The structure of the bladder neck in male bladder neck obstruction.

A light microscope and neurohistochemical study is presented of full thickness biopsies from the bladder neck of 10 middle-aged males with urodynamically proven bladder neck obstruction. Apart from varying degrees of collagen deposition in seven cases, no abnormality was present in the detrusor and pre-prostatic components of the bladder neck muscles or in the distribution of cholinergic nerve fibres. The normal noradrenergic innervation to the pre-prostatic sphincter was absent in all specimens; this may be age-related.