title: Valved shunt as a treatment for obstructive uropathy: does pressure make a difference?
abstract: OBJECTIVE
  A valved ventriculo-peritoneal shunt (V-P shunt) as a vesico-amniotic shunt (V-A shunt) preserves the filling/emptying cycle and normal bladder development in fetal lambs with bladder outlet obstruction. The optimal pressure for such shunts is unknown.
  
  
  METHODS
  We created obstructive uropathy in 60-day gestation fetal lambs. A V-A shunt was placed 3 weeks later, using a low-pressure (Group L: 15-54 mmH2O) or a high-pressure (Group H: 95-150 mmH2O) V-P shunt. We included non-shunted (obstructive uropathy, Group O) and control lambs (Group C). All were delivered at 130 days. Bladder volumes, bladder thickness, renal and bladder histology were compared.
  
  
  RESULTS
  Seventeen lambs had an obstructive uropathy created. Five Group L (four survived), four Group H (three survived) and five Group O survived. Body weight and crown-to-rump lengths of the three groups were not significantly different. Group H lambs had a dilated urachus, urinary ascites and severe ureteral dilatation similar to Group O lambs. There were four Group C lambs. Bladder volume was 10, 15 and 1,150 ml in Group H, 115 ± 67.9 ml in Group L, 128 ± 99.8 ml in Group O and 24.5 ± 3.84 ml in Group C. Unlike Group O lambs, Group L did not have urinary ascites, urinomas or renal dysplasia.
  
  
  CONCLUSIONS
  Low-pressure shunts preserved both bladder volume and renal development. High-pressure shunts did neither.
authors: Division of Pediatric Surgery, St. Marianna University School of Medicine, Sugao, Miyamae-ku, Kawasaki, Japan. h2kita@marianna-u.ac.jp
authors: Hiroaki
authors: H
authors: Kitagawa
authors: Yasuji
authors: Y
authors: Seki
authors: Hideki
authors: H
authors: Nagae
authors: Takeshi
authors: T
authors: Aoba
authors: Shutaro
authors: S
authors: Manabe
authors: Kei
authors: K
authors: Ooyama
authors: Junki
authors: J
authors: Koike
authors: Masayuki
authors: M
authors: Takagi
authors: Jane
authors: J
authors: Zuccollo
authors: Shinobu
authors: S
authors: Tatsunami
authors: Kevin C
authors: KC
authors: Pringle
mesh_terms: D000818:Animals; D004108:Dilatation, Pathologic; D005260:Female; D046128:Fetal Therapies; D008297:Male; D011312:Pressure; D012756:Sheep; D014497:Urachus / Q000473:pathology; D001743:Urinary Bladder / Q000196:embryology; D001748:Urinary Bladder Neck Obstruction / Q000196:embryology / Q000601:surgery*; D017287:Ventriculoperitoneal Shunt / Q000379:methods
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