Pentoxifylline inhibits intimal hyperplasia and vascular smooth muscle cell proliferation in a rabbit carotid artery anastomosis model

This study aimed to evaluate the inhibitory effect of pentoxifylline, a phosphodiesterase inhibitor on intimal hyperplasia (IH) and vascular smooth muscle cell proliferation in an anastomosis model of rabbit carotid artery (CA). Right CAs of 18 male New Zealand white rabbits were anastomosed under general anesthesia. After the surgical procedure, 18 rabbits were separated into three study groups, 6 in each. Group 1 (control group) did not receive any treatment. Group 2 and 3 were treated with 100 mg/kg/day subcutaneous pentoxifylline for 7 and 21 days, respectively. After 28 days, histopathological assessments and histomorphometric measurements were performed on the CA segments. In the histological sections, IH was less evident in the anastomosed vessel wall in pentoxifylline-treated groups than in Group 1. The mean luminal diameter (LD), luminal area (LA), intimal thickness (IT), and intima/media ratio (IMR) for Group 1 were 472.63 ± 13.28 μm, 301,973.33 ± 12,951.27 μm2, 200,844.67 ± 8,375.38 μm, and 0.52 ± 0.01, respectively. The LD and LA were significantly higher, and the IT and IMR were significantly lower for Group 2 and 3 compared with Group 1 (p 0.05). Subcutaneous pentoxifylline treatment, even for duration of only seven days decreases IH in arterial anastomosis sites in a rabbit CA anastomosis model.   Key words: Pentoxifylline, vascular graft, anastomosis, carotid arteries.