1. Congenital anomalies of kidney and urinary system
Dr. Alia Al-Ibrahim
Consultant Pediatric Nephrology
Clinical assistant professor

2. CONTENTS: 1- Anatomy of urinary system 2- Function of urinary system
3- Normal development
4- Congenital anomalies of urinary system:
Dysgenesis of the kidney
-Agenesis
- Hypo plastic
- Dysplastic
- A plastic
Abnormalities in shape & position
- Ectopic Kidney
- Horse shoe Kidney
- Crossed fused Ectopia
Abnormalities of collecting system
- Hydronephrosis
- Bladder extrophy
- PUV
- Patent Urachus
Clinical presentation
Antenatal screening
Postnatal Evaluation

3. Development of Urinary system:
The Urinary system goes through three phases on its way to becoming fully functioning :
1- Pronephros
2- Mesonephros
3- Metanephros
Starting from 4th wk & end on 36 wk of intra uterine life

4. Normal Anatomy of the Urinary system
4 wks gestation : kidney start development
9 wks : first glomeruli , Bladder
36 wks : nephrogenesis ceases ( 1 million glomeruli in each kidney).
Postnatal increase in the size of the kidney is due to enlargement of the Glomerular diameter & significant increase in tubular volume & length

5. Active period of nephrogenesis between 20-36wks, cease around 36 wks

8. Nephron
Nephron: Glomerulus, Bowman's capsule, convoluted tubule, loop of Henle
Formation begin at 8th wk.
Postnatal increase in the size of the kidney is due to enlargement of the Glomerular diameter & significant increase in tubular volume & length.

10. Ascent of kidneys:
A: 5th -6th wk the mature kidneys lie in the pelvis with their hila pointed anteriorly
B: 7th wk the hilum points medially , kidneys in the abdomen.
C: 9th wk kidneys in the retroperitoneal position at level of L1 , complete rotation , anteromedially.

11. Normal Function of the Urinary system:
Kidney :
1- Filters blood- remove and eliminate soluble waste ( urine).
2- Regulates blood volume and composition.
3- Maintains water and electrolyte balance.
4- Hormonal production; Erythropoietin, Renin.
5- Metabolizes vitamin D to active form.
Ureters:
convey urine from kidneys to bladder.
Urinary bladder:
Temporary urine storage.
Urethra:
Conveys urine from bladder to outside.

12. Abnormalities during development:
1- Dysgenesis of the Kidney
a- Renal Agenesis(absent Kidney) : Failure of the ureteral bud to
communicate with the
metanephric blastema
1:500 – 1: 3200 live births

13. AGENISIS
UNILATERAL
BILATERAL

14. 1- Unilateral : absent kidney, no symptoms. Avoid contact sport, other
kidney hypertrophy , check for abnormality ( 50% )
Incidence increase with single umbilical artery
absent ureter & hemitrigone. Hypertrophy, VUR in contra lateral kidney
2- Bilateral: Incompatible with extra uterine life
Oligohyddramnios , no kidneys , non visualized bladder in antenatal US
Death shortly after birth from
pulmonary Hypoplasia ( Potter’s syn)
Detected by US 12th wk of gestation
higher in boys.
5% recurrent risk in subsequent pregnancy
Associated anomalies include: Anorectal, CVS, Skeletal.

15. b- Renal Hypoplasia : Small size, non dysplastic, less than normal # of calyces &
nephron .
1- Unilateral: Incident diagnosis ( another urinary tract problem or HTN).
2- Bilateral: CRF manifestations.
3- Segmental Hypoplasia: ( Ask-Upmark Kidney).
C-Aplasia : rudimentary kidney

16. d-Renal dysplasia: Abnormality in the structure cartilages, cyst ( Abnormal metanephric differentiation) May affect all or part of the kidney.
1- Cystic
2- cartilelages
Hereditary : ARPKD
ADPKD
Congenital: MCDK

17. Multicystic dysplastic kidney (MCDK):
Non- functioning kidney replaced by large non-communicating cysts of
varying sizes, no renal cortex, atretic ureter.
Unilateral , 2 times more in male.
Detected during antenatal US.
Investigations & diagnosis:
1- US.
2- DMSA ( no function in the affected side) , hypertrophy
of contra-lateral kidney.
3- MCUG : contra-lateral VUR (20%).
Complications:
1- Malignancy: Wilm's’ tumor, adenocarcinoma& embryonic
carcinoma.
2- HTN: cured by nephrectomy.
3- Infection, bleeding into, or rupture of cysts if large.

18. Management:
Conservative:
1- cysts < 5cm , high chance of involution, or cause no problems.
2- reviewed annually for:
- BP
- urinary protein.
- US for cysts involution, of MCDK.
growth of contra-lateral kidney. Up to 2yrs of
age then at
5yrs of age if normal.
Nephrectomy:
1- no involution by 2 yrs of age.
2- HTN
3- infections

19. 11- Abnormalities in shape & position:
a- Ectopic Kidney: Failure of ascent of the kidney during
embryogenesis. Incidence 1;900
Associated anomalies: VUR, undesended testis in , hypospadius, Genital
abnormalities in girls
Blood supply from internal, external iliac artery ,& or aorta
Ectopic in contra lateral side 90% fusion

20. b- Fusion Anomalies 1- horseshoe Kidney: 1:500
-Commonest form of fusion (95%).
-The lower poles of both kidneys unit across the midline
-The isthmus of horse shoe kidney lie at the level of L4-L5, is more susceptible to trauma
-More common in male, Turner syndrome, trisomy 18
Complications:
50% VUR, abnormal vascular supply.
Stone & hydronephrosis 2° PUJO.
Wilm’s tumor
HTN
Diagnosis: DMSA, MCUG ,DTPA .
can be missed by us.

21. 2- Crossed fused Ectopia:
one kidney cross the midline to the other side and lie in an abnormal rotate
position & fused upper pole fused to the normal kidney lower pole.
ureter inserted in normal position.
anomalies of uro-gent.system

22. III-Abnormalities of the collecting system:
A- Duplex kidney :
1% , Familial, more in girls , 70% unilateral.
Two pelvicalyceal system within the kidney, complete or partial.
Kidney larger than normal.
Complete:
-Kidney has 2 moieties, each with its own ureter>
The upper pole ureter opens lowermost & medially into the bladder .
May be ectopic draining in vagina, posterior urethra.
Ureterocoele ( obstruction).
The lower pole ureter cause reflux, , PUJO, dysplastic part.
Incomplete:
-Uncomplicated divided pelvis, or 2 Ureters join before entering
the bladder.

23. Hydronephrosis:
Dilatation of renal pelvis & collecting system.
% antenatal US.
Several grading system ( Renal pelvic diameter).
Antenatal US ( WKS).
- severity of antenatal US.
- Unilateral vs. bilateral
- Renal parenchyma thin or Echogenic.
- Bladder
- Amniotic fluid
Causes:
1- Transient
2- Physiological
3- UPJO
4- VUR
5- Megaureter
6- Ureterocoele
7- PUV

24. Postnatal evaluation:
1- Physical exam: Abdominal mass, palpable bladder.
2- US
3- VCUG : detect VUR, PUV.
4- Diuretic Renogram : detect urinary obstruction with persistent
hydronephrosis

25. Ureteropelvic junction obstruction ( UPJ):
Detected antenatal, frequent cause of hydronephrosis
More common in Left side, Ectopic, malrotation, horseshoe kidney
Bilateral 40%
Present: mass, UTI, Pain, Hematuria

26. Bladder extrophy:
Failure of abdominal wall to close during fetal development & results
In protrusion of the posterior bladder wall through the lower abdominal wall.
Symphsis pubis diastasis.
Multiple abnormalities in pelvis, bladder, urethra, & external
genitalia.
- Common in males
Associated abnormalities:
1- VUR
2- Incontinence
3- Repeated UTI

27. Posterior urethral valve (PUV):Commonest obstructive
Uropathy in boys , 1:
Congenital valve in the posterior urethra due to persistent urogenital membrane.
Associated with renal dysplasia ( Back pressure,
common developmental insult).
Risk of perinatal mortality & risk of chronic kidney disease:
1- US suggestive at < 24 wks gestation.
2- Severe bilateral hydronephrosis.
3- Oligohyddramnios.
4- Echogenic kidneys.
Postnatal presentations:
1- pulmonary Hypoplasia.
2- Poor urinary stream
3- Voiding dysfunction.
4- Urosepsis.
5- FTT.

28. Renal & urological manifestation:
1- Chronic kidney diseases. 60% dysplastic kidney
2- VUR
3- Bladder dysfunction.
Management:
1- correction of electrolytes.
2- Treatment of sepsis.
3- Resp.distress
4- Temporary relieve of pressure
5- cystoscopy : valve ablation
6- Vesicostomy

29. Prune belly syndrome ( Eagle-Barrett syndrome, Triad syndrome)
Triad of:
1- Deficiency or absence of anterior abdominal wall musculature.
2- Bilateral cryptorchidism
3- Ureter ,bladder,& urethral abnormalities( megacystis, Megaureter 2°
dysplasia.
Other systemic abnormalities in 75%:
1- GI : malrotation, gastroschisis.
2- Heart: CHD
3- Skeletal: talipes equinovarus, CDH.
4- Pulmonary hypoplasia

30. Clinical presentation :
Wide spectrum
1- Antenatal screening %.
2- UTI
3- Hypertension
4- Proteinuria
5- Renal impairment
6- Hematuria
7- Stones
Antenatal Screening US
1- Fetal kidney
2- Collecting system
3- Amniotic fluid
Postnatal Exam:
Physical exam: Associated anomalies
Urgent evaluation : Bilateral involvement, solitary affected kidney,
oligohyddramnios.
Renal studies: Renal US, VCUG, MAG3

31. Take home messages:
1- Congenital anomalies of the kidney are significant causes of ESRF in
children.
2- These anomalies often do not exist in isolation.
3- May present beyond the neonatal period.
4- Bilateral involvement. Oligohyddramnios, solitary kidney require urgent
evaluation.
5- Long –term follow-up of renal & bladder function is important.

32. THANKS ?