MP1-04 DRAMATIC EFFECTS OF BILATERAL BIPOLAR L6-S1 TRUNK NEUROSTIMULATION ON CONTINUOUS CYSTOMETRIC PARAMETERS BEFORE AND AFTER BLADDER IRRITATION

Abstract

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research I1 Apr 2014MP1-04 DRAMATIC EFFECTS OF BILATERAL BIPOLAR L6-S1 TRUNK NEUROSTIMULATION ON CONTINUOUS CYSTOMETRIC PARAMETERS BEFORE AND AFTER BLADDER IRRITATION Matthew O. Fraser, Alexis A. Dieter, Danielle J. Degoski, and Paul C. Dolber Matthew O. FraserMatthew O. Fraser More articles by this author , Alexis A. DieterAlexis A. Dieter More articles by this author , Danielle J. DegoskiDanielle J. Degoski More articles by this author , and Paul C. DolberPaul C. Dolber More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.102AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Sacral neurostimulation (SN) has been found to be effective in the treatment of overactive bladder and urge incontinence. However, the precise mechanisms of action (MOA) by which this occurs remain unknown. Further understanding of the MOA requires a robust experimental model with a greater therapeutic window than is currently available. We examined the effects of bilateral bipolar L6-S1 trunk SN on lower urinary tract function, as determined by continuous cystometry (CMG), in female rats before and after intraluminal irritation. METHODS A catheter was secured in the bladder dome in 10 urethanized female SD rats. The L6-S1 trunks were isolated from surrounding sacral tissues with a small sheet of parafilm. Fine diameter wire electrodes were positioned rostrally and caudally on the nerves bilaterally. CMG was performed with saline at 0.1 ml/min. SN parameters were 10 Hz, 0.1 msec pulse duration, at below threshold intensities for hind quarter movement. After SN testing with saline, half of the rats were switched to 0.25% acetic acid (AA) to induce bladder irritation. SN efficacy was again tested. Outcome measures were bladder capacity (BC), filling compliance (FC), and nonvoiding contraction (NVC) count, maximum amplitude (Max Amp), and period. Pre- and during-SN data with saline were compared using the Wilcoxon test, and saline vs. AA, pre- and during-SN, by non-parametric 2-Way RM ANOVA. P<0.05 was considered significant. RESULTS BC was increased 66% by SN with saline (n=10, P=0.0020) and 432% during AA (n=5, P=0.0038). AA resulted in a 61% reduction of BC (n=5, P=0.0292). In 4 rats, SN resulted in elimination of the void reflex during saline and, in 2/4, under AA. FC was unaffected by SN or infusate. SN increased NVC count to 77% (n=10, P=0.0020) and 429% (n=5, P=0.0041) of pre-SN counts under saline and AA, resp. AA resulted in a reduction to 63% of saline counts (n=5, P=0.0301). Linear regression revealed a positive relationship between NVC count and BC (P<0.0001, R2=0.81). NVC Max Amp were increased 67% (n=10, P=0.0076) and 109% (n=5, P=0.0830(NS)) by SN under saline and AA, resp. No effect of AA on NVC Max Amp was observed. CONCLUSIONS In our novel model, bilateral bipolar SN of the L6-S1 trunks increases BC without affecting normal myogenic motor activity associated with filling. That such stimulation is capable of completely abolishing the micturition reflex in some animals, with or without intraluminal irritation, demonstrates the utility of this model for future pharmacologic dissection of the MOA for this therapeutic approach. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e2 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Matthew O. Fraser More articles by this author Alexis A. Dieter More articles by this author Danielle J. Degoski More articles by this author Paul C. Dolber More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...