INITIAL CLINICAL-EXPERIENCE WITH THE TORONTO STENTLESS PORCINE VALVE(TM)

We report our initial experience from April 1992 to November 1993 with a stentless porcine valve (Toronto SPV(TM) Valve, St. Jude Medical) f or aortic valve replacement (AVR) in 21 consecutive patients and compa re this group to a matched cohort that underwent AVR with a Hancock II (Medtronic) bioprosthesis. There were no hospital deaths in either gr oup. Postoperative hospitalization was 5.5 +/- 0.8 versus 7.0 +/- 2.3 days (p = 0.004). Aortic cross-clamp time was 114.5 +/- 15.7 min in th e SPV group and 96.0 +/- 25.0 min in the Hancock II group (p = 0.003). Complications in the SPV group were: one patient suffered perioperati ve infarction, one patient required late reoperation for left main ste nosis, and one patient died suddenly following femoral thrombectomy at another center. Complications in the Hancock II group included: one p atient with postoperative low output syndrome, and two late deaths (on e from an aortic dissection and the other from chronic liver disease s econdary to alcohol abuse). Comparison data indicate that the average size valve implanted in the SPV group was higher than in the Hancock I I group (26.3 +/- 1.9 vs 24.0 +/- 1.9, p = 0.001). In the SPV group, 1 6 patients had 0 or trivial regurgitation and 1+ regurgitation was see n in 5 patients; regurgitation did not change over a 12-month follow-u p. We observed a decrease in gradients over time (p < 0.01). Our resul ts are compatible with a hypothesis that the ventricle undergoes remod eling over time, once the obstruction is relieved. We think the stentl ess design is an important feature that allows this to occur. Furtherm ore, this design allows for the implantation of a larger size valve fo r the same body size, as well as for decreased shear forces during dia stole, with accompanying better hemodynamics, and potential improvemen t in longevity. These results indicate that the SPV valve has excellen t hemodynamic characteristics that do not appear to change over a shor t follow-up period.