I can't really point to any articles in particular, but I think that the primary risk lies with the original surgery during the rectal dissection, in particular. Certainly, anytime you are having surgery in the general area, there is risk of impotence. Usually, it is temporary, due to swelling from the trauma, but rarely, the nerve damage can be permanent.
With a mucosectomy or pouch advancement after your original surgery, the pelvic cavity is not entered to any great degree, and these are typically done transanally, so less risk. Good questions to go over with your surgeon if you are considering the surgery.
The bigger risk is incontinence, due to damage to those nerves from the stretching of the anal canal and sphincters, along with traumatizing the delicate area at the dentate line (the transition between the anal canal and the rectum, where the nerves of continence are contained).
Jan