This document discusses pelvi-ureteric junction obstruction (PUJO). It notes that PUJO is the most common site of congenital ureteral obstruction, occurring in about 1 in 1250 births with a male to female ratio of 2:1. PUJO can be either intrinsic, due to adynamic smooth muscle, or extrinsic, due to aberrant vessels or bands. Diagnosis is typically made through antenatal ultrasound showing pelvic dilation or postnatally through ultrasound and renography demonstrating obstruction. Surgical management includes open pyeloplasty techniques or minimally invasive approaches like laparoscopy or endopyelotomy.

1. Pelvi-Ureteric Junction
Obstruction

2. Contents
 Embryology
 Incidence
 Etiology
 Pathogenesis
 Diagnosis
 Surgical management

4. Incidence
 1 in 1250 births.
 M:F = 2:1
 Bilateral in 10-36%
 Most common site of congenital ureteral
obstruction.

5. Etiology
 Two types of PUJO – Koff
 Intrinsic – most common (adynamic)
 Extrinsic – aberrant vessels, adhesive bands,
AVMs and Ostling folds.
 Intra luminal – ureteral valves, fibro-
epithelial polyps

6. Pathogenesis
 Chang and colleagues – deleted
Calcineurin B type 1 (CnB1) gene –
aperistalsis.
 Wang and colleagues – antagonized
BMP4 and Nogin protein – inhibition of
smooth muscle formation – adynamic
segment.

7. Clinical features
 Antenatal USG
 Postnatally
 Episodic flank pain
 Abdominal pain
 UTI
 Dietl crisis – cyclic abdominal pain with
vomiting.

8. Diagnosis
 Ante-natal : sonographic features
 Pelviectasis
 Normal amniotic fluid volume
 No ureteral dilatation
 Normal thickness of the bladder wall
 Normal cycling of the bladder

9.  Postnatal diagnosis
 USG Abdomen
 Highly accurate in the diagnosis of
hydronephrosis.
 Pelviectasis and caliectasis, absence of
ureterectasis, normal bladder cycling and normal
bladder thickness

10. Post natal diagnosis
continued...
 Cannot diagnose obstruction.
 Limiting factor - renal function

11. Renograms
 Technitium 99m renal scintigraphy
 Diethylene triamine pentaacetic acid(DTPA) –
neither secreted nor absorbed.
 Mercapto acetyl tri glycine (MAG 3) – secreted from
renal tubules
 Di-mercapto succinic acid (DMSA) – strong affinity
to renal tubular cells.
 Arbitrary threshold for surgical intervention –
35%

12.  VCUG – VUR is associated with PUJO in
9-14%.
 Magnetic Resonance Urography
 Doppler study – vascular imaging.

13. Surgical management
 Open technique
 Minimal invasive techniques
 Laparoscopy
 Endopyelotomy

14. Open technique
 Anaesthesia
 Position of the patient

15. Surgery...
 Incision
 Flank incision – tip of twelfth rib towards the
umbilicus
 Extra-peritoneal approach.
 External oblique, internal oblique, latissimus
dorsi and serratus posterior divided

16. Surgery...
 Diaphragm released from the tip of 12th
rib
 Peritoneum separated from Gerota’s fascia
 Self retaining retractor
 Kidney mobilized
 Ureter identified, looped, traced towards
kidney.

17. Surgery...
 Division of PUJ

18.  Anderson Hynes

19.  Foley Y-V plasty

20.  Spiral flap

21.  Excision of PUJ and spatulation of the ureter
 Ureteral stent/nephrostomy tube
 Anastomosis – lower lip of renal pelvis to the
spatulated apex of ureter.
 Posterior layer first - continuous or intermittent
 6-0 or 5-0 sutures
 Suturing continued until pelvis closed.

22.  Bladder catheter
 Perinephric drain

23. Laparoscopy

24. Laparoscopy
 Infants vs older children
 Pain
 Length of hospital stay
 Population based comparison of laparoscopic and open pyeloplasty in paediatric‐
pelvi ureretic junction obstruction - John Knoedler, Leona Han, Candace Granberg,‐
Stephen Kramer, George Chow, Matthew Gettman, Brittany Kimball, James Moriarty,
Simon Kim, Douglas Husmann

25. Thank You