[Primary megabladder in adults. Comments apropos of 21 cases]

Based on a review of 21 cases, clinical, urodynamic and therapeutic a of primary megalocystis in adults are discussed. This rare entity is defined as an abnormally large bladder capacity in the absence of any obstruction or neurologic lesion, and without effects on the upper urinary tract. The residue is constant whereas, paradoxically, dysuria may be absent and mictional output normal (8 of the 21 cases). Urodynamic tests distinguished two groups of patients: one in which bladder contractility was still present but decreased rapidly as a function of volume to be excreted, while flow was good; the other in which bladder contractility and flow were altered. Therapeutic possibilities are discussed as a function of results obtained. Depending upon the structural alterations of the bladder wall, medical treatment (cholinergic drugs) are usually ineffective. An interesting solution is the use of abdominal pushes in cases with hypo- or acontractile bladder. Aleatory results of surgery to reduce bladder capacity and/or reinforce bladder contraction suggest its use only as first intention surgery for bladders with retained contractile possibilities. Operations on bladder neck in women carry the risk of incontinence and should be considered only as function of results of other methods, and with the reservation that closure pressure should be at least 80 cm initially. Finally, abstention under surveillance is also an alternative in this context.