Urology- congenital abnormalities Flashcards
Development of kidneys
Of metanephric origin
- The ureteric bud grows out from hindgut to metanephric blastema
- The ureteric bud activates the metanephric cells to initiate further development of kidneys
- Formation of renal tubules, collecting duct and pelvis.
Abnormal meeting of the ureteric bud to the metanephric cells causes dysplastic kidneys.
Duplex kidney
- Definition
- Types
- Complications
Occurs when the ureteric bud divides into 2.
Complete duplex
- Two divisions of the ureter enter the kidney but still join into one ureter before entering the bladder.
- Usually clinically insignificant
Incomplete duplex
- The divided ureter to not meet, this meets they can open up at different ends.
- Can cause reflux if ureter opens up far away from trigone.
- Ureter can open into ectopic region: vagina, urethra, vulvar vestibule.
Unilateral absent kidney
- Description
- Prognosis
- Cause
Unilateral kidney agenesis
- Possibly due to the failure of the ureteric bud to meet the metanephic mesenchyme.
- Associated with many Mullerian duct abnormalities
Individuals with one kidney can function normally as long as the kidney is healthy.
Mayer- Rokitansky syndrome
A Mullerian duct abnormality.
Includes
- Unilateral kidney agenesis
- Vagina agenesis leading to hematoclopos
- Uterine abnormalities
- Fallopian tube abnormality
Hematoclopos
Build up of menstrual blood in the uterus.
Can be caused by vaginal atresia (Closed/ absent vagina) seen in Mayer-Rokitansky syndrome
Horseshoe kidney
Fusion of the kidneys
- Caused by the abnormal migration of the kidneys during kidney development.
Kidneys migrate upwards during development.
Diagnosing UTI in children
UTI common in children
Pyuria
- Puss in urine
- Mid-stream urine difficult to obtain in children
- Suprapubic aspiration to collect urine is more viable.
Dipstick
- Nitrites
Vesicouretral reflux (VUR)
- Description
- Mechanism
- Presentation
Retrograde flow of urine from bladder into ureter/ kidney
Mechanism
- Normally the ureter enter the bladder runs submucosally for a region before entering cavity.
- This creates a valve structure, absent in VUR
Presents with
- UTI
- Dilated kidney
- Dilated ureter
- Can be asymptomatic
- Increases risk of hypertension in later life
Grades of VUR
The higher the grade, the more dilation is present and the further up the urine has travelled.
Grades 1-3
- Usually does not required surgical intervention as many kids stop refluxing after 5
- Monitored with antibiotics and follow up
Diagnosing reflux nephropathy
DMSA scan
- Radioactive scan
Diagnoses acute pyelonephritis where there is tissue damage.
MAG3 scan
Radioisotope renogram
- Imaging for the kidneys
Helps to diagnose obstruction and dilation.
Micturating cystourethrogram
X ray that analyses bladder and urethra
- Assesses vesicouteric reflux especially in young children
Mega-ureter
Abnormally dilated ureter
- More common in males
- Not due to reflux
Associations
- Ureterocele
- Simple stenosis (rare)
Posterior urethral valve
- Description
- Treatment
Only occurs in males
- Fold of mucosa that causes obstruction in the posterior male urethra in utero.
Treatment
- Valve ablation can be done in utero
Prognosis
- Dependant on how much renal damage has been done by the obstruction
- Many individuals affected have to get transplants later in life,
Buried penis
When the penis is partially/ fully hidden below the surface of the skin
- The scrotal and foreskin fuse to hide penis
Congenital cause
- Maldevelopment of penile skin shaft.
Treatment
- Reconstructive surgery
