From July 1992 to October 1994, we inserted new Toronto SPV stentless
aortic heterografts (SJM Med, Inc., St Paul, Minneapolis, USA) in 40 o
f a series of 50 consecutive patients older than 70 years. The mean ag
e was 75.7 years (range 70 - 86 years). All, except 4 patients, were p
re-operatively in NYHA functional class III or higher. The aortic clam
p time was significantly higher in the stentless group (75 v. 53 minut
es, P < 0.001). The average 255 mm size of the implanted valves stands
in stark contrast to the low body surface area (1.69 m(2)) of this pa
tient group. The surgeon's (in)experience was the major reason for the
drawbacks (5/50) associated with a stentless procedure. The follow-up
period ranged from 2 to 27 months and was complete in 100% of cases.
We encountered 1 hospital death and no late deaths (97.5% actuarial su
rvival). The mean NYHA class at follow-up was 1.5, and without excepti
on patients were in class I or II. We noted one transient ischaemic at
tack immediately postoperatively and another later incident in a patie
nt with a previous severe vascular history. With a low-intensity antic
oagulation regimen for the first 3 months, there were two incidents of
haemorrhaging necessitating premature anticoagulation withdrawal. Ech
ocardiographic transthoracic valvular gradients compared favourably wi
th the reported gradients of other biological valves, especially the s
maller ones and significantly better haemodynamics were noted in most
cases 6 months after implantation. Comparison of data with stented val
ves implanted during the same period indicates that the average size o
f the stentless valves was significantly higher (223 v. 255 mm, P < 0.
001) in an equivalent population.