Dilated ureter > 7 mm diameter.
Often detected antenatally.
Important to determine if obstructed, refluxing, both or neither.
3 broad categories:
- Obstructed megaureter
Usually due to intrinsic, primary obstruction or stenosis at the distal ureter/VUJ – “VUJ obstruction”.
Can also be due to an aperistaltic segment near bladder.
Markedly dilated ureter proximally to a “normal” or thinned segment at VUJ typical finding.
Need to exclude reflux with MCUG, and PUV in boys first.
Indications for treatment:
- Poorly functioning kidney < 35 – 40 % on renogram
- Recurrent UTIs or other symptoms
Treatment = ureteric reimplantation (Cohen cross-trigonal or Politano-Leadbetter) – preferably after 1st birthday at least. May need to plicate or taper ureter. Bilateral cases may think about reimplant/hitch one side with TUU.
Can be temporised with a ureteric stent.
- Non-refluxing, non-obstructed megaureter
Dilated but not obstructed. Often unclear aetiology – ?VUJ obstruction which has resolved, but with ongoing stretched, dilated ureter.
Surveil – may occasionally need treatment if recurrent UTIs etc.
- Refluxing megaureter
Treat as per reflux.