aortic stenosis

My mom, who is 88, has very severe aortic stenosis.  She recently (a few days ago) went to her regular doctor for a checkup and the doctor felt she was in minor heart failure (one of her legs is a bit swollen.)    She's 93 pounds, frail, so we've been holding off having surgery.  Now, we feel there might be no other option.

Open heart surgery is out of the question.  But we're thinking about minimally invasive surgery to do a valve replacement.  Has anyone here ever had that surgery?  If so, how long does the surgery last?  And how long is a typical recovery period for surgery like that?  A good friend of mine, who's 48, just had minimally invasive heart surgery to repair major tears in his mitral valve and the surgery lasted 5 1/2 hours.  His surgery was in May 2008 and he STILL hasn't completely recovered.

We're seeing her cardiologist next week and already have a 2nd option surgeon/cardiologist in mind.  But, I've found that a lot of docctors try and sell you on surgery without looking at the patient's full story.   So I'd like to hear from people who've been through this.  
I'd appreciate any feedback.
Thanks.