Since getting this stuff inside me, I have been very interested in how it was done & what exactly was used.
What I want to know is what is the Onyx Material consistency when cured inside the skull within the arteries & veins after contacting and mixing with our blood/plasma
I did ask my neuro on the way out last time - he said solid - I want to know what type of solid. Is it semi spongy like silicone or rubber based adhesive, or - is it rock hard like a two part epoxy after being cured
My guess would be rock solid if Onyx is capable of capturing the delivery catheter after introductiion. If it were only spongy I wold assume there would be no such thing as âretained cathetersâ. I do know that Onyx was never studied or approved as a stand alone implant which is what we have. The device approval process is long and expensive for companies so I believe the initial approval process was for temporary use before additional treatment i.e. craniotomy or radiosurgery. Surgeons can use devices any way they see fit regardless of FDA indications or instructions for use.
I seen quite a few mentions of lost catheters(and some strokes from it), but even a soft pliable adhesive would snag a catheter. Kind alike if you let a straw left in when the adhesive dries, even if itâs soft - I asked my neurosurgeons specifically if any devices were used permanently or lost - they said no, nothing - no devices at all were left inside(they seemed very proud of this). Onyx 18 & 34 both were used < this is the first mention I have seen of both weights being used - let alone on a dAVF
From what I recall Onyx was later approved for permanent AVM repair - but, not for dAVFâs < Iâll look this up again - I read so much info on this stuff
Itâs just amazing that this thing was repaired with it - specially being considered a permanent solution + it being a dAVF
My main neurosurgeonâs work amazes me more than any magician - a complete occlusion of this thing on the 1st try. I read the footnotes a few times. They are tough to understand, but what I did fully understand is how many attempts they made trying to get to it & getting stuck, then having to pull back and go it again with a different type of catheter(it was either a total of 3 or 4 tries). - my whole groin was black & blue from a few inches above the knee to a few inches under my belly button. . . This had to be such a tough battle in the OR - shoot, everything recovered within 3 months or so. I donât even have any marks now where they entered the arteries. It amazes me that my double mastectomy left scars 10x bigger
The Onyx is considered the âdeviceâ and what requires the FDA approval. However, physicians have the freedom to use any device âoff labelâ or beyond what has been 'approved. The catheter delivery systems, while also âdevicesâ are not what I was referring to regarding FDA indications and IFUs. The catheters are symply the tools to deliver the device and I believe you already know this.
They donât officially consider Onyx a device - again, I asked. Itâs some sort of grey area - they said coils, clips, shunts & so on are devices.
But, yes - in all reality, Onyx is the device used for the repair.
But, I could have sworn seeing somewhere where it stated that Onyx was approved as a permanent solution.
I was watching a few craniotomy videos last nite, where they used Onyx to restrict blood flow to the area. The texture & look kinda reminds me of black caviar - it doesnât look very uniform, like it does in their animated re-enactments
Onyx was initially introduced to the market to stop or reduce flow to avms prior to either craniotomy or radiosurgery. Also, it would reduce blood loss during resection of avm, as well as provide visual assistance in identifying the portions to be removed. Avm and Onyx were developed to both be resected during a craniotomy. The onyx was not approved or intended to act as an implant like a a coil, clip like you mentioned. Whether âimplant statusâ was ever approved over the years, idk? If you read the first page of the pdf document from 2003 I posted, it clearly states that no long-term safety and efficacy studies were performed, as that was not the initial intended use. I guess the best place to research more is to find the current IFU for Onyx from either Covidien or Medtronic who now own the product. GK
First statement under WARNINGS from 2003 IFU. I know this was from when Onyx was first introduced for FDA approval for âpre-surgicalâ use. Based the number of successful cases where Onyx was the sole treatment, like ours, perhaps the Manufactures didnât see the need to get FDA implant designation b/c that process is VERY expensive. Attached is the PDF I was referring to. GK > https://www.accessdata.fda.gov/cdrh_docs/pdf3/P030004c.pdf
Well, good sir - you are correct(at least all of the reading material I finally went through matched up)
This is right off their site & is current:
Onyx 18/34 is Designed for presurgical embolization of brain arteriovenous malformations (bAVMs)
And, this would it explain its texture a bit more
During presurgical embolization of bAVMs, with the Onyx⢠LES system, the DMSO solvent dissipates into the blood and interstitial fluids, causing the EVOH copolymer and suspended tantalum to precipitate in situ into a spongy, coherent substance. The Onyx⢠liquid embolic system begins to form a skin and solidifies over time from the outside to the inside. < I still wonder what kind of solid. ie, epoxy hard like or semi pliable - sounds like the first from the description. . . Which would explain what the neurosurgeons at BNI all call it an âOnyx Castâ
This is what I remember seeing that just gave me goose bumps when reading it -
The safety and effectiveness has not been studied in the following patient populations:
Pregnant and nursing women
Individuals less than 18 years old
Individuals with aneurysms not associated with a bAVM nidus, or distal feeders to a bAVM nidus or dural AV fistulas < the last one is what I have, a nice dAVF
So, yeah - all in all, so far - I feel fine. Lol
Just wanted to poke around for some more info on the material