Yes absolutely, they far prefer it if they can repair an existing valve if possible. In fact it is only a very small proportion of people who require repair work, most people are just monitored a couple of times a year and if necessary put on medication. However, those who have severe prolapse will nearly always have it repaired rather than a replacement.
Look at this site, it's very informative.
Here's a portion of it....
Although most patients with mitral valve prolapse require no treatment or treatment with oral medications, in very rare cases, surgery (mitral valve replacement or repair) may be required. Rare patients with mitral valve prolapse may suffer strokes because of increased blood clotting. These patients can be treated with a combination of a blood thinner (anticoagulant) and a beta-blocker.
For some insight, mitral regurgitation from mitral valve prolapse is the most common reason for surgical treatment. Mitral valve prolapse occurs when the leaflets and supporting cords of the mitral valve have excess tissue, and they weaken. With each contraction of the left ventricle, the valve leaflets bulge (prolapse) into the left atrium. This common heart defect may prevent the mitral valve from closing tightly and lead to regurgitation. Mitral valve prolapse is common. Many who have it never develop severe regurgitation.
If not treated, mitral valve regurgitation can lead to congestive heart failure. Treatment depends on the severity of regurgitation, how far mitral valve disease has progressed, and signs and symptoms of the disease.
Mitral regurgitation may result from damage to the cords that anchor the flaps of the mitral valve to the heart wall. Over time, these cords may stretch or suddenly tear, especially in people who have mitral valve prolapse. A sudden tear can cause substantial leakage through the mitral valve.
I have moderate to severe mitral valve regurgitation for years and the condition is related to the leaflets not properly closing the one-way valve opening. If there are clots, etc., it is due to an enlargement of the left atrium caused by advanced MVR and an enlarged left atrium can cause A-fib (fluttering of the atrium rather than pumping causing clots). (rare), heart failure, etc.>>> •"Anticoagulant medications prevent blood clots, especially in patients who have heart rhythm problems such as atrial fibrillation or have had heart valve surgery and have a replacement valve made of metallic material". source Mayo Clinic. I think this was explained on another thread.
Mayo Clinic one of the leading hospital for valve problems. "The first objective guidelines for this surgery were established by a Mayo Clinic study of 456 patients who had mitral valve regurgitation that had not yet produced significant symptoms. The study found that patients with a regurgitant orifice (the orifice through which blood flows backwards) larger than 40 mm² who were treated only with medication were more than five times more likely to die than those with the same severity of regurgitation who underwent valve repair surgery.
The most common reason for mitral valve surgery is regurgitation (leakage) due to mitral valve prolapse and other causes. Valves with regurgitation are usually repairable and rarely require replacement".
Cleveland Clinic one of the best heart centers in the world.
Advantages of Mitral Valve Repair
Mitral valve repair is the best option for nearly all patients with a leaking (regurgitant) mitral valve and for many with a narrowed (stenotic) mitral valve.
Compared to valve replacement, 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 (anticoagulation). For these reasons, Cleveland Clinic surgeons are committed to mitral valve repair.
Hope this helps. Take care.