Pain Management

Generally patients prefer IPG systems because the totally implantable IPG systems are seen as more comfortable, convenient and cosmetically appealing than external neurostimulators. In addition, unlike RF systems, IPG systems do not cause skin irritations. For these reasons, patients will often be more compliant, and overall therapy will be more effective. Patients using IPG systems may also have greater ease in daily activities, such as working, exercising and sleeping.

Extension
The extension cable connects the power source to the lead. Using an extension rather than a lead connected to the IPG gives additional benefits in terms of being easier to handle in case of revisions and offering more comfort for patients.

Leads and electrodes
The lead is a polyurethane-encased wire connected to a set of electrodes. The lead conducts electrical pulses from the extension to the electrodes, which deliver the pulses to large nerve fibres in the dorsal column or the periphery. Electrodes are fixed at the end of the lead, usually in groups of four. Optimal lead positioning always requires the cooperation of the patient and is the key to success with this therapy.

• In a prospective study of SCS in patients with intractable leg pain, a success rate of 53% was reported at six weeks [6]
• In a multicentre study of SCS for the relief of chronic back and extremity pain in 70 patients, pain was successfully managed in 56% of patients after 1 year of follow-up [9]
• In 30 patients treated with SCS for low back pain and radicular pain after multiple failed back surgeries, 75% continued to report at least 50% pain relief after 34 months of follow up [10]

SCS: dual stimulation studies

• The ability to add a second lead if necessary may improve success in a wider range of patients, including patients with difficult to treat conditions such as axial low back pain
• In a trial of 41 patients with chronic, intractable low back pain, 69% were satisfied with treatment and 75% would repeat procedure if they had known the outcome before the operation. [11]
• 90% of patients required the addition of a second lead.
• In a trial in 21 patients with FBS, patients' pain scores substantially decreased, and 76% of patients' indicated satisfaction with dual lead SCS treatment after nearly 40 months of follow-up. [12]
• In a trial in 23 patients with complex back and leg pain, and a history of back surgery, patients visual analogue scores improved by a mean of 58% for back pain, and 45% for leg pain with dual lead SCS treatment. [13]

Dual lead SCS provides good low back and leg pain relief

VAS pain ratings before and after dual lead SCS implants (n=17) [12]

        SCS: Cost effectiveness

• SCS has been shown to be a more cost effective treatment for FBS than re-operation [14]
          - Surgery success rates decrease with the number of re-operations. [7]
• The actual mean cumulative cost for SCS therapy for a 5-year period was $29,123 per patient compared with $38,029 per patient for conventional pain therapy. [15]

• In a prospective trial of SCS compared with re-operation, not only was there a clinical advantage for SCS, but this therapy was also the most cost-effective over 3 years of follow-up. [1]
• A cost analysis model of patients with FBS indicates that SCS therapy can lead to cost savings over conservative treatment by reducing patients' needs for medical care. [16]
• On average, given current screening and efficacy rates, SCS therapy pays for itself in 5.5 years; in patients who respond well to SCS treatment, the therapy pays for itself in 2.1 years. [16]