Studies on the overactive bladder with special reference to diagnosis, classification and surgical treatment

Abstract

The overactive bladder (OB) is a symptom of disturbed neuromuscular control of the lower urinary tract. The cause is sometimes obvious, but even a lesion that is minor and difficult to detect might be of significance. The diagnosis is set by cystometry and in order to create a uniform classification the Standardisation Committee of the International Continence Society (ICS) have suggested that OB with known neuropathy should be called "detrusor hyperreflexia" while in all other cases the term "unstable detrusor" should be used. The aim of this study was to investigate patients diagnosed as having "unstable detrusor". They were all classified according to a functional system, which includes the bladder cooling test. In this system, three subtypes are easily distinguished: phasic detrusor instability, uninhibited overactive bladder and spinal detrusor hyperreflexia.A further entity having urgency and urgency incontinence but with urodynamically stable detrusor, characterised by a steep pressure slope at the end of filling, was identified. In order to separate poor compliance from tonic bladder contraction, the bladder was treated with 150ml 2% lidocaine before a second cystometry.We also tested the hypothesis that "unstable bladder" in fact is an expression of a subtle neurological disorder. A trained neurologist performed a thorough neurological examination including analysis of cerebrospinal fluid as well as biothesiometer testing in a group of patients with OB without known neurological disease or symptoms. Two more recent surgical techniques for treatment of OB were evaluated, sacral nerve stimulation and clam ileocystoplasty.Results: Intravesical lidocaine reduced bladder pressure in three out of twenty-one patients and revealed an instability in another five. Of the forty-five patients, eighty-two per cent exhibited neurological signs when examined in detail. Nineteen per cent had immunopathy in cerebrospinal fluid. Eighteen per cent received a neurological diagnosis. A total of thirty patients were submitted to an acute test with sacral neuromodulation resulting in nine permanent implants. All patients had a positive effect of the implant at some time during the postoperative period. However, the effect varied over time and was also influenced by external factors. A remarkable spread of positions was noted regarding the temporary electrode. In thirty patients operated upon, the clam ileocystoplasty restored continence and reduced urge symptoms in ninety per cent, in accordance with their reporting of satisfaction with their voiding postoperatively.Conclusions: OB can present itself with different cystometric patterns.The current classification seams inadequate in several respects. Sacral neuromodulation is a promising treatment for OB. Patient selection, electrode position and stimulation parameters should be the subject of further studies. This technique should be reserved for specialised centres. For the treatment of severe urgency incontinence, the clam ileocystoplasty is an effective alternative for the well-motivated patient.