3. Aortic Root Replacement with the "Freestyle" Stentless Procine Aortic Root Bioprosthesis
Neal D. Kon, A. Robert Cordell, Sandy M. Adair, John E. Dobbins, Dulane W. Kitzman
Wake Forest University School of Medicine
Winston-Salem, N.C.
Aortic root replacement with a stentless porcine valve offers the advantages of superior hemodynamics, laminar flow patterns, lack of need for anticoagulation, and perhaps improved durability. In 1992, we began implanting the "Freestyle" stentless procine valve as part of a multicenter worldwide evaluation.
Our hundred-four patients were operated on from Sept. 17, 1992 to Oct. 10, 1997. The mean age was 71.7± 7.07 years. Four patients had an intra-aortic cylinder technique used to replace the aortic valve, and 100 patients had a free standing total aortic root replacement. There were four deaths either in the hospital or within 30 days of surgery for an operative mortality rate of 3.8 percent. No patient experienced structural valve deterioration, non-structural valve dysfunction, paravalvular leak, unacceptable hemodynamic performance, or endocarditis. The incident of thromboembolic complication was 3.8 percent, all of which were cerebrovascular.
The echocardiographic mean
gradients, effective orifice area, cardiac output, and the incident of
aortic regurgitation are summarized in the table below. Reduction of LV
mass index in 15 patients with predominantly aortic stenosis fell from
126.30 ± 29.39 gm/m2 preoperatively to 102.50 ±
40.19 gm/m2 at one year.
| HEMODYNAMIC DATA | INCIDENCE OF POSTOPERATIVE AI |
| Time Internal | (N) | Mean Gradient ± SD | EOA cm1 | Cardiac Output (L/min) | None | Trivial | Mild | Moderate | Severe |
| Discharge | (100) | 9.57 ± 3.63 | 1.53 ± 0.39 | 4.53 ± 1.11 | 94.0% | 4.0% | 2.0% | 0% | 0% |
| 3 - 6 months | (88) | 7.11 ± 0.32 | 1.76 ± 0.32 | 4.65 ± 0.99 | 95.5% | 3.4% | 1.1% | 0% | 0% |
| 1 year | (67) | 7.62 ± 3.46 | 1.98 ± 0.40 | 4.59 ± 0.98 | 92.5% | 6.0% | 1.5% | 0% | 0% |
| 2 year | (45) | 6.69 ± 2.88 | 1.76 ± 0.35 | 4.32 ± 1.15 | 91.1% | 8.9% | 0% | 0% | 0% |
| 3 year | (30) | 8.15 ± 3.74 | 1.75 ± 0.42 | 4.92 ± 1.79 | 96.7% | 3.3% | 0% | 0% | 0% |
| 4 year | (20) | 7.31 ± 2.66 | 1.75 ± 0.21 | 4.73 ± 0.50 | 100% | 0% | 0% | 0% | 0% |
| 5 year | (4) | 6.00 ± 2.83 | 1.77 ± 0.38 | 4.25 ± 0.63 | 100% | 0% | 0% | 0% | 0% |
In conclusion, the Medtronic "Freestyle" aortic root bioprosthesis can be used safely to replace the aortic root for aortic valve and aortic root pathology. Root replacement allows optimal hemodynamic performance with no significant aortic regurgitation. Further follow up is needed to determine valve durability. "Trademark of Medtronic, Inc."