Unsafe for Humans But OK for Dogs?

In 2015 a group of MDs from NYU patented a Nitinol wire stent design for vocal fold paresis in humans. Now there's a marketing campaign underway to sell this product design to veterinarians. But here's the thing:

• The FDA has concerns about biocompatibility and structural failure of flexible-wire products like the Dextonix DexStent-LN Nitinol laryngeal stent. Read the FDA's 2022 Nitinol Safety Profile.

• Fracturing risks with the DexStent-LN have been confirmed by Dextronix, as stated on the product web page:
  

“Since the original studies took place, the stent has been mechanically reinforced by us against the risk of stent fracture and the stent Nitinol materials and delivery system have been re igned and improved for longterm reliability. Initial implantation in canine patients with laryngeal paralysis show promising outcomes, but the number of implantations is so far relatively small and caution is advised. We will update this page when newer and better information becomes available.” [Dextronix website, access date 10/22/2023]

This appears to mean that this product has not been tested at all since this redesign took place. In other words, by Dextronix' own admission, this updated product is untested. How can Dextronix justify implanting an untested metal wire device into the airway of people's companion animals? We don't mind saying we’re having a hard time comprending it.

• Adverse Effects include fracture according to the product documentation . But what does that mean? Can a fractured metal wire object such as the DexStent LE result in a jagged or sharp edge of metal puncturing or tearing laryngeal or tracheal tissue leading to serious injury? Dextronix makes no public statements about what the ramifications of such a fracture can be. That's another thing we're having a hard time comprehending.

• A high-tech proprietary 'delivery device' is required to implant or remove the Dextronix stent. That brings up a lot of questions. In an emergency situation, will a primary vet, local internist or emergency facilities be able to extract the stent without the device? If the device is damaged or fractured, can the delivery device remove it at all?

• Dextronix quoted the cost of the DexStent LE in 2020 at about $1200, not including the cost of the delivery device, procedure, meds, imaging, or client care. That would bring the Dextronix stent implant cost into the same range as tieback surgery, i.e., several thousand dollars depending on location.

But those are product-technical issues, not ethical ones. The ethical issues arise when we start thinking about not the what, but the why:

• This device's patent applies to a HUMAN medical device, not a veterinary one. The patent holders know that their investors won’t see a penny of return on their multi-million-dollar investment without FDA approval. They also know that humane animal testing adds considerably to the development costs of the human-medical product. Here's what the product's patentholder, Dr. Robert Ward, had to say about that in November of 2022:

“The problem is, and you probably know, if you’re in a no-kill lab and you get the dogs adopted, they have to stay around for a month before they become adopted, and the cost of food, the cost of room and board, that adds a lot of expense to the project.”

Is this a 'problem' Dr. Ward thinks he can solve by just putting this device in peoples' companion animals and seeing what happens? But what if the dog is on vacation with the family and has an adverse reaction, and the local vet doesn't have the delivery device? Isn’t that exactly why there are humane testing facilities that monitor animals 24/7, and why respectable companies don’t complain about the expense?

• The FDA doesn’t regulate veterinary devices at all, a fact that is certainly not lost on Dextronix management.

So what's to stop them from pushing a veterinary version of the product to market? That would give them access to real-world data using real-world dogs, i.e., yours and mine, and what's better, you and I would be footing the bill.

So am I saying that the Dextronix DexStent LE is intended primarily to 1) test the human product on dogs, and 2) make a lot of money by getting veterinarians to put their untested product in your dog? Or, in other words, am I saying that Dextronix wants you to pay for your dog to be a guinea pig for their untested human-medical product?

No, I'm not saying that because I don't want to get sued. But it's a question every veterinarian should be asking themselves before they embrace this untested product design. If a veterinarian implants this device knowing that Nitinol wire products are under FDA scrutiny, what are the legal implications down the road? These are questions all of us — clients as well as veterinarians — should be asking ourselves before any pieces of Nitinol wire are implanted into any of our dogs' throats.