Detrusor wall thickness and lower urinary tract function after spinal cord injury

Abstract

Objective To determine any relationship among detrusor wall thickness (DWT),bladder capacity (BC) and neurogenic lower urinary tract dysfunction (NLUTD),and to study the clinical implications of using DWT to predict the risk of renal injury after spinal cord injury (SCI).Methods Forty-eight adults with NLUTD due to SCI were recruited for the SCI group,and another 41 healthy adults formed a control group.Both groups underwent urodynamic evaluation and maximum bladder capacity (MBC) detection.The DWT of all subjects was measured by ultrasound imaging of the anterior bladder wall.Thereafter,the SCI group was divided into low and high risk subgroups based on the results of the urodynamic tests.Patients with detrusor leak point pressure ＜40 cmH2O were classified as low risk.Results At MBC,the average DWT in the SCI group was (0.97 ± 0.31)mm and (0.59 ± 0.08)mm in the control group,demonstrating a significant difference in DWT between patients with NLUTD and normal adults.The average DWT among the patients with type A detrusor sphincter dyssynergia was (1.10 ± 0.34)mm,which was significantly higher than among the patients with external urethral sphincter contraction without detrusor contraction (type C).DWT was significantly correlated with detrusor leak point pressure.A DWT of 0.87 mm (sensitivity 89.5％,specificity 58.6％) could be used as a critical point for predicting risk of renal injury in patients with NLUTD.Conclusions DWT is significantly greater among SCI patients with NLUTD and it correlates positively with detrusor leak point pressure.DWT could be used as a risk predictor for renal injury in patients with NLUTD due to SCI. Key words: Detrusor wall thickness; Spinal cord injury; Urinary tract dysfunction; Urology