Urinary Systems Flashcards
What are the 2 renal anomalies that are associated with other abnormalities:
VATER
VACTERL
VATER:
vertebral defect
anal atresia
tracheo-esophageal fistula
radial defects and renal anomalies
VACTERL:
vertebral defect anal atresia cardiac defects tracheo-esophageal fistula radial defects and renal anomalies limb abnormalities
Bilateral renal agenesis is a lethal cogenital anomaly. What happens?
failure of the ureteric bud to develop, so then no nephrons do not form.
no urine is produced
oligohydramnios
pulomnary hypoplasia is cause of death
*one diagnosed, parents are at risk for having another child with renal agenesis (4%)
Potter Syndrome:
bilateral renal agenesis and oligohydramnios and anhydramnios
also has facial abnormalities (low set ears, beaked nose, epicanthic folds and downward slanted eyes
IUGR
limb deformities
“lying down” adrenal sign is associated with
renal agenesis
What excludes the diagnosis of bilateral renal agenesis?
visualization of normal fetal bladder (be careful it’s not urachal diverticulum)
Unilateral renal agenesis:
more common than bilateral
associated w/ normal AFV and visualization of the bladder
If kidney is not found in the renal fossa, what could it be?
absence/ectopic
contralateral kidney may be enlarged and vesicoureteral reflux may occur
Associated abnormalities: genital. cardiac, skeletal, GI
*risk increases when parent also has unilateral agenesis
Renal Ectopia:
pelvic, crossed, crossed fused, horseshoe
The most common form of renal ectopia is
pelvic kidney (seen adjacent to the bladder) can be hypoplastic or dysplastic
Horseshoe kidney tissue attaches where?
lower poles
Horseshoe kidney:
relatively benign but it has a higher incidence with vesicoureteral reflux, renal calculi, UTI’s and hydropnephrosis
Horseshoe kidney can be associated with:
Urogenital Cardiac Skeletal CNS Chromosomal Turner syndrome, trisomy 18, trisomy 9
What is the most common neoplasm in the fetus and newborn?
congenital mesoblastic nephroma (benign hamartoma composed of mesochymal tissue)
What two renal neoplasms are indistinguishable from each other?
Wilm’s tumor
congenital mesoblastic nephroma
Wilm’s is a malignant lesion that is extremely rare and composed of epithelial tissue
What are the 3 classifications of renal cystic disease?
dysplastic (severe obstruction most likely during embryogenesis)
hereditary (PKD)
non-dysplastic (simple)
Multi Cystic Dysplastic Kidney:
most common form of cystic disease in childhood
one of the most common abdo masses in the neonate
a/w atretic ureter and pelvoinfundibular atresia (passage is closed)
How do cysts form from obstruction
complete obstruction or atresia impairs ureteral branching and results in decreased division of collecting tubules and inhibition of induction and maturation of nephrons
the collecting tubules enlarge and develop cysts in their terminal portions
Multi Cystic Dysplastic Kidney appearance:
multiple cysts of varying size
no normal renal tissue present
kidney not functional
not usually transmitted and is not a/w with liver or panc disease
contralateral kidney, bladder and AFI is normal
normally unilateral
MCDK can be mistaken for? What can be used to tell the difference?
hydronephrosis
hydronephrosis communicates with itself
kidney cysts do not communicate
Multicystic renal dysplasia is bilateral in _____ ______ of cases
19-24%
Unilateral obstructive cystic renal dysplasia is caused by:
ureteropelvic or vesicouteral junction obstruction
Bilateral obstructive cystic renal dysplasia is caused by:
severe bladder outlet obstruction, usually urethral atresia or posterior urethral valves
Infantile autosomal recessive polycystic kidney disease:
2 sets of abnormal genes in order for disease to develop
involves kidneys and liver
lots of appearances (perinatal or juvenile)
Difference between perinatal and juvenile infantile autosomal recessive PKD:
perinatal-severe renal disease, minimal hepatic fibrosis and early death from pulmonary hypoplasia
juvenile – minimal renal disease, marked hepatic fibrosis and longer survival
Can see infantile autosomal recessive PKD at what GA?
as early as 16W (oligohydramnios + renal changes)
IPKD can be associated with:
Meckel-Gruber syndrome (IPKD, encephalocele and polydactyl)
What’s commonly associated with IPKD?
an elevated KC/AC ratio (40%) is an indication of renal enlargement and commonly associated with infantile polycystic kidney disease
What is often seen with adult autosomal dominant PKD?
nephromegaly w/ or w/o an increase in echogenicity
sometimes normal appearance so people may not be aware
Simple renal cysts:
seen as early as 14-16W, most resolve by 20-24W
will do f/u so they make sure it doesn’t become multicystic
Mild pyelectasis:
mild dilatation of renal pelvis
can be transient, physiological phlegmon,, or pathologic
Hydronephrosis:
dilation of renal pelvis and calyces
most common fetal abnormality detected with prenatal U/S
most often from obstruction
Renal pelvic diameter is abnormal when
RPD >5mm at 18-23W or RPD >7mm in the 3rd trimester
When measuring for hydronephrosis, where do we measure
measure the fluid and also the kidney itself
What are the grades of hydroneprhosi:
grade 0: no hydroneprhosis, intact central renal complex
grade 1: only dilated renal pelvis, some fluid in renal pelvis
grade 2: dilated renal pelvis and few calices are visible
grade 3: calices are dilated
grade 4: dilation of renal pelvis and calices and with thin parenchyma
What’s the most common cause of neonatal hydronephrosis?
UPJ obstruction (muscular abnormality)
UVJ is second most common
Metanephros develop from the what at what week?
metanephric diverticulum (ureteric bud) 7th week GA
What is the ureteric bud:
outgrowth of mesonephric duct
gives rise to the ureter, renal pelvis, calcyes and collecting tubules
interacts with metanephric mesoderm to induce formation of the nephrons
Kidneys ascend to adult position by week:
11
The allantois constricts to become a :
fibrous cord, the urachus, which extends from apex of bladder to the umbilicus
Bladder develops from the:
upper part of urogenital sinus and connected to the allantois
What does the allantois become after birth?
it becomes obliterated and forms the urachus (fibrous cord), which becomes the median umbilical ligament
The urine becomes a major source of amniotic fluid when?
16wks
