This document summarizes a case of bladder outlet obstruction in a female patient. Over three scans taken four weeks apart, the patient was found to have bilateral hydronephrosis, enlarged kidneys, a thickened bladder wall, and dilated ureters, consistent with lower urinary tract obstruction likely due to posterior urethral valves. Posterior urethral valves can cause back pressure in the urinary system and lead to complications if not treated. The patient was advised to follow up with a pediatric urologist.

1. Case of Bladder outlet
obstruction-PUV
Dr Kruti Savalia

2. Case
• A female patient Mrs X aged 28 years was reffered to us for second
opinion for hydronephrosis on 22/06/2022

3. 1 st scan-GA 24.1 week
• It was diagnosed as bilateral gross
hydronephrosis with peripheral
calyceleal dilatation-UTD 2/3
• Both kidneys enlarged size 35/37 mm

4. • Bilateral ureter dilated and showing
peristalsis
• UB wall hypertrophied
• Thickness 4 mm

5. • Persistently enlarged urinary bladder size 30 mm
Key hole sign seen

6. Advice
• Non lethal anomaly with guarded prognosis
• Other parameters were normal including AFI
• Paediatric urosurgeon reference advised
• Follow up after 4 weeks advised
• Patient counselled

7. Second scan after 4 weeks at GA 28.5 days
• Bilateral gross hydronephrosis with peripheral calyceleal dilatation-UTD 2/3
• Both kidneys enlarged size 50/42 mm

8. • UB wall hypertrophied-thickness
was 4.1 mm
• Bilateral ureter dilated

9. • Other parameters were normal including AFI
• Diagnosis and advise were same as previous scan

10. 3rd scan after 4 weeks at GA 33.5 days
• Bilateral gross hydronephrosis with
peripheral calyceal dilatation
• Both kidneys enlarged- 57/57 mm
• UB wall hypertrophied
• Thickness was 5.5 mm

11. • Other parameters were normal.
• Afi was reduced-oligohydramnios
• Diagnosis and advise were same as previous scan

12. Diagnosis
• All these findings suggestive of LUTO-Lower urinary track obstruction
due to BOO-bladder outlet obstruction
• Probably due to posterior urethral valve
• Comes under UTD 2/3

13. Bladder outlet obstruction
• Most common cause is PUV-posterior urethral valve
• PUVs are membranes within posteror aspect of urethra
• Affects male fetuses
• Represent with-enlarged bladder and urethra-keyhole sign
• Ureters and renal pelvis also dilated
• With worsening-bladder wall becomes hypertrophied with
trabeculations
• Renal parenchymal destruction and dysplasia results from back
pressure-atrophic changes

14. • Severe cases also present with oligohydramnios, peripheral urinomas
and urinary ascites
• Phenotypic changes in newborn-potter facies and contracture of
extremities
• Pulmonary hypoplasia
• Poor prognosis-hyperechogenic cystic renal parenchyma and renal
cortical cysts
• Electrolyte measurement in fetal urine-transabdominal
vesicocentesis-controversial role

15. • Vesico amniotic shunting to divert urine to amniotic cavity from
obstructed bladder-long term results not convincing
• PLUTO-Percutaneous shunting in lower urinary tract obstruction-
stopped now-poor recruitment
• Fetoscopic placement of trans urethral stent-under trial

17. Causes of Enlarged Bladder
• Posterior urethral valves
• Anterior urethral valves/Congenital megalourethra
• Urethral atresia
• Megacystitis microcolon intestinal hypoperistalsis syndrome
• Cloacal malformation
• Megacystitis/megaureter
• Prolapsed ureterocele/Vesicoureter reflux

18. Differential Diagnosis
• Congenital megalourethra/Anterior urethral valves-dilated elongated
penile urethra-male fetus
• Prune Belly syndrome-USG features are similar but bladder and
urethral dilatation are not as marked-male fetus
• Transient Dilation-resolves after birth
• Congenital megacystitis/Vesicoureteral reflux/Transient BOO-
cystourethrogram distinguish it
• Duplex collecting system/Ureterocele-septum/cyst within bladder

19. • Urethral atresia-common in female-complete obstruction
• Cloacal malformation-usg features same-female fetus
• MMIHS-Mega cystitis microcolon intestinal hypoperistalsis syndrome-
common in female, small bowel obstruction, intestinal malrotation,
liquor normal or polyhydramnios, associate with cardiac defects, cleft
lip, palate, omphalocele

20. Post natal follow up
• Findings were correlated with
antenatal findings.

22. THANK YOU