Paediatric Urology
- Problems of genitalia + urinary tract in children
- Diagnosed by antenatal USG / UTI after birth
Scope:
1. UTI
- Penile disorders
- Phimosis
- Hypospadias
- Chordee
- Buried penis - Scrotal pathology
- Undescended testes
- Torsion
- Varicocele - Vesicoureteral reflux
- Urinary obstruction
- PUJO
- VUJO
- Posterior urethral valve (PUV) - Bladder function condition
- Neurogenic bladder
- Other voiding dysfunction problems - Congenital anomalies
- Hydronephrosis
- Duplex kidneys
- Cystic kidney disease - Stone disease
- Paediatric oncology
- GU trauma
- Disorders of sex development
History
- ***Age
- ***Presenting complaint
- History
- Medications + allergy
- Past medical history
- Antenatal USG - Elimination / Voiding history
- Voiding frequency
- Holding maneuvers (may suggest neurogenic bladder)
- Incontinence (day + night)
- Bowel movements (hard stool / constipation put more pressure on bladder)
- Fluid intake (type + volume) - Family history
- Recurrent UTI
- Nocturnal enuresis (paternal side / uncles)
- Vesicoureteral reflux
- Cystic kidney disease / Absence of kidney
- Hypospadias / Cryptochidism
P/E
- Abdominal exam
- Masses
- Pain (tender spot)
- Palpable bladder
- Ballotable kidneys - GU exam
- Nappy rash (signify continuous dribbling of urine)
- Labial adhesions (cause urinary leakage)
- Urethral prolapse (in female can cause constipation, other symptoms: haematuria, urinary leakage)
- Ureterocele prolapse (obstruction of urinary tract, need to check esp. in those UTI + high fever)
- Urethral opening (location)
- Foreskin (phimosis vs retractable) - Back exam
- Sacral dimples
- Hairy patches
—> Spina bifida occulta - Watch peeing process
- Urine stream (strong, any deviation of stream signify abnormal urethral opening) - Post-void residual
Phimosis, Circumcision and other prepuce disorder
Phimosis: a pathological condition
- secondary to Balanitis xerotica obliterans (BXO)
- chronic + progressive inflammatory condition characterised by hyperkeratosis (~ lichen sclerosis in skin) affecting glans + prepuce —> scarred + non-retractile foreskin, narrow preputial ring, meatal stenosis if glans involved
Physiological phimosis:
- physiological tightness of foreskin
- natural condition in which prepuce cannot be retracted
- natural adhesion between glans and prepuce
- with time will become retractable
- only problematic when complications arise e.g. UTI
Signs:
- Ballooning of prepuce during peeing
- Balanitis
Circumcision
Indications:
- BXO
- Severe recurrent attacks of balanoposthitis
- Recurrent febrile UTI
- Penile malignancy
- Traumatic foreskin injury where it cannot be salvaged
- Underlying urological anomalies (to prevent UTI)
—> NO absolute medical indication for circumcision in ***neonatal period
Potential medical advantages:
- ↓ incidence of UTI in first year of life
- Prevent phimosis
- Prevent balanoposthitis (superficial infection of glans + foreskin)
- ↓ incidence of penile cancer
- may ↓ incidence of STD / HIV (safe sex practice ONLY way to prevent STD / HIV)
Method:
1. Device method
- Gomco clamp
- Plastibell clamp
- Mogen clamp
2. Surgical operation
- Free hand surgery
Complications:
- 0.2-0.5% overall
- Bleeding
- Injury to penis (e.g. amputation of glans)
- Skin issues (taking off / leaving on too much, skin bridges, inclusion cysts, penile curvature (∵ uneven skin removal), urethrocutaneous fistula)
- Long term (***meatal stenosis)
Foreskin care
- By 3 yo 90% boys will have retractable foreskin
Suggestion to parents:
- Normal cleaning
- No forceful retraction
- Teach boys to pull back foreskin to void
Treatment only necessary for foreskin causing **infection / **difficulty voiding
Paraphimosis
- Painful constriction of glans penis by foreskin which has been retracted behind the corona
- Urgent condition
Treatment:
- Manual reduction +/- Dorsal slit of foreskin
Buried / Hidden penis
May have problem with loss of anchoring of penis and pubic symphysis
- Webbed penis
- penis enclosed by skin of scrotum which extends onto its shaft - Trapped penis
- normal-sized penis that is partially stuck in the pubic fat pad, scarring / adhesion prevent retraction of fat pad - Concealed penis
- normal size penis hidden in pubic fat pad but is retractable
Management:
- Preputioplasty
Testicular pain
Causes:
1. Testicular torsion
2. Torsion of testicular appendix
3. Orchitis
4. Epididymitis
5. Constipation / other abdominal conditions
Testicular torsion:
- Adolescent (not always)
- **Sudden onset
- Severe sharp pain
- **Sometimes only abdominal pain
- **N+V
- Abnormal lie of the testicle (e.g. transverse lie / oblique lie)
- **High lying testicle
- ***Ideally fix within 6 hours
Torsion of testicular appendix:
- Sudden onset of pain
- Pre-adolescent
- **Pinpoint tenderness
- **Blue dot sign (not always, bluish patch discolouration on scrotum)
- Over time can cause local inflammation which looks like epididymitis / torsion of testes on USG —> may need surgical exploration of scrotum
Epididymitis / Orchitis:
- Adolescent / older
- ***Gradual onset
- Tender superior portion (esp. tip of epididymis)
- May be preceded by URTI / UTI
Investigation:
- Look like torsion —> straight to operation
- Urinalysis + culture —> if normal —> unlikely to be epididymitis
- Scrotal USG (but should not waste time in highly suspicious patients)
Undescended testicle (Cryptorchidism)
- Most common birth abnormality involving male genitalia (0.8% incidence at 6 months)
- All (except premature infants) will descend in first 3 months of life —> if undescended at 3 months —> ***Refer specialist + Plan for surgery
- ***Retractile testicle is a normal descended testicle that is pulled out of the scrotum by an overactive cremasteric reflex (normal position during normal situation)
P/E:
- Bimanual examination (one hand on abdomen swiping testicles down to scrotum, other hand try grasp testicle from scrotum)
—> Palpable undescended testicle (i.e. within Scrotum / Inguinal canal) —> Orchidopexy
—> Retractile testicle —> Monitor —> If ascending testis syndrome —> Orchidopexy
—> Non-palpable testicle —> EUA
—> Palpable testis —> Orchidopexy
—> Non-palpable —> Laparoscopy (try to find testicle) —>
1. Intraabdominal testicles —> Primary / Staged Fowler-Stephens Orchidopexy
2. Vas / vessels entering canal (i.e. testis should be in inguinal canal but just not enter scrotum) —> Inguinal exploration + orchidopexy
3. Blind-ending vas / vessels (i.e. no testicles at all) —> Vanishing testis
Fowler-Stephens orchidopexy:
- indication: >2 cm from inguinal ring
- clip spermatic vessels >1 cm cranial to testis
- wait >=6 months then perform laparoscopic stage 2 Fowler-Stephen orchidopexy
Hypospadias
Disease spectrum (different level of urethral opening):
- mild: glandular / subcoronal
- moderate: mid-penile
- severe: perineal / scrotal
Clinical features:
- Ventral + proximally located urethral meatus
- Chordee (ventral curvature of penis)
- Hooded prepuce (deficient ventral prepuce)
Epidemiology:
- Incidence: 1/300 male births
- Associations:
—> Cryptorchidism (9.3%) (Hypospadias + Cryptorchidism —> need to consider whether there is disorder of sexual differentiation —> chromosomal abnormality)
—> Inguinal hernia (9%)
Factors (Multifactorial):
- Endocrine (disruption in synthetic biopathway of androgens, maybe a delay in maturation of HPG axis)
- Genetic (familial rate 7%)
- Environmental (endocrine disrupters in environment may be responsible for increase in incidence)
- Maternal (maternal progrestin exposure may increase likelihood of hypospadias, some studies show a marked increase in hypospadias in women undergoing IVF)
Management:
- ***Do NOT circumcise (need foreskin for reconstruction, others: buccal mucosa, tunica vaginalis)
- NO need imaging studies
- Refer to paediatric urologist within 1st year of life
- Always consider DSD (Disorder of sexual differentiation) if hypospadias associated with undescended testes
Operative strategy:
- Mathieu urethroplasty
- Snodgrass urethroplasty
***Enuresis
Enuresis:
- Involuntary urinary leakage only during night time
- Apply to patients >=5 yo only
Primary:
- Always wet the bed at night since birth
Secondary:
- Was dry at night (>=6 months) and now wetting the bed again
Prevalence:
- 15-20% of 5 yo
- 1-2% adolescents (majority will outgrow enuresis)
Cause (Multifactorial):
- Genetic
- Maturational delay
- Difficulty wakening
- Psychological (e.g. ADHD)
***Causes of Urinary incontinence
- ***Primary nocturnal enuresis (most common)
- ***Anatomic incontinence
- Ectopic ureter (Extravesical)
- Obstruction (PUV, (PUJO, VUJO, Labial adhesions, Urethral prolapse, Ureterocele))
- Anomalies (Exstrophy, (Abnormal urethral opening)) - ***Neurogenic incontinence
- Congenital (Neural tube defects (Spina bifida, Myelomeningocele, Anorectal malformations))
- Acquired (Trauma, Tumour, Anoxic brain injury, Extensive pelvic surgery) - ***Functional incontinence (when no anatomical / neurological cause found)
- Detrusor overactivity
- Infrequent voider (Lazy bladder)
- Dysfunctional voiding (DSD) - Miscellaneous (UTI, Polyuria)
Primary Monosymptomatic Nocturnal Enuresis (PMNE)
- Primary: wet bed since birth, never been dry
- Monosymptomatic: no other symptoms
—> no daytime enuresis
—> no urinary frequency
—> no urgency
—> no pain
—> no UTI - Nocturnal enuresis: only wet at night time
Diagnosis:
- ***Clinical diagnosis
- Important to differentiate from “Non-monosymptomatic” / Secondary enuresis —> need investigations
Investigations:
1. ***Bladder diary
- distinguish MNE from NMNE
- volume intake
- bladder capacity
- daytime + nocturnal urine production
- consecutive 48 hours
- ***Urinalysis
- UTI
- osmolarity issues
Others (Urinalysis and ***nothing further if only PMNE, only when refractory to treatment / daytime symptoms):
3. USG urinary system
4. XR spine (spina bifida occulta)
5. Urodynamic study
Treatment:
1. **Reassurance
2. **Lifestyle modification (no liquids after dinner, void before sleep, no caffeinated beverages)
3. **Star chart
4. **Bed / Enuresis alarm
5. ***DDAVP for large night time urine volume
Prognosis:
- Patient usually outgrow
***Antenatal hydronephrosis
Dilation of the renal collecting system during antenatal period
- incidence 1/100 pregnancy (only 1/500 are significant abnormalities)
**Causes:
1. **Normal (most common)
2. **Vesicoureteral reflux (VUR)
3. **Multicystic dysplastic kidney (MCDK)
4. **Obstructive uropathies
- Posterior urethral valve (PUV)
- Pelvi-ureteric junction obstruction (PUJO)
- Vesicoureteric junction obstruction (VUJO / megaureter)
5. **Prune Belly syndrome
Grading:
1. Quantitative Antero-Posterior diameter (APD):
- AP diameter between ***renal pelvis
- easy to understand
- inter + intra-observer error
- some important parameters are missing e.g. ureteral dilatation, calyceal dilatation, bladder abnormalities
- SFU grading (Qualitative):
- description of dilatation of renal pelvis and calyces —> see whether there is parenchymal involvement
- parenchymal thickness
- grade 1-4
- APD >4mm (2nd trimester) / >7mm (3rd trimester) - UT dilatation (Combined Quantitative + Qualitative classification):
- ADP
- Calyceal dilation
- Parenchymal thickness
- Appearance
- Bladder abnormalities
- Urethral abnormalities
- Based on gestational age
—> used pre / post-natally
Investigations:
1. Mild-Moderate Unilateral hydronephrosis
- USG at **2-6 weeks
- +/- **MCUG / ***MAG3 radionuclei scan
- Bilateral / Severe hydronephrosis / Dilated posterior urethra
- ***Day 2 USG
- +/- MCUG / MAG3 radionuclei scan
MCUG:
- only show VUR, PUV
- cannot show PUJO / VUJO (∵ contrast normally cannot flow back up anyway)
MAG3 scan:
- show drainage function
- prolonged diuretic t1/2 signify obstructive component
(3. RFT
- Too early for baby (only reflect mother’s renal function))
Indications of MCUG
- SFU and Canadian urological association
- SFU grade 4
- SFU grade 3 individualised approach
- SFU grade 0-2 deferred - Bilateral disease
- Dilated ureter
- Duplex kidney
- Abnormal bladder
- Ureterocele
- Abnormal renal cortex
***UTI
Presentation:
Young children (non-specific):
- Febrile
- Decreased appetite
- Lethargy
Older children (more specific):
- Febrile (implies pyelonephritis)
- Dysuria
- Frequency
- Abdominal / Loin pain
History:
1. Fever
- Voiding history
- Voiding frequency
- Holding maneuvers (may suggest neurogenic bladder)
- Incontinence (day + night)
- Bowel movements (hard stool / constipation put more pressure on bladder)
- Fluid intake (type + volume) - Family history
- Recurrent UTI
Investigations:
1. Urinalysis
- Cath specimen ideally
- Bag specimens (but can be contaminated easily)
- Radiology (for Febrile UTI)
- USG
- MCUG
- DMSA —> document that it is a pyelonephritis
Diagnosis:
- ***Clean catch urine sample preferred
- if not successful:
—> Bag urine (easy but not a good choice)
—> Catheterised sample (transurethral / suprapubic)
Treatment:
1. Lower tract infection
- short course antibiotic
- Upper tract (fever, back pain, N+V)
- 2 week course antibiotic
- admission if very ill
- quick treatment decreases chance of scarring
***Vesicoureteral reflux (VUR)
- Common cause of UTI in children
- Abnormal retrograde flow of bladder urine back into upper urinary tract through ***incompetent VUJ
- Sibling predisposition (40% of siblings)
- 25-30% of antenatal hydronephrosis + 1% of newborn
Presentation:
1. Hydronephrosis in Antenatal USG
2. UTI
- up to 30% with other GU anomalies
- males present earlier due to shorter ureters but girls 2x more likely to have reflux
3. Renal scarring
Grading:
- Grade 1, 2: mild
- Grade 3: moderate
- Grade 4, 5: severe
(SpC Paed:
Grade 1: Fills ureter without dilation
Grade 2: Fills ureter + collecting system without dilation
Grade 3: Mildly dilates ureter + collecting system with mild blunting of calyces
Grade 4: Grossly dilates ureter + collecting system with blunting of calyces
Grade 5: Gross dilates collecting system: ALL calyces blunted with loss of papillary impression +/- Intrarenal reflux + Significant ureteral dilation + tortuosity)
Classification:
1. Primary
- deficiency in formation of VUJ
- majority resolve with time (75% will outgrow)
- Secondary
- a result of urinary tract ***dysfunction
—> dysfunctional voiding
—> neuropathic bladder
—> obstruction
—> ?infection
- must correct the predisposing factor
Investigation:
1. **MCUG (gold standard, involves catheterisation + radiation)
2. **Voiding USG (involve catheterisation but no radiation)
Treatment:
1. ***Antibiotic prophylaxis + observation
- Amoxicillin (for <2 months)
- TMP-SMX (co-trimoxazole / septrin) / Nitrofurantoin QHS
- Surveillance USG
- MCUG
- Protect kidney growth until it stops at 5 yo (then can stop antibiotics) (SpC Revision)
- Surgical intervention
- Indications: breakthrough infections, poor compliance with medications, renal scarring
- **Endoscopic: “Deflux” bulking agent injection
- **Operative ureteric reimplantation: Open vs Laparoscopic vs Robotic - Circumcision
- Boys under 6 months of age: Risk of UTI ↓ by 10x
- ***Grade 4/5 boys under 2 yo - General advice
- Primary VUR presenting with UTI
—> treat constipation +/- bladder bowel dysfunction
—> adequate fluid intake
—> appropriate + prompt evaluation of febrile illness
—> consider circumcision for boys
Paediatric cystic kidney disease: MCDK, PKD
- Multicystic dysplastic kidney (MCDK) (多囊性發育不良腎)
- Most severe form of renal dysplasia
- Multiple large cysts replacing normal kidney / Ureteral atresia
- **More common than PKD
- **Sporadic (+/- VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities))
- **Unilateral
- **Presentation: Unilateral mass
- Involute over time —> Follow with serial USG + remove if doesn’t involute
- Urological testing on healthy kidney
- **Check urinary tract (90% with other GU anomalies)
- DMSA show **non-functioning kidney - Polycystic kidney disease (多囊腎)
- Most commonly **inherited kidney disease
- **Genetic, with variable expression
- **Bilateral
- **Presentation: HT, Renal insufficiency, Oliguria, Family history
- ***Cysts may also be in liver, spleen, pancreas
- Results in hypertension
- “Snowstorm” appearance of infantile polycystic disease
***Obstructive uropathies
- Posterior urethral valves (PUV)
- Pelvi-ureteric junction obstruction (PUJO)
- Vesicoureteric junction obstruction (VUJO / megaureter)
***1. Posterior urethral valves (PUV)
- ***Congenital membrane (between anterior and posterior urethra) which (partially) obstruct urethra
- can cause problem at bladder, ureter, kidney
- most common cause of neonatal obstructive uropathy in **males (*NOT affect female)
- incidence 1/5000-1/8000
Presentation:
- Antenatal
—> Severe cases can present with ***Potter’s sequence (oligohydraminios, pulmonary hypoplasia, uterine molding)
- Bilateral hydronephrosis
- Distended bladder
- Poor urinary stream (+/- dribbling)
Macroscopic appearance:
- Dilated proximal urethra
- Thickened trabeculated bladder
- Dilated ureters
- Hydronephrosis
Diagnosis:
- MCUG (dilated posterior urethra + narrow anterior urethra)
Therapeutic goal:
- Relieve obstruction
- Preserve renal function + Avoid renal failure (30% at risk for progressive renal insufficiency)
Treatment:
1. Immediate: Foley to decompress bladder
2. Surgical
- Ablation of valves
- Urinary diversion
- Fetal therapy with vesicoamniotic shunt (no good evidence)
Monitoring:
- Blood test monitoring
- Post-obstructive diuresis
Prognosis:
- 1/3 can still progress to renal failure despite surgical treatment due to damage done antenatally
***2. Pelvi-ureteric junction obstruction (PUJO)
- Most common cause of congenital hydronephrosis
- Abnormal muscle development at PUJ
- M>F
- Can be associated with other congenital abnormalities (e.g. VATER)
Presentation:
- Prenatal: Hydronephrosis (***Unilateral)
- Postnatal: Renal mass (Hydronephrosis) / workup after UTI
Imaging:
- USG (see dilatation of renal pelvis)
- MAG3 / DTPA scan (***obstructive pattern on diuretic enhanced radionucleotide scan)
- CT / MR urogram (Not standard)
Treatment:
1. Pyeloplasty (Anderson-Hynes)
- removing blockage + reconnecting ureter to renal pelvis
- stent (double J) may be left across the pyeloplasty anastomosis / a nephrostomy may be left above the repair to decompress the kidney
Collecting system abnormalities
- Duplication
- Partial (only 1 ureteric opening into bladder)
- Complete (2 ureteric openings into bladder)
—> associated with Ureterocele - Ureterocele
- Intravesicle
- Ectopic
—> terminal cystic dilatation of ureter, associated with duplication anomalies
—> both can cause obstruction to upper urinary tract
Paediatric renal tumours
Neonates:
Renal:
1. Mesoblastic nephroma
2. Wilms tumour (Nephroblastoma) (less common)
3. Clear cell sarcoma (less common)
4. Rhabdoid tumour (less common)
Adrenal:
1. Phaeochromocytoma
2. Neuroblastoma
-
Interactive Tutorial: Paediatric Urology28
-
Interactive Tutorial: BPH26
-
Case Study: Urology 1: BPH13
-
Case Study: Urology 2 & Interactive Tutorial: Urological Cancer21
-
Case Study: Breast Surgery17
-
Interactive Tutorial: Hydrocephalus & Paediatric Neurosurgery16
-
Interactive Tutorial: Carcinoma Of Lung13
-
Interactive Tutorial: Chest Trauma And Lung Transplant22
-
Interactive Tutorial: Surgery Treatment Of Coronary Artery Disease And Heart Transplant28
-
Interactive Tutorial: Surgery For Heart Valve Disease26
-
Practical Skills: Common Bedside Ultrasound Examination10
