Scanning electron microscopy and evans blue staining for assessing endothelial trauma and reconstitution after venous thrombectomy.

Thrombectomy and a temporary arteriovenous fistula as treatment for deep venous thrombosis has been shown to cause a severe endothelial trauma in an experimental dog study. In vivo staining with Evans blue has been compared to scanning electron microscopy findings to assess the extent of the trauma and the time necessary for endothelial reconstitution. A good correlation between these techniques was found. After the initial almost complete denudation of the veins, new endothelium grew out from small branch openings and valve pockets within four weeks except in the proximity of the arteriovenous fistula where endothelialization was still incomplete after four months.