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Abstract
Background and aims SCS delivers energy to the spinal cord with the goal of symptom relief from chronic intractable pain. Research suggests targeting stimulation at the midline of the spinal cord, starting at the T9-T10 disc space for back pain.1 2 Recently, the effects of high energy parameters at this target have been explored, particularly stimulation at 1000 Hz.3 4
The Vectors study evaluates whether there is significant improvement in pain starting with HD stimulation at 1000 Hz when leads span the T9-T10 disc space.
Methods Post-market, single-arm study evaluating the efficacy of SCS (IntellisTM implantable neurostimulator) starting with HD stimulation, targeting the T9-T10 disc space following paresthesia mapping (EvolveSM workflow). Subjects with chronic intractable low-back and leg pain (VAS ≥50 mm) were enrolled.
Primary endpoint Change in overall pain (VAS) at 3-month visit compared to baseline.
Results 98 subjects completed the 3-month visit. Overall pain decreased 45.8 mm on the VAS. 87% of subjects had > 50% improvement in at least one pain domain (overall, back or leg). Benefits were observed in the ODI; 65.3% improved by at least 1 category and EQ-5D; 75.5% of subjects improved on at least one dimension and no worse in other dimensions. 70% of subjects achieved a personal activity goal and 81.6% reported therapy satisfaction.
Responder rates and 95% confidence intervalsSubjects were defined as responders if they had at least a 50% improvement in their pain, as assessed by the VAS, from Baseline to the 3-Month Visit. Responders rates for Overall, Low-Back, and Leg are presented.
Change in painNinety-eight subjects implented with an Intellis™ completed their 3-Month Visit. Change in VAS for Overall, Back, and Leg are presented.
ODI categories at baseline and 3 monthsPrecent of subjects in the Severe/Crippled/Bed-bound disability categories decreased from 82.6% at Baseline to 34.7% at 3 Months.
Change in EQ-5D at 3 monthsOf the 98 subjects who completed a 3-Month Visit, 74(75.5%) improved in at least 1 dimension an no worse in other dimension. EQ VAS improved from Basline (56.5) to 3months (70.3)
Percentage of subjects who achieved activity goal by visit70% of subjects had achieved an activity goal set at their Basline visit by the 3-Month Visit.
Subject satisfication with therapyEight subject (81.61%) were satisfied with their therapy at the 3-Month visit
Conclusions Vectors PM provides evidence for SCS starting with HD stimulation (the EvolveSM workflow). a statistically significant reduction in pain was achieved at 3-months follow-up. Benefits were also observed in quality of life and function. Subjects are followed through 12-months post-implant to assess sustainability of outcomes.