PS:
I suggest you add to your board that now there are only one type of mechanical valve but a number of makers which produce almost identical designs. Open Pivot or Open Hinge
This is a good historical round up
https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.108.778886
from Fig one these are the only mechanical valve types and only A is currently in use or is approved
The type C is what people like Dick have and type B had a relatively short life.
Now if you've ever bought an appliance you'll know that what the maker claims and what you may get are often almost right and occasionally more like "a maker wish list"
So while On-X marketing will claim the following
you need to wear your Critical Thinking hat (you read that article link; right?) and not just swallow the food that was spooned into your mouth (because it wasn't your parent, but a company in a country which allows direct marketing of valves to patients as if they were dishwashers.
Some Critical thoughts
- what determined "optimal criteria" in their claim of "optimal length" claim
- does the claim of 90 degree opening stack up in reality?
I can answer the second point
https://www.valvereplacement.org/threads/aortic-valve-choices.887840/page-2#post-902334
So if you were buying a washing machine (and you were like me) you'd read the magazines which actively test the devices and evaluate claims like; power consumption, water use, how clean they make dishes.
That's what we cite Peer Review Journals for ... that's the source of data. Now this data is of course complex and you must read more than the abstract if you really want to know. Or just cite it here and see what your peers think of it.
The answers found in peer review differ from the answers in "Consumer Reivew" not just because the questions are tougher, but because
the intended audience is more demanding.
For example:
https://pubmed.ncbi.nlm.nih.gov/17655477/
From the Abstract:
The hemodynamic and the thrombogenic performance of two commercially available bileaflet mechanical heart valves (MHVs)--the ATS Open Pivot Valve (ATS) and the St. Jude Regent Valve (SJM), was compared using a state of the art computational fluid dynamics-fluid structure interaction (CFD-FSI) methodology.
assumptions include:
An aortic flow waveform (60 beats/min, cardiac output 4 l/min) was applied at the inlet.
so your critical mind should immediately assume that higher blood circulation rates will change these actual numbers, but how is perhaps just pressure jet
Platelet stress accumulation during forward flow indicated that no platelets experienced a stress accumulation higher than 35 dyne x s/cm2, the threshold for platelet activation (Hellums criterion). However, during the regurgitation flow phase, 0.81% of the platelets in the SJM valve experienced a stress accumulation higher than 35 dyne x s/cm2, compared with 0.63% for the ATS valve.
again your critical mind should be asking about "platelet stresses" and asking what that means if you don't know (
I'm sure its been mentioned by me, but I'll mention again that platelet aggregations form the basis for thrombosis. Having that happen in the middle of your artery out to your brain means a triggered thrombosis is now heading for your head. Which is why we have anti-platelet drugs and anticoagulation).
That whole article is worth a read just to get your head around the valve technology described. Eg
I'd say it takes a good undisturbed hour to read (and google points mentioned you don't know).
If you aren't putting in that level of time on reading then
- you probably aren't going to get the benefit from the answers you find
- meaning your engine is going but your wheels are spinning and you're getting nowhere
These are complex questions and so the answers aren't simple, sort of like you can't properly answer in a way to engender confidence when someone asks "did aliens make the pyramids" with "no".
Ultimately to make an informed decision you need to be informed (meaning also understand it). I personally don't think many patients can make an informed decision, thats not being unkind, its just being realistic.
So pick a St Jude.
(I have an ATS because my surgeon thought it was better, after I got it I started reading about it. The more I learned the more I found the answers are unclear. I have no reservations about my valve.)
Ultimately I still recommend my own blog post as all the basics
http://cjeastwd.blogspot.com/2014/01/heart-valve-information-for-choices.html
it also contains the link to Dr Schaffs presentation which I also still recommend.
HTH