Significance of low compliance bladder in cauda equina injury

Abstract

STUDY DESIGN: Prospective investigation using serial urodynamic studies. OBJECTIVE: To evaluate type of neurogenic bladder and to observe changes of autonomous detrusor contraction (ADC) after the normalization of the compliance and capacity of the bladder in cauda equina injury. SETTING: Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: Urodynamic studies were performed in 50 patients with complete cauda equina injury from trauma with an infusion ratio of 30 ml/min. Findings of urodynamic studies and clinical features of patients with low compliance were compared with those of the normal compliant patients. Fourteen patients with low compliance received oral administration of oxybutynin and propiverine and intravesical instillation of oxybutynin to increase the compliance and capacity of the bladder, and follow-up urodynamic studies to monitor the change were undertaken. RESULTS: Bladder compliance was decreased in 14 (28%) patients and normal in 36 (72%) patients. There was a significantly long time interval between the onset of injury and the initiation of rehabilitative treatment in the neurogenic bladder group with low compliance when compared to those of the normal compliance group (P < 0.05). Clean intermittent catheterization was used as the voiding method, significantly less than the normal compliance group (P < 0.05). ADC was observed in six out of fourteen patients with low compliance neurogenic bladder, but none in the normal compliance group. Upon the completion of conservative treatment, ADC disappeared in four patients whose compliance and capacity of the bladder were normalized on follow-up urodynamic studies. CONCLUSION: ADC was only observed in the low compliant bladder and as ADC disappeared when compliance and capacity of the bladder was normalized; low compliance appeared to be the main cause of ADC. In addition, this study supports that the maintenance of compliance of the bladder may be the most important factor in the management of neurogenic bladder.