This is the first clinical research trial in which intravenous Prostaglandin E1 (PGE1 is a vasoactive hormone) will be used as supportive treatment along with the angioplasty procedure to treat or open up a blocked artery within one lower limb or the most affected of two limbs in subjects with Peripheral Arterial Occlusive Disease.

PAOD results in a decrease in arterial blood flow to the lower limb and feet with symptoms that can include, pain at rest, a numbing sensation in limb or feet, limited ability to walk before pain occurs. PAOD can occur along with diabetic ulcers.

Proposed treatment will be given at a medical center with an overnight hospital stay. Treatment includes angioplasty to open up one or two occluded arteries in a lower limb plus a drug (Liprostin) a special formulation of liposomal Prostaglandin E1,or PGE1, a natural occuring vasoactive hormone). Drug treatment is given twice to each artery to be treated, just before and after angioplasty. When angioplasty procedure is completed, a 12 hour intravenous infusion of Liprostin is given to complete the treatment procedure.

A total of 12 PAOD subjects will be enrolled in a single center: Memorial Hermann Hospital, Houston, TX.

Study will begin in February, 2003 with the last (12th) subject to be enrolled, likely by August, 20

Inclusion Criteria:

• Male or female subjects, 18 years and older
• Diagnosis of Peripheral Arterial Occlusive Disease [PAOD]
• Subject is a candidate for immediate angioplasty of the lower limb
• Subject must complete 2 treadmill tests at Screen in which walking distance is limited by PAOD and not due to angina or fatigue

Exclusion Criteria:

• Lower limb peripheral re-vascularization procedures in past 3 months
• History of myocardial infarction in the past 6 months
• Malignant disease, uncontrolled hypertension or Class III heart failure
• Aortic occlusion, thrombosed popliteal aneurysm, severe hemorrhagic disorder, or a long iliac occlusion