Urodynamic evaluation of sacral neuromodulation for urge urinary incontinence.
OBJECTIVE
To evaluate the urodynamic data before and 6 months after implantation of sacral neuromodulation (SNM, an established treatment for voiding dysfunction, including refractory urge urinary incontinence, UI) and to assess the correlation between the urodynamic data and clinical efficacy in patients with UI.


METHODS
In all, 111 patients with a >50% reduction in UI symptoms during a percutaneous nerve evaluation test qualified for surgical implantation of SNM. Patients were categorized in two subgroups, i.e. those with UI with or without confirmed detrusor overactivity (DO) at baseline. At the 6-month follow-up all patients had a second urodynamic investigation, with the stimulator switched on.


RESULTS
At baseline, there was urodynamically confirmed DO in 67 patients, while 44 showed no DO. A review of filling cystometry variables showed a statistically significant improvement in bladder volumes at first sensation of filling (FSF) and at maximum fill volume (MFV) before voiding for both UI subgroups, compared with baseline. In 51% of the patients with UI and DO at baseline, the DO resolved during the follow-up. However, those patients were no more clinically successful than those who still had DO (P = 0.73). At the 6-month follow-up, 55 of 84 implanted patients showed clinical benefit, having a >or=50% improvement in primary voiding diary variables. Patients with UI but no DO had a higher rate of clinical success (73%) than patients with UI and DO (61%), but the difference was not statistically significant.


CONCLUSIONS
These urodynamic results show a statistically significant improvement in FSF and MFV in patients with UI with or with no DO after SNM. Although there was a urodynamic and clinical improvement in both groups, patients with UI but no DO are at least as successful as patients with UI and DO. Therefore in patients with UI, DO should not be a prerequisite selection criterion for using SNM.
Groenendijk
Pieter M
PM
Leiden University Medical Centre, Leiden, The Netherlands. groenenp@rdgg.nl
Lycklama à Nyeholt
August A B
AA
Heesakkers
John P F A
JP
van Kerrebroeck
Philip E V
PE
Hassouna
Magdy M
MM
Gajewski
Jerzy B
JB
Cappellano
Francesco
F
Siegel
Steven W
SW
Fall
Magnus
M
Dijkema
Hero E
HE
Jonas
Udo
U
van den Hombergh
Ubi
U
D004599:Electric Stimulation Therapy; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008160:Lumbosacral Plexus; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome; D053201:Urinary Bladder, Overactive / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D053202:Urinary Incontinence, Urge / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D014563:Urodynamics / Q000502:physiology*