Presentation on theme: "Congenital anomalies of kidney and urinary system"— Presentation transcript:
1 Congenital anomalies of kidney and urinary system Dr. Alia Al-IbrahimConsultant Pediatric NephrologyClinical assistant professor
2 CONTENTS: 1- Anatomy of urinary system 2- Function of urinary system 3- Normal development4- Congenital anomalies of urinary system:Dysgenesis of the kidney-Agenesis- Hypo plastic- Dysplastic- A plasticAbnormalities in shape & position- Ectopic Kidney- Horse shoe Kidney- Crossed fused EctopiaAbnormalities of collecting system- Hydronephrosis- Bladder extrophy- PUV- Patent UrachusClinical presentationAntenatal screeningPostnatal Evaluation
3 Development of Urinary system: The Urinary system goes through three phases on its way to becoming fully functioning :1- Pronephros2- Mesonephros3- MetanephrosStarting from 4th wk & end on 36 wk of intra uterine life
4 Normal Anatomy of the Urinary system 4 wks gestation : kidney start development9 wks : first glomeruli , Bladder36 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 NephronNephron: Glomerulus, Bowman's capsule, convoluted tubule, loop of HenleFormation 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 anteriorlyB: 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 Kidneya- Renal Agenesis(absent Kidney) : Failure of the ureteral bud tocommunicate with themetanephric blastema1:500 – 1: 3200 live births
14 1- Unilateral : absent kidney, no symptoms. Avoid contact sport, other kidney hypertrophy , check for abnormality ( 50% )Incidence increase with single umbilical arteryabsent ureter & hemitrigone. Hypertrophy, VUR in contra lateral kidney2- Bilateral: Incompatible with extra uterine lifeOligohyddramnios , no kidneys , non visualized bladder in antenatal USDeath shortly after birth frompulmonary Hypoplasia ( Potter’s syn)Detected by US 12th wk of gestationhigher in boys.5% recurrent risk in subsequent pregnancyAssociated 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- Cystic2- cartilelagesHereditary : ARPKDADPKDCongenital: MCDK
17 Multicystic dysplastic kidney (MCDK): Non- functioning kidney replaced by large non-communicating cysts ofvarying 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) , hypertrophyof contra-lateral kidney.3- MCUG : contra-lateral VUR (20%).Complications:1- Malignancy: Wilm's’ tumor, adenocarcinoma& embryoniccarcinoma.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 ofage then at5yrs of age if normal.Nephrectomy:1- no involution by 2 yrs of age.2- HTN3- infections
19 11- Abnormalities in shape & position: a- Ectopic Kidney: Failure of ascent of the kidney duringembryogenesis. Incidence 1;900Associated anomalies: VUR, undesended testis in , hypospadius, Genitalabnormalities in girlsBlood supply from internal, external iliac artery ,& or aortaEctopic 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 18Complications:50% VUR, abnormal vascular supply.Stone & hydronephrosis 2° PUJO.Wilm’s tumorHTNDiagnosis: 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 rotateposition & 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 enteringthe 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 fluidCauses:1- Transient2- Physiological3- UPJO4- VUR5- Megaureter6- Ureterocoele7- PUV
25 Ureteropelvic junction obstruction ( UPJ): Detected antenatal, frequent cause of hydronephrosisMore common in Left side, Ectopic, malrotation, horseshoe kidneyBilateral 40%Present: mass, UTI, Pain, Hematuria
26 Bladder extrophy:Failure of abdominal wall to close during fetal development & resultsIn protrusion of the posterior bladder wall through the lower abdominal wall.Symphsis pubis diastasis.Multiple abnormalities in pelvis, bladder, urethra, & externalgenitalia.- Common in malesAssociated abnormalities:1- VUR2- Incontinence3- 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 stream3- Voiding dysfunction.4- Urosepsis.5- FTT.
31 Take home messages:1- Congenital anomalies of the kidney are significant causes of ESRF inchildren.2- These anomalies often do not exist in isolation.3- May present beyond the neonatal period.4- Bilateral involvement. Oligohyddramnios, solitary kidney require urgentevaluation.5- Long –term follow-up of renal & bladder function is important.