Introduction: To evaluate the effects of percutaneous radiofrequency sacral rhizotomy in spinal cord injured (SCI) patients on urodynamic parameters (maximum cystometric capacity - MCC and detrusor pressure at maximum cystometric capacity - PdetMCC). Material and Methods: This prospective study assessed eight patients with SCI (four men and four women) with a mean age of 31.3 years (22 to 41). Mean interval period between spinal cord lesion and rhizotomy was 53.5 months (20 to 96). All patients underwent an anesthetic block of the 3rd sacral root bilaterally using 0.5% bupivacaine under fluoroscopic control. Those who responded with an increase on bladder capacity were selected to undergo the percutaneous radiofrequency sacral rhizotomy. All patients underwent urodynamic evaluation at 6 and 12 months following the procedure. MCC and PdetMCC were recorded. Results: All patients presented a significant improvement on MCC after 12 months. The mean vesical volume increased from 100.2 +/- 57.1 to 282.9 +/- 133.4 ml (p<0.05). The P(det)MCC reduced from 82.4 +/- 31.7 to 69.9 +/- 28.7 cmH(2)O (p=0.2). Three patients with autonomic dysreflexia had complete relief of symptoms after the procedure. At 12 months, recurrence of detrusor hyperactivity was observed in all patients. One patient presented abolishment of reflex erections after the procedure. No major complications related to the rhizotomy were noted. Conclusions: Percutaneous radiofrequency sacral rhizotomy is a minimally invasive technique with low morbidity able to increase MCC. There is a trend towards the reduction of the PdetMCC in SCI patients at 12 months, although statistical significance was not reached. (C) 2010 AEU. Published by Elsevier Espana, S.L. All rights reserved.356325330