Radiations ionisantes délivrées par voie externe sur l'anastomose prothéto-artérielle pour limiter l’hyperplasie intimale et étude de la résistance biomécanique. Expérimentations et résultats

Abstract

Purpose. – To evaluate the use of external ionizing radiation for the prevention of intimal hyperplasia in anastomosis between PTFE and artery. Methods. – Bypass using a 6 mm PTFE was performed on a swine subrenal aorta with a distal conventional anastomosis ( N = 35) associated (test group; N = 17) or not (control group; N = 18) with post-operative external radiation (20 Gy) on this anastomosis. At 45 days, histological studies and morphometric studies were performed on the aorta receiving the anastomosis. Two protocols were performed, the first protocol with standard analysis and the animals were randomly assigned to either group (test group; N = 11 and control group; N = 13) and the second protocol with test of extraction comparing the biomechanical resistance between the irradiated group ( N = 6) and the control group ( N = 5). Results. – Twenty-one animals survived the procedure in the first protocol, 11 in the second. The endothelium was restored in either group. Histological recasting was observed in the media after radiation with fibrosis and areas of necrosis. Intimal thickness was significantly lower after irradiation in the heel ( P < 0.01), the head ( P < 0.01) and the suture line ( P < 0.001) of the artery in the first protocol. The intimal thickness was also significantly lower in the second protocol after radiation in the heel ( P < 0.05) and the head of the artery ( P < 0.05). There was no difference between the two groups comparing the resistance. Conclusion. – After external irradiation, the thickness parameter of the intima decreased significantly in comparison with the control group with similar resistance. Media fibrosis and necrosis need to be confirmed by further investigation.