Renal scarring in spinal cord injury: a progressive process?

STUDY DESIGN: A retrospective analysis. OBJECTIVES: To examine the natural history of renal scarring in the spinal cord injured population. SETTING: United Kingdom. METHODS: All spinal cord injured patients with renal scars at our establishment were considered eligible. A total of 27 patients with renal scars were identified. No patient had renal scarring at presentation on radiological imaging. All patients had annual renal imaging with a mean follow up period of 19.1 years. The presence of new scars was considered as evidence of progression. RESULTS: In all, 59% of kidneys developed renal scars with a mean time interval between spinal injury and renal scar development of 13 years. Of these kidneys with scars, only 15.6% demonstrated progression of the scarring process. There were no deaths due to renal causes. CONCLUSION: The aetiology of renal scarring is multifactorial. The findings of this study suggest that renal scarring in the spinal cord injured population is predominantly a nonprogressive process once a scar has developed. This is in concordance with the belief that renal scarring in the paediatric population with vesicoureteric reflux is also a stable, nonprogressive process.

Use of Memokath temporary urethral stent in treatment of detrusor-sphincter dyssynergia.

In spinal-injured patients, detrusor-sphincter dyssynergia (DSD) can lead to high intravesical pressures, upper tract dilation, and recurrent infections. The standard treatment for DSD is sphincterotomy and, more recently, permanent sphincter stenting. Many spinal-injury patients would prefer a reversible treatment because of concern about fertility or because they are awaiting a "miracle cure." There is also concern over the theoretical long-term risk of squamous carcinoma after permanent stenting. In view of this, the Memokath, a thermosensitive temporary stent, has been undergoing trials at our center to determine which patients could benefit. Fourteen Memokath stents have been inserted in spinal-injured patients with DSD at our center, and they have been followed up for as long as 2 years. Stents were placed under cystoscopic guidance as a day case procedure. The stents were inserted either through the sphincter alone (short [4-cm] stents; 3 patients) or through the sphincter and bladder neck (long [5-7-cm] stents; 11 patients). There were no complications during surgery in either placement or removal of these stents. There was a significant (p < 0.001) reduction in the residual urine volume after stenting. Preoperative hydronephrosis and attacks of autonomic dysreflexia noted in some patients also resolved after stenting. Short stents that bridge the external urethral sphincter were ineffective in emptying the neuropathic bladder. Therefore, we advise that only long stents that lie across both the bladder neck and the external sphincter be used. Because of its easily reversible nature, the Memokath should be adopted for use in patients who are unsure about their preferred option of bladder management and those involved in a fertility program.