ANTERIOR URETHRAL VALVE

A CASE REPORT

Abstract

A ten-year-old boy was seen on November 4, 1975 complaining of urinary incontinence and enuresis nocturna. His mother said that since birth his urinary stream had always been poor and he had never been dry both day and night, and he had often high fever attacks and terminal micturitional pain. On physical examination there was no remarkable finding except slight strabism. At micturition he strained to pass urine as a poor stream and he had terminal dribbling. Laboratory examinations were not remarkable but pyuria. On X-ray examinations spina bifida occulta was seen on plain films (KUB). Excretory urography revealed a large irregular bladder with diverticula but no change in the upper urinary tracts (Fig. 1). Residual urine was seen after voiding. A retrograde urethrogram showed a linear filling defect on ventral wall of peno-scrotal functional urethra (Fig. 2). The ventral wall below the filling defect was rough and slightly dilated. Under general anesthesia 14 F metal catheter was inserted smoothly into the urinary bladder. Cystoscopic examination revealed marked trabeculation and diverticula with normal mucosa. A normal curve was taken on cystometric examination. We suspected a lower urinary tract obstruction due to anterior urethral diverticulum.
On September 9, 1976 external urethrotomy was done but no diverticulum could be found. The wound was closed leaving an indwelling Foley 12 catheter. Four days after the operation the catheter was removed and then a urethrocutaneous fistula was made spontaneously. On October 5, 1976 retrograde urethrography was performed again (Fig. 3). The same filling defect was seen in the anterior urethra and urethrocutaneous fistula was observed proximal to the filling defect. For the first time we came to consider an anterior urethral valve. On October 18, 1976 external urethrotomy was done again. Bulbous urethra was cut longitudinally at about 1cm proximal to the filling defect. A small malleable probe was modified by bending the tip sharply against itself to create a small hook. The hooked probe which was inserted from the external urethral orifice was moved from the wound to the external orifice. It was apparent that stroking the ventral wall of the penile urethra revealed a snagging effect. A valve in the peno-scrotal junction was identified as a fold of normal mucosa, 5mm in length, 7-8mm in width, 1mm in thickness. The valve arose symmetrically from the lateral urethral walls at 4° and 8°, extending from proximal to distal. Beyond the point of fusion the valves formed a thin transverse membrane that is fused distally to the urethral floor forming an end-pouch in the urethra (Fig. 4). It was thought that the obstructing action is produced as in a flutter valve by the ballooning of the valve into the urethral lumen during micturition. The valve was completely excised by electric fulgulation and the urethra was closed by 0000 atraumatic dexon in layers. Indwelling urethral catheter drainage was instituted for 78 days because a urethrocutaneous fistula was made in the wound. The fistula was closed spontaneously 15 days after the urethral catheter had been removed. Following removal of the catheter the child urinates with forceful stream and has no urinary incontinence and no enuresis nocturna. Fig. 5, Fig. 6 are postoperative voiding and retrograde cystourethrography respectively.
Anterior valve in the male urethra is a rare congenital disease which produces lower urinary tract obstruction. Twenty-eight cases in Europe and USA, twenty-three cases in Japan have been reported in the literature. Our case is the 52nd reported case of the diagnosis and treatment of a valve of the anterior urethra.
In our case enuresis nocturna was one of the chief complaints. We emphasized that the importance of the voiding cystourethrography in diagnosis and of transurethral resection of the valve in treatment.