Abstract
To determine the effects of cod-liver oil and a combination of cod-liver oil and dipyridamole on vein-graft intimal hyperplasia, 76 segments of undistended jugular vein were interposed between bilaterally divided femoral arteries in 38 mongrel dogs who received a 2% cholesterol diet. Ten control animals received the diet alone, 8 received cod-liver oil containing 1.8 g of eicosapentaenoic acid daily 1 week before and for 6 weeks after operation, and 20 dogs received 1.8 g of eicosapentaenoic acid and 75 mg of dipyridamole daily 1 week before and for 6 weeks after operation. A similar and significant (p less than 0.01) increase in serum cholesterol was observed in all three groups. Prothrombin, partial thromboplastin and clotting times and the platelet count were unchanged in the controls and in those receiving cod-liver oil. Clotting time increased in the animals receiving a combination of cod-liver oil and dipyridamole (p less than 0.001). Measurements (406 +/- 27) of intimal thickness were made from each graft. Intimal thickness was 3.7 +/- 0.1 micron before implantation and increased to 78 +/- 8 micron after in the controls. Cod-liver oil limited the increase in intimal thickening, to 24 +/- 3 micron (p less than 0.001); cod-liver oil and dipyridamole further reduced the increase in intimal thickening, to 17 +/- 1.4 micron (p less than 0.001). The data indicate that a combination of cod-liver oil and dipyridamole is more effective than cod-liver oil alone in reducing canine vein-graft intimal hyperplasia (p less than 0.03).