1. Congenital (UPJ) Ureteropelvic
Junction Obstruction
Mohammed Nabil J AlAli
5th Year Medical Student
At
Powerpoint Templates King Faisal University
Page
Group B (210006209) 1

2. Outlines:
-OVERVIEW
-PATHOPHYSIOLOGY
- ETIOLOGY
- CLINICAL PRESENTATION
- DIAGNOSIS
- DIFFERENTIAL DIAGNOSIS
- FOLLOW-UP
- MANAGEMENT
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3. OVERVIEW
• It is a partial or total blockage of
the flow of urine that occurs
where the ureter enters the
kidney.
• It is the most common pathologic
cause of antenatally detected
hydronephrosis
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4. EPIDEMIOLOGY
• Most common site of urinary tract
obstruction in children
• Majority are discovered antenatally
– 1:1500 secrend by ultrasound
– It is the most common anatomical cause of
antenatal hydronephrosis
– Boys > girls
– Most cases on the left
– 10-40% bilateral
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5. PATHOPHYSIOLOGY
• It is caused by anatomic lesions or
functional disturbances that restrict
urinary flow, resulting in hydronephrosis.
• Most cases are thought to be due to
partial obstruction, because complete
obstruction results in rapid destruction of
the kidney.
•In some cases, partial obstruction may
also lead to progressive deterioration of
renal function. Templates
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6. Development of the
equilibrium state resulting
in stable renal function
depends on:
• Urinary rate and output
• Anatomy and degree of UPJ
obstruction
• Compliance of the renal pelvis
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7. ETIOLOGY
• It is both congenital and acquired
conditions.
• Usually caused by intrinsic stenosis
of the proximal ureter, and less
commonly by extrinsic compression
of the UPJ.
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8. Intrinsic narrowing
• In most cases of UPJ obstruction, the
upper segment of the ureter is narrowed
or kinked, resulting in obstruction of
urinary flow.
• Although the underlying mechanism is
not proven, it is thought that there is an
embryologic disruption of the proximal
ureter that alters circular musculature
development and/or collagen fibers, and
composition between and around the
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muscular cells
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9. Extrinsic narrowing
In about 10 % of pediatric UPJ
obstruction, an aberrant or accessory
renal artery or arterial branch may
cross the lower pole of the kidney,
resulting in compression of the UPJ
and blockage of urinary flow
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10. CLINICAL PRESENTATION
• Historically presented as a
palpable mass
– Newborn
• Antenatal hydronephrosis 80%
• UTI, hematuria, failure to thrive, feeding
difficulties, sepsis, azotemia
– Later in life
• 30% diagnosed after UTI
• 25% diagnosed after hematuria
• Episodic abdominal pain and vomiting
due to intermittent obstruction
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11. Associated Anomalies
• Another urologic abnormality-50%
– Contralateral UPJ 10-40%
– Renal dysplasia, aplasia, MCKD
– VUR up to 40%
• Found in 21% of VATER patients
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12. DIAGNOSIS
• It is generally suspected when
imaging studies, usually
ultrasonography, demonstrate
hydronephrosis.
• The diagnosis is confirmed by
diuretic renography.
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13. Ultrasonography (US)
Most cases of UPJ obstruction present as
a result of detecting hydronephrosis by
prenatal ultrasonographic screening
Abnormal
calyces
Normal
kidney
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14. Diuretic renography
• It (renal scan and the administration of a
diuretic) is used to diagnose urinary tract
obstruction.
• It measures the drainage time from the
renal pelvis (referred to as washout) and
assesses total and each individual kidney's
renal function.
•The washout measurement correlates
with the degree of obstruction.
In general, a half-life greater than 20
minutes to clear the isotope from the
kidney is considered indicative of
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obstruction.

15. Computed tomographic scan (CT)
- It is an alternative to ultrasonography in the
symptomatic child.
-It is not the preferred modality due to its radiation
exposure.
- In UPJ obstruction, the CT scan typically shows
hydronephrosis without a dilated ureter.
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16. Magnetic resonance imaging (MRI)
- It can be used to diagnose UPJ type
hydronephrosis.
-The advantage of MRI is the ability to
discern accurate anatomy defining the point
of obstruction.
-Also determine the split function of the
kidney and simulate the diuretic renogram
by providing washout data.
-The disadvantage of MRI is the cost and
the need for general
anesthesia and/or sedation
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17. Voiding cystourethrogram (VCUG)
-It is performed in patients with hydronephrosis
to confirm the presence or absence of VUR of
both the affected and contralateral kidneys.
-Ten percent of patients with UPJ obstruction
have contralateral low-grade vesicoureteral
reflux.
-Identification of VUR is important because
children with concurrent VUR and UPJ
obstruction may be at higher risk for severe
infection. Powerpoint Templates
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18. DIFFERENTIAL DIAGNOSIS
• It includes other causes of
hydronephrosis.
• Imaging studies differentiate UPJ
obstruction from the following conditions:
- Vesicoureteral reflux (VUR)
- Transient hydronephrosis
- Functional hydronephrosis
- Other urological anomalies including
posterior urethral valves, congenital
megaureter, ureterocele, and multicystic
dysplastic kidney
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19. FOLLOW-UP
• U/S on day 2 - 3 of life Persistent
hydronephrosis .
• VCUG to evaluate PUV or VUR
• Prophylactic antibiotics if VUR present
• No PUV or VUR - repeat U/S and diuretic renal
scan at 1 month
• Continued hydro - surgery vs. observation
• observation - U/S and/or renal scan every 3-4
months for 1 year and then every 4-6 months
• surgery - open/endopyelotomy/laparoscopy
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20. MANAGEMENT
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21. Conservative
• Principles:
– 50% of antenatal hydro resolved postpartum
– unable to accurately diagnose true
obstruction
– observations that asymptomatic
hydronephrosis can resolve spontaneously
• Studies with infants with renal
function >35-40% in the affected
kidney and variable washout
patterns
– “Rule of 1/3” - 1/3 stay the same, 1/3
improve, 1/3 worsen
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22. Indications
for Surgical Intervention
• Presence of symptoms associated
with the obstruction
• Impairment of overall renal function
• Progressive impairment of ipsilateral
function
• Development of stones or infection
• Hypertension
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23. Surgical
• Open Pyeloplasty
– Gold Standard
– Dismembered pyeloplasty is the most
common
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24. • Foley V-Y-Plasty
– Good for 1-2 cm obstruction
– Best for high inserting ureter
– Best with relatively small pelvis
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25. • Spiral flap
– Good for long obstructions (better in
adults)
– Length of flap limited only by size of
pelvis
• (keep length: width at 3:1)
• good when UPJ angle > 90
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26. • Endopyelotomy
– Antegrade or retrograde
– Cold knife or electric current
– Acucise is very popular
• dilation balloon with hot wire
– 86% success in adults
– Slightly less effective in children
– Direct vision antegrade approach is
most common
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27. • Laparoscopic pyeloplasty
– Same indications as open or
endourologic procedures
– Dismembered pyeloplasty is most
common procedure performed
• Without crossing vessels, may do any
number of flap procedures
• Up to 94% success rate, similar to open
pyeloplasty
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28. Any Question ?
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29. REFERENCES
- UpToDate
(press on the title )
- Department of Urology Section of Pediatric Urology
(University of Oklahoma ) (press on the title )
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30. Thank you
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