Urinary calculi following traumatic spinal cord injury

Objective. To investigate the time aspect of the development of renal and bladder calculi in individuals with traumatic spinal cord injury (SCI) and a possible relation between the development of calculi and the bladder-emptying method. Material and methods. The study comprised a retrospective data collection from medical records and a questionnaire follow-up at least 10 years after the SCI. Results. A total of 236 individuals with SCI (82% male, 18% female; 47% tetraplegic, 53% paraplegic) who were injured between 1956 and 1990 participated in the study and the response rate was 84.6%. The mean age at the time of follow-up was 50.5 years (range 28-84 years). The mean duration from the time of SCI was 24.1 years (range 10-45 years). During follow-up 47 participants (20%) had at least one episode of renal calculi and 32 (14%) had at least one episode of bladder calculi. The risk of first renal and bladder calculus was highest within the first 6 months post-injury. The cumulative proportion of calculi-free participants 45 years post-injury was 62% for renal calculi and 85% for bladder calculi. For participants who did not develop renal calculi within the first 2 years post-injury, the risk of having a renal calculus within the next 43 years was 34%. For bladder calculi the corresponding risk of having a bladder calculus within the next 43 years was 5%. No significant differences were found regarding the bladder-emptying method and either renal or bladder calculi, only a non-significant trend that more participants with bladder calculi used indwelling catheters. Participants with renal or bladder calculi were not statistically significantly different from the remainder of the study group regarding gender, para- or tetraplegia or Frankel classification. Conclusions. The risk of developing renal and bladder calculi was higher in the SCI population compared to the normal population. Bladder calculi primarily occur early post-injury and renal calculi appear both early post-injury and years later. Therefore, it is important to follow individuals with SCI regularly by means of urological investigations from the time of the injury until death.