Congenital Anomalies of Kidney PDF

Congenital Anomalies of Kidney Dr. Kenan ÖZTORUN, MD, FEBU Üroloji AD 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...

Congenital Anomalies of Kidney Dr. Kenan ÖZTORUN, MD, FEBU Üroloji AD 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 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 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  AGENISIS UNILATERAL BILATERAL 1- Unilateral : absent kidney, no symptoms. Avoid contact sport to protect the contralateral kidney, other kidney will be hypertrophied due to increase workload. Hypertrophy, VUR in contra lateral kidney, because in 50% of the cases, there may be other urinary anomalies specially VUR. Sometimes unilateral agenesis might be asymptomatic and discovered incidentally with UTI or hypertension, but can lose the kidney when exposed to harsh trauma. 2- Bilateral: Incompatible with extra uterine life. Oligohydramnios , no kidneys , non visualized bladder in antenatal US Death shortly after birth from pulmonary Hypoplasia ( Potter’s syndrome: pulmonary hypoplasia due to lack of amniotic fluid, they come with flat compressed face, flat nasal bridge, receding chin, wide philtrum, and low- set ears) Any renal congenital abnormality is detected by US 12th wk of gestation. higher in boys except duplex syndrome. 5% recurrent risk in subsequent pregnancy In oligohydramnios think of bilateral renal agenesis, and associated anomalies include: Anorectal, CVS, Skeleta B- Renal Hypoplasia : Small size, non dysplastic, less than normal # of calyces & nephrons. Everything is the same, but smaller size and less # of glomeruli. 1- Unilateral: Incident diagnosis ( another urinary tract problem or HTN). 2- Bilateral: CRF manifestations. It’s compatible with life. 3- Segmental Hypoplasia: ( Ask-Upmark Kidney: kidney with partially developed or atrophic renal cortex.). C- Aplasia: rudimentary kidney  D- Renal dysplasia: Abnormality in the structure cartilages, cyst ( Abnormal metanephric differentiation) May affect all or part of the kidney. 1- Cystic 2- Cartilages Hereditary (polycystic is always bilateral): ARPKD bilateral in children. ADPKD mainly occurs in adults, but can occur in children Congenital: MCDK its always unilateral because if bilateral it’s incompatible with life. The kidney is larger than normal. Multicystic dysplastic kidney (MCDK): - Non- functioning kidney replaced by large non-communicating (because of septae between the cysts) cysts of varying sizes, no renal cortex, atretic ureter. Most common large mass in the abdomen. - Unilateral , 2 times more in male. - Detected during antenatal US. - Can be detected incidentally by UTI. Investigations & diagnosis: 1- US. Can differentiate between it and hydronephrosis. 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. Retention. Management: Conservative: 1- cysts < 5cm , high chance of involution, which means the kidney is shrinking, or cause no problems. If > 5cm, it most likely will not involute so follow up the patients for any complication, and if they develop complications do a nephrectomy. Nephrectomy: 1- no involution by 2 yrs of age. Some do nephrectomy at the age of 5 because they fear malignancy or any complications.. 2- HTN 3- recurrent infections. 11- Abnormalities in shape & position: a- Ectopic Kidney: Failure of ascent of the kidney during embryogenesis. Incidence 1;900. most commonly in pelvis. It can also be thoracic (very rare), iliac or crossed. Associated anomalies: VUR, undesended testis in, hypospadias, Genital abnormalities in girls Ectopic in contra lateral side 90% fusion b- Fusion Anomalies 1- Horseshoe Kidney: - 1:500, Commonest form of fusion (95%). -The lower poles of both kidneys unite across the midline -The isthmus of horse shoe kidney lie at the level of L4-L5, is more susceptible to trauma (avoid severe aggressive sports) -More common in male, Turner syndrome (always look for horseshoe kidney), trisomy 18 Complications: - 50% VUR, abnormal vascular supply. - Stone (ureter is no longer positioned anterolaterally, and kidney causes pressure on it, leading to hydronephrosis 2° PUJO. - Wilm’s tumor - HTN due to vascular abnormality. 2- Crossed fused Ectopia: - one kidney cross the midline to the other side and lie in an abnormal rotation - position & fused upper pole fused to the normal kidney’s lower pole. - ureters inserted in normal position. - anomalies of urogenital system 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. - Diagnosed by IVP or CT Urography Incomplete: -Uncomplicated divided pelvis, or 2 Ureters join before entering the bladder.  A- Duplex kidney : Complete: 2 ureters draining to the bladder -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). - If the duplex anomaly affected the upper calcyeal system it will open to the lower pole of the bladder causing ureterocele, if it affected the lower calyceal system it will open to the upper pole of the bladder causing VUR. - The lower pole ureter cause reflux, , PUJO, dysplastic part.  A- Duplex kidney : Incomplete: Uncomplicated divided pelvis, or 2 Ureters join before entering the bladder. Hydronephrosis: Dilatation of renal pelvis & collecting system. - 0.6- 4.5% antenatal US, that can be detected by 12 weeks, but most accurate between 18-20 weeks. - - Hydronephrosis consists of communicating cysts, unlike MCDK. - Several grading system ( Renal pelvic diameter). - Antenatal US ( 18-20 WKS). Or incidentally post-natally. Severity of antenatal US. Mild, moderate or severe. Unilateral vs. bilateral (bilateral is an emergency). If bilateral there will be obstruction in the lower tract. If bladder is palpable the obstruction is below the bladder. Renal parenchyma thin or Echogenic. Bladder Amniotic fluid Causes: 1- Transient 2- Physiological 3- UPJO commonest cause. 4- VUR 5- Megaureter 6- Ureterocoele 7- PUV 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 Notes: Dilatation only won’t lead to infection unless its accompanied by an anatomical obstruction. You have to give prophylactic antibiotic. Ureteropelvic junction obstruction ( UPJ): Detected antenatal, most frequent cause of hydronephrosis More common in Left side, Ectopic, malrotation, horseshoe kidney Present: mass, UTI, Pain, Hematuria  ETIOLOGY - Intrinsic obstruction may result from stenosis due to scarring of ureteral valves. - Extrinsic obstruction by ureteral hypoplasia may result in abnormal peristaltic emptying of the renal pelvis into the ureter through the UPJ. - Crossing lower-pole renal vessel(s) or entrapment of the ureter by a vessel can prohibit urinary flow down the ureter. - Rotation of the kidney and renal hypermobility - Iatrogenic obstruction caused by prior surgical intervention to treat other disorders or failed repair of a primary UPJ obstruction.  EPIDEMIOLOGY - By Ultrasound 1\100 of pregnancies present with fetal upper urinary tract dilatation 1\500 are diagnosed with significant urologic problems - UPJ obstruction is present in 50% of patients diagnosed with antenatal hydronephrosis - The male-to-female ratio of is 3-4:1 - The left kidney is more commonly affected than the right kidney - UPJ obstruction is less common in adults - UPJ obstruction is bilateral in 10% of cases CLINICAL PRESENTATION Adults Neonates - Back and flank pain - Hydronephrosis Older children correlates with periods - Urinary tract infection of increased fluid (UTI) intake ingestion of a - Flank mass food with diuretic - Intermittent flank properties pain secondary to a - Urinary tract infection primary UPJ obstruction (UTI) - Hematuria if it is - Pyelonephritis associated with - Hypertension  ULTRASONOGRAPH Y Often show a dilated renal pelvis with a collapsed proximal ureter with doppler sonography the obstructed kidneys can show higher resistive indices.  DIURETIC RENOGRAPHY It is performed to differentiate between obstructive vs nonobstructive hydronephrosis. - PUJ "obstruction" will demonstrate excretion (downward slope on renogram) after administration of diuretic from the collecting system. - Mechanical obstructive hydronephrosis will demonstrate no downward slope on renogram, with retained tracer in collecting system.  MEDICAL THERAPY Currently, no available medical therapy is capable of reversing UPJ obstruction in either adults or children. In children\ initially conservative treatment with monitoring. Intervention is indicated in the event of significantly impaired renal drainage or poor renal growth.  SUGRICAL THERAPY The accepted criteria for intervention in infants and children including: 1- clearance half-time (T 1/2) greater than 20 minutes 2- Differential function less than 40%. 3- Ongoing parenchymal thinning with or without contralateral compensatory hypertrophy. 4- Associated symptoms like: pain, hypertension, hematuria, secondary renal calculi, and recurrent urinary  PYELOPLASTY - Open, Laparoscopic or RALP - The obstructed segment is completely resected, with reanastomosis of the renal pelvis and ureter in a dependent funneled fashion. The success rate exceeds 95%. - Open Pyeloplasty Gold Standard - Anderson-Hynes dismembered pyeloplasty is the most common  ENDOPYELOTOMY - Incision of the area with a balloon catheter to help ensure a complete incision followed by prolonged ureteral stenting, for a period of 4-8 weeks. Success rates are 80-90%. - Anterograde or retrograde - Slightly less effective in FINALLY Thank you ♥♡