Overactive bladder (OAB) is a condition of urgency symptoms without or with incontinence. There are several modalities for the OAB treatment, including behavioral therapy, pharmacological agents, botulinum toxin-A (BTX-A), and sacral neuromodulator (SNM). SNM has progressed as a revolutionary therapeutic approach for OAB. However, there is no data on the effectiveness of SNM in comparison with SNM combination. 
Aim:
To identify the treatment outcomes of OAB by SNM and SNM combined therapy by reviewing the previous research reported on this subject.

The PRISMA guidance was considered while writing this review. Databases of PubMed, Scopus, Science Direct and Google Scholar were explored to get relevant literature using a variety of terms, including "SNM, OAB, Outcomes, Combination, Adjuvant, Therapy, Impact, Effect, Comparison, and Medication." The searching procedure was restricted to literature published after 2015 till now to search articles written for one decade. All the produced titles were revised thoroughly to prevent missing significant studies. 
The inclusion of the studies was carried out in several steps; the first involved the exclusion of articles published in 2015 and earlier and those that involved other therapeutic modalities. The second step was the exclusion of duplicate titles to reduce the frequency of the articles and avoid duplication of the same data. Also, the articles conducted on children were excluded as we focused on the adult population only. The research comparing SNM and other modalities was excluded. The remaining articles were revised to include only original articles written in the English language, while non-original articles and those written in other languages were excluded

Nine studies were recruited based on the criteria with a total number of 118 subjects. There was only two studies reported treatment with SNM combined with mediation, whereas the remaining seven studies reported SNM treatment alone.

We found only two studies reporting using SNM with other therapies that met our criteria. One compared SNM and solifenacin with solifenacin alone. We found that the combination approach was superior to solifenacin alone, as the combination resulted in a potential reduction in symptoms and improved HQROL. 
The other study revealed that a few proportions (14.1%) required a combination approach of SNM and medication. In earlier research published in 2011 and enrolled 88 subjects, it was found that 22.7% of the subjects who had SNM restarted an anticholinergic therapy, and 10.2% were on such agents at the time of implantation, resulting in 25% being on combination approach. There, 84.2% of the cases that restarted the medication reported considerable improvement. Therefore, a combination of SNM and medication may not be superior to SNM alone. Hence, by the combination of the findings of the two studies that reported SNM combination, we can suggest that the combination of SNM with medication is superior to medication alone but comparable to SNM alone.

SNM is a safe and effective approach for the management of OAB even for idiopathic condition. It is associated with improved OAB symptoms and as a result improved QOL. Also, SNM is associated with few complications that can be managed. The combination of SNM and medication is superior to medication alone, but combination of SNM and medication is almost comparable to SNM alone. The combination therapy may provide greater efficacy for patients who experience inadequate control with no increased safety risk. However, it was stated that there is scarcity in the studies examining the combination therapy with SNM. Therefore, this review focused on the comparison between SNM alone and SNM with adjuvant therapy based on the available literature.