I'm hoping some of you can point me in the right direction. I am trying to assist a hospital customer with a rather serious issue concerning the Aquarius apheresis instrument, which I believe is manufactured by Edwards Lifesciences. More specifically, the filter used with the device, the Asahi AP 05H(L), clogs and blocks blood flow with the usual citrate concentrations used for therapeutic apheresis. When the staff at the hospital call the filter manufacturer, they are told the filter "doesn't like citrate", which sounds really screwy to me!

The filter folks have told the staff that they need to heparaize the patients in order to use this machine, and not use citrate. This would be great except a couple of patients they had tried to do procedures on were post-cardiac surgery and had some bleeding issues afterward.

There doesn't seem to be any customer support at all for this instrument and the staff are scared that they will have a really serious event. It is a community hospital not near a large city, so if there was an issue, it could potentially be a real problem.

Has anyone used this instrument, or have any advice on whether citrate can or cannot be used with the filter? Thanks for any help you can give. MJD

Just an update after speaking with Edwards Lifesciences--they apparently do not make this instrument and have no idea who does.

I will try to search the FDA CBER site for a new device clearance and check other manufacturers.

The hunt is on!

Wow! That is a good one! I'm probably not going to be able to help you with this - as I know nothing about the machine. But one thought is that Citrate does drop the pH of blood, and that could what potentially interacts with the Asahi filter??

Good Luck with that!! It sounds like it might be time for a new apheresis device!!

Sir,

It looks like a situation like the one when we use the CODE SPECTRA for stem cell apheresis ? If my memory is right, we do use "very little amounts" of heparin while doing the procedure with COBE , in order to reduce the incidence of "citrate toxicity" ...But in these situations we add heparin to the saline line ......and not to the patient or citrate line ...

Maybe the poor the company person could not explain properly ...

with regards and wishes..

engeekay2003

Comparing the Aquarius instrument with the Spectra apheresis instrument is a stretch since Spectra separates by centrifugal force not by filtration. Most systems that use filtration by hollow fiber or flat membrane do use heparin as an anticoagulant. Column apheresis (eg. Prosorba) also uses heparin. In the "old days" (1970's) heparin was used in both centrifugation and filtration procedures. Post procedure, the heparin was often counteracted by an injection of protamine sulfate, even in donor collections. Protamine sulfate has its own adverse affects so should be considered carefully, under physician direction, if used. Since most filters tested can activate complement, using citrate along with heparin has been shown to decrease or eliminate the activation of complement. The anticoagulant function of citrate is accomplished by the binding of Calcium which is required for the coagulation cascade, Calcium is also required for the activation of the Complement cascade. Therefore using citrate in filtration apheresis serves a dual purpose.

Surely this Aquarius instrument has an operators manual? If not, then its use cannot comply with the requirement to follow mfrs instructions. If so, and its use requires the use of heparin as the anticoagulant, then perhaps the responsible physician could prescribe the addition of NaCitrate or ACD along with the heparin, and consider using protamine sulfate post procedure if post procedure bleeding is a concern.

Edwards Lifesciences LTD does indeed distribute the Aquarius instument. See attached.

aquarius_ic_p4.pdf

Edwards Lifesciences Ltd - Aquarius - FSN.pdf