Hydronephrosis and vesicoureteral reflux

Question 1

Hydronephrosis

Answer 1

Dilation of renal calyces. Usually secondary to obstruction of the urinary tract.

In peds patients, the obstruction is often at the ureteropelvic junction.

In adults, it may be due to BPH, neurogenic bladder (diabetes/spinal cord injury), tumors, AA, or renal calculi. Can also be caused by high-output urinary flow and vesicoureteral reflux.

Question 2

History and exam for hydronephrosis

Answer 2

May be ASx, or may present with flank/back pain, lowUO, abdominal pain and UTIs

left untreated, hydro resulting from urinary obstruction leads to HTN, acute or chronic renal failure, or sepsis and has a very poor prognosis

Question 3

Dx of hydronephrosis

Answer 3

1) US* or CT to detect dilation of renal calyces and/or ureter
2) Increased BUN and Cr provide evidence of secondary renal failure

Question 4

Tx for hydro

Answer 4

1) Surgically correct any anatomic obstruction; use laser or sound wave lithotripsy if calculi are causing obstruction
2) Ureteral stent placement across the obstructed area of the urinary tract and/or perc nephrostomy tube placement to relieve pressure may be appropriate if urinary outflow tract is not sufficiently cleared of obstruction. Foley or suprapubic cath may be needed for lower urinary tract obstruction (BPH)

Question 5

Vesicoureteral reflux

Answer 5

Retrograde projection of urine from the bladder to the ureters and kidneys. May be due to posterior urethral valves, urethral or meatal stenosis, or a neurogenic bladder.

1) Mild reflux (grades 1-2) - no ureteral or renal pelvic dilation. Often resolves on its own
2) Moderate to severe (grades 3-4) - ureteral dilation with associated caliceal blunting in severe cases

Question 6

History and exam for VU reflux

Answer 6

Patients present with recurrent UTIs, typically in childhood.

Prenatal US may identify hydro

Question 7

Dx of VU reflux

Answer 7

Obtain a voiding cystourethrogram to detect abnormalities at ureteral insertion sites and to classify the grade of reflux

For kids under 2 with their first febrile UTI, an US should first be obtained and a VCUG only performed if there is evidence of scarring, hydro, or other findings suspicious for high grade VUR

Question 8

Tx for VUR

Answer 8

1) Treat infections aggressively. Treat mild reflux with daily ppx ABx (amoxicillin if less than 2 months old, otherwise TMP-SMX or nitrofurantoin) until reflux resolves
2) Surgery (ureteral reimplantation) is reserved for kids with persistent high grade reflux. Inadequate treatment can lead to progressive renal scarring and ESRD

Question 9

Most common congenital urethral obstruction

Answer 9

Posterior urethral valves

Classically, male infant with a distended, palpable bladder and low urine output