154 Engineering Ethics: An Industrial Perspective
THE BACK STORY
FDA GOOD MANUFACTURING PRACTICES
Medical devices are regulated in the United States by the Food and
Drug Administration (FDA). Before a new device can be sold, it must
receive FDA approval. For a Class III device, which is designed to support
or sustain human life or prevent impairment of human health, its device
manufacturer typically submits a premarket approval (PMA) application.
A PMA application contains a device description and nonclinical labora-
tory studies on biocompatibility, stress, and wear. It also contains a clinical
investigation section with human safety and effectiveness data, device
failure and replacement data, patient complaints, and results of statistical
analysis. A key component of a PMA application is a copy of all proposed
labeling, including information for use and instructions for use.
A PMA application is subjected to FDA’s required process of scientific
review to assure device safety and effectiveness, which typically takes longer
than 180 days. Upon approval, postapproval requirements such as continued
safety evaluations may be imposed. For continued PMA approval, an annual
postapproval report must be submitted to FDA. If a device or device
malfunction may have caused or contributed to a death or serious injury, a
medical device report (MDR) must be filed within 30 days of becoming
aware of the event. If a device failure necessitates a labeling, manufacturing,
or device modification, a PMA supplement must be submitted. These post-
market surveillance procedures were implemented as a direct result of the
Bjork-Shiley heart valve defect (see Chapter 8).
MEDICAL DEVICE BACKGROUND
Guidant Corporation’s wholly owned subsidiary, Endovascular
Technologies, Inc. (EVT), was located in Menlo Park, California. EVT
manufactured the Class III Ancure Endograft System, a treatment for
abdominal aortic aneurysms. An aneurysm is a diseased or weakened
section of an artery wall that tends to bulge because of hardening or
general deterioration of the arteries. The aorta is the largest artery in
the body and transports oxygenated blood out of the heart. An abdomi-
nal aortic aneurysm (AAA) is a widening of the aorta in the area of the
abdomen (Figure 13.1).
Traditionally, when an AAA diameter increases to greater than 5 centime-
ters and the patient is able to tolerate surgery, surgical repair is performed to
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2003: Guidant Ancure Endograft System 155
Figure 13.1 Abdominal aortic aneurysm.
Reprinted with permission of the Society of Interventional Radiologists © 2005,
http://www.SIRweb.org.All rights reserved.
prevent AAA rupture. An incision is made in the abdomen, the intestines are
moved aside, the damaged portion of the aorta is removed, and a polyester
patch is sewn in its place. After this surgery, the patient requires 6 months to
recover.
A minimally invasive procedure to implant this patch, or endograft,
in the aorta is preferable to surgical repair. The Ancure device consisted
of a graft housed within a delivery catheter, or tube. The catheter was
inserted in a vein in the groin and then moved to the AAA. The delivery
catheter included a balloon catheter that, when inflated, floated through
the blood and helped guide the device over a guidewire and secure the
attachment system for the graft (Figure 13.2). Once the graft was uncom-
pressed because its jacket was retracted, angled metal hooks and a self-
expanding cylindrical metal frame attached the graft to the AAA (FDA,
1999). The delivery catheter was then removed from the body. Blood then
flowed through the graft, avoiding the aneurysm, which typically shrank
over time.
In the initial clinical studies submitted in the PMA application, there
were 9 deaths out of 510 patients, for a 1.8% rate of device deaths, compared
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156 Engineering Ethics: An Industrial Perspective
Figure 13.2 Guidant Ancure Endograft System.
Reprinted from FDA, 1999.
with the control AAA surgery, which resulted in 3 deaths out of 111 patients,
or a rate of 2.7% deaths. In 4 out of 510 device cases (1%), complications
such as failure to access the aneurysm or to accurately place the graft caused
conversion to standard surgery (FDA, 1999).
CLINICAL PERFORMANCE AFTER FDA APPROVAL
FDA approved the Ancure device for sale in the United States on
September 30, 1999. The conditions of approval included performance of
a long-term follow-up study and sales case support for each device case
performed (FDA, 1999). Each Ancure device cost approximately $10,000.
The Ancure device received approval on the same day as its major competi-
tor device, which was manufactured by Medtronic and considered easier to
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