Re: Mitral Valve repair or replacement

Posted By CCF Cardio MD-SGM on March 31, 1998 at 20:27:35:

In Reply to: Mitral Valve repair or replacement posted by Juney Ahn on March 22, 1998 at 19:18:05:






Hello. My husband is 59 years old and he is having surgery
on 4-2-98 for mitral valve repair/replacement. He also had
a heart attack five weeks ago, and the angiogram found 80%
blockage in his right coronary artery, near the bottom of the
heart, where the artery is relatively small. Im afraid we have
many questions, and very much appreciate your help. Since his surgery
is so impending, if at all possible, we would indeed appreciate your
reponse before the operation.
-What is the new minimally invasive technique for valve
repair/replacement surgery. Who is a candidate for this
technique, what is involved, and when will it become widely
available?
-The operation will be performed at Kaiser Foundation
Hospitals Los Angeles Medical Center. Can you tell us
anything about this unit and/or its reputation for quality?
-How many surgeries does the Cleveland Clinic do for valve
repair/replacement per year? How many of these result in
valve repair, how many of these repairs are succcessful,
and how long on average do the repairs last?
-Is it true that porcine mitral valves wear out because of
calcification? Is it actual calcium that deposits? Is there anything that can
be done with diet, etc., to reduce calcification and make the
valve last longer? Are there other causes for them wearing out?
-My husband has always had a lot of plaque on his teeth.
Could this mean that the porcine mitral valve will become
calcified sooner?
Does the porcine valve and St. Jude valve compare in these
areas: Rejection rate, infection rate, defect rate, rate for
severe complications.
-It was explained that the porcine valve has two metal
structural pieces on it and that it does not look as neat and
aesthetic as the mechanical valve when sutured in. Do these
aesthetic differences have any effect on the function of the
valves?
-We were told that a venous graft was always used for the
right coronary artery? Is this true? We would rather not have
another incision in the leg if at all possible.
- If the artery is too small to be bypassed, do we have to worry
that it will get blocked again at that point again and cause another heart
attack? Or, when an artery is that small, do other surrounding
blood vessels take over supplying that part of the heart?
Thank you very much!



______-
Dear Juney,

Mitral valve disease is not infrequently a cause of significant symptoms and functional
impairment. In the last decade, surgical reconstruction(repair) of MR has become the preferred
treatment of this problem. However, not all valves are candidates for repair procedures. Historically,
diseased mitral valves underwent replacement with mechanical (metal) or tissue (bovine or porcine)
prostheses. Although the replacement valves function extremely well, they create other problems,
including a need for chronic anticoagulation(blood thinning) to prevent clot formation with the mechanical valves, problems with degeneration and failure of the tissue prostheses, as well as increased risk for infection of the prosthetic material (endocarditis) affecting both types of valves.. The decision on whether to attempt repair of a mitral valve, as opposed to replacement with a prosthesis, involves factors relating to the mechanism of the valve's dysfunction, the degree of calcification, and other factors noted in the pre and intra-operative evaluation of the valve.   You should discuss this decision with your surgeon and cardiologist.
Minimally invasive surgery involves a smaller incision and different surgical approach to the valve, but the patient is still placed on heart-lung bypass, much like the typical "median sternotomy" approach.  Your husband's need for a bypass graft may limit or prevent his ability to be a minimally invasive candidate.  In the final analysis, this is a decision that needs to be made by an experienced surgeon, familiar with both types of surgical approaches.  Regarding the harvest of venous graft material from the leg, this is fairly routine and unavoidable in bypasses of the right coronary artery.  Should the graft fail or not be feasible due to technical problems such as excessively small target site, then the problem of coronary disease would be managed with medicines.  In any case, medical management of coronary disease risk factors is imperative, including cholesterol reduction, smoking cessation, and others.  
I can't comment on the particular hospital you're considering for this procedure.  In the best of worlds, all patients would undergo major surgery at large hospitals with extensive experience and large annual caseloads.  Large academic medical centers have been repeatedly shown to produce the best results.  We're proud to be the largest center for valve surgery in the United States, with over 1200 valve surgeries in 1997.  
Tooth plaque doesn't play an important role in tissue valve degeneration.  Antibiotics during tooth cleaning or other dental procedures are helpful, however, in reducing the risk of valve infection-- endocarditis.  
Best of luck. Information in the Heart Forum is for general purposes only. Specific diagnoses and
therapies can only be provided by your physician.