膀胱頚部硬化症の病因に関する考察

Abstract

Bladder neck contracture is not a single pathological entity, though most of the patients develop symptoms of bladder outlet obstruction earlier in life than adenomatous hyperplasia. We have applied the term 'bladder neck contracture' to the cases in whom no remarkable enlargement of the prostate was noticed by palpation in the presence of subjective and objective (based on urodynamic study) signs of obstruction, and in whom radiological examinations visuahzed verumontanum clearly suggesting that no adenomatous enlargement had developed around it. Therefore, this term includes true circular contracture at the neck, prostatic fibrosis and some of the fibromuscular hyperplasia of the prostate. However, clinical differentiation of these pathological conditions is not a matter of ease. Moreover, some of the cases in whom neuropathic dysfunction is disclosed by neurological examinations could be included when insufficient urodynamic studies are performed to exclude this possibility. We have studied 93 patients diagnosed and treated as bladder neck contracture in our hospital to conjecture etiology of this disease. Thirteen patients of them (14%) had revealed chronic prostatitis on their clinical course. While observing with urodynamic studies and microscopical, bacteriological and immunological examinations of the expressed prostatic fluid (EPS), some of them developed persistent and progressive dysuria after clinical improvement associated with the decrease of immunoglobulin secretion into EPS. The histological examination of the resected specimens obtained by TUR showed varying degrees of infiltration by plasma cells and macrophages, remarkable increase of collagen fiber and immunoglobulin deposits. This suggests that a inflammatory reaction has provoked the increase of fibrous tissue and collagen fiber causing the contracture at the neck. Based on the data presented, it might be a plausible assumption that the progtessive diminishment of immunoglobulin contents in EPS is a preceding parameter of bladder neck contracture caused by fibrosis of the prostatic urethra in the course of long-standing inflammation of the prostate.