Spinal Cord Stimulator Complication Rates: A Single-Institution, 22-Year Study (1999-2021).

Background: Since the initial introduction in 1967 of spinal cord stimulation (SCS) in the field of neuromodulation, SCS has been utilized to treat a multitude of chronic pain disorders refractory to both conservative and surgical management. Although efficacious when indicated, SCS has associated risks.

Objectives: The goals of this study are to explore the trend of rates of SCS complications in 2 approximately equally sized cohorts (1999-2015 and 2016-2021) within a single institution over a 22-year period.

Study design: A retrospective cohort study.

Setting: A tertiary care academic hospital.

Methods: A retrospective chart review with pre-existing institutional review board approval was performed on 2 cohorts, one comprising 257 patients between 2016 and 2021 and the other comprising 262 patients between 1999 and 2015, who underwent percutaneous SCS implantation provided by 2 experienced interventional chronic pain specialists. The patients' demographics and complications were recorded in the REDCAP database. Data were collected on complications of both the biological (allergic/foreign-body reactions, dural puncture/leaks, infections, pain over implantation site, poor wound healing, skin erosions, neurological injuries, and subcutaneous/epidural hematomas) and device-related (electrical leaks, inadequate pain coverage, lead fractures, lead migrations, ligamentum flavum stimulation, recharging/battery failures, and unwanted stimulation) varieties. The chart review included records that started 6 months prior to SCS placement and ended at a period of at least one year of follow-up after placement.

Results: Of the patients studied between 2016 and 2021, the mean age was 58.5 ± 13.0 years, with men representing 46.3% and women 53.7% of the patients studied. Of those studied between 1999 and 2015, the mean age was 50.6 +/- 12.3 years, with men representing 42.4% of the patients and women 57.6%. The overall complication rates were 14.0% (36/257) and 38.9% (102/262) for 2016-2021 and 1999-2015, respectively. The rate of biological complications was nearly 3 times lower in the 2016-2021 group than in the 1999-2015 group (4.3% [11/257] vs 12.2% [32/262], P < 0.001). In the 1999-2015 group, the leading biological complication was infection, the rate of which decreased in the 2016-2021 group (3.4% [9/262] vs 1.9% [5/257], P < 0.42). The rate of device complications was nearly 3 times lower in the 2016-2021 group than in the 1999-2015 group (9.7% [25/257] vs. 26.7% [70/262], P < 0.0001). The leading device complication was inadequate pain coverage (12.2% [32/262] vs 7.4% [19/257], P < 0.08). No serious neurological injury or death occurred in either cohort.

Limitations: Limitations were inherent to this study's design, since it was a retrospective cohort study.

Conclusion: The rate of SCS-related complications decreased from one group to the next, with the most recent group demonstrating a statistically significant decrease in both device and biological complications. Our results are consistent with SCS literature trends that demonstrate decreasing complications, which may be due to technological advancements in SCS device technology and improved complication mitigation strategies. Further prospective research utilizing multicenter data is needed to better define the overall trend of SCS complications.