1. Dr. Mamdouh Abdul Salam Pediatric Urology
Megaureter
Dr. Mamdouh Abdul Salam
Pediatric Urology

2. Megaureter = Grossly dilated ureter Non specific Non reflecting
Definition
Megaureter = Grossly dilated ureter
Non specific
Non reflecting
Etiology
Potentional outcome
Pathopysiology

3. Anatomy Ureter ureteropelvic junction Middle spindle
Ureterovesical junction
Juxtavesicoureter Terminal ureter
submucosal
Intremural segment

5. Classification

6. Pathophysiology
Obstructed Megaureter
Localized deficien`cy of muscle fibres within the UVJ
Hypertrophy of the circulr muscle bundles immediately promixal to the deficiency…………………Adynamic distal segment.
Intramural part…… composed of circulatory fibres instead of longitudinal fibres
Degree of obstruction= Percentage of circular fibres
Three types of obstructed Megaureter:
Dense collagen infiltration of terminal ureter
Distal circular muscular hypertrophy
Distal muscular dysplasia

7. Pathophysiology Primary obstructed ectopic ureter:
Additional thick collar of smooth muscle Does not resolve spontaneously ? Require early intervention
Spontaneous improvement of obstructed megaureter:
Segmental maturational development of terminal ureter
Correlation with Transforming Growth Factor –β (TGF-β)
depletion within the first 2 years of life.
Gene assessment:↑Angiotensen II Type 2.
Adrenergic regulation: contractile function of the smooth muscle wall of the megaureter.

8. Pathophysiology Refluxing Megaureter
Laterally positioned, gaping ureteral orifice
Bladder filling and repeated cyclic voiding→ pressure transmitted to the ureter→ Megaureter.
↑ Collagen Type III……..Less distensible fiber→Stiffer ureter→ ? ↓ success rate of operative correction of refluxing megaureter compared to obstructed megaureter.

9. Diagnosis Fetal Ultrasonography
Pre Fetal US era: Children with Hydronephrosis
PUJ obstruction (22%)
PUV (19%)
Ectopic ureterocele (14%)
Megaureter (8%)
Fetal US era : Antenatal Hydronephrosis
PUJ Obstruction (41%)
Megaureter (23%)

10. Diagnosis 1- ULTRASONOGRAPHY
A Keyhole in the assessment of the Megaureter.
Size, shape, tortuosity of the ureter
Assessment of the renal pelvis
Tracing of the distal ureteric insertion→ectopic position
obstructed ureterocele
Peristaltic wave of the urine→ obstructed distal segment
The echogenicity of the kidney

11. Diagnosis 2- Voiding cystourethrography To diagnose VUR
Anatomical appearance of the bladder, bladder neck, urethra and ureter
CYCLICAL VUCG;
When ectopic or sphincteric ureter is suspected

12. Diagnosis 3- Renography
Diuresis renal scintigraphy provides the greatest quantitative information of functional and dynamic data.
Renal uptake and excretion
Time to peak activity
Time to half peak after Frusemide washout
MAG3 depend on effective renal plasma flow (preferable)
DTPA depend on glomerular filtration rate ( ↓ in neonates)
Two sets of activity curves → one over the kidney
→one over the ureter

13. Diagnosis 5- Percutaneous Perfusion Studies 6- Excretory urography
4-Magnrtic Resonance Urography(MRU)
Provides greater insight into anatomic abnormalities
Gadolinium- enhanced MRU in renal insufficiency
Limited use → need for sedation/ GA
→ ↑ expense
5- Percutaneous Perfusion Studies
Whitaker test:→Invasive
→ Sedation/ GA
→ infusion rate 10 ml/min may overcome
the peristaltic flow potential of normal
ureter
Monitoring of the renal pelvic pressure while documenting passage of the contrast material from the distal ureter into the bladder (≥ 14 cm water)
6- Excretory urography

14. Treatment 1- Nonobstructed, Nonrefluxig Megaureter
Initial Medical treatment
Prophylactic antibiotic
Occur in 6-10% in infants with ANH
Spontaneous resolution in 72%
Grade I within 13 months
Grade II
Grade III
Grade IV &V

15. Treatment 2- Obstructed Megaureter Initial Conservative TTT
Surgical TTT → Symptomatic patient
→Compromised renal function
→ Progressive HUN
Timing : Beyond 1 year ?
Ureteric reimplantation +/- Tapering (Imbrication/Excisonal)
Early intervention → Temporizing Distal
Cutaneous ureterostomy or
Internal Temporary Diversion

16. Treatment 3- Refluxing Megaureter Initial conservative TTT
Surgical TTT → Symptomatic patient
→ Compromised renal function
Megacystitis Megaureter:
Timed double viding
Clean Intermittent Catherization ↓
Operative intervention

17. Treatment

18. Treatment

19. Thank You