[HSF] re: Porcine vs pericardial for Hal and others

[Giulio Rizzoli]

At 16.16 02/01/2008, you wrote:
> > > Ani,> Not to quibble, but the CCF paper you 
> cited had more AI than AS as the > cause of 
> failures in pericardial valves. > > Hal>
>
>Any

The paper You mention comes from Padova and is 
mostly based on an old experience with the Pericarbon valve.
This is a more focused paper

Pathology of the Pericarbon bovine pericardial 
xenograft implanted in humans.  J

Heart Valve Dis. 1998 Mar;7(2):180-9
Valente M, Thiene G , Padova
BACKGROUND AND AIMS OF THE STUDY: Pericarbon is a 
new-generation bovine pericardial bioprosthesis 
designed to withstand mechanical wear. Following 
optimal in vitro testing and animal experiments, 
clinical trials were initiated in many European 
centers and explants sent to our department for 
pathological evaluation. This included gross, 
radiographic, histologic and ultrastructural 
investigations. METHODS: Between 1986 and 1996, 
24 bioprostheses (eight aortic, 11 mitral, two 
mitro-aortic, one tricuspid) were collected from 
22 patients (10 males and 12 females; mean age 
57.0 +/- 18.9 years) either at autopsy (nine) or 
reoperation (15). RESULTS: Ten bioprostheses 
explanted < 2 months after surgery were either 
normal or failed because of surgical problems or 
non-structural causes. Among the other 14 
bioprostheses (mean placement 41.9 +/- 23.6 
months; range: 7 to 90 months), structural 
deterioration occurred in seven and was due to 
dystrophic calcification with stenosis in five 
(three aortic, two mitral), mixed lesion in one 
(mitral), and incompetence in one by 
calcium-related commissural tear (mitral). At the 
ultrastructural level, calcification was detected 
either on cell debris or upon collagen fibers. No 
bioprosthesis failed because of fibrous tissue 
overgrowth. Of the remaining seven bioprostheses, 
vegetative endocarditis occurred in two, 
thrombosis in one, and aseptic paravalvular leak 
in one; whereas three showed no signs of 
dysfunction. CONCLUSIONS: This pathologic 
experience with the Pericarbon valve showed 
calcification to be the main cause of late 
structural failure, causing mainly cusp stiffness 
and bioprosthesis stenosis. Tissue rupture or 
abrupt dysfunction never occurred. Thus, 
prevention of mineralization remains the main challenge.

It is also my impression that pericardium should 
be more resistant to tear than porcine tissue but 
I find it difficoult to extrapolate a general 
mode of failure from human explants ( valve 
construction variability, tissue variability, 
fixation, additive, and final the surgeon and 
hospit component) certainly for some unexplained 
reason the pericarbon valve were particularly 
affected from Distrophic Calcification.
                                                                                                               Giulio 
Rizzoli

Giulio Rizzoli MD FETCS
Cardiochirurgia Padova
tel. 049 821-2408
fax 049 821-2409
e-mail giulio.rizzoli at unipd.it

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