Hydronephrosis

Question 1

What is hydronephrosis?

Answer 1

Hydronephrosis is swelling of one or both kidneys because of the inability of urine to drain resulting in build-up in the kidney.

This can occur from a blockage in the ureters or from an anatomical defect.

Question 2

Who does it affect?

Answer 2

Hydronephrosis can happen at any age.

=> Hydronephrosis in children may be diagnosed during infancy or prenatal ultrasound

Question 3

What is the clinical presentation of hydronephrosis?

Answer 3

Asymptomatic or mild symptoms:

=> Pain on urinating

=> Frequency

=> Urgency

More severe symptoms:

=> Pain in the flank and back that may radiate to lower abdomen or groin

=> Incomplete voiding

=> Nausea & vomiting

=> Fever

=> Failure to thrive, in infants

Question 4

What are the causes of hydronephrosis?

Answer 4

1. Acute unilateral obstructive uropathy => sudden development of obstruction in one of your ureters

The most common cause of acute unilateral obstructive uropathy:

i. Kidney stone
ii. Obstruction
iii. Blood clots

Common site of obstruction:

i. Ureteropelvic junction (kidney meets ureter)
ii. Vesicoureteric junction (ureter meets bladder) - less common
2. Enlarged prostate gland i.e. BPH, prostatitis
3. Pregnancy
4. Tumours in or near ureter
5. Narrowing of ureters due to congenital defect or injury

Question 5

What is the pathology underlying hydronephrosis?

Answer 5

Obstruction of ureter leads to back flow of urine into the kidney

=> this is known as vesicoureteral reflux

=> causing the kidney to swell up, increasing the pressure

=> if left untreated for long, the pressure can cause permanent kidney damage

Question 6

How is hydronephrosis diagnosed?

Answer 6

1. Ultrasound of kidney and bladder = gold standard
2. Blood test: U&E, FBC, eGFR, serum creatinine
3. Urinalysis: infection, proteins, stones
4. Palpable kidney
5. Catheter to drain urine => if small amount if urine drained, it could mean obstruction is in bladder or urethra

Question 7

How do you treat hydronephrosis?

Answer 7

Treatment depends on the underlying cause:

If due to blockage:

i. insert a ureteral stent allowing the ureter to drain into the bladder
ii. insert a nephrostomy tube allowing blocked urine to drain through the back
iii. prescribe antibiotics to control infection

Scar tissue, blood clot or kidney stone => endoscopic surgery to remove the affected area and join the healthy areas together

Question 8

What is a common complication of hydronephrosis?

What are the assoc. symptoms?

Answer 8

UTI => due to reflux and stasis of urine

Pyelonephritis

Symptoms:
cloudy urine
painful urination
burning with urination
weak urine stream
back pain
bladder pain
fever
chills

Question 9

Read urinary tract obstruction pg 640-41 in Ox handbook

Answer 9

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