The thrombus formation is the most common cause of vessel obstruction after microvascular anastomosis and the change in the vessel wall is the most important factor in pathogenesis of thrombus formation. In the proximal portion of the ligated side branch of the artery, development of hypertension and turbulent flow with resultant continuous hemodynamic stress on the arterial wall could be expected. The histology of the arterial wall could be changed as a result of hemodynamic stress and such histologic changes could have an effect on the thrombus formation after microvascular anastomosis.
In this study, the superficial epigastric artery of a rat, which was side branch of the femoral artery was ligated (5 rats, 10 specimens in each group). The specimen was obtained from the proximal portion of the ligation after specific time elpase and stained with H & E and victoria blue and observed under the light microscope (3 hours, 1, 3 days, 1, 2, 4 weeks).
The following results were obtained.
1. Duration of ligation of less than 3 days resulted in the inflammatory cell aggregation and congestion of capillaries around the artery. There were no other specific findings.
2. From 1 week after ligation, intimal thickening due to subendothelial hyperplasia began and increased as further time elapsed but without statistical significance (P > 0.05).
3. The incidence of intimal thickening due to subendothelial hyperplasia was higher at the site near to ligation (P < 0.05).
4. From 2 weeks after ligation, many elastic fibers were observed as an extracellular component in the thickened intima.
5. Changes within the tunica media and advantitia were not found.
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