L22 - Renal abnormalities

Question 1

KIDNEY DEVELOPMENT

i) what first outpouches close to the mesonephric duct?
ii) what effect does it have on the metanephric blastema?
iii) what occurs in the ureteric bud which leads to formation of a duplex system?

Answer 1

i) ureteric bud
ii) ureteric bud induces metanephric blastema to be become a kidney
iii) if the ureteric bud branches before it meets the metanephric blastema

Question 2

CONGENITAL KIDNEY PROBLEMS

i) what is mayer rokitansky syndrome? what benign condition is it commonly associated with?
ii) what forms if the lower poles of the kidney fuse across the midline?
iii) what can CAs predispose to?

Answer 2

i) vaginal agenesis, uterus and fallopian tube abnormality associated with unilateral absent kidney
ii) horseshoe kidney
iii) UTIs

Question 3

UTI

i) what is pyuria?
ii) what might it be difficult to obtain?
iii) what should be looked for on urine dipstick?
iv) what is the most common surgical cause of UTI?

Answer 3

i) lots of WBC in urine - 10 or more per m3
ii) mid stream urine
iii) nitrites
iv) VUR - vesicouretral reflux

Question 4

VESICO URETRAL REFLUX

i) what is it?
ii) what may it cause?
iii) how many it be diagnosed? (2) what may be seen?
iv) how many grades of VUR are there?
v) what can it result in? which imaging technique can be used to see this?
vi) how is it uusually managed? after what age may it self resolve? what may be prescribed?

Answer 4

i) when urine flows backwards from bladder > ureter/kidney
ii) can cause UTI

iii) diaganosed antenatally or after UTI
- may see a dilated ureter

iv) 5
v) can result in kidney damage > chronic scarring due to pyelonephritis - use DMSA scan

vi) usually non operative and resolves with age (5 years)
- can prescribe trimethoprim (prohylactic antibiotics

Question 5

STING

i) what can it be used to correct?
ii) what does it involve?

Answer 5

i) can be used for surgical correction of reflux
ii) involves injecting a gel/polysaccharide where ureters and bladder meets > stops backflow

Question 6

HYDRONEPHROSIS

i) what is it? what causes it?
ii) what can a UTI here result in?
iii) when may it be diagnosed? which imaging can be used (2)
iv) what happens to the structure of the system?

Answer 6

i) swelling of the kidney due to build up of urine
- happens when urine cant drain out the kidney due to obstruction

ii) UTI can result in pyonephrosis > pus build up in collecting sys
iii) can be diagnosed antenatally > US or nuclear MCU scan

Question 7

MEGA URETER

i) what has happened to the ureter? why? (2)
ii) what may it be associated with?
iii) what does it need to be differentiated from?
iv) which type of scan can look for obstruction?

Answer 7

i) dilated ureter due to reflux/obstruction where ureter joins bladder
ii) may be associated with other probelsms such as duplex system
iii) needs to be differen from VUR
iv) MAG3 scan

Question 8

POSTERIOR URETHRAL VALVES

i) what is it?
ii) when does it normally present?
iii) which sex does it only affect?
iv) what does outcome depend on?

Answer 8

i) urethral blockage near the bladder which causes urine to be pushed back to the kidney = swelling/cant pass urine
ii) normally presents in neonatal period or can be antenatally diagnosed
iii) only affects boys
iv) outcome dep on initial renal damage

Question 9

STRUCTURAL ABNORMALITIES

i) in buried penis is the penis normally sized or small?
ii) what is hypospadias?
iii) what can cause bilateral undesc testes/hypospadias/ambigous genetalia?
iv) what is a ureterocele? what CA is it most commonly found with?
v) what can cause a hydrocele hernia?

Answer 9

i) normal sized but buried in body
ii) opening of the penis is on the underside of penis instead of tip
iii) congenital adrenal hyperplasia
iv) distal ureter balloons where it enters the bladder forming a pouch > commonly occ with duplex system
v) when testes descend > tunica vaginalis usually disappears but if it doesnt it can cause hernia

Question 10

UNDESCENDED TESTES

i) what is it?
ii) what % of newborn boys does it occur in? what % ascend spontaneously? what % of boys age 1 have it?
iii) what can predispose?
iv) why is it important to treat? (2)
v) where may ectopic testes be?
vi) what is the best investigation?

Answer 10

i) when testis cannot be manipulated to the bottom of the scrotum without undue tension of the spermatic cord

ii) 3.4% of newborn boys
- 2/3 ascend spontaneously
1% age 1 boys have it

iii) familial predisposition

iv) can turn malignant
- testes will not produce sperm if they are not in the scrotum due to temperature difference bet abdomen and scrotum

v) ectopic > abdo wall, thigh, base of penis

vi) laproscopy
- fowler stephens tehcnique