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17410

Persistent Flank Pain and Voiding Dysfunction: A Case of Missed Anterior Urethral Valves

Saturday, October 20, 2012
Grand Oaks Mansion (Mardi Gras World)
Janae Preece, MD, Division of Urology, University of Maryland Medical Center, Baltimore, MD, Kristina D. Suson, MD, Division of Pediatric Urology, The Johns Hopkins Hospital, Baltimore, MD and Ming-Hsien Wang, MD, Urology, Division of Pediatric Urology, Johns Hopkins School of Medicine, Baltimore, MD

Case Report: An eleven year old boy presented with a long history of left flank pain and enuresis and a new finding of left renal atrophy.  The patient's left flank pain began at age three during potty training.  At age four, he underwent CT scan and ultrasound, revealing a thickened bladder and a smaller left kidney (7.1 cm left, 8.0 cm right). Urine studies were normal.  Pediatric urology at an outside institution thought the pain was musculoskeletal. 

The patient began experiencing penile pain concomitant to the flank pain and he was reevaluated after a particularly severe episode at age ten. Repeat ultrasound showed a lack of left renal growth (7.1 cm left, 10.9 cm right). A MAG-3 revealed no obstruction but noted a minimally functioning left kidney (13%).  Our pediatric urology team was subsequently consulted and obtained a VCUG (Figure 1).  This was abnormal only for a bladder capacity of 500 mL, and the patient required two attempts to void to completion. 

Due to the patient's difficulty voiding and poor left renal function, cystoscopy was performed. A membranous structure in the anterior urethra was noted and resected endoscopically (Figures 2 A-D).  A Foley catheter was left in place for 24 hours. Post operatively, the patient has improved bladder emptying and is free of flank and penile pain. He continues to have occasional nocturnal enuresis.

Discussion: Anterior urethral valves (AUV) are a lesser known cause of urinary obstruction, being ten times less frequent than posterior urethral valves (PUV).  They can occur at any portion of the urethra and are often associated with urethral diverticula.  Milder cases may present at an older age with a multitude of urologic complaints including urinary tract infection, penile swelling, enuresis, and post void dribbling.  Severe cases present with urinary retention, hydronephrosis, vesicoureteral reflux, and even bladder rupture.  As with PUV, urinary obstruction from AUV may lead to bladder dysfunction and even upper tract damage. Our patient developed permanent renal injury due to his AUV.  Given the possibility of serious sequelae, AUV are an important diagnosis to consider in children with common urologic complaints such as urinary dribbling, difficulty voiding, weak stream, urinary tract infections, and enuresis. Endoscopic valve ablation has been shown to improve bladder function and symptoms in those with AUV. Urologic consultation is therefore warranted in patients who fail conservative management such as bladder and bowel management, behavioral therapy, and medication in order to rule out this disease.

Kajbafzadeh, AM, Payabvash S, Karimian G. Urodynamic changes in patients with anterior urethral valves: Before and after endoscopic valve ablation. Journal of Pediatric Urology  2007 3:295-300.

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