UPJ obstruction is a common cause of urinary tract obstruction in children, primarily identified antenatally, and occurs more frequently in males. Diagnosis typically involves ultrasound, with significant variability in interpretation and outcomes; indications for surgical intervention include symptoms and impaired renal function. Surgical options range from open pyeloplasty to laparoscopic techniques, with ongoing monitoring of obstructed kidneys to determine the necessity for intervention.

1. UPJ OBSTRUCTION
BY
HASSAAN ALI GAD

2. UPJ OBSTRUCTION
-Most common site of urinary tract
obstruction in children
-Majority are discovered antenatally
-1:800-1500 pregnancies
-80% antenatal hydronephrosis
-2:1 boys : girls
-2/3 on the left
-10-40% bilateral

3. ETIOLOGY
-Extrinsic compression by an aberrant
accessory or early branching vessel to the
lower pole
-15-52% of the cases in children
*Most common cause in adults
-Secondary UPJ obstruction
-Severe VUR or lower urinary tract obstruction
-permanent kink at the UPJ due to tortuosity
high inserting ureter

4. PATHOLOGICAL CHANGES
Intrinsic lesion with the ureteropelvic wall
Inefficient drainage through an aperistaltic segment
Over distention of the pelvis leads to hypertrophy and
decreased GFR
If high grade obstruction, penal parenchymal changes
and impaired function result
Histology shows loss of normal smooth muscle,
hypertrophy, and fibrosis
Less commonly: valvular mucosal folds, persistant
fetal convolutions, upper ureteral polyps

5. ASSOCIATED ANOMALIES
-Another urologic abnormality-50%
-Contralateral UPJ 10-40%
-Renal dysplasia, aplasia,
-VUR up to 40%

6. 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

7. DIAGNOSIS
-Most are diagnosed antenatally
-Hydronephrosis on prenatal ultrasound
-Most are asymptomatic at birth
*The major question:
-Is the obstruction clinically significant?
-Radiologic evaluation helps to determine this,
however there is no perfect way to diagnose
obstruction

8. DIAGNOSIS
Renal U/S
1st study performed in the neonate
Lacks specificity to determine significance
Doppler U/S
PSV-EDV/PSV=Tests Resistive Index
Increases sensitivity and specificity of U/S
RI > 0.7 may be significant
Wide range of variability limits this test

9. DIAGNOSIS
Diuretic Renal Scan
Standardized protocol in children
Catheterization
Measure urine output every 10 minutes
Renogram acquisition for 20 minutes or until pelvis full
Lasix 1 mg/kg
Diuresis renogram acquisition for 20 minutes
Gives good differential function and drainage
pattern

10. DIAGNOSIS
Disadvantages
Variable response to Lasix
Variable timing of Lasix administration
Variable renal pelvic compliance
Do not correlate well with pressure-flow studies
Not as helpful with equivocal results

11. DIAGNOSIS
IVP
-functional study
-usually wait until 4 wks. Old
-pelviectasis after drainage
Retrograde pyelograms
-mainly in cases of non-functioning kidneys
-can r/o distal obstruction

12. DIAGNOSIS
Pressure-flow (Whitaker)
fill pelvis at 10ml/min normal saline
difference between pelvis and bladder
invasive
questionable accuracy if compliant pelvis
injection at non-physiologic rates
obstruction if pressure difference > 15-22 cm

13. WHITAKER TEST: FLOW ACROSS UPJ
OBSTRUCTIONS
Pressure dependent Volume dependent
Intrinsic obstruction Extrinsic obstruction

14. 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

15. CONSERVATIVE MANAGEMENT
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

16. 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

17. SURGICAL MANAGEMENT
Open Pyeloplasty
Gold Standard
Dismembered pyeloplasty is the most common
removal of stenotic or adynamic segment
proximal ureter is mobilized, spatulated
posteriorlaterally
reanastomosed to the pelvis
pelvic reduction may be necessary is large and
redundant
stent or nephrostomy tube if desired
Foley for 24 hours (48 - 72 if VUR present)
Penrose for 3 - 5 days
Prevents urinoma formation

18. DISMEMBERED PYELOPLASTY

19. SURGICAL OPTIONS
Foley V-Y-Plasty
Good for 1-2 cm obstruction
Best for high inserting ureter
Best with relatively small pelvis

20. Foley Y-V-Plasty

21. SURGICAL OPTIONS
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

22. Spiral Flap

23. SURGICAL MANAGEMENT
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
retrograde less useful due to small ureteral caliber
primary success - 62-94% secondary success 66-100%
less successful if associated with a crossing vessel

24. SURGICAL MANAGEMENT
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

25. CONCLUSIONS
More children are diagnosed with antenatal
U/S
Current diagnostic tests do not differentiate
between kidneys that will need surgery and
those that will improve spontaneously
Solitary kidney, bilateral UPJ, or poorly
functioning kidneys should be considered for
earlier surgery

26. THANKS