Which valve do you have? What size? Leaking mechanical valve sounds like a prosthesis mismatch, but how would it leak? Is a leaflet stuck?
It's hard for any of us to know for sure, but paravalvular leak is one pretty rare but still very real complications that can result after valve replacement. It can happen to any prosthetic valve, and is actually more common with mechanical valves (I do not know the reason, if any real reason, so it might even be just a factor of the makeup of the patient groups that have been studied) in the literature I've read. It is actually more well known these days with the introduction of transcatheter valves since it is a much more frequent complication with those types of valves. Anyway, an interesting things to me is that symptomatic presentation of paravalvular leak with a standard prosthetic valve (mechanical or tissue) is usually indicated to be anywhere from 1% to 5% while in studies that use TEE to evaluate the incidence has been shown to be up to 20%. TEE of course detects far more insignificant leaks. Also, paravalvular leak is usually more common in the mitral position than aortic.
I've read of several different causes of paravalvular leak, none of which are usually simple (like a missed suture, in other words). Infectious endocarditis is one in which the sutures around the sewing ring eventually can be disrupted. Just the technical aspects of the surgery itself can lead to it as well, though. Despite the best efforts of highly skilled surgeons sometimes the various parts just do not perfectly seal. Fortunately, in most cases, it is mild and without symptoms, but in other cases, the leak can be more pronounced.
So, virginian777, while I don't have personal experience with this, it is certainly something that does rarely happen. I'm still curious though about your symptoms. You mention things unrelated to the valve, do you have symptoms your doctor(s) are attributing to the valve leak? In other words, are they convinced that it is a severe leak with symptoms that will in fact be improved by another surgery? Now obviously, surgery is never recommended unless necessary...so just trying to understand more the specifics of your situation. Best wishes to you moving forward and please keep us posted as this develops.