Urogenital ImagingDiverticulum, bladder
may be
congenital or acquired. Most bladder diverticuli are acquired in association with longstanding bladder outlet
obstruction. They are most commonly seen in older men with
benign prostatic enlargement, prostatitis or
carcinoma of the prostate. They may also be seen with urethral stricture and
congenital urethral valve or stricture in infants. In females, bladder diverticuli may develop in outlet obstructions secondary to urethral
carcinoma or diverticuli.
Congenital diverticula are uncommon and occur almost exclusively in boys.
Congenital diverticula arise as a result of
herniation of the bladder
mucosa through the detrusor muscle. The wall of the diverticulum is usually quite thin but does contain muscle, adventitia and bladder
mucosa.
Congenital diverticula occur most commonly immediately adjacent to the ureteric orifice, the so-called Hutch diverticula (Fig.1). These diverticula most often result in vesicoureteric reflux, but may also produce ureteric obstruction. On occasion, they may arise posterior and lateral to the ureteric orifice and can produce bladder outlet obstruction.
Congenital diverticula are generally wide mouthed. All diverticula enlarge during voiding; thus voiding will accentuate obstructive symptoms produced by the diverticula. Therefore, a postvoid film is frequently useful for identifying persistent contrast within the diverticula, with emptying of the remainder of the bladder. In contrast to Hutch diverticula, bladder ears are anterior, contract with bladder contraction, and disappear with aging.
Treatment of patients with Hutch diverticula is geared toward relieving symptoms related to obstruction or reflux. When significant reflux or obstruction is present, the diverticula can be surgically excised with reimplantation of the ureter. In mild cases, serial follow-up is all that is required.
Bladder diverticula are well demonstrated by intravenous urography or cystography (Fig.2) (Fig.3) but may also be seen on ultrasound, CT or MRI.
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