Ultrastructure of the varicose great saphenous vein after the treatment with intravascular laser occlusion

Ying GU; Lina HAN; Fanguang LIU

ABSTRACT

BACKGROUND:

Studies about the mechanism of laser occlusion on the varicose great saphenous vein are rare.

OBJECTIVE:

To explore the ultrastructural changes of the great varicose saphnous vein after it was occluded with laser.

DESIGN:

An observational study.

SETTING:

Laser Department of the General Hospital of Chinese PLA .PARTICI PANTS There were 42 patients with varicose great saphenous veins that were occluded with laser in clinic of the General Hospital of Chinese PLA from January to April 2004. The inclusive criteria There must be obvious vein tangles beneath the undystrophic skin at ankle without apparent thrombus inside the vein. The patients involved should be voluntary to take part in the study. Finally 9 patients were enrolled in this study.INTERVENTION The great saphenous vein was intravenously occluded with laser of 810 nm and the working power was 12 W and the exposure time was 1 s. The occluded vein sample was taken out 3 hours after the occlusion.MAINOUTCOME

MEASURES:

The ultrastrncture of the occluded vein was observed histopathologically. Normal vein and prereatment varicose vein served as control.

RESULTS:

The normal vein wall can be divided into 3 layers the internal layer was composed of the simple endothelial cells; the median layer was composed of the smooth muscle cells, elastic fibers and collagenous fibers; the external layer was composed of the loose connective tissues. However, the internal layer of the varicose vein was incomplete, and the endothelial cells were loosely connected. The smooth muscle cells became hyperplasic, hypertrophic or atrophic. The elastic fibers decreased in number in contrast to the increase of collagenous fibers. After laser occlusion, in the vein lumen there was a large number of blood cells. The platelets became flattened with pseudopods and adhered to collagenous fibers. The endothelial cells and smooth muscle cells near the lumen were damaged and the cytoplasma leaked and fused with extracellular matrix. Broken collagenous and elastic fibers could be seen near the lumen and some were observed in the lumen. There was no structure change in the external layer and adjacent elastic fibers and collagenous fibers.

CONCLUSION:

Laser occlusion damaged the internal layer and part of median layer of the varicose vein, caused aggregation of the blood cells in the lumen and promoted the adhesion of platelets to vein walls.