Lower Urinary Tract Obstruction ‘LUTO’ or Bladder Outlet Obstruction ‘BOO’
Miss Harriet Corbett Consultant Paediatric Urologist Aims
• To give an overview of • the anomalies we encounter • presentation of LUTO • how to investigate suspected LUTO • how to manage them • long term outcomes Causes of LUTO • ‘Partial’ obstruction • Posterior Urethral Valves • Obstructing ureteroceles • Neuropathic bladder (functional) • other, rare –In association with a ‘patent cloaca’ –Anterior urethral valves, Cobbs collar, Congenital urethral stricture, Polyps
• ‘Complete’ obstruction • Urethral atresia Posterior Urethral Valves
• Commonest cause of LUTO in children • Males only • 1:5,000 • Sporadic – Only v. rare familial cases
• Associations – Trisomy 21 (not in all series) – Kupferman 1996 Paediatr nephrol (find association), Qureshi 2000 Fetal Diagn (do not) – UDT in up to 12-17% Posterior Urethral Valves
Obliquely orientated membrane (not actually valves)
From region of veru through external sphincter to anterior urethral wall a very wide spectrum (veru) Posterior Urethral Valves
• Young’s classification - no longer considered valid: Type I – pair of oblique postero-anterior folds directed distally from veru (95%) veru enlarged ?in fact a single membrane, bicuspid due to catheters Type II – folds between veru and bladder neck *?if these exist - considered to be non-obstructing Type III – membrane/diaphragm distal to veru (5%)
• Dewan et al. 1990s – If perform cystoscopy before catheter, find Type III – Catheter converts it to Type I – Proposed new terminology: COPUM Congenital Obstructing Posterior Urethral Membrane A membrane rather than valve leaflets Posterior Urethral Valves
• Embryology - theories • e.g. abnormal integration of Wolffian ducts into the urethral wall, abnormal cloacal membrane • Krishnan et al. J Urol 2006: • persistent urogenital membrane Pathophysiology
• Urinary tract obstruction – May be evident as early as 14 weeks – reduced liquor volume – reduced volume of urine passed – consequences on fatal lung – and posture – abnormal bladder wall – chronic raised intravesical pressure – abnormal proximal urinary tract – dilated ureters, abnormal kidneys Uterus
Oligohydramnios Small lungs Hydronephroureter
Damaged kidneys
Damaged bladder
Club feet Why do they matter so much?
• Respiratory insufficiency in severe cases – May be fatal • Commonest cause of BOO/LUTO in childhood • Commonest cause of childhood renal failure – Approx 25% ESRF • Bladder dysfunction – In 25-30% Presentation of PUV
1. Antenatal • must be considered in any baby (boy) with bilateral AN hydro or abnormal bladder 2. Early postnatal 3. Infants 4. Childhood 5. Later Antenatal USS
• Urinary tract = commonest system to find anomalies – Mild dilatation of renal pelvis in 1:100 pregnancies – Significant problems 1:500
• 70% of anomalies are detected at 20 weeks
• BUT: 80% of antenatal findings are non specific Aetiology & incidence of antenatal hydronephrosis
Transient hydronephrosis 41–88%
Pelviureteric Junction obstruction (PUJ) 10–30%
Vesicoureteric reflux 10–20%
Vesicoureteric junction obstruction (VUJ) or 5–10% megaureters
Ureterocele/ectopic ureter/duplex system 5–7%
Multicystic dysplastic kidney 4–6%
Posterior Urethral Valves/urethral atresia 1–2%
Nguyen HT et al. The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol 2010:6:212-31 Which ones to worry about • OLIGOHYDRAMNIOS – risk of pulmonary hypoplasia • Anything BILATERAL – Ureters or kidneys • Anything that includes bladder abnormality – Especially the ‘Keyhole’ sign • Abnormal solitary kidneys Antenatal diagnosis
• 55% suspected at 20wks • Further 20-30% detected later • Bad signs Detect <24wks (later = better) Oligohydramnios ‘Bright’ kidneys
....Consider TOP if v.early/severe oligo....
Refs: Sarhan, 2008 & BAPS CASS survey 2018 PLUTO
• Percutaneous shunting for Lower Urinary Tract Obstruction – LUTO : 60% PUV, 21% other, 5% c’some etc – Metanalysis of literature to date suggests a benefit from shunting in utero – ANY fetus with LUTO where it is uncertain if shunting will help to be randomised to shunt/no shunt – Needed 200 patients to show 20% difference in mortality – Didn’t recruit enough
What to do with a baby with antenatal urological abnormality Ultrasound Scan • Timing depends upon antenatal scan so it does matter what the antenatal scan showed afterall!
• Urgent postnatal ultrasound at 24-72 hour old, if: • oligohydramnios / lung abnormality • bilateral dilation OR unilateral with bladder abnormality • solitary abnormal kidney • if normal :repeat 3 to 7 days later • if still normal repeat at 6 weeks • if still normal, no follow up required
Protocol 1 1. Renal dilation with oligohydramnios or lung abnormality 2. Bilateral renal dilation 3. Unilateral renal dilation with ureteric dilation or bladder abnormality or contralateral kidney abnormal
Urgent postnatal ultrasound Discuss with Paediatric urologist
MCU* Urgent to exclude valves
Posterior urethral valves Vesicoureteric reflux No PUV, No VUR
Antibiotics URGENT MAG3 Referral REFERAL 3months Paeds/nephrology/urology
Referral Urology ‘False Alarm’ - bilat hydro due to VUR PUV case 1: baby AT
• Bilateral hydronephrosis & oligohydramnios on 34 week scan • Elective CS delivery at 36 weeks • Ventilated for respiratory distress – Pneumothorax
– O2 requirement • Creatinine 147 on D3
Beware the early USS
• This baby had normal kidneys on a Day 1 USS – But they looked like this on day 13 PUV case 2: Stoke baby
• Antenatal diagnosis of bilateral hydronephrosis and dilated bladder • Catheterised after birth, transferred to AH • USS = gross bladder wall thickening & significant bilateral hydro • MCUG = poor bladder with PUV
18 months post treatment Management 1
• Drain bladder – Ideally URETHRAL catheter • Beware v. thick bladder wall obstructing VUJ – SPC difficult due to thick wall • Alternatives: vesicostomy, ureterostomy(ies), nephrostomy(ies) • Monitor U&E – Nephrology input – Allow stabilisation before anything else Micturating CystoUrethroGram B
PU
Bladder B
Posterior B urethra PU
PU B B
PU PU Management 2
• Endoscopic ablation – Resectoscope – Cold knife – Whittaker hook etc. • +/- circumcision
• Rpt cystoscopy at 3/12 • Monitor …. Long term • Through puberty Presentation of PUV
1. Antenatal 2. Early postnatal • respiratory distress and abnormal U&E • urosepsis • clinical LUTO = big bladder, big kidneys, big abdomen (urinary ascites) 3. Infants 4. Childhood 5. Later PUV case 2: TH
• Antenatal dx of club feet - nil else • Presented at 6 weeks of age with frank haematuria • likely UTI (>1000 WCC, but mixed growth) • terrible USS
Presentation of PUV
1. Antenatal 2. Early postnatal 3. Infants • soft signs - FTT, vomiting, poor feeding • urosepsis - often very unwell • clinical LUTO = big bladder, big kidneys, big abdomen (urinary ascites) 4. Childhood 5. Later Presentation of PUV
1. Antenatal 2. Early postnatal 3. Infants 4. Childhood 5. or Later FTT, UTIs, wetting, abnormal voiding Renal failure DC
• presented at 16 years of age with frank haematuria • First ever urinary tract symptom • Though imperfect bladder function likely overlooked in view of T21 • Trisomy 21 • UTI
Long term: rule of thirds
BLADDER: • ⅓ normal • ⅓ poor .... Late potty training, wetting • ⅓ bad .... Overactive/poor compliance/myogenic failure with time - may need ISC/surgery etc KIDNEYS • ⅓ normal • ⅓ marginal • ⅓ poor progressing to CRF / transplant • ***↑nadir creatinine and bladder dysfunction are risk factors for ESRF (DeFoor 2008 J Urol) Long term....
Bladder Infection Crucial to Minimise to protect upper protect tracts Kidneys kidneys Protect by minimising infection, VUR etc
Blood Fertility pressure Poor semen, poor ejaculation & UDT Non - PUV Causes of LUTO
• Obstructing ureteroceles • Neuropathic bladder (functional) • other, rare • Urethral atresia • In association with a ‘patent cloaca’ • Anterior urethral valves, Cobbs collar, Congenital urethral stricture, Polyps Obstructing Ureteroceles
The minority of ureteroceles • Most detected antenatally • associated with duplex systems • (single system ureteroceles often innocent) Duplex systems: plenty of scope for abnormality
but… both moieties may be normal
Duplex systems:
if abnormal: lower moiety - ureter inserts lateral and above medial ureter, may be ‘too lateral’
- likely to have VUR
Duplex systems: if abnormal: upper moiety - ureter inserts medially and below, often ectopic, may have ureterocele
The Weigert-Meyer rule states that the upper pole ureter is the ectopic ureter and its orifice inserts inferomedially in the bladder in relationship to the lower pole normal ureter. » Ureteroceles » obstruct their own moiety » often No / poor function (dysplastic) » if not causing other problem then nil to do » BUT » if obstructing lower pole ureter / other side / bladder neck » OR get infected above… » need puncture » or other op » may prolapse / be very ectopic » vagina » urethra Obstructing ureterocele: TH
• Term boy with bilateral antenatal hydronephrosis • Well at birth • Initial early scan ‘not bad’ – but repeated according to protocol
• Repeat scan ~1 week later – quite abnormal
Urethral Atresia
Technically non survivable No urine = no amniotic fluid Potters syndrome equivalent Urethral Atresia
Survivable if… urine can pass e.g. Patent Urachus, Vesicoamniotic shunt Summary
PUV is the commonest cause of LUTO Be suspicious – any boy may have PUV! Urologists happy to advise Any Questions?