title: Comparison of bladder rupture pressure after intestinal bladder augmentation (ileocystoplasty) and myomyotomy (autoaugmentation).
abstract: OBJECTIVE
  To compare the risk of bladder rupture of bladder augmentation using ileocystoplasty versus that of autoaugmentation with myomyotomy in a rat model.
  
  
  METHODS
  Bladder rupture pressure and volume of three groups of female Sprague-Dawley rats were determined by cystometry. The first group of 11 rats had undergone ileocystoplasty using a detubularized 1 -cm segment of ileum. A second group of 9 rats had undergone autoaugmentation with myomyotomy. One month after surgery the animals were studied cystometrically to determine the bladder rupture pressure, then killed. A third group, consisting of 10 nonoperated rats, was studied and served as controls.
  
  
  RESULTS
  Nonoperated, control rat bladders were able to sustain 154 +/- 43 mm Hg pressure and 2.5 +/- 2.0 mL volume prior to bladder rupture. Conventional ileocystoplasty was noted to increase bladder capacity to 4.0 +/- 1.9 mL, but decrease rupture pressure to 111 +/- 49 mm Hg. Myomyotomy resulted in a mean bladder rupture volume of 1.2 +/- 0.4 mL, with a rupture pressure of 101 +/- 13 mm Hg. The rupture pressure after myomyotomy is significantly lower than that of the native bladder (P < 0.001), whereas the rupture volume after myomyotomy is significantly lower than either after the ileocystoplasty or with the native bladder (P < 0.001). Bladder rupture occurred at the augmented ileal bladder dome in 7 of 11 ileocystoplasty animals and at the anastomotic suture line in 4 animals. Bladder rupture occurred at the area of bladder diverticulum in all 9 myomyotomy animals. Among controls, no specific site pattern of bladder rupture was noted.
  
  
  CONCLUSIONS
  Bladder augmentation with myomyotomy increases vulnerability to urinary extravasation, evidenced by a significantly reduced rupture pressure and bladder volume at rupture when compared to the native bladder.
authors.affiliation: Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Rivas
authors.forename: M B
authors.initials: MB
authors.lastname: Chancellor
authors.forename: B
authors.initials: B
authors.lastname: Huang
authors.forename: A
authors.initials: A
authors.lastname: Epple
authors.forename: T E
authors.initials: TE
authors.lastname: Figueroa
mesh_terms: D000818:Animals; D005260:Female; D007082:Ileum / Q000637:transplantation*; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012422:Rupture, Spontaneous; D001743:Urinary Bladder / Q000503:physiopathology / Q000601:surgery*; D001745:Urinary Bladder Diseases / Q000209:etiology* / Q000503:physiopathology