What is the Stewart Procedure? (Columbia 3f Bioroot)
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The Stewart Procedure [Columbia (3f) Bioroot for Replacement of the Aortic Valve and Root]
Patients who need aortic root and valve replacement have been able to receive mechanical valves (called the Bentall procedure) since 1960. While mechanical devices have provided a lifesaving option for patients with aortic root aneurysms or valve disease, they have nevertheless been imperfect. Use of mechanical valves requires patients to take anticoagulation medication long-term, which can be problematic for all patients, but especially active patients. Homografts and xenografts (tissues taken from the patient's own body, or from an animal donor, respectively) have been used as well, but these grafts can become severely calcified over time and make reoperation hazardous.
To address the need for a better alternative, Dr. Allan Stewart developed a novel stentless biologic aortic root-valve conduit (currently called 'the Columbia Bioroot,' or, by other physicians who have adapted the technique, 'the Stewart procedure'). The conduit contains a new stentless equine pericardial valve (3f) marketed by ATS Medical and a fabric graft that simulates the ascending aorta (the Gelweave Valsalva graft, marketed by Vascutek). This composite bioroot provides an improved alternative for patients who require an operative procedure on the aortic root.
The Columbia Bioroot improves upon previously available forms in several ways. It allows for a larger valve to be used (29mm stentless valve), which significantly improves patients' blood flow compared to other valves. Its prefabrication and increased ease of implantation contribute to shorter operative time, reduced need for cardiopulmonary bypass (use of the heart-lung machine), reduced blood transfusion, and decreased length of stay in the hospital. It works well in patients who require reoperation because of its unique construction. Long term, it is expected that this device will have better durability than available alternatives, because its design distributes stress better than conventional devices, and because the functioning of the valve more closely resembles the native aorta.
As of January 2010, the 3f bioprosthesis has been used in more than 100 patients who required aortic root and valve replacement. Results to date indicate that this composite graft is safe and effective in the short term. A study is currently underway to evaluate the longevity of the 3f prosthesis, and also to compare outcomes of this new prosthesis with valve-sparing root replacement.