Sacral neuromodulation is a well-accepted treatment in urology for overactive bladder (OAB) and non-obstructive urinary retention (NOUR). The implant of the internal pulse generator (IPG) is usually preceded by a test using a temporary of definitive electrode. However, the duration of the test period varies between different centers, and no clear guidelines exist upon the optimal duration of the test, although a longer test identifies more patients that respond to this treatment.[1]
This study evaluates the clinical responses upon sacral neuromodulation with the tined lead procedure (TLP) during a three weeks test period with weekly reprogramming.

In this prospective study from September 2015 until March 2018, 71 patients (age 20-79Y) with OAB or NOUR underwent a tined lead procedure. 
Patient setup was done the same day as the TLP. The following electrode settings were tested: 0-3+/0-1+/0-2+/1-0+/1-2+/1-3+/2-0+/2-1+/2-3+/3-0+/3-1+/3-2+. Square wave pulses with pulse width of 210 µsec and 14 Hz frequency were delivered at the respective electrodes with increasing amplitudes up to the sensory threshold. The amplitude was noted as well as the point that the patient marked. After one week patients were evaluated on their findings. If there was no changing or less than 50% improvement of the complaints, the electrode settings were tested again, and other electrode configuration was programmed. The same procedure could be repeated after two weeks, if necessary. Test success was defined as more than 50% improvement on voiding diary parameters: frequency and incontinence episodes for OAB and number of self-catheterizations for NOUR.

16 Patients (22,8%) were male and 55 patients (77,4%) female. 45 Patients (63,3%) were primarily treated for OAB and 26 patients (37,2%) for NOUR. Neurogenic disorders were present in 9 (12,6 %) of the patients and bladder pain complaints in 2 (2,8%) patients.
All  71 records were useful. 
After the three weeks test period: 42 of the 71 patients (59,1%) were considered successful test responders. After the first week, 20 of the 71 (33,8%) patients had an improvement of 50% and didn’t need other parameter settings during the test phase. 4 patients out of 71 didn’t received other settings due to circumstances and also didn’t get the IPG implant. The other 47 patients (66,1%) were reprogrammed based upon their sensory responses after 1 week. At the end of the second week 23 out of 47 patients (48,9%) received a third reprogramming, 8 out of 23 (34,7%)  had an improvement of 50% or more. At the end of the third week 22 out of 47 (46,8%) patients met the criteria for test responders.

This study shows that almost half of the study subjects responding to the test procedure (22/47; 46,8%) were reprogrammed after 1 or 2 weeks possibly suggesting the initial settings used to start the test period were not the most optimal ones. Furthermore, out of the 29 patients that failed the test period, 14 (48,3%) patients didn't received reprogramming after one or two weeks due to lack of patient responsibility to contact the treatment center, thereby reducing their own chance of a succesful test procedure.

Close follow up of patients during tined lead testing with reprogramming sessions may help to identify patients which were initially programmed with a suboptimal electrode configuration settings and thereby increasing efficacy rates of the tined lead procedure. To achieve such a close follow up, the patient should be clearly informed of its benefits.

Kessler TM, Madersbacher H, Kiss G. Prolonged sacral neuromodulation testing using permanent leads: a more reliable patient selection method? Eur Urol 2005; 47: 660-5.