6 Posterior Urethral Valves (PUV) Congenital Proximal Urethral ObstructionAbnormal congenital mucosal folds in the prostatic urethra that look like a thin membrane that impairs bladder drainage
7 PUV Defined Type I Type II Type III Obstructing membrane that extends distally from each side of the verumontanum towards the membranous urethra where they fuse anteriorlyType IIDescribed as folds extending cephalad from the verumontanum to the bladder neckType IIIRepresent a diaphragm or ring-like membrane with a central aperture just distal to the verumontanumThought to represent incompelte dissolution of the urogenital membrane
8 Type I PUVObstructing membrane radiating distally from the posterior edge of the verumontanum to the membranous urethraDuring voiding, the fused anterior portion bulges into the urethra with a narrow posterior openingPossibly due to anomalous insertion of the mesonephric ducts into the primitive fetal cloaca
10 Type III PUV Represent incomplete dissolution of the UG membrane Distal to the verumontanum at the membranous urethraRing-like with a central opening, “wind sock valve”
11 Incidence Males only 1:5000 – 8000 male births Type I > 95% Type III - 5%Children with Type III PUVs have a worse prognosis as a group50% of patients with PUV will have vesicoureteral reflux50% unilateral, 50% bilateral
12 Clinical Presentation Varies by degree of obstructionSymptoms vary by age of presentationAntenatalBilateral hydronephrosisDistended and thickened bladderDilated prostatic urethraOligohydramnios - accounts for co-presentation of pulmonary hypoplasia.
13 Clinical Presentation NewbornPalpable abdominal massDistended bladder, hydronephrotic kidneyBladder may feel like a small walnut in the suprapubic areaAscites40% of time due to obstructive uropathyHistory of OligohydramniosRespiratory distress from pulmonary hypoplasiaSeverity often does not correlate with degree obstructionPrimary cause of death in newborns
14 Clinical Presentation Early InfancyDribbling / poor urinary streamUrosepsisDehydrationElectrolyte abnormalitiesUremiaFailure to thrive; due to renal insufficiencyToddlersBetter renal function (less obstruction)Febrile UTIVoiding dysfunction – incontinenceDaytime incontinence may be the only symptom in boys with less severe obstruction
15 Initial Management Bladder Drainage A 5 or 8 Fr pediatric feeding tube is idealA Foley catheter should not be used, due to the tendency of the balloon to occlude the ureteral orifice and cause a bladder spasm.Secondary obstructionBroad spectrum antibiotic coverageMetabolic panelAssess renal function and metabolic abnormalitiesAcidosis, hyperkalemia common problems
16 Radiologic Evaluation of the Lower Tract VCUGMandatory for all PUV evaluationsShowing a dilated prostatic urethra, valve leaflets, detrusor hypertrophy, bladder diverticula, bladder neck hypertrophy, and narrow penile urethra stream, as well as possible incomplete emptying
17 Radiologic Evaluation of the Lower Tract U/SExamining the prostatic urethra for characteristic dilation and thickening of the bladder wall
19 Radiologic Studies- Upper Tract Renal UltrasoundExamination for bilateral hydronephrosis and signs of lower tract obstructive processRenal ScanAssesses the function of the kidneys
20 Management Transurethral Valve Ablation Incise at 4, 8 & 12 o’clock positions via Pediatric resectoscopeAvoid urethral sphincterCatheter drainage for 1-2 daysVCUG at 2 months to ensure destruction of valvesRegular U/S to evaluate resolution of hydronephrosis
21 Management Transurethral Valve Ablation Alternatively, 8F cystoscope with a Bugbee electrode adjacentInsulated crochet hook (“Whitaker hook”)When urethra too small to accommodate cystoscope/Bugbee
22 Case studyOur patient had a very narrow urethra and therefore the approach was with the 8F cystoscope with a Bugbee electrode attached.
23 Case studyOperative images captured by cystoscope camera.
25 Vesicoureteral Reflux Present in %Usually SecondaryHigh intravesical pressures33% resolve spontaneously when obstruction treated33% do well on prophylactic antibiotics
26 Vesical Dysfunction 50% have abnormal bladder function Presents as incontinenceNot due to sphincter dysfunction or damagePrimary myogenic failureUninhibited contractionsMay lead to progressive renal deterioration
27 Adverse Prognostic Factors Presentation after the age of 1 yearFailure of Cr to fall below month following initiation of therapy/drainageBilateral vesicoureteral refluxDiurnal incontinence beyond 5 years of agePrenatal diagnosis in the second trimester
28 Favorable Prognostic Factors Creatinine falling below 1.0 one month after treatment initiatedAbsence of VURPreservation of the corticomedullary junction of the kidneys by renal U/SRadiologic evidence of a “pop-off” valve
29 “Pop-off” ValvesA mechanism by which high intravesical or intrapelvic pressure is dissipatedAllows for normal development of one or both kidneys by one of three mechanisms(1) Urinary ascitesUrine leaks from the fornices of the kidneys or from a bladder rupture(2) “VURD” syndromeMassive unilateral reflux into a non-functioning kidney(3) Large bladder diverticulumCausing aberrant micturition into the diverticulum, thereby taking pressure off the developing renal units
30 Conclusions: Posterior Urethral Valves Two PUV types, Type I the most common, Type III with a worse prognosisPrognosis improved with improved symptoms within 1 month of therapy or the presence of a “Pop-off” valveDrainage, antibiotics and correction of metabolic disturbances key to initial careVCUG, U/S and renal nuclear scan to evaluateMajority managed by valve ablationLong-term sequelae significant, primarily renal disease