Hi. I'm writing a transman with paraplegia and had an off-handed thought that spiralled into a, "this comes up nowhere in the story but is essential information I must know," thought.
Would a person unable to feel their body from the waist down be able to feel a phalloplasty or not? Assuming they got it after losing the feeling in their body.
This was a really interesting question. My default assumption was that they would not be able to feel it, but I decided to do some more research about phalloplasty and genital nerve sensation.
I'm going to assume you're talking about a complete spinal cord injury somewhere between T2-L1, which will result in full loss of sensation and control from the affected area downwards.
Most phallo will use skin and nerves from the arm to construct the penis, and replace the tissue from there with tissue from the thigh. There is the option to use tissue directly from the thigh to construct the phallus, but they have a different shape and usually less sensation than the radial (arm) skin graft method, even though there are fewer surgical sites.
After phalloplasty, the moved nerves need time to heal and reconnect to the nerves nearby. So for example, the thigh nerves now in the arm will heal and reconnect to the other nerves in the arm, restoring sensation to that area. There are reports that this can cause, in some patients, permanent nerve damage in the surgical sites.
This suggests that the nerves will mostly or completely connect to the existing nervous structure, which again made me think that complete paraplegics who get phallo will not have sensation even if the nerves heal correctly and completely.
So I did some more research and found some literature on procedures to restore genital function and sensation in low-level spinal cord injuries. This procedure is effective regardless of genital situation, to restore function, sensation, or control to the sacral area. The final answer to your question is...
It is possible to create or restore sensation in the sacral area, if you have a spinal cord injury below the L1 level (so, not completely paralyzed from the waist down). This is because procedures that restore genital sensation connect the dorsal nerves to nearby lumbar nerves, specifically the ilioinguinal nerve, which is located in the inner thigh and is at the L1 level.
So no, assuming your character has an L1 or higher complete SCI, they would not have sensation in a neophallus. But that doesn't mean they shouldn't look into getting phallo! Especially with an SCI that would require catheterization, a phallo could still reduce dysphoria.
not answering the actual question, but it's trans man, two words. A trans man is a type of man - just like a paraplegic man is -, not some secret third thing.