Effect of intravenous iloprost and alprostadil (PGE1) on peripheral resistance during femoro-distal reconstructions.

Background: A prospective, randomised study was undertaken to investigate the effect of intravenous infusion of either iloprost, the stable prostacyclin (PGI2) analogue, or alprostadil (prostaglandin E1) on peripheral resistance (PR) during femoro-distal reconstruction.

Methods: A prospective randomised study was performed with 35 patients. The PR Measurement of peripheral resistance involved a silicon tube temporarily inserted between the donor and recipient vessel. A flowmeter probe and a pressure transducer were inserted into the tube. The peripheral resistance was calculated as a quotient of pressure and flow under approximate physiological conditions. Patients received either alprostadil (4.4 ng/min/kg) or iloprost (2 ng/min/kg) intravenously over ten minutes. After the end of the infusion, the measurements were taken for five minutes.

Results: Baseline peripheral resistance was similar for both groups (iloprost 0.76+/-0.54 mmHg/ml/min, alprostadil 0.72+/-0.35 mmHg/ml/min, p>0.05). Following the measurement procedure, the final peripheral resistance in the iloprost group was reduced (0.57+/-0.33 mmHg/ml/min), but the difference to the alprostadil group (0.70+/-0.36 mmHg/ml/min) was not significant (p>0.05). The different decrease of ratio peripheral resistance (quotient between final and baseline resistance times one hundred) was highly significant (iloprost: 79.4+/-13.4% vs alprostadil: 97.0+/-15.6%, p<0.01).

Conclusions: Intravenous application of prostanoids, infused with usual doses over ten minutes during femoro-distal reconstructions, produces significant differences in decrease of peripheral resistance. Alprostadil only causes a slight drop of resistance, whereas iloprost causes a significant higher reduction of peripheral resistance.