To compare the histological injury on the inferior saphenous vein of Beagle dogs after DSA-guided injection of two commonly used foam sclerosing agents, such as polycacol and sodium cod liver oil.

Twelve Beagle dogs were selected and randomly devided into group A (polidocanol foam injection group) and group B (sodium morrhuat foam injection group) , n=6. DSA fluoroscopy was performed on the saphenous venography. The 1% polydocaine foam sclerosing agent was injected into the left anterior, left posterior and right hind limbs, and 5% cod liver foam sclerosing agent was injected into the left anterior, left posterior and right hind limbs. Saphenous veins were removed after 30 min, 2 d and 28 d of injection and stained by HE or Massion. The histological changes of endothelium and medial membrane of saphenous vein were observed under light microscope.

Both foam hardeners could cause vascular endothelial injury and thickening of the medial membrane of the wall of canine saphenous vein. After 30 min, the partial loss of endothelial cells and thickening of smooth muscle in the middle layer were observed in both groups, and no significant histological difference was found between the two groups. After 2 d, the membrane damage rate in group A was higher than that in group B[ (63.6±9.4) % vs. (49.2±4.4) %], and the difference was statistically significant (P<0.05) . After 28 d, the endothelial cells of groups A and B were completely exfoliated, and the smooth muscle of the middle layer was thickened and even extended to the outer membrane, with no significant histological difference. There was no significant change in vascular endothelial injury in group A with the extension of time, while the thickness of the median increased with the extension of time; in group B, the vascular endothelial injury increased with the extension of time, and the thickness of the median increased with the extension of time.

Both polydodecol and sodium ovalerate can cause endothelial and terminal damage to vascular walls, and produce collagen fibrosis. The effect of polydodecol on vascular fibrosis is greater than sodium.