Effect of cilostazol on neointimal hyperplasia in iliac arteries of pigs after transluminal angioplasty Efeito do cilostazol na hiperplasia neointimal em artérias ilíacas de suínos submetidas à angioplastia transluminal

Objective: to evaluate whether systemic administration of cilostazol reduces neointimal hyperplasia in iliac arteries of pigs submitted to balloon catheter angioplasty. Methods: twenty pigs underwent angioplasty with a 6x40 mm balloon catheter in the right common iliac artery, guided by Doppler ultrasound. The animals were randomized into two groups: group 1 (n=10), which received 50mg cilostazol twice a day, and group 2 (n=10), control. After 30 days, the animals were killed and the iliac arteries prepared for histological analysis. The histological sections were digitized and analyzed by digital morphometry. Statistical analysis was performed using the Student t and Mann-Whitney tests. Results: when comparing the iliac arteries submitted to angioplasty with those not subjected to angioplasty, there was significant neointimal hyperplasia (0.228 versus 0.119 mm; p=0.0001). In arteries undergoing angioplasty, there was no difference between group 1 (cilostazol) and group 2 (control) as for the lumen area (2.277 versus 2.575 mm; p=0.08), the tunica intima (0.219 versus 0.237 mm; p=0.64), the tunica media (2.262 vs. 2.393 mm; p=0.53) and the neointimal occlusion percentage (8.857 vs. 9.257 %; p=0.82). Conclusion: the use of cilostazol 50mg administered in two daily doses did not reduce neointimal hyperplasia in iliac arteries of pigs submitted to balloon angioplasty