The Journal of Thoracic and Cardiovascular Surgery, Vol 73, 601-604, Copyright © 1977 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Effects of dipyridamol and methylprednisolone on intimal thickening in vein grafts
WR Brody, JW Brown, BA Reitz, DL Fry and LL Michaelis
Fibrous intimal proliferation severe enough to produce occlusion has been
observed in vein segments used for aorta-coronary bypass grafts. In an
attempt to improve graft patency and decrease intimal fibrous thickening,
animals with vein grafts were treated with dipyridamole or
methylprednisolone for 8 to 12 weeks. Femoral vein segments were used to
bypass the femoral artery in 36 dogs. Thirty-four of these grafts were
patent at 8 weeks, with no statistically significant differences between
control and drug treatment groups. Intimal thickness measurements were
taken at three different points along the graft: proximal (upstream end),
middle,and distal (downstream end). Dogs treated with methylprednisolone
had significantly less intimal thickening (214 versus 125 mu, p less than
0.05) than did control animals in the middle of the veins but there was no
difference in thickness measurements at the proximal and distal ends.
Dipyridamole- treated animals did not differ from control dogs. Although
these data show decreasing intimal thickening in the middle of grafts with
methylprednisolone therapy, the intimal thickness was still considerably
greater than normal. The lack of response near the anastomotic sites
suggests that clinical application of either agent to improve long-term
patency is unwarranted.
