What is new in detrusor-sphincter dyssynergia treatment in spinal cord injury patients?

Abstract

Unbalanced bladder function represents one of the main problems in spinal cord injured patients. Bladder outlet obstruction, especially detrusor-sphincter dyssynergia, is the principal cause of impaired voiding. Currently, intermittent self-catheterization with eventual additional anticholinergic drugs is the best conservative method to achieve low pressure voiding and continence. Electrical stimulation to empty the bladder is possible at various stimulation sites: the bladder wall, the pelvic nerves, the sacral roots and the spinal cord. With respect to electrode application, stimulation of the sacral roots is most attractive. Several selective procedures aiming to overcome the concomitant stimulation-induced external urethral sphincter contractions have been described. Some of these are widely used and doing well in humans (post-stimulus voiding principle), whereas others are still undergoing experimentation (collision blocks, anodal blocks, quasitrapezoidal impulse). Whatever the choosen method, electrical stimulation of the bladder is to be reserved for selected cases. If the introduction of the self-catheterization failed, sphincterotomy remained, until recently, the only alternative to overcome detrusor- sphincter dyssynergia. However, post-operative complications and long-term failure are not infrequent. Botulinum-A injections into the external urethral sphincter to induce partial paralysis, represents an attractive alternative to surgical sphincterotomy. Easiness of the method and satisfactory long-term results have encouraged physicians to use it more often in neurogenic voiding disorders. Reversibility and innocuousness of the procedure enhanced patients acceptance.