Urogenital disorders Flashcards
What is renal agenesis?
- Failure to develop one or both kidneys
- Unilateral renal agenesis affects 1/750 live births worldwide
- Bilateral renal agenesis affects 1.5/10,000 foetuses and many do not survive to birth
What are the clinical features of renal agenesis?
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Bilateral: no urine is produced in the womb so there is an abnormally low amount of amniotic fluid = oligohydramnios
- Consequently lung hypoplasia occurs and babies are born with the oligohydramnios sequence/ Potter’s sequence
- Potter’s sequence = a consequence of any pathology causing severe oligohydramnios. Clubbed feet, cranial abnormalities and pulmonary hypoplasia. Because the foetus does not have the protection of amniotic fluid it is compressed, amniotic fluid is also essential for lung development in the foetus because it allows for airway expansion and provides the amino acid proline which is needed for lung development
- Unilateral renal agenesis is usually asymptomatic
How is renal agenesis managed?
- Bilateral - very poor prognosis, increased risk of intrauterine death and babies that are born usually die after birth due to respiratory insufficiency
- Unilateral - no management required
Multi-cystic dysplastic kidney
Non functioning kidney full of cysts
- Usually unilateral
- Occurs in 1 in 2500
- Not hereditary but cause is unclear
Clinical features of multi-cystic dysplastic kidney
- Usually detected antenatally via USS
- Abdominal mass may be felt in the neonate
- Usually no other symptoms
How is multi-cystic dysplastic kidney managed?
- Mainly monitoring of the healthy kidney using USS
- Abnormal kidney usually shrinks by the age of 10 but if it doesn’t there is a risk of malignancy so some patients choose to have the kidney removed
- Prognosis is good but the normal kidney is at risk of vesicoureteric reflux (flow of urine back into kidney) and requires monitoring because health of the remaining kidney is essential
- Bilateral multi-cystic dysplastic kidney is not compatible with life
What is duplex kidney?
Anatomical variation where the pelvicalyceal and ureteric systems are doubled
Affects 1 in 750
What are the clinical features of a duplex kidney?
- Many are asymptomatic
- Can cause recurrent UTI because the duplicated ureter is prone to hydronephrosis and reflux.
- Condition is identified on USS
Management of duplex kidney
- If asymptomatic - no management is needed
- If recurrent UTIs monitoring and prophylactic antibiotics
What is hydronephrosis?
Dilation of the renal collecting system due to a blockage - the site of the blockage determines whether it is unilateral or bilateral hydronephrosis
Clinical features of hydronephrosis
- Usually asymptomatic
- Identified on antenatal USS
- Cause of the dilation is determined by either micturating cystourethrography for urinary reflux or a radio-isotope scan for ureteric blockage
Management of hydronephrosis
- Depends on the cause and the damage
- Obstruction rarely requires intervention as the narrowing tends to resolve as children grow
What are posterior urethral valves?
Congenital abnormality in which a membrane develops in the posterior neck of the urethra in the prostatic region - this obstructs urine flow from the bladder
- Most common cause of bladder obstruction in male babies - affects 1/8000 live births
- Females are not affected
- Cause not known - it is thought that development of the male urethra is disrupted during weeks 9-14 as the Wolffian duct integrates abnormally
Section of urethra affected is that nearest to the bladder
- Referred to a congenital obstructive condition
Clinical features of posterior urethral valves
- Obstruction of the flow of urine results in:
- Dribbling of urine and poor urine stream
- Enlarged bladder with a thickened wall causing the wall to become less compliant
- Bilateral hydronephrosis as the urine has nowhere to go but backwards
- Recurrent UTI due to urine stagnation
- If the obstruction is severe it can cause oligohydramnios and Potter’s sequence
If baby boys are found to have bilateral hydronephrosis this raises suspicion of posterior urethral valves
How are is posterior urethral valves diagnosed?
- USS, micturating cystourethrography and cystoscopy
Management of posterior urethral valves
- Catheter inserted to allow urine to drain and then the valve is surgically ablated
What is vesicoureteric reflux?
The backwards flow of urine resulting in dilation of the renal tract
- Affects 1/100 with girls more commonly affected than boys
- Frequently familial
- Occurs due to anatomical abnormalities at the vesicoureteric junction or secondary to conditions leading to bladder obstruction e.g. posterior urethral valves
- Can be unilateral or bilateral
Clinical features of vesicoureteric reflux
- Either detected following investigations for hydronephrosis or following a UTI in an infant or toddler
- Reflux causes recurrent UTIs or pyelonephritis because the urine stagnates
- Recurrent infections can cause scarring of the kidney
Diagnosis of vesicoureteric reflux
- Suspected if hydronephrosis is seen or recurrent UTIs occur with unusual organisms
- Diagnosis confirmed using micturating cystourethrography in which contrast inserted in the bladder is shown to travel up the ureters into the kidneys
Management of vesicoureteric reflux
- Depends on severity
- Prophylactic antibiotics to prevent infection in a bid to reduce damage to the kidneys
- Most children grow out of it
- If the problem persists surgery may be required to prevent serious scarring to the kidneys
What is hypospadias?
Congenital condition in which the opening of the urethra is not in its usual position at the tip of the penis
- Occurs due to abnormal fusion of the urethral folds
- 1/300 males are affected so it is fairly common
- Openings occur along the ventral/ underside of the penis
- 80% are mild with the opening still being located in the glans of the penis
- Moderate hypospadias occur when the opening is in the shaft of the penis
- In severe cases the opening is in the scrotum or perineum
- There may be an associated downward curvature of the penis
- Surgical correction is often required - the foreskin is often needed for surgery so babies with this condition should not be circumcised
What is the most common UTI-causing organism?
E.coli
Clinical features of UTIs in children
- Depend on the age of the child and which part of the tract is affected
- Babies: symptoms are non-specific so a UTI has to be actively excluded in any baby who is unwell or has a fever
- Verbal children >4yrs: dysuria, frequency, loin/ abdo pain, incontinence fever, vomiting
Diagnosing a UTI in a child
- Ideally a clean catch urine sample will be obtained but this is rather tricky
- Children over the age of 3 - diagnostic test is urine dipstick showing nitrates and leucocyte esterase
- If UTIs are recurrent a culture sample is also sent to ensure effective antibiotics are being used
- In babies and children <3yrs urinalysis results are unreliable so diagnosis depends on microscopy and culture
Management of UTI in children
- infants less than 3 months old should be referred immediately to a paediatrician
- IV antibiotics for any child who is systemically unwell or if they are <3 months
- All other children are treated with a course of oral antibiotics e.g. trimethoprim or co-amoxiclav with the treatment duration depending on the location of the infection (upper = 7-10 days, lower = 3 days)
- For recurrent UTIs look at the previous culture results to guide antibiotic therapy
Epidemiology of UTIs in children
Urinary tract infections (UTI) are more common in boys until 3 months of age (due to more congenital abnormalities) after which the incidence is substantially higher in girls. At least 8% of girls and 2% of boys will have a UTI in childhood
What is noctural enuresis?
Bed wetting - involuntary voiding of urine while sleeping
Primary vs secondary enuresis
Primary nocturnal enuresis: child has never been consistently dry for a period of 6 months
Secondary nocturnal enuresis: child has previously been dry for at least 6 months
Epidemiology of enuresis
- Common
- 2.6% of 7 year olds wet the bed on 2 or more nights per week
- Boys affected more than girls