Contractile detrusor

For prognostic and therapeutic reasons, only functional classifications based on the reflex activity of the different muscle groups involved in storing and evacuating urine should be used. One commonly used classification is based primarily on the reflex activity of the detrusor muscle, defining three types contractile detrusor (detrusor hyperreflexia), acontractile detrusor (detrusor areflexia), and intermediate detrusor (mixed type). 

Fig. 16.1. Male, 15 years old. Lumbosacral myelomeningocele, contractile detrusor, sphincter detrusor dyssynergia VCU. Contrast-filled bulging posterior urethra, minimal leakage around the catheter, massive reflux of contrast into dilated prostatic ducts. Filling defect (arrowhead) indicates prostatic concrement...

The bladder neck is usually competent in infants and children with contractile detrusors, whereas it is mostly nonobstructive and incompetent in children with intermediate or acontractile bladders at their usual bladder volumes. 

Fig. 16.7a,b. Male, 4 years old. Lumbar myelomeningocele, contractile detrusor VCU. a Closed bladder neck during bladder filling, bladder trabeculation, and sacculation, b Uninhibited detrusor contractions, massive back-up flow of contrast infusion contrast filled bulging bladder neck (arrow) up to contracted external sphincter (sphincter detrusor dyssynergia), some leakage around the catheter... 

Filling cystometry provides information on bladder capacity, detrusor contractility, and the presence of uninhibited bladder contractions, which could also cause LUTS... 

DHIC detrusor hyperactivity with impaired contractility... 

Babiychuk EB, Draeger A 2000 Annexins in cell membrane dynamics. Ca2+-regulated association of lipid microdomains. J Cell Biol 150 1113-1124 Ber DM 2001 Excitation-contraction coupling and cardiac contractile force, 2nd edn. Kluwer Academic Publishers, Dordrecht/Boston/London Blaustein MP, Golovina VA 2001 Structural complexity and functional diversity of endoplasmic reticulum Ca2+ stores. Trends Neurosci 24 602—608 Flynn ER, Bradley KN, Muir TC, McCarron JG 2001 Functionally separate intracellular Ca2+ stores in smooth muscle. J Biol Chem 276 36411-36418 Fry CH, WuCl 997 Initiation of contraction in detrusor smooth muscle. Scand J Urol Nephrol Suppl 184 7-14... 

Brading The appearance of spontaneous contractile activity in detrusor strips depends very much on their thickness. 

Bladder underactivity may also result in overflow incontinence. Under certain circumstances, the detrusor muscle of the bladder may become progressively weakened and eventually lose the ability to voluntarily contract. In the absence of adequate contractility, the bladder is unable to empty completely, and large volumes of residual urine... 

Various types of UI may coexist in the same patient. The combination of bladder overactivity and urethral underactivity is termed mixed incontinence. This is often a difficult diagnosis to make because of the often-confusing array of presenting symptoms. Bladder overactivity may also coexist with impaired bladder contractility. This is most common in the elderly and is termed detrusor hyperactivity with impaired contractility. ... 

Resnick NM, Yalla S. Detrusor hyperactivity with impaired contractile function. An unrecognized but common cause of incontinence in the elderly patient. JAMA 1987 257 3076-3081. 

Malmqvist U, Arner A, Uvelius B (1991b) Cytoskeletal and contractile proteins in detrusor smooth muscle from bladders with outlet obstruction—a comparative study in rat and man. Scand J Urol Nephrol 25 261-267... 

A recently published immunohistochemical study revealed that specimens of exstrophied bladders reveal fewer myelinated nerve fibers than normal individuals (Mathews et al. 1999). Normally, the innervation of the detrusor determines its ability to contract. Since the exstrophied bladder does not store any urine during intrauterine development, there is no need for contractions and innervation, which may explain the above-mentioned difference in innervation (Mathews et al. 1999). Up to now it is unclear whether this finding can predict contractility of the former exstrophied bladder. 

Based on the reflex activity of the detrusor muscle and the fact that most children with myelodysplasia do not fit into the classical anatomical and neurological categories, a classification system with three types of bladder dysfunction (contractile, acontrac-tile, and intermediate) is in use (Rickwood et al. 1982). 

In contractile bladders (hyperreflexive detrusor), uninhibited detrusor contractions lead to a sudden bladder-neck opening in a formerly normally configured bladder base, with bulging of the posterior urethra up to the contracted external sphincter. This VCU finding is the manifestation of sphincter detru-... 

A novel series of 1-aryl-3-(thiophen-2-yl)-1 H-1,2,4-triazol-5(4H)-one derivatives was synthesized and evaluated as detrusor muscle relaxants for the treatment of urinary incontinence. The effects of these compounds on bladder contractile function were determined in vitro by using isolated rat bladder strips from male Sprague-Dawley rats that were pre-contracted with carbachol. The results of the SAR studies in this series led to the identification of several potent smooth muscle relaxants. The design, synthesis, and SAR of the series will be presented. 

Kropp, B. R, B. D. Sawyer, H. E. Shannon et al. 1996b. Characterization of small intestinal submucosa regenerated canine detrusor Assessment of reinnervation, in vitro compliance and contractility. 

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