Megaureter
Key points
BAPU consensus 2014
Definition: >7mm
Antibiotic prophylaxis if hydroureteronephrosis (HUN)
MCUG for all bilateral HUN and males with unilateral HUN
Once bladder outlet obstruction and vesicoureteric reflux VURexcluded - MAG3 for VUJO if >10mm
Obstructing if increase in HUN on USS or differential function <40%
Avoid re-implant in infancy due to small bladder - use side to side refluxing ureteroneocystostomy
Whitaker test
To differentiate upper tract obstruction from non-obstructed dilatation (now mostly obsolete)
Nephrostomy + urethral catheter with pressure sensors
Inject contrast and measure pressure differential
Management:
Only 10-30% require intervention
Likely to resolve if <10mm
If refluxing, manage same as VUR
Obstructing megaureter/HUN -
Balloon dilatation and stent
9.5Fr Cystoscope
Example balloon sizes - 4 and 6 mm
Can have cutting and non-cutting balloons
If cannot stent (due to tortuous system etc), then ureterostomy/nephrostomy/ureterocystostomy (anastomosis of ureter to side of bladder - can be done side to side without disconnecting ureter)
Kaefer procedure (2014 JPU paper)- refluxing end to side ureter-bladder anastomosis
Do not do formal ureteric reimplant before age 1 - risk of bladder injury and unable to create long enough submucosal tunnel to prevent reflux
After age 1 - consider re-implant (Cohen/Lich Gregoir/Politano-Leadbetter)
If very dilated ureter - at re-implant do Starr plication
If bilateral reimplant - reimplant 1 ureter then anastomose other side to it
Follow up USS and MAG3 post op
References
Farrugia MK, Hitchcock R, Radford A, Burki T, Robb A, Murphy F; British Association of Paediatric Urologists. British Association of Paediatric Urologists consensus statement on the management of the primary obstructive megaureter. J Pediatr Urol. 2014 Feb;10(1):26-33. doi: 10.1016/j.jpurol.2013.09.018. Epub 2013 Oct 16. PMID: 24206785.
Contini G, Mele E, Capozza N, Castagnetti M. Endoscopic balloon dilatation for the treatment of primary obstructive megaureter <24 months of age: Does the size of the balloon influence results? J Pediatr Urol. 2023 Apr;19(2):198.e1-198.e9. doi: 10.1016/j.jpurol.2022.11.021. Epub 2022 Nov 24. PMID: 36494270.
Kaefer M, Misseri R, Frank E, Rhee A, Lee SD. Refluxing ureteral reimplantation: a logical method for managing neonatal UVJ obstruction. J Pediatr Urol. 2014 Oct;10(5):824-30. doi: 10.1016/j.jpurol.2014.01.027. Epub 2014 Feb 28. PMID: 24850437.