1. 1. CONGENITALANOMALIES Embryology: The embryological developmentof the kidneyisalongand continuousprocesswhichbegins inthe 3rd weekandiscompletedbyabout34-35 weeksof fetal life. Kidneyorganogenesisischaracterisedby3distinctandlinkedstages: pronephros, mesonephrosand metanephros.
2. 2. 1. Mesonephros: Mesonephros appearsinthe 4thweekof gestationasa more complex structure immediately afterthe involutionof the pronephrictubules. Mesonephros containsthe vesicles -the precursorof mesonephricnephronandthe mesonephricduct.The proximal endof the mesonephricductformsa 2-layeredcup, Bowmanscapsule. The glomerulusiscompletedaftercapillariesvascularise thisprimitive Bowmanscapsule.
3. 3. The mesonephricnephronsare capable of producingurine bythe 9th weeksof gestation and continue todoso until theirinvolution. At the mesonephricstage,mostcellsinthisorganhave involutedbythe 11th-12th weekas the metanephrosbeginsfunctioning. 2. Metanephros: The final stage of the kidneyisthe differentationof the metanephros andarise fromthe uretericbudand the metanephricblastema(mesenchyme). The renal pelvis,majorandminorcalycesandterminal collectingductare formedbythe 10- 13th wksof ges. Aftermorphogenesiseachkidneycontainsapprox amillionnephrons. Pathogenesis:abnormal development CAKUT: Congenital Anomaliesof the Kidneyand Urinary Tract Anomalies of the upperurinarytract: Anomaliesof number Anomaliesof ascent Anomaliesof formandfusion Anomaliesof rotation Anomaliesof renal vasculature Anomaliesof the collectingsystem
4. 4. Anomalies of kidney: 1. Anomaliesof number Renal aplasia(solitarykidney) Agenesis Bilateral .( Potterssyndrome-incompatible withlife) Unilateral Supernumerary. 2. Anomaliesof ascent(position) ectopickidney 3. Anomaliesof form&fusion Crossedectopiawith&withoutfusion. o Inferiorectopia. o Sigmoid. o Lump. o L-shaped. o Disc. o Superiorectopia.
5. 5. Horseshoe kidney: The lowerpole of bothkidneysare fusedwitheachotherandconnectedbyan isthmus. Both kidneysare lowerthanthe normal,asthere ascentare blockedbythe inferior mesenteric artery The longitudinal axisof the kidneysisdirected downwardandmedially. 4. Anomaliesof size &structure: Hypoplasia Multicystickidney Polycystickidney: - Infantile - Adult. Othercysticdisease. Medullarysponge kidney. Medullarycysticdisease Polycystickidney: Hereditaryconditioncharacterizedbyprogressivedistortionof the renal parenchymaby multiple cystsandperitubularfibrosis. Types: Infantilepolycystickidneys:autosomal recessive,rapiddestructionof the renal parenchyma of bothsides. Adultpolycystickidneys: autosomal dominantslowlyprogressive disease causingslow destructionof the renal parenchymaof bothsides. Cystsof the liver,spleen,andpancreasmaybe notedinboth types.
6. 6. CONGENITALHYDRONEPHROSIS Commonabnormalityof neonatal kidney Frequentcauses: 1. Ureteropelvicjunctionobstruction 2. Vesicoureteral reflux Lessfrequentcauses: 1. Primarymegaureter 2. Duplex anomalies 3. Posteriorurethral valves 1. UPJ obstruction: Obstructionof flowfromrenal pelvistoproximalureter Pathology /US 1. Dilatedcalyces 2. Dilatedrenal pelvis 3. Visiblerenal parenchyma 4. No ureteral dilatation Natural Hx: - No change overmanyyears(mostcommon) - Spontaneousregression - Progressive obstranddeteriorationof renal fn Management: 1. US followupq 4-6 monthsin mildormoderate case 2. Dismemberedpyeloplastyinsevere case Anomalies of ureter PRIMARY MEGAURETER = dilatedureter Likelydue tostricture or stenosis Aperistalticsegmentof distal ureter US: - Ureteral dilatation - Absentordecreasedureteral jet Differential diagnosis:Reluxingureter - Requirescystogram - US not reliable toseparate obstructedandrefluxingsystem Management: 1. US follumupq 4-6 monthsinmildor modcases 2. Reimplantationandtaperinginseverecases 3. Reimplantationrare inmildormod VESICOURETERALREFLUX (VUR) Retrograde passage of urine frombladdertoupperurinarytract
7. 7. VUR = mostcommonurologicabnormalityinkids 1% newborns 30 - 45% of childrenwithUTI UTI (upper) =mostcommon seriousbacterial infectionof childreninthe developed worldin the age of conjugate pneumococcal andH. fluvaccines(Israel isnotthere yet!! why?) Management: A. Basedon the rationale that: a. In the absence of UTI, VUR doesnot cause renal scarring. b. Uncomplicatedprimaryrefluxhas a natural tendencytoresolve spontaneously - the likelihoodof resolutionisinverselyproportional tograde. B. Maintainingurinesterilityisthe cornerstone of"watchful waiting" medical management. The classicapproach has beentoofferdailylow-dose prophylacticantibioticsuppressionof infectionsasthe firstline of treatment. Urine surveillance Treatmentof underlyingbladderdysfunction Treatmentof constipation Patient/parentseducation Indicationsforsurgery: 1. Functional symptomaticbreakthroughUTI. 2. Anatomical VUR urological abnormalitiese.g.uretericduplication(lesslikelytoresolve spontaneously). RENAL DUPLICATION Upper pole ureter: - Has ectopicinsertion - Can endinbladderor outside bladder - Obstructed Lowerpole - Has normal insertion - Refluxes
8. 8. URETEROCELE A ureterocoeleisacysticdilatationof the lowerendof the ureter. It may occur witha single system, orinvolvesthe ureterof one segmentof a duplicated kidney. The ureterocoele maybe locatedinthe bladder,oritmay openin an ectopiclocationbelow the bladderneck Treatment: 1. Endoscopicincisionorureterocele (unroofing) 2. Upper pole nephrectomy 3. Reinsertionof upperploeureterintolowerpole ureter 4. Lowerpole ureterreimplantation ECTOPICURETER Sitesof insertion: - Girls:urethra,vagina,vestibule - Boys:prostaticurethra,genital tract Urinary incontinence ingirlsif insertionisbelow external spinchter Infectionorepididymitisinboys Treatment: 1. Upper pole nephrectomy 2. Reinsertionof upperpoleureterintolower pole ureter 3. Lowerpole ureterimplantation UROGENITAL SINUS
9. 9. Urogenital sinusforms: - Bladder - Pelvicurethra Male Female Membranous& prostaticurethra Urethra - Definitive urogenitalsinus Male Female Penile urethra Vagina POSTERIORURETHRAL VALVES Most commoncause of obstructive uropathyinmales Doesnot affectfemales Incidence:1/5000-1/8000 Cause:congenital membranewhich(partially) obstructsurethra Clinical presentation: 1. bilateral flankmasses(hydronephrosis) 2. distendedbladder 3. poor urinarystream(+/- dribbling) Diagnostictest:VCUG TherapeuticGoal: Preserve renal function,avoidrenalfailure (30% at risk forprogressive renal insufficiency) BLADDER EXSTROPHY (Exstrophyepispadiascomplex) Spectrumof severity : 1. Small defectcanresultinepispadias 2. large defectcan resultinexposure of posteriorbladderwall Occurs in1 in 30,000 births Exposedbladdermucosaisedematousandfriable HYPOSPADIAS Incidence:upto1:250 births Associations:undescendedtesticles(DSD),inguinal hernias Management:recognition,avoidanceof circumcision Surgery:usuallyby2 yearsof life
10. 10. AMBIGOUS GENITALIA CAH isthe most commondiagnosisinvirilizedXXinfants Presentation Hypoglycemia,vomiting,diarrhea,hypovolemia,hyponatremiawith hyperkalemia, and shock Management Monitorelectrolytes,glucose 17-OHP high(Newbornscreen/LabStudies) Treatment: glucocorticoids(hydrocortisone) May require mineralocorticoidsinsalt-wasters EPISPADIAS (openingof external meatusatthe bladder) Veryrare - more oftenassociatedwithbladderexstrophy Needearlyreferral forparental counseling Patientsmaybe totallyincontinent