Presentation on theme: "Dr. Mamdouh Abdul Salam Pediatric Urol ogy. Megaureter = Grossly dilated ureter Non specific Non reflecting Etiology Potentional outcome Pathopysiology."— Presentation transcript:
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
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.
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.
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%)
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
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
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
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
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 24 Grade III 35 Grade IV &V 49
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