Clinical outcomes: Vectors study 12‑month results Spinal cord stimulation

Vectors study

Vectors is a prospective, multicenter, single-arm study of targeted stimulation parameters in spinal cord stimulation (SCS) designed to evaluate the long-term efficacy of the therapy when the Evolve™ workflow is used.

• Population: patients with chronic intractable low-back and leg pain
• Sample size: Baseline for the study was 103 patients. 98 patients completed a three month post-implant follow-up visit, 96 at six months, and 91 patients at 12 months.
• Centers: 20 sites in the United States
• Device: The Intellis™ platform with AdaptiveStim™ technology

Outcomes were assessed according to the following:

• Primary outcome measurement: Demonstrate a significant improvement in overall pain intensity using high dose (HD) stimulation starting at (90/1000) targeting T9/T10 disc space as measured by visual analogue scale (VAS) from baseline to a three-month visit.
• Secondary pain outcomes (3-, 6-, and 12-month follow-ups):
  • Pain relief as measured by change in VAS (0-100) for overall, low-back, and leg pain.
  • The responder rate (defined as a ≥ 50% improvement in pain measured by the VAS) for overall, low-back, and leg pain.
• Additional outcomes  (3-, 6-, and 12-month follow-ups):
  • Change in Oswestry Disability Index (ODI)
  • Change in EuroQol (EQ-5D)
  • Personal goal achievement (3 months only) 
  • Therapy satisfaction
  • Patient Global Impression of Change (PGIC)

SCS screening trial success rate

90% of subjects experienced a successful screening trial (85% with HD stimulation).

Changes in pain

Statistically significant pain relief was achieved at three months follow up. Clinically significant and sustained pain relief was observed for overall pain, back pain and leg pain at 12 month follow-up.

Note: Pain relief was measured using patient reported pain using VAS (scale 0mm - no pain, to 100mm - worst possible pain).

Access to multiple therapy options¹

At 12 months post-implant, 95% of patients remained on HD therapy with low dose (LD) therapy still an option. Importantly, 5% of patients were benefiting from maintained access to LD stimulation.

NOTE: The effectiveness of low dose stimulation has been well established in multiple clinical studies. With the increasing use of HD stimulation, Vectors provides additional evidence for the use of HD and LD stimulation.

Improved functional capacity¹

Function: As measured by the Oswestry disability index (ODI) at 3, 6, and 12 months
At 12 months, 76% of subjects had improved in at least one ODI category.

NOTE: The ODI score is produced from patient-completed questionnaires that include six statements in each of 10 sections concerning impairments like pain and abilities such as personal care, lifting, reading, driving, and recreation. The scale is interpreted as: 0%–⁠20% (minimal disability); 20%–⁠40% (moderate disability); 40%–⁠60% (severe disability); 60%–⁠80% (severely disabled in several areas of life/crippled); 80%–⁠100% (bed bound or exaggerating symptoms).³

Function: As measured by individual patient activity goals³

70% of patients had achieved a personal activity goal by three months post-implant.

NOTE: Each patient set an individual and specific activity goal that was important to them at the beginning of the study. Once patients achieved an activity goal a new goal was set for future follow up. Patient goals were only collected and assessed through the 3 month follow up visit. 

Function: As measured by Euro-QoL (EQ-5D) at 3, 6, and 12 months^2,3

At 12 months, 77% of subjects were better on at least one dimension of the EQ-5D and no worse on any dimensions.

Patient global impression of change and satisfaction¹

At 12-month follow-up, 86% of subjects rated themselves as “Somewhat better” to “A great deal better.”

Satisfaction with Intellis SCS increased from 80% at 3 months to 85% at 12-month follow-up.

Building long-term evidence for the Evolve™ workflow

Medtronic is invested in building long-term evidence for the Evolve™ workflow powered by Intellis™ with AdaptiveStim™ technology.

Vectors results powered by the Evolve™ workflow:

A workflow is guidance only. Physicians should use their medical judgment and product labelling to optimize therapy for individual patients, which may require discontinuation or modification of a workflow.