Posterior Urethral Valves Clinical Presentation

Updated: Apr 02, 2020
  • Author: Martin David Bomalaski, MD, FAAP; Chief Editor: Marc Cendron, MD  more...
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Antenatal diagnosis

The widespread use of antenatal ultrasonography (US) has enabled diagnosis of posterior urethral valves (PUVs) in many more individuals, with most cases of bladder outlet obstruction recognized in the second and third trimester of gestation. The diagnosis is usually made before or at birth when a boy is evaluated for antenatal hydronephrosis. Despite widespread use of antenatal US, some patients with PUVs do present later in life (see below).

In 1989, Thomas reported that 10% of patients with antenatal hydronephrosis detected by US had PUVs. [11]  In a 1993 report, Dinneen et al reported the sensitivity of antenatal US to be only 45% in detecting PUVs in 45 patients who presented when younger than 6 months. [12] With improvements in technology, the sensitivity has increased over the last 10 years.

Patients who have PUVs that are not diagnosed on antenatal US and who do not present with overt urinary pathology are at risk for delayed presentation of PUVs.

Delayed presentation

Indicators of possible PUVs later in childhood include the following [13] :

PUVs manifest along a spectrum of disease severity. The clinical significance of minivalves has been debated. Some studies have indicated that the significance of minor radiographic narrowing in older boys may be differentiated by means of urodynamic studies. Those with detrusor/sphincter dyssynergy may have functional or nonanatomic obstruction, and those with detrusor/sphincter synergy may have true anatomic obstruction that benefits from surgical incision. [14]

PUVs are sometimes discovered during evaluation of abdominal mass or renal failure.

Incidental diagnosis

Hydronephrosis or proteinuria found on examination for unrelated conditions may be the first sign of PUVs.


Physical Examination

Most patients with PUV have normal findings on physical examination. When present, abnormal physical findings are the result of severe renal insufficiency.

Neonates may present with severe pulmonary distress caused by lung underdevelopment lung due to oligohydramnios. An appropriate volume of amniotic fluid (produced by the kidneys) is necessary for complete and proper branching of the bronchial tree and alveoli. Physical findings can include the following:

  • Poor fetal breathing movements
  • Small chest cavity
  • Abdominal mass ( ascites)
  • Limb deformities (skin dimpling)
  • Indentation of the knees and elbows due to compression within the uterus

In older children, physical findings can include poor growth, hypertension, and lethargy. An intermittent or weak urinary stream is an unreliable sign. A large lower abdominal mass may represent a markedly distended urinary bladder.