Study finds minimally invasive surgical repair for diseased mitral valves safe, effective
In the past, the two primary surgical treatments for mitral valve disease have been to either repair the patient's diseased valve, or replace it with a metal, mechanical valve or an animal tissue valve. The majority of those procedures are open-heart operations that require a major incision in the chest.
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Dr. Sabat Hashim explains mitral valve repair at Yale-New Haven Hospital.
But a recent study published in the September 2009 Annals of Surgery concludes that minimally invasive surgery to repair a diseased mitral valve is safe and effective for complex mitral valve defects.
From 2003-2009, cardiothoracic surgeons at University of Maryland Medical Center performed small-incision mitral valve surgery to repair the valve through only a two-inch incision in the right side of the chest on 187 patients with mitral valve disease. At the conclusion of the six-year study, the surgeons evaluated their results with respect to safety, durability and effectiveness.
"Our experience with 187 patients demonstrates that small-incision mitral valve surgery can be performed safely and effectively with a short hospital stay and a rapid recovery," said lead author James S. Gammie, M.D., a cardiac surgeon at the University of Maryland Medical Center. "This approach is our method of choice for all patients with mitral regurgitation, except those that are exceptionally obese, and those that are more than 75 years of age."
Mitral valve surgery was first performed in 1960, when surgeons replaced the diseased, native valve with an artificial valve. For the next 20 years, replacement with a metal or animal tissue valve was the gold standard. Dr. Gammie says no device is as good as a patient's own valve. The metal valve tends to form blood clots, which can lead to a stroke, so patients must take a blood-thinning medication for the rest of their lives. The tissue valves are less likely to cause clots, but they last only 10-15 years. However, patients with a repaired valve, rather than a replacement valve, can expect it to last for the rest of their lives.
The most common complications from mitral valve surgery are stroke, kidney failure and infections, none of which occurred among the 187 consecutive patients who received the minimally invasive repair procedure, beginning in 2003. Echocardiograms taken just prior to discharge, which were read by cardiologists who did not know the method of mitral repair or surgical approach, showed that 99 percent of the repaired valves were working properly. The median hospital stay was four days. All patients survived the surgery and 2½ years later, 99 percent of the patients were still alive.
According to the University of Maryland investigators, "The results of the present experience with small-incision mitral valve surgery are at least equivalent, and perhaps superior to, results of conventional sternotomy-based (a full breastbone incision) mitral valve repair."
What the news means to youBy Sabat Hashim, MD
The follow-up period of the 187 patients who underwent small-incision mitral valve repair surgery is relatively short; nevertheless, the good results reflect the skills and expertise of the participating surgeons, who experienced a repair rate of 100 percent with zero mortality and very low complications.
To perform small incision of any kind requires a mastery of the repair techniques including adjustments to novel instruments and alternative ways to bypass and protect the heart.
It appears the authors have mastered both. Given these excellent results and the prerequisite to attain them, however, one should not assume that duplicating them in any center is possible.
Mitral valve repair is technically more difficult than replacement, and operative success is dependent on the skill of the cardiovascular surgeon. Repair involves a lengthier and more complex surgery and requires the dedication of a committed and extremely proficient surgical team. At a comprehensive heart center like Yale-New Haven, this procedure is performed with a high degree of success and low operative risk.
When Yale-New Haven began performing mitral valve repair in 1984, it became the first center in Connecticut and one of a few in the country to introduce this cutting-edge procedure. The repair — which may involve the removal or reconstruction of valve leaflets, or implantation of an annuloplasty ring to reinforce the frame of the valve — is the preferred choice in many cases because the patient's own tissue is preserved during the procedure. The only artificial materials present in some cases are the annuloplasty ring and possible artifical Gore-tex Chordae that is used in the repair, which become covered by the patient's own tissue. In about three to six months, there is no prosthetic material exposed to the blood.
In 1995, Yale-New Haven surgeons introduced the minimally invasive small-incision technique for mitral valve repair with excellent results and a zero percent mortality. Using a different incision through the lower breast bone, the whole operation is conducted through a 2- to 3-inch incision using a window through the lower sternum of the structure of the thoracic chest. This minimally invasive procedure does not disrupt the ribs or upper sternum and offers patients a more discreet scar versus the traditional incision of the midline. Post-operative discomfort is reduced and patients can drive a week after discharge, instead of the usual 2-3 weeks.
Mitral valve repair is the best option for all patients with a leaking (regurgitate) mitral valve, also known as Barlow's or floppy valve syndrome. Although valve replacement is sometimes considered in lieu of repair, mitral valve repair provides better long-term survival, better preservation of heart function, lower risk of complications, and usually avoids the need for long-term use of blood thinners. Despite the benefits of repair over replacement, only about 55 percent of mitral valves nationwide are repaired. At Yale-New Haven Hospital, our surgical team has the skill and experience to carefully consider all options and implement the most appropriate treatment to our patients.
We applaud this study, the first of its kind that shows the esthetic benefits of a mini incision for mitral valve repair. Without compromising on the distinctive advantages of the operation, of course, longer evaluation is necessary to ascertain that those repairs are as durable as those made with the standard incision.
Dr. Hashim is the Director of the Mitral Valve Repair Center at Yale-New Haven Hospital and associate professor of cardiothoracic surgery at Yale School of Medicine.