Purpose: Fogarty balloon denudation in experimental animals often serves as a model for percutaneous transluminal coronary angioplasty (PTCA). We compared the healing response of the arterial wall with the use of Fogarty and PTCA balloon dilation.
Methods: Carotid arteries of rabbits were injured with a 2F Fogarty (n = 9) or a 3 mm PTCA balloon (n = 6). At 1 day endothelial cell removal was qualitatively evaluated in Fogarty balloon lesions and in PTCA balloon lesions with a modified "en face" silver nitrate staining. Medial necrosis was morphometrically determined as percentage medial area. After 21 days endothelial cell coverage was assessed in the center of the lesion with an antibody to CD31 and intimal proliferation with an antibody to the nuclear antigen Ki-67. Intimal hyperplasia area was measured with morphometry. Acute lumen gain directly after Fogarty balloon dilation and PTCA balloon dilation was determined by serial angiography. All data are means +/- SEM.
Results: At 21 days intimal hyperplasia area was higher in the Fogarty balloon lesions than in the PTCA balloon lesions. Intimal hyperplasia area was 0.19 +/- 0.02 mm2 and 0.03 +/- 0.01 mm2, respectively. Immediately after injury the acute gain in luminal diameter did not differ between Fogarty and PTCA balloon dilation (0.37 +/- 0.03 mm and 0.38 +/- 0.05 mm, respectively). At 1 day after injury endothelial cell removal was complete in all segments. Medial necrosis caused by Fogarty (67% +/- 7%) and PTCA balloon dilation (74% +/- 9%) did not differ. At 21 days endothelial cell coverage was almost complete both in the Fogarty balloon lesions and in the PTCA balloon lesions. Intimal proliferation was also higher in the Fogarty balloon lesions than in the PTCA balloon lesions.
Conclusion: Despite comparable endothelial cell abrasion and medial necrosis, Fogarty balloon injury elicited significantly augmented intimal hyperplasia compared with PTCA balloon dilation.