The disease is progressive.  The blood vessels that were affected will eventually completely close.  The blood vessels that grew after the surgery will basically take their place. 

However, the disease seems to pick the blood vessels it is going to affect, narrows them, and then stops.  I had visions of my son later having narrowing in an artery to his liver . . . or his big toe.  But the doctor that treated the narrowing in the artery to his kidney (making him doubly rare -- because it was NOT just the cerebral arteries) had seen other moyamoya patients and was the one to assure me of this.  That went a long way in making me feel better.

My son was 7 when he was diagnosed.  At the time, most of the Circle of Willis (a major blood vessel formation in the brain) was affected by the moyamoya.  The narrowing in the artery to the kidney was discovered at the same time.  He had the surgery for the brain a couple months later in Boston with Dr. Scott.  He had the surgery for the kidney a few days before his 9th birthday by Dr. James Stanley at the University of Michigan's Mott's Children's Hospital.  It was Dr. Stanley who gave me this information.  (He did, however, lose the kidney due to other complications -- a whole other story in itself -- that supports PARENT education and advocacy with doctors!!)

My son is now seventeen.  He is doing very well.  That fact that your son had no strokes is a wonderful thing!!  My son had three incredibly mild strokes.  You would not be able to tell if you met him today.  Dr. Scott says the prognosis is based on the condition of the brain at the time of surgery (well, actually, the time of follow-up when the vessels have had a chance to grow).  Everyone's healing is different due to the extent of the strokes, the age at stroke, and the differences between each person's body.  Because your son had NO strokes, his prognosis should be that much better.  He doesn't have that damage that needs to heal. 

While I am not a physician, I think it sounds like your son will be able to live a normal, happy life.  And my son too!

Kimber -- mom to Matthew, three strokes at the age of 7 and doubly rare with renal moyamoya -- though now only a single kidney, Laura, 22, Jacob, 14, and Kay, 10. 

I also worry, it has been 6 months since my second edas and still have no idea what the future holds, Has anyone had any ill effects post surgery?

I am 50 yrs old. I have had symptoms of MM since pre-school. Had stroke and bypass surgery at 40.  I think the significant point is that no one really knows our prognosis. This certainly was the hardest part for me for the last ten years. Unfortunately I have no wisdom to share that can make it easier.  However,  I am 50 with no significant disabilities. That's a good long time.
Russ

My daughter had her bilateral direct bypass with Dr. Steinberg back in August of 2007.  She is now 11 years old.  She's had TIA's ranging from 3 minutes to an hour since the surgery.  The more intense ones happen once or twice a year and the shorter 3-5 minute TIAs happen one a month to 3 times a week.  Stanford had no explanation except that prognosis differs for each patient.  Our local neurologist assumed it was seizures so she was put on Keppra, which appeared to lesson the intensity and frequency.  However, her recent incident took her to the emergency room.  CAT Scan and MRI showed no signs of stroke/irregularities.  However, when she was asked to hyperventilate during her EEG, she felt numbness on her left side, similar to her experience with TIAs.  What was concerning was that the EEG showed no irregularities.  Based on this test, our neurologist was inclined to conclude that the episodes were TIAs as opposed to seizures.  We have a 3 year followup with Stanford in June of this year.  We may have to move this date up.  I'll keep everyone posted.  Please let me know if anyone has any insight.