Page 106 - Bladder Dysfunction in the Context of the Bladder-Brain Connection - Ilse Groenendijk.pdf

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Chapter 5
parameters significantly changed; bladder volume at first sensation, bladder capacity, maximum detrusor pressure and Qmax.22-24 The acute effect of SNM on UDS has never been investigated.
Therefore, the aim of this study is to evaluate the acute effect of SNM on the different UDS parameters.
MATERIALS AND METHODS
The present study was approved by the local medical research ethics committee (METC 2017-471). Prior to the study, written informed consent was obtained from all patients.
Patients
Patients with OAB and urodynamically proven detrusor overactivity, who were sched- uled for PNE, were eligible for screening. Exclusion criteria were age under 18 years, intravesical botulinumtoxinA injections in the past 9 months, predominant stress urinary incontinence, bladder pain syndrome, neurogenic bladder, urinary tract infec- tion, having an indwelling catheter, previous radiotherapy of the pelvis, pregnancy and malignancies of the lower urinary tract.
Intervention
Our standard care procedure for PNE was performed and is as follows. All anticholiner- gics and β3-adrenoceptor-agonists were stopped two weeks prior to the PNE. The PNE is done in the outpatient clinic under local anesthesia. PNE’s were performed using the PNE-sets of Medtronic (4 patients) or Axonics (6 patients). A test electrode is inserted into one of the S3 foramens of the sacrum. Placement is considered correct if stimula- tion is felt in the vagina, penis, perineum or anus. The electrode is then connected to the external nerve stimulator (ENS). In the current study, the patient underwent a urodynamic study (UDS 1) after placing the electrode but before the ENS was turned on. This study was performed according to ICS criteria, using a 7 Fr transurethral double lumen catheter and an 8 Fr rectal pressure sensor.25,26 The bladder filling rate was 50 ml/min. The patient was asked to indicate the first sensation of bladder filling, the first desire to void and the moment of a strong desire to void. Permission to void was then given. Post void residual volume was determined through the catheter. Next, the ENS was turned on with the stimulation amplitude just above the sensory threshold and the pulse width and frequency set at 210 usec and 14 Hz, respectively. The urodynamic study was then repeated (UDS 2). The patients were given antibiotics for three days to prevent urinary tract infections following the urodynamic study. After the urodynamic study, the standard procedure was resumed, that is, the patient completed a bladder