Valve-Sparing Aortic Root Replacement for the Treatment
of Marfan Syndrome
March / April 2005
Patients with Marfan Syndrome (MFS) and others with aortic
root aneurysms are experiencing excellent outcomes from the
David-V Re-implantation technique, a procedure that replaces
diseased tissue while sparing the patient’s own aortic
valve.
“We have a very large aortic surgery program and substantial
experience with aortic root surgery in general,” says
Joseph
E. Bavaria, MD, vice-chief of cardiothoracic surgery,
director of the complex aortic surgery program and professor
of surgery at the Hospital of the University of Pennsylvania. “We
have operated on more than 1,000 aortic roots since 1996
and have performed about 25 valve-sparing operations. Nationwide,
this procedure has only been performed in significant numbers
in the past two years. Our results are excellent and we have
a zero mortality rate for this particular operation.”
Because the David-V eliminates all aortic tissue except
the valve, there is no tissue left to enlarge over time and
stretch the valves again. The native aortic valve is then
re-suspended inside a newly fashioned root of polyester fiber
and shaped to the ideal diameters and geometry of the aortic
root.
Previously, conventional treatment had been to replace the
entire aortic root, incorporating a mechanical valve. While
this proved a viable procedure for most patients, there are
some individuals who are unable to adjust to the accompanying
need for anticoagulation therapy. By preserving and repairing
the patient’s own valve tissue, the potential for prosthetic
valve deterioration is eliminated, as is the need for long-term
anticoagulants.
The valve-sparing operation is no more risky than other
approaches such as the composite graft and is clearly superior
to not performing surgery at all, according to Reed
E. Pyeritz, MD, PhD, chief of the division of medical genetics and professor
of medicine at the Hospital of the University of Pennsylvania. “We
just completed a study that has been accepted for publication,” he
says. “In a formal decision analysis, we took a theoretical
patient with MFS and projected the results of a composite
graft versus a valve-sparing operation. The valve-sparing
operation, in theory, added a couple of years to his life
expectancy because it eliminated any complications from anticoagulants
and greatly reduced the risk of aortic dissection.”
“We proceed when the risk of surgery is lower than
the risk of rupture or dissection,” says Erin Davis,
RN. “We know what the risk of rupture is at pre-determined
aortic diameters. For patients with MFS, depending on their
clinical presentation, we feel that once the aortic diameter
is between 4.5 and 5 cm, the risk of dissection or rupture
is higher than the risk associated with surgery. For patients
with other diseases, we use the same process with higher
diameters and we consider their aortic valve function, as
well.
“Most patients come in on an elective basis because
they have a dilated aorta on some sort of abnormal imaging
scan,” Davis continues. “They are usually very
well-educated, young people who have done their homework.
Because they are relatively asymptomatic, the ease of post-operative
recovery can be pleasantly surprising. After a five to seven
day hospital stay, they usually make an excellent recovery.”
After the sternotomy, most patients return to work in six
to twelve weeks, depending on the nature of their work and
how they are feeling. They will have lifetime restrictions
on lifting because that type of isometric exercise can elevate
blood pressure, putting their aorta at risk. “We try
to limit the need for re-do surgery down the road,” Davis
says.
Surgeons who perform the David-V procedure believe it should
be available to all patients who present with aortic root
aneurysm and fairly normal valve anatomy. The reality is
that most hospitals and medical centers do not have the capability. “Those
patients should be referred to major centers where they can
get state-of-the-art care for this particular pathology,” concludes
Dr. Bavaria. “If performed properly, this is the best
option.”
Symptoms of Marfan Syndrome |
MFS is a genetic condition that
affects the connective tissue of the body. It causes
very serious, potential problems in many body systems,
including the skeleton, eyes, nervous system, skin,
lungs, heart and blood vessels. Patients with MFS tend
to be tall and slender with long arms and legs. They
can have deformity of the chest because of a curvature
of the spine or protrusion or depression of the breastbone.The
lethal aspect of the condition is the enlargement
of the aorta, typically the first part of the ascending
aorta, the aortic root. If this condition is not
fixed,
the patient can develop aortic regurgitation that
can progress to heart failure or a tear in the aortic
wall,
called a dissection, which can be fatal.
MFS can occur in both men and women of any race
or ethnic origin. There is no specific lab test to
identify the condition, however, a detailed family
history along with a complete examination focusing
specifically on the system involved (e.g., echocardiogram)
can be useful in making the diagnosis.
Before good surgical techniques were devised, patients
with MFS typically only survived into their 30s or
40s. The development of surgical aortic root repair
has dramatically increased the lifespan of these
patients to near normal.
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Referring Physicians: To speak with a Penn physician
or refer a patient, contact PennHealth through the secure online
referral form or by calling
1-800-789-PENN
(7366). |
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