[Disorders of bladder compliance and neurogenic bladder]

Bladder compliance is defined as the relationship between change in bladder volume and change in detrusor pressure (DV/DP). The pathophysiology of neurogenic disorders of bladder compliance is still poorly understood. Experimental reduction of blood flow in the bladder wall, bilateral hypogastric nerve section in rats, the study of spinalized rat bladders, and reduction of oestrogen 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 on the central nervous system, it is very important to improve our understanding of the pathophysiology of neurogenic disorders of bladder compliance. The reversibility of these disorders constitutes a major therapeutic challenge and their functional consequences constitute a crucial prognostic element of neurogenic bladder. Disorders of bladder compliance can be assessed clinically from two points of view: 1) The natural history of onset of these disorders in neurogenic bladder. Clinical experience demonstrates certain risk factors for the development of these disorders, such as the voiding mode (intermittent self-catheterization or by a carer versus indwelling catheter), the level of the spinal cord lesion (suprasacral versus sacral, incomplete versus complete, and cauda equina lesions), and the presence of myelomeningocele. 2) Data derived from conservative management of these disorders in patients with neurogenic bladder: urethral dilatation, various types of sphincterotomy, vesical denervation, alpha-blockers, sympatholytics, vanilloids (resiniferatoxin and capsaicin), intra-detrusor botulinum toxin and intrathecal baclofen have been shown to improve disorders of compliance of neurogenic bladder.