To evaluate the impact of previous back pain, spinal infiltration or radio frequent denervation procedures (SIDP) and back surgery on the outcome of sacral neuromodulation (SNM) using percutaneous nerve evaluation (PNE) and tined lead procedure (TLP).

All patients who underwent test stimulation for sacral neuromodulation between October 2011 and December 2016 were retrospectively included in our database. Medical files were thoroughly searched for primary indication of SNM, history of back pain, SIDP and major back surgery (all subdivided in cervical, thoracic or lumbosacral problems). The outcome of the test stimulation was evaluated and those with >50% improvement in the predominant complaint (incontinence/urgency/frequency/residual urine/CIC) were considered a success and proceeded to IPG implant. Chi-square analysis was used to compare implant rate between groups.

Of 128 patients who underwent test stimulation (95,3% TLP; 4,7% PNE), 82 (64,1%) received an implantable pulse generator .
Mean age was 53,16 ± 16,00 years and 80,3% were female.
Primary indications for SNM were idiopathic overactive bladder(OAB) dry: 8,6%, OAB wet: 51,6%, non-obstructive urinary retention (NOUR): 22,7% and OAB or retention due to neurogenic bladder: 17,2%. Back complaints were present in 52 patients (40,6%%; 13,5% cervical, 5,8% thoracic, 53,8% lumbosacral, 19,2% multiple complaints and 7.7% unspecified). Of these, back surgery and/or SID was performed in 34 patients (26.6%: 17.6% cervical surgery, 17.6% lumbosacral SID, 47.1% lumbosacral surgery, 14.7% multiple procedures and 2.9% unspecified). The other 76 (59,4%) constituted the control group.
No statistical difference in mean age, the distribution of sex and the prevalence of primary indications were withheld between the control group and group with backpain and prior back surgery, respectively (p=0,072 and p=0,093, p=0,729 and p=0,877, p=0,385 and p=0,764).
Chi-square analysis showed no significant difference in implant rate between the control group (67,1%) and the group with back complaints (59,6%) (p=0,386) nor between the control group and the group with prior back surgery (58,8%) (p=0,458).
Also, no significant difference in implant rate was noted between groups when stratified according to the location of back pain (p=0,586), the location of back surgery and/or SIDP (p=0,788) and the primary indication for SNM (p=0,386, p=0,458).

A large number of SNM patients have back complaints and/or prior back surgery. Although the patients without back pain, SIDP and/or back surgery had a higher implant rate compared to those with, no statistical difference could be withheld, possibly due to a relative small sample size. However, the majority of patients with backpain, SIDP and/or prior back surgery proceeded to a definitive implant. In addition, the outcome appears to be independent of the location of the back pain or surgery and the primary indication for SNM.

SNM seems to be a valid treatment option in patients with prior back pain or back surgery.