[Neurogenic bladder: pathophysiology of the disorder of compliance]

Bladder compliance is defined by the ratio of the increase of intravesical pressures to the increase of volume (_V/_P). The pathophysiology of disorders of compliance in neurogenic bladder is still poorly elucidated. It can be evaluated in terms of three elements: 1) The natural history of the appearance of these disorders in neurogenic bladders. Clinical experience shows the existence of prognostic factors that determine the development of these disorders, such as the voiding mode adopted (self-catheterization/hetero-catheterization versus indwelling catheter), the level of the spinal cord lesion (suprasacral versus sacral, incomplete versus complete, and cauda equina lesions), and the presence of meningomyelocele. 2). Data derived from conservative management of these disorders in neurogenic bladders: urethral dilatation, various sphincterotomies, bladder disafferentation, alpha-blockers, vanilloids (resiniferatoxin and capsaicin), intra-detrusor botulinum toxin and intrathecal baclofen, have demonstrated a marked improvement of disorders of compliance associated with neurogenic bladder 3). Data derived from experimentations. Morphometric studies on animal or human bladder strips have demonstrated an increased expression of proteolytic enzymes and endogenous tissue inhibitors of metalloproteinases (MMP-1) and type III collagen mRNA in hypocompliant neurogenic bladders. Reduction of bladder wall blood flow, bilateral section of hypogastric nerves in rats, study of the bladders of spinalized rats, and reduction of oestrogenic hormone impregnation, show that these conditions induce loss of the viscoelastic properties of the bladder With the arrival of new treatments, active on afferent and/or efferent pathways or even on the central nervous system, it is very important to further our understanding of the pathophysiology of disorders of compliance in neurogenic bladders. Reversibility of these disorders constitutes a major therapeutic challenge and its functional consequences make it a critical prognostic factor for the outcome of neurogenic bladder