Valvular 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.
A 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.
Mitral 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.
Dr. 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.
Aortic 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.
Tissue 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 with time.
Another 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.
Dr. 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.