0022-5347/99/1626-2112/0 THE JOURNAL OF UROLOGY® Copyright © 1999 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 162, 2112–2113, December 1999 Printed in U.S.A.
CONGENITAL BLADDER DIVERTICULUM: A RARE CAUSE OF BLADDER OUTLET OBSTRUCTION IN CHILDREN M. ZIA-UL-MIRAJ From the Department of Paediatric Urology, Children’s Hospital and Institute of Child Health, Lahore, Pakistan KEY WORDS: bladder outlet obstruction, diverticulum, bladder, abnormalities
The majority of bladder diverticula in children are associated with neurogenic bladder or infravesical obstructive conditions, particularly posterior urethral valves. Congenital bladder diverticulum is not associated with such conditions and is due to inherent muscular weakness rather than obstruction.1 Compared to diverticula associated with obstruction, congenital bladder diverticulum develops in a smooth walled bladder, and is often solitary and larger. This condition may lead to various sequelae, including recurrent urinary tract infection, vesicoureteral reflux, stone formation and incontinence. It may rarely present with bladder outlet obstruction. A case of bladder diverticulum presenting as acute urinary retention is reported. CASE REPORT
Z. A., a 2-year-old boy, presented with acute urinary retention. History included recurrent episodes of fever, a lower abdominal mass and difficult voiding. Ultrasound showed a large posterior bladder diverticulum and right hydroureteronephrosis (fig. 1). Voiding cystourethrography confirmed a large diverticulum arising from the postero-inferior aspect of the bladder, extending behind and compressing the bladder neck and posterior urethra (fig. 2). There was associated grade IV vesicoureteral reflux on the right side but no evidence of any obstructive urethral lesion. DiethylenetetraAccepted for publication July 30, 1999. FIG. 2. Voiding cystourethrogram confirms large bladder diverticulum (D) compressing bladder (B), bladder neck and proximal urethra. Grade IV vesicoureteral reflux was confirmed on right side as right ureter drained into diverticulum.
minepentaacetic acid renal scan revealed 32 and 68% differential renal function on the right and left side, respectively. The diverticulum was approached intravesically and extravesically through a Pfannenstiel incision. It arose from the right aspect of the trigone and extended behind the bladder neck. The right ureter opened into the posterolateral diverticulum wall. The diverticulum was densely adherent to the rectum and vas deferens, and was excised by careful sharp and blunt dissection, with care taken to avoid trauma to adjacent structures. The muscular defect in the bladder was repaired and the ureter was reimplanted using the crosstrigonal advancement technique. Convalescence was unremarkable and the boy voided with a good stream. At 6-month followup he was asymptomatic. Voiding cystourethrography showed a well healed bladder with no evidence of vesicoureteral reflux. DISCUSSION
Congenital bladder diverticulum is uncommon. It is frequently located on the trigonal margin in close proximity to the ureteral hiatus, which may progressively become incorporated into the diverticulum.1, 2 While often asymptomatic, congenital bladder diverticulum may cause various problems, such as vesicoureteral reflux, recurrent urinary tract infection, stone formation and incontinence.1 A low lying diverticulum may rarely attain large size sufficient to com-
FIG. 1. Ultrasound shows large diverticulum (Div) arising from bladder. Arrow indicates diverticulum neck. 2112
2113
CONGENITAL BLADDER DIVERTICULUM
press the bladder neck and posterior urethra.1, 3 Resultant obstruction further diverts urine into the diverticulum, leading to a self-perpetuating cycle.1 Sheldon and Essig, who described a similar case in 1994, reviewed the literature and noted only 10 such cases reported previously.1 All patients, including the current patient, were male and at least 50% had associated vesicoureteral reflux. While the asymptomatic and incidently found diverticulum may be ignored, it is generally agreed that those causing various complications must be surgically treated.1, 3 Diverticulectomy may be performed by an extravesical, intravesical or combined approach. Since the diverticulum is usually adherent to adjacent structures, such as the rectum, ureter and vas deferens, careful extravesical dissection is imperative
during excision. The muscular defect in the bladder should be meticulously repaired and the ipsilateral ureter almost always requires reimplantation. REFERENCES
1. Sheldon, C. A. and Essig, K. A.: Congenital bladder diverticulum causing bladder outlet obstruction: case report and review of the literature. Ped. Surg. Int., 9: 141, 1994. 2. Taylor, W. N., Alton, D., Torguri, A., Churchill, B. M. and Schillinger, J. F.: Bladder diverticula causing posterior urethral obstruction in children. J. Urol., 122: 415, 1979. 3. Vergese, M. and Belman, A. B.: Urinary retention secondary to congenital bladder diverticula in infants. J. Urol., 132: 1186, 1984.