The Unstable Detrusor

Abstract

The unstable detrusor (detrusor instability), a common condition in men and women, causes significant morbidity in sufferers and a great financial expense to health care providers. The condition is associated with symptoms of urinary frequency, urgency and urge incontinence. The embarrassing nature of these symptoms means patients are often reluctant to seek medical help and as a consequence there is under-reporting. Epidemiological studies are difficult to perform but appear to show that incidence increases with age and that the unstable detrusor is the commonest cause of male urinary incontinence. The aetiology is still much debated with reasoned arguments for both neurogenic and myogenic causes, though in truth, the likely explanation is multifactorial rather than a single underlying pathological process. The diagnosis can only be made on urodynamic testing. Before deciding on suitable treatment, the clinician must assess the disease severity and also its impact on patient quality of life. This is because perceived improvement in patient quality of life must outweigh any potential morbidity associated with treatment. Pharmacotherapy is based on blocking bladder muscarinic receptors. Unfortu-nately, no treatment is bladder specific and therefore most drug therapies have unwanted systemic anticholinergic side effects. Surgical treatment often involves a degree of bladder denervation to reduce bladder activity. This can consequently produce voiding difficulties which necessitate patients to self-catheterise on a longterm basis.

Loss of ryanodine receptor calcium‐release channel expression associated with overactive urinary bladder smooth muscle contractions in a detrusor instability model

“…In the present study we used a BOO‐induced model of DI in rats, which shares similar pathogenesis with DI after obstruction in other animal models, and in humans in clinical practice [2,3,18]. The bladder responds to the increased afterload by hypertrophy to normalize wall tension, and with persistent afterload, myogenic disorders appear, including DI.…”

Nocturia: A non‐specific but important symptom of urological disease

“…In both cases, the storage symptom of nocturia is considered to result from an insufficient bladder capacity (Fig. 1), possibly related to non‐voiding detrusor contractions 30,31 . Other local factors leading to nocturia and possibly occurring in association with LUTS/BPH and/or OAB include a decreased structural bladder capacity.…”

“…1), possibly related to non-voiding detrusor contractions. 30,31 Other local factors leading to nocturia and possibly occurring in association with LUTS/BPH and/or OAB include a decreased structural bladder capacity. Although LUTS/BPH can be brought about by disease-related factors such as cancer in situ, fibrosis, radiation therapy and ageing can also contribute to a decrease in bladder capacity.…”

Altered expression of calcium‐activated K and Cl channels in detrusor overactivity of rats with partial bladder outlet obstruction

“…Sometimes these kinds of spontaneous contractions are sensitive to some ion‐channel antagonists, but not to nerve blockers, and are distinct from the micturition contractions under normal innervation [1,2]. DO induced by partial BOO (PBOO) is thought to be neurogenic and/or myogenic, resulting from changes in detrusor innervation, cell‐to‐cell communication, and myocyte excitability [3–5]. The myogenic basis is associated with an increase in the excitability and spontaneous contractile activity of the DO myocytes [3].…”