The predictive value of a repeat micturating cystourethrogram for remnant leaflets after primary endoscopic ablation of posterior urethral valves.
OBJECTIVE
We routinely perform a cystourethroscopy 3 months after initial ablation of posterior urethral valves. The aim of this study was to determine the predictive value of the urethral appearance on preoperative micturating cystourethrogram (MCUG) for further valve resection at check cystoscopy.


METHODS
We retrospectively reviewed 31 consecutive boys (aged 4-18 months) who underwent check cystoscopy and repeat MCUG between 2006 and 2008.


RESULTS
Repeat MCUG suggested remnant valves in 10, but no residual leaflets were identified cystoscopically in 4. In 20 boys, the valves appeared completely ablated on MCUG but valve leaflets received further resection in 10. One study was undiagnostic. Residual valves were resected in 83% (5/6) where valves and urethral dilatation were noted on MCUG. Where MCUG suggested either valves or persistent dilatation alone, further resection occurred in 40% (4/10). Remnant leaflets were also present in half of those (7/14) in whom the repeat MCUG had shown complete ablation and resolved/reduced posterior urethral dilatation.


CONCLUSIONS
The positive predictive value of valve leaflets and/or posterior urethral dilatation on repeat MCUG for subsequent resection of valve remnants was 56%; the negative predictive value was 50%. We found repeat MCUG alone imprecise in excluding residual valve tissue and recommend check cystoscopy in all.
Department of Paediatric Urology, Great Ormond Street Hospital NHS Trust, London WC1N 1EH, UK. naima.smeulders@talktalk.net
Naima
N
Smeulders
Erica
E
Makin
Divyesh
D
Desai
Patrick G
PG
Duffy
Costa
C
Healy
Peter M
PM
Cuckow
Abaraham
A
Cherian
Melanie P
MP
Hiorns
Imran
I
Mushtaq
D003558:Cystoscopy; D004724:Endoscopy; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014525:Urethral Stricture / Q000473:pathology* / Q000601:surgery*; D014554:Urination; D013520:Urologic Surgical Procedures