Evaluation of the in vivo function of the Hancock porcine xenograft in the aortic position.

We evaluated the in vivo hemodynamic function of the stent-mounted glutaraldehyde-fixed porcine xenograft in 23 patients who had undergone aortic valve replacement from 2 days to 24 months prior to the study. Functional aortic valve orifice areas for the porcine xenograft ranged from 0.58 to 3.0 sq. cm., the average area being 1.36 sq. cm. Six patients had calculated prosthetic valve orifice areas less than 1.0 sq. cm. Valve orifice area did not correlate significantly with valve size or the time interval from surgery to postoperative study. Left ventricular stroke volume showed a significant, positive correlation with calculated xenograft orifice area. Systemic thromboembolism was not encountered. One patient required reoperation for xenograft stenosis caused by dense fibrin deposition on the aortic leaflets. We conclude that use of the stent-mounted glutaraldehyde-fixed porcine xenograft can be associated with significant functional stenosis which may be related to annulus size or inertial properties of the valve. These factors should be taken into consideration when considering use of the stent-mounted glutaraldehyde-fixed porcine xenograft in individual patients.