Congenital bladder diverticulum presenting as bladder outlet obstruction in infants and children.
PURPOSE
Congenital primary bladder diverticulum is a rare cause of infra-vesical obstruction. We present a series of 12 cases who presented with urinary retention secondary to a large primary bladder diverticulum. The aim is to high light the diagnostic difficulties and management issues of congenital bladder diverticulae.


METHODS
We reviewed the case sheets of 12 patients with congenital bladder diverticulae who presented as lower tract obstruction with or without infection at a tertiary care centre in the last 10 years. All patients had urine examinations (complete microscopic with culture), serum creatinine, ultrasonography, intravenous urogram, voiding cystourethrogram with or without cystoscopy. The cases were managed by extravesical mobilization of diverticulae, diverticulectomy, and ureteric re-implantation. All patients (aged 1-36 months, mean 16.8 months) presented with retention of urine but 4 of them had symptoms of fever, tachycardia, abdominal distension and vomiting. Serum creatinine was normal in 10 out of 12 cases, but was high in two. Urine cultures grew Escherichia coli in 5 cases. Ultrasonography showed moderate to severe hydronephrosis on the left side in 5 cases, on the right side in 4 cases and bilateral in 3 cases but diverticulae could be located in only 8 cases. Intravenous urogram revealed hydrouretero-nephrosis in 9 cases, a poor functioning kidney with hydrouretero-nephrosis in 3 cases and bilateral hydrouretero-nephrosis in 3 cases. A Voiding Cystourethrogram confirmed the diagnosis in all cases. Vesicoureteric reflux (Grade 4-5) into the ipsilateral ureter was seen in 9 children of which it was bilateral in three cases.


RESULTS
All children underwent extravesical diverticulectomy with re-implantation of the ipsilateral ureter in 9 cases, bilateral in 3 cases. All had an uneventful recovery except for one who had a suprapubic leak which healed on conservative treatment. Postoperative ultrasonograms showed mild hydronephrosis in 2 cases and micturating cystourethrograms revealed a grade III V-U reflux in one case which was managed conservatively. Patients are maintaining a sterile urine culture after a follow up of 6-36 months.


CONCLUSION
Primary bladder diverticulum should be kept as a differential diagnosis in cases of bladder outlet obstruction in infants and children. A carefully done voiding cystourethrogram is the hallmark of diagnosis. Good results can be achieved by diverticulectomy and primary definitive repair with ureteric re-implantation even in infants.