Experimental microsurgical vein grafts: quantitative temporal analysis of progressive media fibroplasia.

Abstract

The sequential histopathologic changes in microvenous grafts placed in a microarterial system were studied. In 48 Sprague Dawley rats, a 1 cm segment of epigastric vein was interposed into a defect created in the femoral artery. Grafts were explored at 1, 2, 4, and 12 weeks. After an initial smooth muscle hyperplasia, a progressive fibroplasia of the media was observed. Only small focal areas of intimal hyperplasia were seen. The width of the media was measured with an eyepiece micrometer. A statistically significant (P < 0.01) increase in width from 17 microns at 1 week to 462 microns at 12 weeks was noted. Although this process has been described before, this is the first quantitative assessment.