CIGARETTE-SMOKING INCREASES THE DEVELOPMENT OF INTIMAL HYPERPLASIA AFTER VASCULAR INJURY

Purpose: Our purpose was to determine whether exposure to cigarette sm oke increases the development of intimal hyperplasia (IH) after vascul ar injury. Methods: Sixteen adult male Sprague-Dawley rats underwent s tandardized balloon catheter injury of the left common carotid artery. For 4 weeks before and 4 weeks after injury, animals in the experimen tal group (n = 8) were exposed to cigarette smoke with an automated va cuum pump device. Animals in the control group (n = 8) were restrained in the smoking device for an identical amount of time and underwent a rterial injury at 4 weeks but were not exposed to cigarette smoke. Car otid arteries were perfusion-fixed in vivo, prepared as histologic cro ss sections, and stained for elastin. IH was measured by planimetry an d is reported both as the absolute area of IH and as the ratio (IH/IEL ) of the absolute area of IH to the normalized area enclosed by the in ternal elastic lamina (expressed as a percent). Results: The absolute area of IH was 2.09 +/- 0.34 for the experimental group compared with 0.94 +/- 0.25 for the control group; mean IH/IEL was 43.7% +/- 7.1% fo r the experimental group versus 17.7% +/- 4.7% for the control group ( p < 0.05, two-tailed unpaired t test). Conclusions: Inhalation of ciga rette smoke increases the development of intimal hyperplasia in a rat model of balloon catheter arterial injury.