Washington University in St. Louis published a paper on a small study they conducted comparing direct vs indirect surgeries on 15 patients.

The conclusion: In long-term angiographic follow-up, direct bypass procedures—alone or with indirect procedures—provided more consistent and complete MCA revascularization, while indirect procedures produced less robust, time-dependent MCA revascularization.

See the full article here:  http://w3.cns.org/dp/2011CNS/33.pdf

DJ

I would be cautious about making any conclusions or worrying about what could have been.  My daughter had direct by-pass at Stanford.  Although we asked several times, they were never clear on whether the new blood flow is equivalent to a normal child.  They just tell us she has 'good' blood flow.  Nevertheless, considering that the by-pass vessel is narrower than your normal artery, you would have to conclude that inherently, the new by-pass has less capacity and therefore, less blood flow.  My daughter continues to struggle with migraines and excessive bleeding during her menstrual cycle.   She is now 13 and had her surgery when she was 9.