182. Save Your Kidneys
Posterior Urethral Valves
Posterior urethral valve (PUV) is a congenital abnormality of the urethra
which occurs in boys. It is the most common cause of obstruction of
the lower urinary tract in boys.
Basic problem and its importance: Folds of tissue within the urethra
lead to incomplete or intermittent blockage to the normal flow of urine
in PUV. A blockage to the urine flow through the urethra causes back
pressure on the urinary bladder. The size of the bladder increases
considerably and its muscle wall becomes very thick.
A very large urinary bladder with elevated bladder pressure leads to an increase in pressure which is felt by the ureters and kidney. This results
in dilatation (widening) of the ureters and the pelvocalyceal (drainage)
system of the kidneys. Such dilatation, if not diagnosed and treated
timely, can lead to chronic kidney disease (CKD) in the long term.
About 25% to 30% children born with PUV are likely to suffer from
end stage kidney disease (ESKD). PUV is therefore a significant cause
of morbidity and mortality in infants and children.
PUV causes obstruction of the lower urinary tract
in boys leading to CKD if not treated in time.
CHP. 23. Urinary Tract Infection in Children 183.
Symptoms:
Common symptoms of posterior urethral valves are weak
urine stream, dribbling of urine, difficulty or straining to when voiding ,
bedwetting, fullness of the lower part of the abdomen (supra pubic
region) due to a palpable urinary bladder and urinary tract infection.
Diagnosis: Ultrasound before birth (antenatal) or after birth in a male
child provides the first clue for the diagnosis of PUV. Confirmation of
the diagnosis of PUV requires the VCUG test that is carried out in the
immediate postnatal period.
Treatment:
Surgeons (urologists) and kidney specialists (nephrologists)
jointly treat PUV. The first treatment for immediate improvement is to
insert a tube into the urinary bladder (usually through the urethra and
occasionally directly through the abdominal wall - suprapubic catheter)
to drain urine continuously. Simultaneous supportive measures such as
treatment of infection, anemia and kidney failure; and correction of
malnutrition, fluid and electrolyte abnormalities help in the improvement
of the general condition.
Definitive treatment of PUV is surgical removal of the valve with the
use of an endoscope. All children need regular lifelong follow up with a
nephrologist subsequently because of the risk of UTI, problems of
growth, electrolyte abnormalities, anemia, high blood pressure and
chronic kidney disease.
Send urine for CS before initiating therapy to identify
causative bacteria & select appropriate antibiotics.