Ovine Graft (Omniflow II) Versus PTFE in Below Knee Arterial Reconstruction

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00845585
Recruitment Status : Withdrawn (found not enough centers for recruitment)
First Posted : February 18, 2009
Last Update Posted : July 17, 2015
Information provided by:
University Hospital Inselspital, Berne

Brief Summary:
The study intends to compare commonly used PTFE grafts with the biologic ovine graft Ominiflow II for below-knee bypass surgery in patients with peripheral artery occlusive disease with no autologous vein graft available. The hypothesis of this randomized trial is that that Omniflow II does not have a higher patency than PTFE over 36 months (one-sided test). An interim analysis will be performed at 18

Condition or disease Intervention/treatment Phase
Peripheral Arterial Occlusive Disease Device: Below Knee Arterial Reconstruction Not Applicable

Detailed Description:


Despite advances in endovascular therapies, arterial bypass to restore blood flow to a patent distal artery often is the best option in the management of lower extremity occlusive arterial disease. The greater saphenous vein is the conduit of choice for infrainguinal reconstructions - but it is not always available or is otherwise unusable in a significant percentage of patients. In those situations, arterial reconstruction using prosthetic material is an option. Synthetic and biological vascular grafts have been used for some three decades. With time, synthetic conduits tend to increase their thrombogenic potential rather than diminish it by formation of neointima. Over time biological grafts have become alternatives to synthetic materials, mainly in the more demanding applications below the knee. For various reasons most biological grafts have been withdrawn from the market and Omniflow II (Bio Nova International, Mel-bourne, Australia) is currently the only biological vascular prosthesis available for peripheral revascularisation.


The Omniflow II prosthesis is a biosynthetic device formed from stabilised sheep collagen with an integral polyester mesh. It is produced by inserting polyester mesh-covered mandrels beneath the cutaneous trunci muscle of adult sheep for a period of 12-14 weeks. The collagen-encapsulated tubes are harvested and stabilised using glutaraldehyde. The design provides long-term structural stability of the prosthesis and compliance that is similar to that of an autologous artery. There are no randomised studies comparing the Omniflow II graft to either autologous vein or PTFE. Extensive in vivo testing has been performed for safety and efficacy. The Omniflow graft is registered in Europe, Australia, Canada and in a range of countries in South America and South East Asia.


All patients between the ages 20 to 90 with peripheral arterial disease with severe, life-style limiting claudication, rest pain or tissue lesions based on occlusion of the femoral or popliteal artery can be considered, if no suitable vein is available for the reconstruction in infrapopliteal reconstructions. Written consent is obtained from all volunteering patients including willingness to participate in the follow-up process. Primary end point of the study is primary patency, defined by duplex scan as freedom from binary restenosis of 50%.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 0 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Ovine Graft (Omniflow II) Versus PTFE in Below Knee Arterial Reconstruction: A Prospective Randomized Multi Centre Study
Study Start Date : January 2009
Estimated Primary Completion Date : January 2015
Estimated Study Completion Date : January 2015

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: Owniflow II Device: Below Knee Arterial Reconstruction
Patency, Reinterventions, Amputations, mortality
Active Comparator: PTFE Device: Below Knee Arterial Reconstruction
Patency, Reinterventions, Amputations, mortality

Primary Outcome Measures :
  1. primary patency, defined by duplex scan as freedom from binary restenosis of 50% [ Time Frame: 36 months ]

Secondary Outcome Measures :
  1. secondary patency [ Time Frame: 3 months ]
  2. limb salvage [ Time Frame: 6 months ]
  3. mortality [ Time Frame: 12 months ]
  4. infections [ Time Frame: 18 months ]
  5. reinterventions [ Time Frame: 24 and 36 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age between 20 to 90
  • Peripheral arterial occlusive disease with life-style limitation, claudication, rest pain, tissue loss,
  • No suitable vein for reconstruction available
  • Written consent obtained

Exclusion Criteria

  • Acute limb threatening ischaemia
  • Patient younger than 20
  • Pregnant women
  • Myocardial infarction during past 30 days
  • Stroke
  • Life expectancy < 1 year

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00845585

Dept. of Cardiovascular Surgery
Bern, Switzerland, 3010
Sponsors and Collaborators
University Hospital Inselspital, Berne
Principal Investigator: Jürg Schmiedli, MD Bern University Hospital


Responsible Party: Jürg Schmidli, MD, Chief of Vascular Surgery, Dept of Cardiovascular Surgery, University Hospital Bern Identifier: NCT00845585     History of Changes
Other Study ID Numbers: 114/08
First Posted: February 18, 2009    Key Record Dates
Last Update Posted: July 17, 2015
Last Verified: November 2010

Keywords provided by University Hospital Inselspital, Berne:
arterial reconstruction
below knee
Ovine graft
Omniflow II
graft patency

Additional relevant MeSH terms:
Arterial Occlusive Diseases
Peripheral Arterial Disease
Vascular Diseases
Cardiovascular Diseases
Peripheral Vascular Diseases