Recurrent kidney stone: a 25-year follow-up study in persons with spinal cord injury

Abstract

Objectives: To document the recurrence rate of kidney stones in patients with spinal cord injury and to assess the potential contributing factors and long-term renal function outcome.

Methods: A consecutive sample of 77 patients with initial kidney stones followed up on a yearly basis between 1973 and 1999 was used to estimate stone recurrence, stratified by demographic and clinical characteristics. Longitudinal data analyses were performed to assess the change in renal function over time among various post-treatment outcomes.

Results: During an average of 7 years (range 1 to 21) of follow-up after the initial stone episode, 19 patients with recurrence, 15 with residual stones, and 43 who were stone free were documented. It was estimated that approximately 34% of the patients with an initial stone would develop a second stone episode within 5 years. This figure did not significantly change during the past 25 years (P = 0.18). Stone recurrence was two or more times greater for men than for women, for whites than for blacks, and for tetraplegics than for paraplegics, but the differences were not statistically significant (P >0.05). Renal function did not significantly decline over time for any of the post-treatment outcomes of the initial stones.

Conclusions: Despite marked improvement in urologic rehabilitation, little progress has been made during the past 25 years in reducing stone recurrence in persons with spinal cord injury. Future studies are required to determine the critical components of the causal pathway to stone formation, which may lead to the establishment of effective prophylactic interventions.