Moon:
Dr. McGinn uses the tissue that is available, if needed. What that means is, that she will use the inverted scrotal and penile tissue to create the vaginal canal, by sowing the two together. If no penile tissue is usable, then she will use just the scrotal tissue.
Dr. McGinn was my surgeon, and in my case, it was just the opposite, and no scrotal tissue was used and just the penile tissue was used.
I'm not familiar with the non-penile inversion technique that you refer to, unless you are referring to using the sigmoid colon for the vaginal canal. I do not think that Dr. McGinn performs a sigmoid colon vaginoplasty.
-Sandy