulomas and microabscesses, in which polymer filaments were later identified. To our knowledge, this complication has not been described previously.
Conclusions: Hydrophilic coating may dislodge and induce a prominent foreign-body granulomatous response or microabscesses. Although the culprit radial artery sheath is now rarely used, embolization coils containing polymers are commonly deployed in clinical practice and may be a source of recurrent inflammatory lesions.