This document discusses posterior urethral valves (PUV), including their etiology, classification, pathophysiology, clinical presentation, diagnosis, and management. PUV are congenital obstructions of the posterior urethra that commonly cause urinary outflow obstruction in boys. Type I valves are the most common. Initial management involves bladder drainage and antibiotics. Surgical valve ablation is usually curative, but long-term sequelae like renal disease are significant due to the primitive tissue injury caused by the obstruction.

1. Etiopathogenesis, evaluation &
Mx of PUV
Dr. Shubham Lavania
20/05/2016

2. Introduction
• A congenital obstruction of the posterior
urethra ascribed to valvelike leaflets
– 1769 by Morgagni
– Langenbeck in 1802
– Hugh Hampton Young coined “posterior urethral
valve”(1919)
– Randall carried out the first endoscopic resection
of valves in 1920

3. Incidence
• The most common structural cause of urinary
outflow obstruction in pediatric practice
• The most common type of obstructive uropathy
leading to childhood renal failure
• 1 of every 5000 to 8000 male births
• 10% of prenatally diagnosed hydronephrosis
• 1 PUV in 1250 fetal ultrasound

4. CLASSIFICATION
• Young classification 1919

5. PUV Defined
• Type I
– Obstructing membrane that extends distally from each
side of the verumontanum towards the membranous
urethra where they fuse anteriorly
• Type II
– Described as folds extending cephalad from the
verumontanum to the bladder neck
• Type III
– Represent a diaphragm or ring-like membrane with a
central aperture just distal to the verumontanum
– Thought to represent incomplete dissolution of the
urogenital membrane

6. 95% 5%
more serious

7. Type 1 PUV
• Develop when the mesonephric ducts
enter the cloaca more anteriorly than
normal.

8. Type 3 PUV
• Incomplete dissolution of the
urogenital membrane

9. Pathophysiology
Primitive tissues mature in an abnormal
environment of high intraluminal pressures
and organ distention
• UNIVERSAL INJURY
IN THE URINARY
TRACT

11. Renal Dysplasia
• Defined as a congenital defect of tissue
development without premalignant potential
• Histological diagnosis
• Cause ?
1- high pelvic pressure during
nephrogenesis
2- primary embryologic abnormality
from abnormal position of uteteric bud

12. Renal Function
• Children with PUV may demonstrate gradual
loss of renal function over time
• Cause:
1- Renal parenchymal dysplasia
2- Incomplete relief of obstruction
3-parenchymal injury from :
* UTI
*HTN
*Progressive glomerulosclerosis
from hyperfiltration
* Obstruction

13. • ESRD
-Occurs in 25% - 40%
-1/3 soon after birth
-2/3 during late teenager

14. Renal Tubular Function
• 50% of patients with PUV have impairment
concentration ability
•  Persistently high urinary flow rate
regardless of fluid intake or state of
hydration
•  severe dehydration and electrolyte
imbalance
•  ureteral dilatation and high resting vesical
pressure

15. Hydronephrosis
• Significant urethral obstruction  variable
degree of ureteral dilatation
• After relief of obstruction : gradual but
substantial reduction of hydronephrosis
• If not reduced we have to role out:
1- High intravesical pressure
2- ureteral muscle weakness
3- UVJ obstruction

16. Vesicoureteral Reflux
• Present in 33 - 50%
• Usually Secondary
– High intravesical pressures
• 33% resolve spontaneously when obstruction
treated
• 33% do well on prophylactic antibiotics

17. BLADDER DYSFUNCTION
• Commonly presented in patient with PUV
• Usually primary, secondary to irreversible
change in organization and function of the
smooth muscle from outlet obstruction
• Present as urinary incontinence (20%)
• Bladder dysfunction persist in 75 % after valve
ablation

18. • May cause deterioration of renal function
• Three groups of dysfunction were described
- Detrusor –hyperreflexia (29%)
- Hypertonic and poor compliant bladder
(31%)
- Myogenic failure and overflow
incontinence (40%)

19. Valve Bladder Syndrome
• The term valve bladder syndrome was coined
by Mitchell in 1982

20. • Factors responsible for devolution of a bladder
into a valve bladder
(1) polyuria.
(2) poor bladder compliance with high-pressure
voiding and elevated wall tension bladder, and
(3) residual urine volume.

21. Clinical Presentation
• Varies by degree of obstruction
– Symptoms vary by age of presentation
• Antenatal
– Bilateral hydronephrosis
– Distended and thickened bladder
– Dilated prostatic urethra
– Oligohydramnios - accounts for co-presentation of
pulmonary hypoplasia.

22. Clinical Presentation
• Newborn
– Palpable abdominal mass
• Distended bladder, hydronephrotic kidney
• Bladder may feel like a small walnut in the suprapubic area
– Ascites
• 40% of time due to obstructive uropathy
– History of Oligohydramnios
– Respiratory distress from pulmonary hypoplasia
• Severity often does not correlate with degree obstruction
• Primary cause of death in newborns

23. Clinical Presentation
• Early Infancy
– Dribbling / poor urinary stream
– Urosepsis
– Dehydration
– Electrolyte abnormalities
– Uremia
– Failure to thrive; due to renal insufficiency
• Toddlers
– Better renal function (less obstruction)
– Febrile UTI
– Voiding dysfunction – incontinence
– Daytime incontinence may be the only symptom in boys with
less severe obstruction

24. Diagnosis
Ultrasonography
• 1 in 1250 ultrasound screenings
• pathognomonic u/s findings:
– thickened, dilated bladder along with bilateral
hydroureter and pelvocaliectasis
– Oligohydramnios
– dilated posterior urethra

25. Antenatal U/S

27. Voiding Cystourethrography
• Gold standard for diagnosing PUV
• Typically showed :

28. • VUR in 50% of patients with PUV
• Normal MCUG exclude PUV

29. Functional assessment
• Radionuclide Renal Scan
– quantification of differential renal function, and
cortical deficits
– DTPA OR MAG-3
– with urethral catheter in place
Exclude obstruction and assess split renal
function

30. • Serum Creatinine
– After 48 hours the infant's baseline laboratory
values may be monitored.
– nadir creatinine value at 1 year of age is
considered an important diagnostic tool

31. Initial Management
• Bladder Drainage
– A 5 or 8 Fr pediatric feeding tube is ideal
– A Foley catheter should not be used, due to the tendency
of the balloon to occlude the ureteral orifice and cause a
bladder spasm.
• Secondary obstruction
– Broad spectrum antibiotic coverage
– Metabolic panel
• Assess renal function and metabolic abnormalities
• Acidosis, hyperkalemia common problems

32. Surgical Intervention
• Valve ablation
• Vesicostomy
• Upper tract diversion
• Circumcision
• Nephroureterectomy

33. • Transurethral Valve Ablation
– Incise at 5, 7 & 12 o’clock positions via Pediatric
resectoscope
• Avoid urethral sphincter
• Catheter drainage for 1-2 days
• VCUG at 2 months to ensure destruction of valves
• Regular U/S to evaluate resolution of hydronephrosis

34. • Transurethral Valve Ablation
– Alternatively, 8F cystoscope with a Bugbee
electrode adjacent
– Insulated crochet hook (“Whitaker hook”)
• When urethra too small to accommodate
cystoscope/Bugbee

35. Antegrade valve ablation
• Zaontz and Firlit
• advantage of avoidance
of instrumentation to
the small male distal
urethra

36. Vesicostomy
• reserved for
– the very lowbirth-weight infant
– continued impaired renal function,
– high bladder urine volumes,
– and upper tract deterioration after valve ablation
or urethral catheterization.

40. •key operative step in creation of the vesicostomy is to
ensure that the posterior wall of the bladder is taut
•accomplished by bringing the dome of the bladder to the
skin

41. Upper tract diversion

43. Circumcision
• Risk of UTI in children with PUV is 50% to
60%
• UTI can quickly progress to pyelonephritis and
sepsis
• Circumcision reduces that risk of UTI by 83%
to 92%,
• Strongly recommended as a prophylactic
measure for any boy diagnosed with posterior
urethral valves

44. Antenatal m/m
• Intervention when antenatal sonography detects
evidence of
– oligohydramnios,
– a dilated bladder, and
– severe hydroureteronephrosis—without renal cortical
cystic lesions—in a fetus with a normal karyotype
• Vesicoamniotic shunting to treat
oligohydramnios offers potential ameliorative
effects on pulmonary function

45. PROGNOSTIC FACTOR
• Good Factors
• Nadir creatinine < 0.8 mg/dl
• S. creatinine < 1 mg/dl
• Pop-off mechanism
• - massive unilateral reflux
• -Urinary Ascitis (urinoma)
• - Large bladder diverticulum

49. Bad Factors
• Age
• Delayed correction
• GFR < 50 % of normal in infancy
• VUR
- Bil -----> 57 % mortality
- Uni. -----> 17 %
- Non -----> 9 %
• Loss of cortico medullary junction
• delayed incontinence beyond 5 years

50. Transplantation in PUV Patients
• The prevalence of end-stage renal disease in
PUV- up to 50%
• Obstructive uropathy as the second most
common cause for transplantation
• Mixed outcome after transplantation
• Transplantation into a valve-affected bladder may
carry a higher risk of ureteral obstruction
• However, there is no increased risk of graft loss
compared to controls

51. Quality of Life with PUV
• have lifetime repercussions
• long-term risk factors
– valve bladder
– erectile dysfunction and infertility
– Risk of urinary tract infections
– associated comorbidities of renal transplantation
• counseling, preparing, and treating valve
patients as they reach adulthood

52. Conclusions:
Posterior Urethral Valves
• Two PUV types, Type I the most common, Type III
with a worse prognosis
• Prognosis improved with improved symptoms
within 1 month of therapy or the presence of a
“Pop-off” valve
• Drainage, antibiotics and correction of metabolic
disturbances key to initial care
• VCUG, U/S and renal nuclear scan to evaluate
• Majority managed by valve ablation
• Long-term sequelae significant, primarily renal
disease