Hi, Does your results shows reduced blood vessels, follicles and sweat glands, or a reduction of the nerve fibers that innervates them ?
The small fibers are sensory and autonomic fibers, the autonomic nerves innervates these organs and they might be affected by SFN.
So the biopsy usually tests for these innervations as an indication for the condition of the autonomic nerve fibers.
The sympathetic branch of the autonomic system innervates the blood vessels and it controls their constriction/dilation (For example increasing the blood flow to an active area that needs more blood, or to an injured area to improve it's healing). When it is affected the blood vessels still exists and the blood reach the feet, but their regulation is damaged. For example I had felt that my feet are freezing. After getting Rituximab (my SFN is likely autoimmune) the first sign of improvement was that my feet defrosted
I hardly have any hair left on my legs, and I stopped sweating in my legs and arms, I don’t know whether the glands and follicles dies when they aren’t activated by the autonomic system and whether this is reversible.

Was the ganglionopathy diagnosed based only on this biopsy or did you have other tests ?