Congenital Anomalies of Kidney & Urinary Tract (CAKUT)
Intro
Bilat renal agenesis
Causes of large cystic kidneys
Obstruction
Antenatal tx
Postnatal tx
majority now identified in utero due to routine USS
1 in 200-400 births
can be managed prospectively
can be a/w abnormal renal development/function, predispose to infection, involve obstruction requiring surgery
opportunity to minimise/prevent progressive renal damage
disadvantage: lots of minor abnormalities detected (e.g. mild unilat pelvic dilatation)
don't require intervention
over-investigation, unnecessary tx, parental anxiety
severe oligohydramnios
Results in Potter syndrome
fatal (stillborn or shortly after birth from resp failure)
multicystic dysplastic kidney (MCDK)
failure of union of ureteric bud (forms ureter, pelvis, calyces, collecting ducts) with nephrogenic mesenchyme
non-functional structure, large fluid filled cysts, no renal tissue, no connection to bladder, no urine produced
1/2 involute by 2y/o, nephrectomy only needed if remains v large or HTN develops (rare)
if bilat results in Potter syndrome
ARPKD
ADPKD
Tuberous sclerosis
both kidneys affected always
both kidneys affected always
both kidneys affected always
some/normal renal function
some/normal renal function
some/normal renal function
1 in 1000
HTN + haematuria in childhood
renal failure in late adulthood
extrarenal features
cysts in liver + pancreas
cerebral aneurysms
mitral valve prolapse
Abnormal caudal migration
pelvic kidney
horseshoe kidney (lower poles fused in midline)
may predispose to infection or obstruction
Duplex system
premature division of ureteric bud
can vary from a bifid renal pelvis to 2 ureters (complete division)
lower ureter often refluxes, high ureter tends to drain ectopically (into uretgra/vagina) or may prolapse (uterocele) causing an obstruction
Bladder extrophy
failure of fusion of intraumbilical midline structures
exposed bladder mucosa
Absent musculature syndrome aka Prune-belly syndrome
Megacystis-megaureters (large bladder, dilated ureters)
cryptorchidism
disrupted N supply (neuropathic bladder)
Bilat
Post urethral valves
due to mucosal folds/membrane
at worst this results in a dysplastic kidney, if bilat will cause Potter's
IU bladder drainage procedures, results disappointing
rarely early delivery
attempt to prevent hydronephrosis, poor renal growth, declining liquor vol, pul hypoplasia
prophylactic antibiotics to prevent UTI
Practice varies between centres
obstruction may not be evident @ first so delay US for 4-6wks UNLESS bilat hydronephrosis in male (must excl post urethral valves asap)
always requires surgery
IU compression of foetus from oligohydramnios due to lack of urine
characteristic facies: low set ears, beaked nose, prominent epicanthic folds, downward slanting eyes
lung hypoplasia
postural deformities (e.g. talipes)
diffuse bilat enlargement of both kidneys
separate cysts of varying size between normal renal parenchyma
Absence/deficiency in ant abdo wall muscles
wrinkled appearance of abdo
mostly males affected
Unilat
in boys
pelviureteric obstruction
vesicoureteric obstruction
bladder neck obstruction
proximal urinary tract will dilate