Silica Gel Fiber Wound Dressing for Chronic Venous Leg Ulcers

Inclusion Criteria: * At least one chronic venous leg ulcer fulfilling all of the following criteria: * Size: \>/= 5 cm2 and \</= 40 cm2 (measured by Visitrak Wound Measurement System) * Duration: \>/= 3 month \< 5 years * Location: Between and including knee and ankle * Depth: Involving dermis, with no exposed muscle, tendon or bone. Characterized by a viable wound bed with granulation tissue * The etiology of the ulcer as "venous" is proven by Duplex or Doppler sonography and with ankle/brachial arterial Doppler pressure index \> 0.8 (exclusion criterion for peripheral arterial disease) and \< 1.3 (exclusion criterion for medial sclerosis), or with a laser Doppler value \> 40 * Treatment with active wound care agents paused for 14 days before start of study treatment Exclusion Criteria: * Only ulcers of other than venous etiology, e.g., diabetic ulcers or ulcers resulting from electrical, chemical, or radiation insult, after contact eczema, etc. * History of radiotherapy to the target ulcer site * Signs of infection as defined by rubor, dolor, calor, tumor, functio laesa. Fever (38°C sublingual, rectal, or ear), rigors, or leukocytosis will be considered as signs of infection in the context of the general appearance of the wound * Target ulcer lacking any sign of granulation tissue (bradytrophic wound bed) * Presence of necrotic tissue * Presence of fistula * History of connective tissue disease, e.g., systemic lupus erythematodes, systemic sclerosis, Sjögren's syndrome or mixed connective tissue disease * Uncontrolled congestive heart failure * Malnutrition (albumin \< 2.5 g/dl; to be measured if clinical signs of malnutrition are being observed) * Uncontrolled diabetes (HbA1c \> 8 %) * Previous organ transplantation * Active malignant disease * Severe rheumatoid arthritis * Undergoing haemodialysis * Active sickle cell disease * Patients who are immunocompromised for reasons such as therapy with corticosteroids, chemotherapy, antiangiogenic or immunosuppressive agents, or due to immunodeficiency syndromes * Pregnant or nursing women * Woman of childbearing potential who are not practicing acceptable methods of birth control during the investigation period * Known allergy to any of the devices' constituents