Topical use of prostacyclin in microvascular surgery

Prostacyclin was investigated for its ability to overcome surgically induced spasm of the femoral artery and to increase blood flow through the rabbit epigastric free flap. Topical prostacyclin (200 ng/ml) and lignocaine (20 mg/ml or 2%) each produced near-maximal vasodilatation of large conducting vessels. This resulted in a significant increase in blood flow after 5 minutes for each form of topical treatment, compared to a saline control. However the vasodilatation obtained from lignocaine tended to wear off over 30 minutes. Treatment with systemic indomethacin did not prevent surgical spasm nor the action of prostacyclin in relieving it. Topical 6-oxo-prostaglandin F1 alpha, the major breakdown metabolite of prostacyclin, was not responsible for the vasodilatory action of prostacyclin. Topical prostacyclin (200 ng/ml) also caused platelet disaggregation and some rebleeding from the anastomotic site, nevertheless there was no significant difference in flap survival between the use of topical prostacyclin and topical lignocaine.