Posterior Urethral Valve

Posterior Urethral Valve (PUV) and it's management.

1. POSTERIOR URETHRAL VALVES Presented by: Anish Dhakal (Aryan)

2. Normal embryologic Development T he cloaca is divided into the anorectal canal & the urogenital sinus upto Week 6 of gestation The urogenital sinus is divided by the mesonephric duct into the vesicourethral canal giving rise to the bladder & pelvic urethra The caudal portion of the urogenital sinus - genital tubercle, forms the phallic urethra At around 14 weeks, complete fusion of the entire urethra

3. Pathogenesis Normal embryologic development of the male urethra between weeks 9 to 14 of gestation is disrupted Probable causes for PUV formation: Persistence of the urogenital membrane with abnormal canalization of the urethra Overgrowth of urethrovaginal folds Abnormal integration of the Wolffian duct into the posterior urethra

4. Introduction Congenital membranes that cause obstruction to antegrade urinary flow in baby boys In the posterior urethra-distal to verumontanum Flap valve Most common cause of severe obstructive uropathy in male children Affecting 1 in 5000-8000 boys

5. Introduction Approximately 30% patients experience end stage renal disease or chronic renal insufficiency Vesicoureteral reflux occurs in 50% of patients Renal changes range from mild hydronephrosis to severe renal dysplasia Oligohydramnios P ulmonary hypoplasia U rinary tract infection, urinary retention and uraemia

6. Classification Type 1  folds going inferiorly from verumontanum to membranous urethra (most common) Type 2  Valves radiating from verumontanum to bladder neck Type 3  Valves are concentric diaphragms within the prostatic urethra

7. Clinical Features Affected boys often discovered prenatally : Maternal Ultrasonography Bilateral Hydronephrosis , Distended bladder Oligohydraminous , if obstruction severe Male neonate: Palpably distended bladder, Urinary stream weak Infant: Failure to thrive because of renal failure,uremia or sepsis Children: Difficulty in achieving diurnal urinary continence or with UTI

8. Diagnosis Ultrasonography Antenatal and Postnatal Bilateral Hydronephrosis Marked distension and hypertrophy of bladder Oligohydraminous in severe cases

9. Diagnosis Voiding Cystourethrogram (VCUG) Best imaging techniques for diagnosis Dilatation and elongation of posterior urethra Vesicoureteral reflux

10. Keyhole Sign ultrasonographic sign seen in boys with posterior urethral valves . proximal  urethra  (which is dilated) and associated thick walled distended bladder

11. Management Prenatal bladder decompression B y percutaneous vesicoamniotic shunt or open fetal surgery S ignificant renal and pulmonary morbidity exist

12. Management Healthy Neonate S mall polyethylene feeding tube (No. 5 or No. 8 French) is inserted in the bladder and left for several days Serum creatinine level remains normal or near normal: Transurethral ablation of valve leaflets If urethra to small: Temporary vesicostomy , when child become older; valve ablation and vesicostomy closed

13. Management If serum creatinine level remains high or increase despite bladder drainage: Suspect secondary ureteral obstruction, irreversible renal damage or renal dysplasia Cutaneous vesicostomy or Cutaneous pyelostomy

14. Management In septic and uremic infant: Life saving measures: correction of electrolyte balance, Infection control Drainage of upper tract by percuatneous nephrostomy, haemodialysis After conditions become stable consider valve ablation

15. Prognosis Favorable prognostic factors: Normal prenatal USG between 18 and 24 wk of gestation Serum creatinine level: < 0.8-1.0 mg/dL after bladder decompression Visulaization of corticomedullary junction on renal sonography

16. Unfavorable prognostic factors: Presence of oligohydraminous in utero Identification of hydronephrosis before 24 weeks of gestation Serum creatinine level: > 1.0 mg/dL after bladder decompression Persistence of diurnal incontinence beyond 5 yr of age

17. VURD Syndrome Valve, Unilateral reflux, dysplasia “ Popoff valve” Preserves integrity of 1 or both kidneys 15% of boys with posterior urethral valve have unilateral reflux into a nonfunctioning dysplastic kidney: VURD syndrome

18. Post Operative Care Anti-microbial prophylaxis: Preventing UTI Evaluated annually with: renal ultrasonogram , physical examination including assessment of somatic growth and blood pressure, urinalysis , electrolytes

19. Some boys with: polyuria with vomiting and/or diarrhea , urine output cannot be used to assess their hydration status . They can become dehydrated quickly Some of these patients have renal tubular acidosis, requiring oral bicarbonate therapy . When vesicoureteral reflux is present,:expectant treatment and prophylactic doses of antibacterial drugs If breakthrough UTI occurs, surgical correction should be undertaken.

20. Boys with urethral valve often do not achieve diurnal urinary continence as early as other boys Incontinence: Uninhibited bladder contraction, bladder atonia , bladder neck dyssynergia or polyuria Polyuria: Overnight catheter drainage Urinary incontinence: Improves with age particularly after puberty

21. Summary Congenital membranes that cause obstruction to the urinary tract in baby boys Antenatal ultrasound typically shows urinary tract dilatation Treatment is valve destruction accompanied by treatment of urinary infection and renal impairment

22. References Norman S. Williams et al ,Bailey and Love ’ s Short Practice of Surgery, 2 6 th edition Kliegman et al, Nelson Textbook of Pediatrics, 20 th Edition Langman’s Medical Embryology, 12 th Edition

23. Thank You