LABORATORY VARIABLES OF BLADDER AUTOAUGMENTATION IN AN ANIMAL-MODEL

Objectives. Evaluations of the functional, radiologic, and pathologic outcomes of autoaugmentation by two surgical techniques (vesicomyectomy versus vesicomyotomy) were compared. Autoaugmentation or vesicomyotomy is being increasingly considered as a simplified method of bladder augmentation in the hypertonic decreased-capacity bladder. Methods. In a series of 35 laboratory sessions, creation of an animal model approximating the small-capacity hypertonic bladder was achieved. Sixteen vesicomyotomies and 16 vesicomyectomies were performed on the 32 stabilized one-third reduced bladders. Three stabilized one-third reduced bladders were used as controls. Results. Radiologic studies show a large diverticulum. A 17.2% net increase in surface area was achieved, compared with the reduced bladder, at the time of pathologic examination. Functional capacity was increased by 43.5% on urodynamic studies, and leak point pressure was decreased by 48.1 %. Histologic and morphometric examinations of the autoaugmentation area showed a few muscle fibers with serosal deposition of collagen. There was less muscle ingrowth at the periphery of the autoaugmentation site utilizing vesicomyectomy. Conclusions. There was no statistical difference between vesicomyotomy and vesicomyectomy with respect to radiologic, pathologic, or urodynamic outcome.