heart problems involve primarily narrowing (stenosis)
or leakage (insufficiency or regurgitation)
of the aortic valve (primary outlet valve of the heart)
or mitral valve (primary valve between the upper and
lower chambers of the heart). All blood pumped by the heart
passes through these valves. Problems can be caused by rheumatic
fever or simply by degenerative changes occurring over many
years of opening and closing every second of the day. Certain
systemic illness and disease can contribute to the development
of valve problems including auto immune disease such as arthritis,
infections and kidney failure.
congenital defect in which the aortic valve has only
two leaflets instead of three is one of the most common causes
of aortic valve narrowing.
valve disease may be due to rheumatic disease but currently
is caused most often by mitral valve prolapse syndrome,
a poorly understood phenomena in which the valve slowly becomes
thickened, elongated and begins to regurgitate blood back
into the upper chamber of the heart causing heart failure.
The mitral valve somewhat resembles a parachute in
that long chords hold it in place. These chords may rupture
and result in sudden worsening of the valve leakage.
to advances in modern surgical techniques, most cases of mitral
valve prolapse can undergo repair of the valve thus preventing
the need for placement of an artifical valve. Repair can be
performed in 90-95% of cases of mitral leakage due
to prolapse syndrome. This allows the patient to be
treated postoperatively with simple blood thinners such as
baby aspirin rather than the more powerful anticoagulant Coumadin
required after most valve replacements and which has some
potentially serious side effects.
Ott and his team have one of the world's largest experiences
with mitral valve repair and replacement and can discuss
the options carefully and honestly with the patient.
valve disease of a degree that requires surgical intervention
usually requires replacement of the valve although repair
is possible depending on the specific anatomic situation and
the experience of the surgeon. The most important decision
facing a patient who requires aortic valve replacement is
the type of valve to use. The decision can only be made after
a thorough, open and honest discussion with a surgeon experienced
with all types of valve devices.
used for replacement are of two basic types: tissue and mechanical.
Mechanical valves are constructed entirely of man made
materials usually pyrolite carbon, a diamond hard material
attached to a Dacron sewing ring to attach it to the patient's
tissue. Current mechanical valves are usually of a
tilting disk one way flow design and have the advantage that
they do not wear out. Mechanical valves do, however,
require lifelong treatment with Coumadin, a blood thinner
that can cause increased susceptibility to bleeding particularly
in older patients.
valves include several types all of which have the advantage
of not requiring Coumadin but only long term treatment with
a platelet inhibitor blood thinner such as enteric coated
baby aspirin which has few side effects. All tissue valves
have the disadvantage that they may wear out with time and
require further valve surgery. However, with current advances
in valve preparation and preservation techniques, one can
expect an 85-90% chance that a tissue valve will remain
functional after 15-20 years. These valves are most appropriate
for patients over 50-60 years of age and are constructed from
either bovine (cow) pericardium or porcine (pig) heart tissue.
In younger more physically active patients, homograft valves
(cryopreserved (deep frozen) human cadaver valves) may
be appropriate because of their favorable hemodynamic characteristics
but they require a more extensive operation and may wear out
valve option suitable primarily for younger patients and children
is the so called Ross switch procedure which consists
of transferring the patient's pulmonary valve to replace the
diseased aortic valve. The pulmonary valve must then be replaced
with a cryopreserved human cadaver valve. This procedure offers
an excellent hemodynamic result, but is a much more extensive
procedure technically, has a higher operative mortality and
leaves the patient with two tissue valves that will eventually
wear out rather than just one. Nonetheless, it is appropriate
to use in specialized cases.
Ott has the advantage of having extensive experience in valve
surgery of all types and will thoroughly discuss the risks
and benefits of each in an honest and unbiased fashion based
on the individual patient’s data, needs and wishes.