Laboratory Studies
Laboratory studies that should be considered for the various pediatric bladder anomalies are as follows:
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Bladder diverticula - None
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Urachal sinus - None
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Urachal cyst - None
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Patent urachus - Analysis of the umbilical drainage for creatinine or urea to determine if the values are consistent with urine may help differentiate the patent urachus from other entities listed in the differential diagnosis
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Vesicourachal diverticulum - None
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Bladder ears - None
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Bladder agenesis - Serum electrolytes, creatinine
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Megacystis - Urine culture, serum creatinine
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Bladder duplication - Urine culture, serum creatinine
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Bladder septation - Urine culture, serum creatinine
Imaging Studies
For bladder diverticula, voiding cystourethrography (VCUG) is the best imaging modality (see the first and second images below). Bladder ultrasonography (US) may also be used to detect bladder diverticula (see the third image below), but it does not provide the same anatomic definition that VCUG does. Intravenous pyelography (IVP) may detect bladder diverticula, particularly those that protrude laterally. Anteriorly or posteriorly placed diverticula may be obscured from view because they are overshadowed by the contrast within the bladder.
Voiding cystourethrogram showing bladder diverticulum arising from posterior aspect of bladder.
Sinography is the best test for detecting a urachal sinus. Other modalities include US, computed tomography (CT), and magnetic resonance imaging (MRI). [20, 5]
US is the best test for detecting a urachal cyst (see the images below). CT or MRI can help delineate the size and location of the cyst. In addition, with infected urachal cysts, CT is used to determine the involvement of adjacent structures secondary to the inflammatory mass. [20]
Bladder anomalies. Sonogram demonstrating urachal cyst. Ultrasound cursors mark extent of cyst.
VCUG may demonstrate a patent urachus, in addition to identifying any evidence of bladder outlet obstruction or vesicoureteral reflux (VUR). It is also the most useful test for detecting a vesicourachal diverticulum.
Bladder ears can be incidentally discovered with VCUG or IVP.
For bladder agenesis, full evaluation is best performed with IVP and VCUG. These two tests delineate both upper-tract and lower-tract anatomy.
In patients with megacystis, VCUG is the best test for demonstrating the enlarged bladder and massive refluxing megaureters (see the image below). Additional studies, such as nuclear medicine renal scanning, are helpful in determining renal function. Cystography and urodynamic studies may be necessary in those children with voiding dysfunction (eg, incomplete bladder emptying, frequent cystitis, or incontinence).
Voiding cystourethrogram showing megacystis. Bilateral vesicoureteral reflux is also observed (grade 3 on right, grade 2 on left).
Full evaluation of bladder duplication is best performed with IVP and VCUG (see the images below). These two tests delineate both upper-tract and lower-tract anatomy.
Intravenous pyelogram demonstrating duplicated bladder. Note how each ureter drains into ipsilateral bladder.
In cases of bladder septation, the use of several imaging modalities, including VCUG, IVP, and bladder US, is often required for full delineation of the anatomy.
Procedures
In some instances, percutaneous drainage of an infected urachal cyst is necessary as a temporary measure. After percutaneous decompression and adequate antibiotic therapy, complete surgical excision of the urachus is necessary.
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Voiding cystourethrogram showing bladder diverticulum arising from posterior aspect of bladder.
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Voiding cystourethrogram showing two posteriorly placed bladder diverticula.
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Bladder sonogram showing two posteriorly placed bladder diverticula.
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Duplicated bladder with urethral catheter placed into each bladder.
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Voiding cystourethrogram demonstrating duplicated bladder.
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Intravenous pyelogram demonstrating duplicated bladder. Note how each ureter drains into ipsilateral bladder.
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Urachal cyst at level of umbilicus.
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Bladder anomalies. Sonogram demonstrating urachal cyst. Ultrasound cursors mark extent of cyst.
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Voiding cystourethrogram showing megacystis. Bilateral vesicoureteral reflux is also observed (grade 3 on right, grade 2 on left).
