Morphological changes after percutaneous transluminal angioplasty

BACKGROUND Percutaneous transluminal angioplasty (PTA) dilates constricted arteries at the circle of Willis to reverse cerebral ischemia caused by cerebral vasospasm. Although 90% of the patients show angiographic improvement after PTA, only 70% show clinical improvement. Why some patients do not improve after PTA is unknown. We report on a 48-year-old woman who failed to improve after PTA and died from aneurysm rerupture. Pathologic studies were performed to determine why PTA failed to reverse the symptoms of cerebral ischemia. METHODS The arteries of the brain were studied by light microscopy using Gomori's trichrome stain. The arteries were also studied by scanning and transmission electron microscopy. RESULTS The arteries that were dilated with PTA showed compression of the connective tissue, stretching of the internal elastic lamina, and a combination of compression and stretching of the smooth muscle. The small arteries and arterioles that had been treated with an infusion of intraarterial papaverine were constricted with a thickened intimal layer. CONCLUSION The persistence of cerebral vasospasm in small and perforating arteries may contribute to the failure of cerebral ischemia to reverse after PTA. (C) 1999 by Elsevier Science Inc.