S
Lawther
AHB Fyfe. Royal
Hospital for Sick Children, Yorkhill, Glashow
A Powls. Dept of Neonatology, Princess Royal Maternity Hospital, Glasgow
SMJ 2008 53(2): 66
Abstract
Bladder extrophy is an uncommon anomaly. We report a male variant presenting with a low set umbilicus and hypoplastic hemiscrotum. Further imaging reveals divergent recti, widened pubic symphysis and renal ectopia. We discuss our investigation and management and review the literature on the topic.
Case Report
A 3kg boy was born at 39 weeks gestation by elective caesarean for breech presentation. Mother is a well 30 year old with no significant medical history. Post-natal examination revealed an abnormally inferior umbilicus and left hypoplastic scrotum with the left testicle palpable in the inguinal canal, (Figure 1). The penile shaft appeared normal, and his anus was patent. A good urinary stream was observed. The infant was feeding and stooling as normal.
Figure 1
Renal USS revealed right sided cross-fused ectopia and an absent left kidney. There was widening of the rectus muscles distally and diastasis of the symphysis pubis. This was felt to be a variant of bladder extrophy without the abdominal wall defect normally seen in this condition. An abdominal x ray confirmed widening of the pubis symphysis and deviation of the coccyx to the left, (Figure 2).
Figure 2
At out patient review at one month of age he was found to have a large, reducible left inguinal hernia and surgical review was expedited. Pre-operative echo showed a small patent foramen ovale. He underwent semi-elective hernia repair and orchidopexy.
Out-patient micturating cysto-urethrogram, showed left sided Grade III reflux with calyseal clubbing on the right consistent with crossed fused ectopia. He was commenced on prophylactic trimethoprim and remains under out-patient follow-up.
Discussion
The extrophy-epispadias complex is a spectrum of congenital abnormalities ranging from epispadias to cloacal extrophy. Variants exist within the spectrum. These variants are thought to arise from the same embryological defect. Classic bladder extrophy comprises abnormalities of the lower urinary tract, external genitalia and musculoskeletal system. The underlying cause is thought to be multifactorial, however, its aetiology remains unknown.
Separation of the cloaca into the urogenital sinus occurs during the first trimester with development of the anterior abdominal wall. An unknown embryological insult causes failure of the cloaca to advance as normal towards the midline resulting in lateralisation of the abdominal wall structures. The cloacal membrane is unstable and may rupture at any time to a variable extent resulting in bladder extrophy or a variant of it[1]. Some studies suggest the pelvic ring defect is the most commonly shared anomaly linking the variants and it is this anomaly that initiates the development of the visceral features[2]. There is a higher incidence of associated congenital malformations with extrophy variants than with classical extrophy[3]. This raises questions whether variants should be classified within the extrophy complex. In depth investigation of variant cases may elucidate shared or unique aetiology of bladder extrophy and variants.
The initial presentation of extrophy variants can be confusing, often delaying diagnosis and treatment. Extrophy variants retain the stigmata of classical extrophy: low set umbilicus, divergent recti, widened pubic symphysis. The urinary tract is involved to varying degrees. Unlike classic extrophy, the sex incidence in the variant population is almost equal [4]. Abdominal wall hernia and abnormalities of the external genitalia are common, approximately 70% of extrophy patients develop inguinal hernia [5]
The long term outcome of extrophy variants remains unclear. Little data exists on the long term voiding and sexual outcome in adulthood in variant patients. More severe variants are likely faced with the same long-term problems as the classic presentation.
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