Presentation delivered at a paediatric clinical meeting of the Federal Medical Center, Lokoja. Nigeria
This presentation doesn't serve as a substitute for texts and/or journals.
3. Introduction 1/2
An abnormal congenital obstructing membrane that is located within the
posterior male urethra.
First described by Hugh Hampton Young in 1919
Crescentic duplication of urethral mucosa forms valves
The paper thin valves arise from the verumontanum and extend
downwards and laterally to the side-walls of the urethra at the
apex of the prostate.
4. Introduction 2/2
During early stages of embryogenesis, the most caudal end of the wolffian
duct is absorbed into the primitive cloaca at the site of the future
verumontanum in the posterior urethra
The homolog to the male verumontanum from which the valves originate
is the female hymen.
Histologic studies suggest that PUVs are formed at approximately 4 weeks’
gestation as the wolffian duct fuses with the developing cloaca
5. Classification
Type I - Valves representing folds extending inferiorly from the
verumontanum to the membranous urethra (~95% of PUVs)
Type II - Bicuspid valves as leaflets radiating from the verumontanum
proximally to the bladder neck
Type III - Valves as concentric diaphragms within the prostatic urethra,
either above or below the verumontanum (~5% of PUVs)
6. Epidemiology
In the United States, PUV is the most common cause of lower urinary tract
obstruction in male neonates; the reported incidence ranges from 1 per 8000
to 1 per 25,000 live births.
Uba et al in Jos reprted 3 – 8 cases per annum, Jaja et al in Port Harcourt
observed that it accounted for 1 in 2447 children seen in their hospital.
A study done by Talabi et al in Ile-Ife in 2015 showed an incidence of 3 cases
per annum with a median age of 5 months at presentation.
The mean age of presentation according to a study done by Orumuah in
UBTH, Benin City is approx. 4years with 56.8% presenting after the age of 1
year.
PUVs occur exclusively in males.
7. Etiology
A PUV is a congenital obstruction caused by a malformation of the
posterior urethra. The significance of this obstruction depends on the
secondary effects on the bladder, ureters, and kidneys.
A type I PUV is believed to result from abnormal insertion and absorption
of the most distal aspects of the wolffian ducts during bladder
development.
Type III PUVs are observed as a membrane in the posterior urethra
believed to originate from incomplete canalization between the anterior
and the posterior urethra.
8. Pathophysiology
Due to the urethral obstruction, there is
• Thickened bladder wall with reduced bladder compliance during filling
• Vesicoureteric reflux
• Hydronephrosis and/or hydroureter
• Progressive renal calyceal dilatation and renal damage
9. Clinical Presentation 1/3
HISTORY
Urinary tract infection (UTI)
Diurnal enuresis in boys older than 5 years
Secondary diurnal enuresis
Voiding pain or dysfunction
Abnormal urinary stream
PUVs are sometimes discovered during evaluation of abdominal mass or
renal failure.
10. Clinical Presentation 2/3
PHYSICAL EXAMS
Most patients with PUV have normal physical examination findings. 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. Findings include:
• Poor fetal breathing movements
• Small chest cavity
• Potter facies
• Indentation of the knees and elbows due to compression within the uterus
11. Clinical Presentation 3/3
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
13. Investigations 1/5
1. Abdominopelvic USS
Renal parenchyma, collecting system dilatation, bladder wall thickness, and
presence of ascites.
Because newborns commonly have relative hypovolemia during the first
few days of life, the recommendations are to perform ultrasonography
after the first week of life if findings from the first ultrasound examination
were normal in a child with previously diagnosed antenatal hydronephrosis
before making a final determination that the hydronephrosis has resolved
14.
15. Investigations 2/5
2. Voiding cystourethrography
VCUG under fluoroscopy, with imaging of the posterior urethra, especially
during the voiding phase.
The diagnosis of PUV is indicated by visualization of the valve leaflets.
Other clues to the diagnosis are a thickened trabeculated bladder, a
dilated or elongated posterior urethra, and a hypertrophied bladder neck.
Diverticula, cellules, vesicoureteral reflux, and reflux into the ejaculatory
ducts secondary to elevated bladder and urethral pressures may also be
present.
16.
17.
18.
19. Investigations 3/5
3. Renal scintigraphy
4. Urodynamic evaluation: information about bladder storage and emptying.
20.
21. Investigations 4/5
5. Cystoscopy
Diagnostic - confirmation with cystoscopy is required in every child in
whom PUV is suggested after VCUG. In some, the filling defect observed
on VCUG may represent only external sphincter contraction during
voiding; in others, the valve leaflets are confirmed.
Therapeutic - valves are disrupted under direct vision by cystoscopy using
an endoscopic loop, Bugbee electrocauterization, or laser fulguration. In
extremely small infants (<2 kg), a 2-French Fogarty catheter may be passed
either under fluoroscopic or direct vision for valve disruption.
23. Management 1/8
MEDICAL INTERVENTION
Short-term goals involve treatment of pulmonary distress, immediate relief
of urethral obstruction (placement of a 5-French feeding tube), and fluid
and electrolyte management.
In children who survive the pulmonary distress, the long-term issues
include treatment of bladder dysfunction and renal insufficiency.
24. Management 2/8
Anticholinergic medications used to improve bladder compliance:
Oxybutinin, Tolderol, Hyoscyamine sulfate
Antibiotics for UTI
Renal replacement therapy
• Peritoneal dialysis
• Renal transplant after the first year of life
25. Management 3/8
NEWBORN CARE
the first step in treatment is to relieve bladder outlet obstruction by
placing a urethral catheter.
Cystoscopic valve ablation or vesicostomy is performed when the child is
stable.
In rare cases, a urethral catheter cannot be placed, because of hypertrophy
of the bladder neck. These patients require cystoscopy under anesthesia
for catheter placement, suprapubic tube placement, or primary
vesicostomy.
26. Management 4/8
SURGICAL INTERVENTION
1. Postnatal primary valve ablation:
Ideal treatment involves transurethral incision of the PUV during the first
few days of life. Current infant resectoscopes are available in 8 French and
smaller sizes.
The valves can be incised at the 12-, 5-, and 7-o'clock positions, with either
a cold knife or an electrocautery.
Some surgeons prefer to leave a catheter in place for 2-3 days after the
procedure. The timing of the postoperative VCUG varies and ranges from
several days to several months.
27. Management 5/8
Comparison of the posterior urethral diameter with anterior urethral
diameter can provide an objective measure of valve ablation
In most patients, the posterior urethra is markedly dilated. Postincision
diameter should decrease if the incision is successful.
One third of patients require a second incision to achieve an appreciable
level of posterior urethral reduction.
28. Management 6/8
2. Vesicostomy:
When urethral size precludes safe valve ablation, a communicating channel
between the bladder and lower abdominal wall (ie, vesicostomy) can be
created to provide bladder drainage.
Vesicostomy use has decreased because most patients can be safely
drained and can undergo valve ablation.
29. Management 7/8
3. Cutaneous ureterostomies
• Loop
• End
• Y – ureterostomies
• Ring type
Complications are that of ureteral devascularization, inadequate drainage
and stomal stenosis
32. Prognosis 1/2
Over the past 30 years, the prognosis of children with PUV has steadily
improved.
In the past, most children were found to have PUV only after presenting
with urosepsis or progressive renal insufficiency.
Older series demonstrated mortality figures approaching 50% by late
adolescence.
Today, most individuals with PUV are discovered when antenatal
ultrasonography reveals hydronephrosis.
Prompt resolution of bladder obstruction, aggressive treatment of bladder
dysfunction, and improved surgical techniques have lowered the neonatal
mortality to less than 3%.
33. Prognosis 2/2
PUVs are the cause of renal insufficiency in approximately 10-15% of
children undergoing renal transplant, and approximately one third of
patients born with PUV progress to ESRD in their lifetimes. the child grows,
renal metabolic demand increases proportionately.
Failure of creatinine to nadir below 0.8 mg/dL in the first year of life is an
indication of limited renal reserve. These patients are at risk for
progression to ESRD
Improved dialysis and transplantation techniques have significantly
improved not only mortality but also quality of life for these children .
Additionally, medical and surgical management can achieve urinary
continence in nearly all patients.
34. Conclusion
Posterior urethral valve remains the commonest cause of bladder outlet
obstruction in male children.
Its management is multimodal and multidisciplinary
Ablation of the valve remains the commonest and more successful means
of surgical intervention.
Prognosis depends on the severity and timing of presentation.
35. References 1/3
Archampong E, et al. BAJA’s Principle and practice of surgery, 5th Edition.
2015
Orumah AJ, et al, African Journal of Paediatric Surgery. 2015 Jan-Mar;12(1):
18-22
Jaja T, et al. Posterior urethral valve in childhood in Port Harcourt, Nigeria.
Port Harcourt Med J. 2012;6:10-6
Uba AF, et al. Posterior urethral valves in childhood: Experience in a center
with scarce facilities. Afr J Urol. 2007;13:124-31
Talabi A, et al. Posterior urethral valves in children: pattern of presentation
and outcome of initial treatment in Ile-Ife, Nigeria. Nigeria Journal of
Surgery. 2015 Jul-Dec; 21(2): 151-156
36. References 2/3
Young HH, Fronz WA, Baldwin JC. Congenital obstruction of the posterior
urthera. J Urol. 1919. 3:289.
Dewan PA, Goh DG. Variable expression of the congenital obstructive
posterior urethral membrane. Urology. 1995 Mar. 45(3):507-9.
Heikkilä J, Holmberg C, Kyllönen L, Rintala R, Taskinen S. Long-term risk of
end stage renal disease in patients with posterior urethral valves. J Urol.
2011 Dec. 186(6):2392-6.
Horowitz M, Harel M, Combs A, Glassberg K. Surveillance cystoscopy in the
management of posterior urethral valves. J Urol. Apr 2009. 181:172.
