Alprostadil in Peripheral Arterial Occlusive Disease (PAOD) Stage IV

Inclusion Criteria: * Subject is at least 45 years of age * Subjects with macro-angiopathy, proven PAOD Stage IV with up to 2 ischaemic skin lesions for more than 2 weeks * Subject has a complete angiography of pelvis, thigh and calf within one month of inclusion * Systolic ankle pressure ≤ 70 mmHg in subjects without media sclerosis of the lower limb artery or systolic big toe pressure ≤ 50 mmHg in diabetics with media sclerosis of the lower limb artery * Subject is not in the position to be primarily revascularized or refuses surgery Exclusion Criteria: * Imminent or foreseeable amputation * Major amputation on the affected extremity * History of chronic alcohol or drug abuse * More than two ischemic ulcerations * One ulcer ≥ 6 cm\^2, both ulcers ≤ 1 cm\^2 or at least one ulcer affecting the bone or tendons * Acute ischemia and peripheral vascular disorders of inflammatory or immunologic origin * Neuropathic or venous ulcers * Buerger's disease * Septic gangrene * Use of vasoactive medication or prostaglandins * Treatment with prostanoids within 3 months prior to inclusion * Surgical or interventional measures performed on the affected extremity within 3 months prior to study drug treatment