When new technology, science or engineering appear in
medical devices, how does FDA assess their safety and
effectiveness?
When existing devices malfunction,
how does FDA verify the root cause of the problem?
Scientists and engineers in FDA laboratories are asking
these questions and finding the answers that help assure
that the latest technology in medical devices is safe
and effective for patients.
In 2009, a patient underwent routine gastric band
surgery, a widely done procedure designed to help
severely overweight people achieve weight loss.
The surgery went well, but a few weeks later,
the band began to leak.
Then the same problem occurred with another
patient.
What was the problem?
And, was it an indication of a larger,
potentially more dangerous problem?
Scientists at FDA's Office of Science and Engineering
Laboratories, who look at products before and after
they enter the market, began to investigate.....
FDA has a special program where we listen to the
clinical concerns of health-care professionals
from across the country and this is called the medical
product safety network.
Through that network, we had a report about a problem
with a lap-band that seemed to be leaking.
An adjustable gastric band, frequently called a lap
band, is a device that's used to treat obesity.
It's a collar that's surgically placed around the
top of the stomach.
Then, using a needle that's inserted into a port
implanted under the skin, liquid fills the collar
squeezing the stomach.
This process works by making patients feel full more
rapidly, so they eat less.
The hospital was very concerned because they had
to repair several different patients' lap bands and they
weren't quite sure what the problem was.
...What they were noting at this hospital was that the
lap band was leaking and therefore, deflating.
We needed to understand where in the path of flow
the leak was occurring.
And we didn't know how widespread this was.
Was this a problem just at this one hospital where we
had the report?
Was it a problem at many different hospitals who
weren't thinking to report it to us?"
So when you get an initial report like this,
you really have many different areas of concern.
We looked at the problem and debated amongst ourselves,
is this an indicator of a larger public health
problem?
And it felt like it could be.
Therefore, we pulled together a group of experts
from across the Center and we talked about the issue,
and we called the hospital together to find out what
they thought the problem may be.
After some investigation at the hospital site,
they determined that they didn't think the problem was
with the lap band but rather with the Huber needle that's
used to inject saline into the lap-band.
Huber Needles have been around since about 1946,
when the patent was first issued.
They're designed so that when the needle pierces a
rubber septum, there is no hole left behind.
The hole, in a sense, heals back up as the needle comes
out.
That's important if you're trying to maintain sterility
or if you have a need for multiple punctures through a
port with no leakage after the fact.
Ports aren't just used for lap bands.
Ports are used in many different kinds of
procedures.
Most commonly, they're placed under the skin for
chemotherapy purposes.
So many cancer patients who are undergoing long-term
chemotherapy will have a port placed under the skin,
and then when they go in for their chemotherapy
treatment, a Huber needle, with a chemotherapy agent,
is placed through the skin into the port,
and goes into the patient's system.
When a Huber Needle "cores", it actually cuts a piece of
rubber out of the septum that creates two potential
problems.
The first is that the material that the port is
supposed to retain can leak out and go places where it
should not.
The second concern is that the foreign body could end
up in the bloodstream, which then can be sent to the
heart, sent to the lungs and sent to the brain - we just
weren't sure.
That was one of the major reasons we wanted to go
ahead and further understand the extent to which Huber
Needles do core, beyond this one simple case.
We realized again that this could be a problem well
beyond that with just lap bands.
This could be a problem for every patient undergoing
chemotherapy with the port.
So we brought the problem to one of our scientists who
has a background in mechanical engineering and
in manufacturing.
He investigated the Huber Needles to determine if we
had a design problem or a manufacturing problem.
The first question I asked myself: how do we test the
needles with the lap band port to see if they create
cores?
We needed to figure out how to test their needles....
We looked for and discovered that there was no standard
design parameter for testing ports with different
needles.
So, we designed our own test.
That was a major part of our effort,
to come up with a test that we could validate and then
we could share, so that other people doing this sort
of work, the manufacturers, our own internal
organizations, could reliably reproduce the test
and believe the data that they got.
We had to determine - was this a problem with one
batch or lot of needles, or was this a problem with all
of the needles that were made?
So, we bought additional needles from the same batch.
And we bought needles from different lots.
When we tested Huber Needles we were trying to follow
standard medical practices which nurses use in
hospitals...
The lab invited me in to demonstrate how the port and
needle are used in real clinical practice on a
patient.
We used the same size needles,
same type of needle and the same size syringe.
I started to see obvious differences in production of
these needles and I...was not sure if this was a
design problem or a manufacturing problem.
It appeared to be both - a design issue and a
manufacturing issue.
The design issue was with the back heel of the
needle's edge, where it was actually cutting the septum
as it was entering the port.
The manufacturing issue was that some designers had a
good design, but they just couldn't produce it
consistently each and every time.
When FDA reviewed Huber Needles,
before this issue was brought to our attention,
we were concerned with other issues related to a medical
device review, such as biocompatability,
consistency, manufature--other issues
related to the performance of the device.
Once we identified the issue,
we brought to their attention that coring was
also an important consideration in the review
of Huber Needles.
We knew we had to take immediate action to inform
the public of our findings as well as to encourage
manufacturers to review their manufacturing
operation and, if necessary, perform a recall.
We met with 10 of the largest manufacturers at FDA
headquarters.
FDA scientists presented their test findings and the
Office of Compliance asked for specific details about
how the firms would prevent defective products from
getting on the market.
We also informed the firms that we'd be following up
with non-compliant manufacturers.
After this, we advised our field offices on how to
inspect these manufacturing facilities.
We also developed safety communications,
such as letters to firms and a website to notify users
and patients about this issue.
In the end, a Huber needle manufacturer conducted a
voluntary recall of more than 2 million Huber
needles.
FDA's public health responsibility spans the
entire life cycle of medical devices,
from the early development of a device,
to the manufacturing of the device,
and then to its use in the market.
At any stage of a device's life cycle,
FDA makes well-supported regulatory decisions based
on the information available.
We call it the "total product life cycle" and the
way this works in this particular instance is that
one group received the issue,
recognized that it was a problem,
went to the group that would do the investigation and
explore and find out what actually was the problem.
Another group then was able to take regulatory actions
that were needed to improve the product at the
manufacturer level.
And the other group was then able to communicate the
problem to all the hospitals so they all would become
aware of the problem with Huber needles.
This was an excellent example of the various
elements within FDA working together to solve a problem.
It involved publishing our results.
And we're partnering with industry to develop a
standardized test method so all the needles can now be
tested the same way.
This new standard is very significant,
because once it is adopted by manufacturers,
it will serve to assure FDA that the needles do not
core.
The testing procedures that we developed and the
enforcement actions that took place,
because of the results that we uncovered,
now allow us to be assured that industry,
going forward, either can identify their own problems,
or can assure us that they've now developed good
manufacturing processes to ensure Huber Needles don't
core.
Signaling a public safety concern....Identifying the
problem...Effective communication...Working with
industry to adopt a sustainable long-term
solution...
This is FDA at its most effective...Achieving its
mission.