NEW TOOLS FOR
ENDOVASCULAR REPAIR OF AORTIC ANEURYSMS.
Research data indicates an increasingly significant
percentage of all elective aortic aneurysm repairs are endovascular
procedures. How are new tools for endovascular repair improving our ability to
provide minimally-invasive options to our patients and how common are secondary
re-interventions following endovascular repair.
You are listening to ReachMD XM-157, The Channel for
Medical Professionals. Welcome to the Clinician's Round Table.
I am you host, Dr. Mark Nolan Hill, Professor of Surgery
and practicing general surgeon and our guest today is Dr. Michael Marin,
Professor and Chair of Surgery at Mount Sinai School of Medicine in New York
City and Founder of Mount Sinai Hospital's Endovascular Surgery Program.
DR. MARK NOLAN HILL:
Welcome Dr. Marin.
DR. MICHAEL MARIN:
Thank you for having me.
DR. MARK NOLAN HILL:
We are discussing new tools for endovascular repair of
aortic aneurysms. Dr. Marin, tell us a bit about your background and how did
you get started in endovascular surgery.
DR. MICHAEL MARIN:
Well, my background has been in the field of surgery. I
trained in general surgery and then in vascular surgery here in New York and
very early in my career, a patient came to my office with a large abdominal
aortic aneurysm, but he was much too sick to survive or be able to sustain
conventional open surgery. This led to an investigation of alternatives and
the introduction to Dr. Juan Parodi, an Argentinian surgeon who had a new idea
of how to fix aortic aneurysms.
DR. MARK NOLAN HILL:
And where did you go from there?
DR. MICHAEL MARIN:
Well, I engaged Dr. Parodi in a conversation about my
patient and about some of his research in the field of endovascular repair and
he suggested that the procedures he was developing allowed the repair of an
aneurysm without general anesthesia and without the typical dissection required
of the abdomen in order to repair the aneurysm. With his technique, a new
lining was inserted into the aorta through the area where the aneurysm existed
and was affixed to the aorta above the aneurysm and below the aneurysm
functionally excluding it from the circulation.
DR. MARK NOLAN HILL:
And how did you follow in this way?
DR. MICHAEL MARIN:
This led to an invitation to Dr. Parodi to join me here in
New York, which he accepted to my and my patient's good fortune and together
with him; I performed the first aortic aneurysm repair in the United States.
DR. MARK NOLAN HILL:
But did you have the supplies necessary to do this?
DR. MICHAEL MARIN:
In its early procedure, Dr. Parodi provided the supplies and
the materials necessary to fabricate the graft for its repair. When this was
completed, I learnt from Dr. Parodi and his staff on how these devices
functioned and worked and then set out myself developing similar devices with
more broad potential applications.
DR. MARK NOLAN HILL:
Were these FDA approved at that time?
DR. MICHAEL MARIN:
At that time, there were no devices in the world that were
commercially produced and certainly none that had gone to FDA screening and FDA
clinical trials.
DR. MARK NOLAN HILL:
Then how you were allowed to place them in a patient.
DR. MICHAEL MARIN:
In order to use them, we did preclinical testing of the
devices, which I built by hand and sterilized and after preclinical testing, we
applied to FDA for permission to use them in a very small segment of patients
who had large serious aortic aneurysms, but were too sick because of other
medical problems to be able to sustain conventional surgery.
DR. MARK NOLAN HILL:
Now moving rapidly to the present day, what percent of
aneurysms are performed by endovascular repair?
DR. MICHAEL MARIN:
At the present time, close to 60% or perhaps even a little
bit more in the United States are done with endovascular devices.
DR. MARK NOLAN HILL:
And you expect this number to continue to increase?
DR. MICHAEL MARIN:
Clearly as devices improve and as skill level improves, I
suspect that this number will increase. Particularly, as we develop systems
that allow us to place the device ever closer to the branch arteries coming off
the middle portion of the aorta.
DR. MARK NOLAN HILL:
Well why isn't it 80%-90%?
DR. MICHAEL MARIN:
Largely because some patients have aneurysms that encroach
upon the renal arteries above and thereby do not give us a suitable
implantation site with traditional devices. Some recent devices have been
developed that allow us to place them even closer including the recently
approved Medtronics Talent device, which has a transrenal attachment system
that allows you to place the device across the renal arteries and fix to a
healthy segment above, but not impact on the circulation to those vessels. The
second reason is that some patients have severely diseased arteries in the
pelvis, mainly the iliac arteries and when these arteries are diseased, it is
impossible or difficult to pass the device through them to get them into the
aortic position. We are now developing new devices and procedures to allow us
to pass these diseased arteries, but it certainly limits the application and
has done so for a number of years.
DR. MARK NOLAN HILL:
And what is the most common reason for failure.
DR. MICHAEL MARIN:
The most common reason for endovascular graft repair failure
is when the proximal aortic neck at the renal arteries is angulated and shortened.
When this anatomic subtype occurs, the device may seat in the correct position,
but because of the bending or twisting of the aorta at that location which is
not terribly uncommon, the device won't seal properly permitting continued
perfusion of the aneurysm sac around the attachment site of the endograft.
DR. MARK NOLAN HILL:
And then what you do?
DR. MICHAEL MARIN:
When that occurs, there are a number of auxiliary procedures
we can do including placing a second graft in at a different angle using
specialized balloons to dilate the device more tightly against the aortic wall,
but in some instances, all these maneuvers are futile and require conversion to
open surgery in order to affect a permanent and durable repair.
If you have just joined us, you are listening to the
Clinician's Round Table on ReachMD XM-157. I am your host, Dr. Mark Nolan Hill
and our guest is Dr. Michael Marin, Professor and Chair of Surgery at Mount
Sinai School of Medicine in New York City and Founder of Mount Sinai Hospital's
Endovascular Surgery Program. We are discussing new tools for endovascular
repair of aortic aneurysms.
DR. MARK NOLAN HILL:
Dr. Marin, what happens when you have to re-intervene on a
patient who has already had an endovascular repair? Is this very difficult?
DR. MICHAEL MARIN:
The operations that are required to modify existing grafts
vary significantly depending on the severity of the problem. In some
instances, it may take nothing more than an inflation of a balloon to seal the
graft properly to the aortic wall
INCOMPLETE DICTATION.
