Prognostic value of urodynamic testing in myelodysplastic patients. Commentary

We herein describe the clinical progress of 42 myelodysplastic patients studied urodynamically and followed for a mean of 7.1 years. Urodynamic evaluation included urethral pressure profilometry, simultaneous determination of urethral pressure, intravesical pressure and external anal or external urethral sphincter electromyography with fluoroscopic voiding cystourethrography. Assessment of urethral function showed 36 patients (86 per cent) with an open vesical outlet and nonfunctional proximal urethra. Cystometrography revealed that 7 of 42 patients (17 per cent) had reflex detrusor activity: 4 with coordinated micturition and 3 with detrusorsphincter dyssynergia. Thirty-five patients (83 per cent) had areflexic detrusor dysfunction: 5 with atonic detrusor response and 30 with a progressive increase in pressure with increasing volume. The intravesical pressure at the time of urethral leakage was 40 cm. water or less in 20 patients and at pressures greater than this value in 22 patients. No patient in the low pressure group had vesicoureteral reflux and only 2 showed ureteral dilatation on excretory urography. In contrast, of the patients in the higher pressure group 15 (68 per cent) showed vesicoureteral reflux and 18 (81 per cent) showed ureteral dilatation on excretory urography. Thus, a striking relationship between the urethral closure pressure and intravesical pressure at the time of urethral leakage and the clinical course in this group of myelodysplastic patients is demonstrated. Every patient with a normally closed vesical outlet was continent on intermittent catheterization and an anticholinergic agent, while only 60 per cent of patients with open bladder outlets similarly treated achieved good urinary control and none was dry. An artificial sphincter device would seem to be a reasonable method to achieve urinary control in the latter patients but the detrusor response to filling also must be considered. Detrusor hypertonia should be controlled or controllable before a sphincter augmenting device can be used safely. Treatment options for patients with high urethral closure pressures include intermittent catheterization and anticholinergic medications or a sphincter ablative procedure to decrease the outlet resistance combined with anticholinergic therapy and implantation of an artificial sphincter. However, only longer followup will determine if these therapeutic regimens will prevent upper urinary tract deterioration.