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膀胱頚部機能不全(Campbell-Walsh Urologyから)

慢性前立腺炎患者さんの多くが機能性膀胱頚部硬化症と、私は信じています。アメリカの文献では、機能性膀胱頚部硬化症という用語はなく、膀胱頚部機能不全・膀胱頚部機能障害Bladder Neck Dysfunctionというカテゴリーに分類されています。

Bladder Neck Dysfunction

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Bladder neck dysfunction is defined here as an incomplete opening of the bladder neck during voluntary or involuntary voiding. It has also been referred to as smooth sphincter dyssynergia, proximal urethral obstruction, primary bladder neck obstruction, and dysfunctional bladder neck. The term smooth sphincter dyssynergia or proximal sphincter dyssynergia is generally used when referring to this urodynamic finding in an individual with autonomic hyperreflexia. In male patients with autonomic hyperreflexia, the neurologic pathophysiology is clear. The term bladder neck dysfunction more often refers to a poorly understood non-neurogenic condition first described over a century ago but first fully characterized by Turner-Warwick and associates in 1973. The dysfunction is found almost exclusively in young and middle-aged men, and characteristically they complain of long-standing voiding/emptying (obstructive) and filling/storage (irritative) symptoms (Webster et al, 1980; Norlen and Blaivas, 1986; Wein and Barrett, 1988; Trockman et al, 1996; Yamanishi et al, 1997). These patients have often been seen by many urologists and have been diagnosed as having psychogenic voiding dysfunction because of a normal prostate on rectal examination, a negligible residual urine volume, and a normal endoscopic bladder appearance. The differential diagnosis also includes anatomic bladder neck contracture, BPH, dysfunctional voiding, prostatitis/prostatosis, neurogenic dysfunction, and low pressure/low flow (see later). Objective evidence of outlet obstruction in these patients is easily obtainable by urodynamic study. Once obstruction is diagnosed, it can be localized at the level of the bladder neck by video-urodynamic study, cystourethrography during a bladder contraction, or micturitional urethral profilometry (see Chapter 58, "Urodynamic and Videourodynamic Evaluation of Voiding Dysfunction"). The diagnosis may also be made indirectly by the urodynamic findings of outlet obstruction in the typical clinical situation in the absence of urethral stricture, prostatic enlargement, and striated sphincter dyssynergia. Involuntary bladder contractions or decreased compliance may occur; Noble and associates (1994) cite the incidence as 50%; this seems high. Trockman and colleagues (1996) quote it as 34%.

The exact cause of this problem is unknown. Some have proposed that there is an abnormal arrangement of musculature in the bladder neck region, so that coordinated detrusor contractions cause bladder neck narrowing instead of the normal funneling (Bates et al, 1975). The occurrence of this problem in young, anxious, and high-strung individuals and its partial relief by α-adrenergic blocking agents have prompted some to speculate that it may in some way be related to sympathetic hyperactivity. When prostatic enlargement develops in individuals with this problem, a double obstruction results, and Turner-Warwick (1984) has applied the term trapped prostate to this entity. The lobes of the prostate cannot expand the bladder neck and therefore expand into the urethra. A patient so affected generally has a lifelong history of voiding dysfunction that has gone relatively unnoticed because he has always accepted this as normal, and exacerbation of these symptoms occurs during a relatively short and early period of prostatic enlargement. Although α-adrenergic blocking agents provide improvement in some patients with bladder neck dysfunction, definitive relief in the male is best achieved by bladder neck incision. In patients with this and a trapped prostate, marked relief is generally effected by a "small" prostatic resection or ablation that includes the bladder neck or a transurethral incision of the bladder neck and prostate. Such patients often note afterward that they have "never" voided as well as after their treatment.


この機能不全は、もっぱら青年・中年の男性で発見される、そして、特徴的なのは、長い時間かけて排尿し/出し切るまで長い(閉塞)のと充満感/残尿感(刺激症状)症状について不満を言う(ウェブスターら1980; NorlenとBlaivas1986;ウィーンとバレット1988;Trockmanら1996;ヤマニシら1997)。







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