Diagnosis of Anterior Urethral Valve by Voiding Urethrography: Report of Two Cases

Despite a natural reluctance to burden the literature with individual case reports, the authors feel justified in presenting 2 cases of anterior urethral valve, since they were unable to find in the literature any account of this abnormality with accompanying roentgenograms. In only one textbook, Williams' Urology in Childhood (1), is the subject discussed, and in that instance only a diagram is reproduced. In the first of the 2 cases to be recorded here, there was a graphic roentgenologic demonstration of the valve. The diagnosis in each instance would have been missed if the rarely taken voiding urethrogram had not been obtained. The father of the first patient was a physician who had attended a number of lectures stressing the importance of a forceful urinary stream. He therefore watched his son urinate and observed that the child's stream lacked the normal projectory little boys so proudly demonstrate. This was the sole complaint which led to a request for an intravenous urogram. In the second case, a prior intravenous urogram in another hospital had shown minimal changes of pyelonephritis in a ten-year-old boy, with no apparent obstructive uropathy. This in itself was unusual because of the sex, since boys are less likely to have pyelonephritis than girls. A voiding urethrogram had not been attempted. Two years later the pyelonephritis was more advanced, and voiding urethrography performed at The Children's Hospital revealed the obvious cause. Congenital valves of the urethra were first described in 1717 by Morgagni, who observed a case at necropsy. This was a posterior urethral valve. Such cases abound in the literature, but no mention can be found of valves occurring in the anterior urethra except in Williams' textbook. Case Reports Case I: A four-year-old male, of normal growth and development, was examined by intravenous urography solely because of inability to urinate with a forceful stream. Figure 1 is the fifteen-minute film following the intravenous injection of 15 ml. of 50 per cent Hypaque. The kidneys were grossly normal, and the ureters were not dilated. There was minimal blunting of the superior calyces on the left side, which suggested the possible presence of minimal pyelonephritis. A subsequent urine culture was negative. The post-voiding film showed the bladder to be empty. If a voiding urethrogram had not been obtained, the diagnosis would have been missed. Figure 2 is a film obtained during the act of voiding. In the middle of the anterior urethra, the diameter abruptly narrowed (arrow). Actually, the valve can be seen on this film, but its significance was not at first realized.