1. Duplex Kidneys Unraveled
Chris Driver
Aberdeen

3. Duplication Anomalies
0.8% population
40% bilateral
Inheritance
autosomal dominant incomplete penetrance
8% in siblings of index case

4. Types of duplex complete incomplete 2 UO’s VERY rarely 2 kidneys
1 UO only
divided outside bladder
usually no clinical issues

5. Embryology
Ureteric Bud Induces Renal Differentiation

6. Duplex ureters cross over

7. Mackie Stephen’s Hypothesis J Urol 1975
↑distance from orthotopic site = ↑ dysplasia

8. Duplex MOST DUPLEXES ARE CLINICALY IRRELEVANT Upper Moiety
Low / ectopic orifice
Lower Moiety
High Lateral orifice

9. If the lower moiety is ectopic....
lateral UO
VU reflux
dysplasia

11. Management of Reflux in Duplex
indication
UTI
progressive scarring
less likely to resolve spontaneously
STING or HIT
En Bloc reimplantation
lower pole hemi-nephroureterectomy

12. If the upper moiety is ectopic.....
low UO
obstruction, ureterocele
extra-vesical ectopic

15. C:\
Ureterocele

19. Management of Duplex Ureterocele
indications
obstruction especially bladder neck
hydronephrosis
loss of function
UTI
remember.....single system (non duplex) ureterocele is rare

20. Endoscopic Puncture
definitive
(temporising)
Risk = induced reflux

21. Definitive management
No upper pole function - Upper pole nephrectomy

22. Definitive management
Good upper pole function, big ureterocele - Uretero-ureterostomy

23. Definitive management
Good upper pole function, small ureterocele – en bloc reimplantation

24. Definitive management
No upper pole function, obstructing ureterocele - heminephroureterectomy

25. Ectopic Ureter “she’s always wet, doctor.....”
primary
continuous
normal voiding pattern otherwise
can be very wet....

26. Extravesical Ectopic Ureter
females
HN HU usually BUT
may not be associated with dilatation
small dysplastic upper moiety
“CRYPTIC DUPLICATION”

27. Investigation of Cryptic Duplication
USS- may miss small non-dilated
IVU- may miss poor function, clues
Retrograde Pyelogram....difficult ++
MRU
new gold standard

30. If so small, why so wet? DYSPLASTIC RENAL TISSUE GOOD RENAL TISSUE
GFR 1ml/min
60 mls/hour
<50% reabsorption in tubules
Urine output 30 mls per hour
= 720mls/day
= very wet!
GOOD RENAL TISSUE
GFR 100ml/min
6000 mls /hour
99.9% reabsorption in tubules
Urine output 60 mls per hour

31. Summary Duplex lower moiety: Reflux upper moiety: Obstruction
ectopic orifice: Incontinence