Urology Flashcards
Definition of unresolved congenital hydronephrosis based on 3rd trimester antenatal ultrasound
> = 7mm
What could a single umbilical artery signify re: the kidney?
Unilateral renal agenesis
Incidence of unilateral renal agenesis
approx 1/750
Potter syndrome
Bilateral renal agenesis Incompatible with life Pulmonary hypoplasia Potter facies (widely set eyes, low set ears, broad/flat nose) Limb anomalies
What is multicystic dysplastic kidney
Usually unilateral, NOT inherited condition causing replacement of the kidney by cysts
May be due to ureteral atresia
Most common cause of abdominal mass in the newborn!
What is the most common cause of an abdominal mass in the newborn?
Multicystic dysplastic kidney
Risks associated with multicystic dysplastic kidney
Hypertension (0.2-1.2%) Wilms Tumour (1/333)
Ask-Upmark kidney
aka segmental hypoplasia
small kidneys with grooves
pts have severe hypertension
resolves w/ nephrectomy
Anatomic kidney anomalies with increased risk of Wilms
Multicystic dysplastic kidney
Horseshoe kidney
Complication of horseshoe kidney
Wilms tumour
stone disease
hydronephrosis (due to UPJ obstruction)
Things that predispose to urinary reflux
kidney duplication (with an extra ureter inserting into bladder on one side)
ureterocele (cyst of the intramural portion of the distal ureter)
ureter diverticulum
neuropathic bladder (in myelomeningocele, sacral agenesis)
posterior urethral valves
renal agenesis, MCDK (predisposes to reflux on the contralateral side)
constipation
Reflux is more likely to resolve if….
lower grade
unilateral
younger age at diagnosis
AAP recommends to treat what grade of VUR?
Grade IV + V
Diagnosis of UTI
Urinanalysis demonstrating pyuria and culture growing > 50,000 CFU/mL (from a cath/suprapubic aspirate)
When do you do a VCUG?
VCUG is indicated if U/S shows hydronephrosis,
scarring, or other findings suggestive of high-grade VUR or obstructive
uropathy, and in other atypical or complex
clinical circumstances
Is there a role for antimicrobial prophylaxis if you are concerned about VUR?
No. The evidence does not support that antimicrobial prophylaxis prevents renal scarring or UTI
How should you counsel parents of a child with VUR?
Prompt assessment when febrile (within 48 hrs) is important - early treatment is key in preventing renal scarring!
Complications of VUR
UTI
hypertension
CKD
How can you manage severe VUR with frequent UTIs?
Can try prophylaxis (Not recommended though - septra or nitrofurantoin)
Deflux injections into ureter
Reimplantation of ureter
symptoms of obstructive renal insufficiency
non-specific! nausea, vomiting mild abdo pain diarrhea poor urine stream
walnut-sized palpable mass just above the pubic symphysis in a newborn boy
posterior urethral valves
palpable abdominal mass in newborn
most likely multicystic dysplastic kidney
could also be hydronephrosis
AP diameter grading system for hydronephrosis
mild = 6-9mm
moderate = 9-15mm
severe = > 15 mm
For what degree of antenatal hydronephrosis would you perform a post-natal RBUS?
> = 10mm in the 3rd trimester
When should do you an urgent post-natal ultrasound?
If severe bilateral hydronephrosis
OR
if severe single kidney hydronephrosis
When should you start a baby with antenatally detected hydronephrosis on prophylactic antibiotics after birth?
when RPD > 10mm in 3rd trimester
OR
SFU grade IV
When does a baby require a post-natal VCUG?
If postnatal U/S shows persistent hydronephrosis RPD >10mm
If the post-natal VCUG does not show reflux, then what do you do?
If RPD 10-15mm, stop antibiotics and repeat U/S at 3 mos & 1 yr
If RPD > 15mm, do diuretic scan to look for obstruction
Gene/protein affected in autosomal recessive polycystic kidney disease
PKHD1, which encodes fibrocystin
What other organ is involved/affected in AR PCKD?
the liver - can cause bile duct proliferation and fibrosis
indistinguishable from congenital hepatic fibrosis
Presentation of AR PCKD?
bilateral flank masses during neonatal period or infancy
DDX PCKD?
Multicystic dysplastic kidney
Wilms
Hydronephrosis
Bilateral renal vein thromboses
Most common hereditary kidney disease
Autosomal dominant polycystic kidney disease (1/500 to 1/1000)
mutations/protein causing autosomal dominant polycystic kidney disease
PKD1/2, encodes polycystin 1/2
Autosomal dominant PCKD - when does it present?
ESRD in 4th/5th decade
Extra-renal symptoms of AD polycystic kidney disease
Cysts in liver, pancreas, spleen, ovaries
Intracranial aneurysms
Mitral valve prolapse
Hernias, intestinal diverticula
Renal cell carcinoma
Repair of UPJ obstruction
pyeloplasty (stenotic segment at UPJ is excised)
Prune-belly syndrome - TRIAD
Deficient abdominal muscles
Undescended testes
Urinary tract abnormalities
What is the likely underlying etiology of prune belly syndrome?
severe urethral obstruction in fetal life
urinary tract abnormalities in prune belly syndrome
massive dilation of ureters / upper tracts / gigantic bladder
how do you decompress suspected PUV?
insertion of an NG tube (NOT a foley catheter - the balloon may cause bladder spasm, inducing severe obstruction)
Unfavourable prognostic factors relating to PUV
- hydronephrosis before 24 weeks GA
- persistently elevated serum creatinine after decompression
- cortical cysts in kidneys
- incontinence > 5 yrs old
What is the bell clapper deformity?
Redundant tunica vaginalis, allowing excessive mobility of the testis - predisposing to torsion (often bilateral)
What reflex should you check if you suspect testicular torsion?
cremasteric (stroke inner thigh, testis retracts) - is almost always absent
Most common cause of testicular pain in boys aged 2-10yrs
torsion of the appendix testis
PE sign for torsion of appendix testis
blue dot sign
management torsion of the appendix testis
bed rest x 24 hrs, NSAIDs x 5 ds
what side do varicocele usually present on?
LEFT
if right-sided, should work up for abdominal mass
Why do you treat varicocele?
if significantly large, can affect fertility! need surgical excision/management
What should you do if a boy has bilateral, non-palpable testes?
Refer to specialist for possible DSD!
When should you refer a child with unilateral undescended testis for surgical management?
at 6 months CGA
will NOT descend after 4 mos
risk factor for cryptorchidism?
prematurity
(testes descend at 7-8 mos GA)
secondary to inguinal hernia repair
risks of cryptorchidism
infertility testicular cancer testicular torsion associated hernia psychologic effects of undescended testis
do boy with retractile testes have an increased risk of infertility or cancer?
POTENTIALLY!
1/3 of retractile testis become “acquired undescended” and then have the same risk of infertility/cancer as undescended
how do you manage non-palpable testes?
referral for diagnostic laparotomy
U/S not sensitive to find testes if they are not located within inguinal canal/ring
what is priapism?
a penile erection at least 4 hrs in duration, unrelated to sexual stimulation
can be ischemic, non-ischemic (high-flow) or intermittent
most common cause of priapism in children
sickle cell disease!
management of priapism in children with HbSS
exchange transfusion
hydration
pain management
oxygen
cause of high-flow, non-ischemic priapism?
usually perineal injury causing caverous arterial laceration/flow
management of urethral prolapse
sitz baths, topical estrogen x 2 weeks (girls)
may require surgery if persistent
flank mass, hematuria, thrombocytopenic
renal vein thrombosis
risk factors for renal vein thrombosis
maternal diabetes prematurity dehydration sepsis polycythemia CHD
most common cause of renal stones in kids
hypercalciuria
most common types of stones in kids
calcium oxalate
increase your risk of stones
hypercalciuria oxaluria stasis infection cystinuria lasix
inhibit formation of stones
citrate
phosphate
magnesium
high flow urine
If struvite stones, think of….
upper UTI with klebsiella or proteus
indications for surgical removal of kidney stone
obstruction infection (Urologic emergency!)
ways to avoid formation of kidney stones…
increase fluid intake decrease meat/protein intake drink lemonade (citrate) - inhibits stone formation limit salt consumption (decreases calcium excretion)
cystinosis causes….
Fanconi syndrome
cystinuria causes…
cystine stones
