1 - pediatric abnormalities Flashcards
most common cause of prenatal hydronephrosis
transient (50-70%)
most common pathologic cause of prenatal hydro
UPJO (10-30%)
% with upjo presenting bilaterally
10%
most common side for UPJO
left > right
muscle fiber type involved in intrinsic UPJO
CIRCULAR muscle fibers at UPJ
how does secondary UPJO due to reflux happen
severe VUR may cause totuous ureter and kinking at UPJ
mgmt of 2ndary UPJO
fix UPJO before reflux
how does mag 3 work in the kidney
tubular secretion
how does DTPA work in kidney
glomerular filtration
how does DMSA work in kidney
proximal tubular binding
purpose of mag 3
function and drainage, same as MAG 3
stent effect on urine leak after pyeloplasty
reduces leakage
endoscopic management for pyeloplasty failure in kids?
not used very often
pro and con of nuclear cystogram in kids
less radiation, poor anatomy
3 indications for surgical correction of VUR
- poor compliance with prophylaxis, 2. breakthrough pyelo on prophylaxis, 3. parental decision
ratio of ureter to tunnel for reimplant
5:01
success rate of reimplant
98%
overall success rate of deflux
72%
2 things that predict improved outcomes in deflux
low grade, multiple injections
post-procedure VCUG for deflux vs reimplant
needed for deflux, not reimplant
definition of megaureter
> 7 mm
2 major classifications of megaureter
obstructed or refluxing
when to observe obstructed megaureter
normally functioning kidney
megaureter vs refluxing ureter - quality
megaureter»_space; refluxing
4 indications for megaureter surgery
- uti, 2. pain, 3. stones, 4. progression
pathophysiology of obstructed megaureter
aperistaltic DISTAL segment of ureter
what makes distal ureter aeristaltic in megaureter
circular fibers on only
3 steps in mgmt of refluxing megaureter
- prophylaxis during observation (1yr), 2. observation for 1st yr, 3. surgery
what kindof megaureter gets cutaneous ureterostomy
refluxing with recurrent pyelo
how to taper megaureter
excision of lateral wall to preserve medial blood supply
what ureter gets taper vs tailor
taper for ureter > 1.5 cm
mgmt of moderate VUR after megaureter surgery
- r/o bladder problem, 2. consider surgical correction (deflux vs re-reimplant)
2 major complications of megaureter surgery
- obstruction, 2. VUR
2 causes of obstruciton after megaureter surgery
- edema, 2. ischemia
mgmt of obstruction after megaureter surgery - 2
- postop edema - transient and resolves w/in 8 wks. may need stent, 2. related to ischemia of ureter - resect ischemic ureter and reimplant
mgmt of VUR after megaureter surg
r/o bladder dysfunction, consider surgical repair - deflux vs reimplant
6 genetic causes of renal cystic disease
- ARPKD, 2. ADPKD, 3. medullary cystic disease, 4. congenital nephrosis, 5. familial hypoplastic glomerulocystic disease, 6. multiple malformation syndromes (VHL, TS, ect)
7 non-genetic cuses of renal cystic disease
- MCDK, 2. benign multilocular cyst (cystic nephroma), 3. simple cyst, 4. medullary sponge kidney, 5. acquired renal cystic disease, 6. sporadic glomerulocystic kidney disease, 7. calyceal diverticulum
ADPKD vs ARPKD - liver
AD - liver cysts later in life, AR - liver fibrosis
ADPKD vs ARPKD - RCC
no increased incidence
ADPKD vs ARPKD - aneurism
ADPKD only - berry aneurism 10-30%
ARPKD and development
oligohydramnios common, pulmonary hypoplasia –> incompatible with life
2 contralateral findings in MCDK
- UPJO (3-12%), 2. VUR (30%)
natural history of MCDK
invoute, no assn with HTN
histology of MCDK
heterogenious non-communicating cysts
most common type of posterior urethral valves
type 1
% with VUR at time of PUV dx
50-70%
outcome of VUR after PUV ablation
30% resolve
findings with PUV in utero
bilateral hydro and bladder distention
fetal urine sampling significance
hypertonic urine is poor prognosis
ascites in PUV due to
40% due to urologic condition
nadir serum creatinine predicting ESRD in newborn
> 1
4 predictos of poor renal function
- renal dysplasia on us, 2. presentation < 1 yo, 3. bilateral VUR, 4. nadir cr > 1.0 in 1st yr of life
where on valves is ablation done
at 5 and 7 oclock
result of complete valve ablation
high risk of urethral and sphincter injuries with complete resection
3 major findings in VCUG of kid with PUV
- trabeculated bladder, 2. hypertrophied bladder neck, 3. dilated and elongated posterior urethra
when to remove dysplastic kidney with high grade VUR inpt with PUV
only if recurrent infection. if no infection, leave it alone
if PUV ablation cant be done because urethra is too small
temporary vesicostomy
what does VURD stand for
valves, unilateral reflux, renal dysplasia
significance of VURD
reflux happens into dysplastic kidney functioning as pop-off valve and protecting other kidney
common bladder problem after PUV ablation
persistent VUR
mgmt of persistent VUR after PUV ablation
make sure bladder function is nl, otherwise make sure bladder is rehabilitated before re-implanting
non-refluxing hydronephrosis in PUV after ablation
1/2 resolve after ablation, if persistent make sure bladder ok
3 outcomes of PUV bladder
- decreased compliance/small capacity, 2. DO, 3. myogenic failure
3 outcomes of PUV bladder and age of presentation
- decreased compliance/small capacity (infants), 2. DO (older kids), 3. myogenic failure (post pubertal)
3 outcomes of PUV bladder and mgmt
- decreased compliance/small capacity (anticholinergics) 2. DO (anticholinergics), 3. myogenic failure (double void, alpha blockers, +/-CIC)
3 predictors of poor outcome in PUV
- nadir cr > 1 at 1 yo 2. renal dysplasia, 3. younger age at presentation
transplant outcome in PUV depends on
good bladder function
how is renal function maximized in PUV
good bladder control
what is weigert myer rule
upper pole oriface is caudal to lower pole oriface
reflux and obstruction in duplication
upper pole obstruction, lower pole reflux
most common location of insertion in males for ectopic ureter
posterior urethra
most common location of insertion in females for ectopic ureter
bladder neck –> incontinence if below sphincter
cause of ureterocele
failure of chwalla membrane to rupture in distal ureter
% ureterocele with reflux - ipsilateral/ contralateral
70% / 10%
vcug finding suggestive of duplication
drooping lilly of lower pole kidney
3 goals in treatment of duplication
- preserve renal function, 2. prevent uti 3. maintain continence
ureterocele mgmt if sepsis
incise asap
ureterocele mgmt if it extends down bladder neck
incise below bladder neck to prevent flap-valve
ureterocele caveat with family
let family know all mgmt options may require additional future surgery
ectopic ureter - 3 mgmt options
- UU or pyeloureterostomy, 2. upper pole hemi-nx, 3. common sheath reimplant
when to do UU/PU in ectopic ureter
when there is no ipsilateral reflux
when to do upper pole heminx in ectopic ureter
no upper pole function
when to do common sheath reimplant in ectopic ureter
if ipsilateral or contralateral reflux is present
prune belly syndrome aka
eagle-barrett
triad of prune belly
- bilateral hydro, 2. bilateral intra-abdominal cryptorchidism, 3. abdominal wall laxity
4 associated urologic findings in prune belly
- renal dysplasia (50%), 2. large bladder +/- urachal diverticulum, 3. dilated posterior urethra (from prostatic hypoplasia not valves), 4. megalourethra
biggest urologic problem in PBS
urine stasis
early orchiopexy in PBS?
by 6 mo
what is megacystis-megaureter
huge bladder with megaureter only, no other physical findings
mgmt of megacystis-megaureter
reimplant
where in the kidney does scarring usually happen after pyelo
polar regions of kidney
fetal ureter bud forms when
5th wk
when can fetal kidneys be visualixed
12-13 wk
when can fetal bladder be seen
14th wk
when is amniotic fluid volume dependent on kidneys
16th wk
what diameter (mm) is fetal hydro mild, moderate, severe
mild 7-9mm, moderate 9- 15 mm, severe > 15 mm
what makes hydro more likely to be pathological - 5
- calyceal dilation, 2. ureteral dilation, 3. chromosomal abnormalities, 4. multiple malformations, 5. oligohydramios
% of the time is hydro transient
40-80%
elevated urine N-acetyl-β-D-glucosaminidase found in what condition
obstructed kidney
elevated urine TGF-β1 found in what condition
unilateral UPJO
hypothesized etiology of posterior urethral valve
terminal ends of wolfian ducts mismigrate and are integrated into urethral wall abnormally resulting in obliquely oriented ridges that act as one way alves
who gets admitted for pyelo for iv abx
- pyelo in infants and “young kids”, 2. renal abscess, 3. urosepsis
when does a UTI always get admitted for IV abx
always in infants < 1 mo old
when not to give bactrim or nitrofurantoin
bactrim < 2 mo, nitrofurantoin < 1 mo
options for antibiotic prophylaxis - 4
- nitrofurantoin, 2. bactrim, 3. keflex, 4. amoxicillin
risk of VUR if parent, sibling, twin have it
parent 50%, sibling 50%, twin 80%
spontaneous resolution rate for grade 1 VUR
90%
spontaneous resolution rate for grade 2 VUR
60-80%
spontaneous resolution rate for grade 3 VUR
50%
spontaneous resolution rate for grade 4 VUR
25-40%
spontaneous resolution rate for grade 5 VUR
<20%
before observing grade 1-2 VUR without abx, need to confirm what
normal bladder/bowel function
most common renal function abnormality associated with PUV
urine concentration defect
