Editing CUA: Antenatal hydronephrosis (2017) (section)

== Answers ==

# What is the differential diagnosis of ANH in order of likelihood?
## Transient primary hydronephrosis
## Uretero-pelvic junction obstruction (UPJO)
## Vesicoureteric reflux (VUR)
## Uretero-vesical junction obstruction (UVJO)
## Primary non-obstructive megaureter
## Ureterocele
## Ectopic ureter
## Megacystis (dilated urinary bladder)
# Describe the SFU grading for ANH

{| class="wikitable"
|Grade
|Ultrasound findings
|-
|0
|Normal kidney (resolved antenatal hydronephrosis)
|-
|1
|Pyelectasis
|-
|2
|Pyelectasis with dilation of 1 or more major calyces (caliectasis)
|-
|3
|Pyelectasis with dilation of all 3 major calyces
|-
|4
|Pyelectasis with parenchymal thinning compared to contralateral kidney
|}

# In the third trimester, what antero-posterior renal pelvic diameter is considered mild, moderate, and severe antenatal hydronephrosis?
#* Mild: 7-8mm
#* Moderate 9-15mm
#* Severe: >15
# When is post-natal evaluation of antenatal hydronephrosis generally indicated?
#* When third trimester US shows APD ≥ 7mm
# What are the indications for a referral to a pediatric urologist for antenatal counselling?
## Dilated bladder
## Severe bilateral AHN
## Renal cortical hyper-echogenicity
## Renal cortical cysts
## History of oligohydramnios
# In which patients should a serum creatinine be obtained as part of the post-natal evaluation?
## Severe bilateral HN
## Solitary kidney
## Abnormal renal echogenicity
# What imaging findings on ultrasound warrant a VCUG in the work-up of ANH?
## Dilated posterior urethra
## Thick or trabeculated detrusor
## Dilated bladder
## Severe bilateral HN
## Increased renal cortical echogenicity
## Renal cortical cysts
## History of oligohydramnios
# When should post-natal US be performed in patients with ANH?
#* If HGHN (SFU 3-4) or APD >15mm, then within first 2 weeks
#* If LGHN (SFU 1-2) or APD 7-10mm, then within first 3 months
# What are the indications for diuretic renography?
#* HGHN (SFU Grades 3 and 4) or APD >15 mm whose VCUG was negative for VUR
# Which patients with ANH may benefit from continuous antibiotic prophylaxis? Which antibiotics are commonly used? Which should be avoided and why?
#* CAP may be of benefit in:
#*# Grades 3 and 4 HN
#*# Females with AHN
#*# Uncircumcised males with AHN
#*# Cases with dilated ureter or bladder abnormality
#* Commonly used prophylaxes in the neonate include amoxicillin, cephalexin, and trimethoprim.
#* TMP/SMX and nitrofurantoin should NOT be used in the neonate because of the respective risk of kernicterus and hemolytic anemia, respectively.
# What are the indications for surgery in obstructive hydronephrosis?
## Loss of DRF of >5% on serial renography (absolute)
## Worsening HN with worsening drainage times on renography (absolute)
## UTI (relative)
## Low DRF on initial renogram (relative)
## Palpable giant HN (relative)
## Concern over non-compliance with follow-up imaging protocols (relative)
## Family preference in cases of persistent HGHN requiring repeated renographic evaluation (relative)