Paediatric Urology Flashcards
From where do the urinary and genital systems develop
Intermediate mesoderm (common mesodermal ridge running along the posterior wall of the abdominal cavity)
What is the origin of the definitive kidney
Metanephros
Where is the ureter/renal pelvis derived
Mesonephric duct
Where is the collecting system of the kidney derived
Ureteric bud from the mesonephric duct
Where is the excretory system (e.g. glomeruli, tubules) of the kidney derived
Metanephric blastema
From where are the bladder (apart from the trigone) and urethra derived
Urogenital sinus (anterior part of the cloaca)
Where is the trigone of the bladder derived
Mesoderm
What sex is the default
Female
When do the gonads acquire male/female morphology
Week 7
Where in the testes is testosterone produced
Leydig cells
What happens to the medullary cords at puberty
Acquire a lumen to form the seminiferous tubules
What structure guides the descent of the testis
Gubernaculum
When do the testes reach A) the inguinal canal, and B) the external inguinal ring
A) 7 months
B) 8 months
When does the Processus Vaginalis close and what are the consequences of this not happening
- 1 year
- Hydrocele or congenital inguinal hernia
What gives rise to the ovarian ligament
Gubernaculum
What gives rise to the round ligament
Uterovaginal canal (Gubernaculum)
What does the mesonephric duct contribute to the male genitalia
- Epididymis
- Vas deferens
- Seminal vesicles
- Ejaculatory ducts
From where are the Fallopian tubes derived
Paramesonephric ducts
Describe the development of the male external genitalia
- Genital tubercle becomes the phallus
- Urethral folds (of cloaca) become the penile urethra
- Genital swellings form the scrotum
What is the result of failure of fusion of the urethral folds
Hypospadias
Describe the development of the female external genitalia
- Genital tubercle forms the clitoris
- Urethral folds do not fuse and become the labia minora
- Genital swellings become labia majora
What is Potter Syndrome
- Bilateral renal agenesis
- Characteristic features of oligohydramnios and characteristic facial appearance
- Pulmonary hypoplasia leads to stillbirth
In whom are lower pole renal vessels common
Children with pelviureteric obstruction
What is the inheritance pattern of adult polycystic kidney disease
Autosomal dominant
What is the inheritance patterns of infant polycystic kidneys
Recessive
What are the associations of APKD
- Cystic change in other organs e.g. liver, spleen, pancreas
- Berry Aneurysms of the circle of Willis
- Mitral valve prolapse
What urological conditions is tuberous sclerosis associated with
- Angiomyolipomata
- Polycystic kidneys
Describe horseshoe kidney
- Fusion of the inferior pole occurs before the kidneys have rotated along the long axis
- The IMA prevents ascent
- Ureter enters the bladder ectopically
Describe uretrocele
- Cystic dilatation of the intramural part of the ureter
- Commonly occurs in association with the upper-pole ureter of a duplex system
Describe a retrocaval ureter
- Abnormality in the development of the posterior cardinal vein
- Ureter lies BEHIND vena cava
- Compression of the ureter can occur between IVC and vertebrae
What is the investigation of choice for assessing PUJ obstruction
MAG-3 scan will show delayed drainage of the kidneys
When is surgery indicated in PUJ obstruction
- Symptomatic
- Increasing hydronephrosis on serial USS
- Declining renal function
When would nephrectomy be considered in PUJ obstruction
If the kidney is functioning poorly (<15% differential function)
How is PUJ obstruction treated
Dismembered retroperitoneal (Anderson-Hynes) pyeloplasty
Define vesicoureteric reflux
Abnormal backflow of urine from the bladder into the ureter and kidney
Describe the pathophysiology of VUR
- Shortened intramural course of ureter due to lateral displacement
- Diminished function of VU junction
Outline the 5 grades of VUR
1 = reflux into ureter only, no dilatation 2 = reflux into renal pelvis on micturition, no dilatation 3 = mild/moderate dilatation of the ureter, pelvis, calyces 4 = dilatation of the renal pelvis and calyces with moderate ureteral tortuosity 5 = gross dilation with ureteral tortuosity
What does VUR predispose to
Recurrent UTI
How is VUR managed
- Prophylactic antibiotics
- Surgery if progressive renal damage or breakthrough UTI
What is the most common cause of bladder outlflow obstruction in boys
Posterior urethral valves
Describe hypospadias
Urethral meatus opens onto the ventral surface of the penis (75% distally located)
What is associated with hypospadias
- Undescended testis
- Inguinal hernia
- Bifid scrotum
- Chordae and renal and ureteric abnormalities
When is surgery performed for hypospadias
Between 9 and 18 months
How is hypospadias treated
- Urethroplasty
- Penile reconstruction
Define a retractile testis
Sits high in the scrotum or inguinal canal but can be milked into the scrotum and stays in the scrotum with minimal tension
Define an undescended testis
During development the testicle has been arrested somewhere along the course of normal descent and does not reach the bottom of the scrotum by 3 months of age
Define a maldescended/ectopic testis
Situated somewhere other than the usual course of descent
What is the increase in risk of malignancy associated with Cryptochidism
10x
When should orchidopexy be performed for undescended testis
Before 1 year (6-18 months)
What structural abnormality are undescended testes typically associated with
Patent processus vaginalis
What is indicated if the testis are impalpable
Laparoscopy
Inheritance pattern of congenital adrenal hyperplasia
Autosomal recessive
Features of Klinefelter syndrome (47 XXY)
- Increased height
- Mild learning disability
- Gynaecomastia
- Infertility
Describe testicular feminisation
- Chromosomally XY
- BUT present as females due to complete androgen insensitivity of the genitalia
What gene codes for Wilm’s tumour
WT1 gene
How are children <6 months of age investigated following UTI
USS 6 weeks post-UTI
How are children aged 6 months to 3 years investigated following atypical UTI
- USS
- DMSA scan
