Effects of carbon dioxide insufflation on anastomosis remodeling at a carotid artery site in rabbits

Introduction
Use of carbon dioxide (CO2) insufflation (CDI) on the surgical field during heart surgery has become widespread, and in some units routine.

Aim
To assess the effects of CDI on endothelial dysfunction in a carotid artery model in rabbits.

Material and methods
Twelve randomly selected rabbits were divided into two groups. Right carotid arteries of the animals were transected and sutured with running suture technique. Then, 1 l/min CO2 insufflation was initiated with a 45° angle. In the control group, the anastomotic field was irrigated with 0.1 ml/s flow of 0.9% saline. At day 28, the carotid artery segments were removed and prepared for histological specimens.

Results
In the cross-sections of the control group vessel samples, thickening of the tunica intima was observed. Scoring the quantity of endothelial nitric oxide synthase (e-NOS) and -smooth muscle actin (-SMA) positive staining revealed a nonsignificant difference between the experimental groups (p = 0.07). In the CO2 group, the intimal hyperplasia (p = 0.2) and the thickness of the tunica media (p = 0.2) were indistinguishable when compared to the control group. The mean luminal diameters and luminal areas of the experimental groups were all evaluated by histomorphometry and a significant differences was found between luminal areas (p = 0.016). On the other hand, no significant difference was found between mean luminal diameters (p = 0.055).

Conclusions
Our study indicated that CDI can affect endothelial cell damage and the mean luminal diameters.