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Spinal Cord Stimulation for Treatment of Pain

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					Medical Policy Manual

Topic: Spinal Cord Stimulation for Treatment of Pain                 Date of Origin: January 1996

Section: Surgery

Policy No: 45                                                        Effective Date: July 1, 2010


IMPORTANT REMINDER

Regence Medical Policies are developed to provide guidance for members and providers regarding
coverage in accordance with contract terms. Benefit determinations are based in all cases on the
applicable contract language. To the extent there may be any conflict between the Medical Policy and
contract language, the contract language takes precedence.

PLEASE NOTE: Contracts exclude from coverage, among other things, services or procedures that are
considered investigational or cosmetic. Providers may bill members for services or procedures that are
considered investigational or cosmetic. Providers are encouraged to inform members before rendering
such services that the members are likely to be financially responsible for the cost of these services.


DESCRIPTION

Spinal cord stimulation delivers low voltage electrical stimulation to the dorsal columns of the spinal
cord to block the sensation of pain. The neurophysiology of pain relief after spinal cord stimulation is
uncertain, but may be related to either activation of an inhibitory system or blockage of facilitatory
circuits. Spinal cord stimulation devices consist of several components:

1. The lead which delivers the electrical stimulation to the spinal cord

2. An extension wire which conducts the electrical stimulation from the power source to the lead

3. A power source which generates the electrical stimulation

The lead may incorporate from four to eight electrodes, with eight electrodes more commonly used for
complex pain patterns, such as bilateral pain, or pain extending from the limbs to the trunk. There are
two basic types of power source. In one type the power source (battery) can be surgically implanted. In
another a radiofrequency receiver is implanted and the power source is worn externally with an antenna
over the receiver. Totally implantable systems are most commonly used.

The patient's pain distribution pattern dictates at what level in the spinal cord the stimulation lead is


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placed. The pain pattern may influence the type of device used. For example, a lead with eight
electrodes may be selected for those with complex pain patterns or bilateral pain. Implantation of the
spinal cord stimulator is typically a two step process. Initially, the electrode is temporarily implanted in
the epidural space, allowing a trial period of stimulation. Once treatment effectiveness is confirmed,
defined as at least 50% reduction in pain, the electrodes and radio-receiver/transducer are permanently
implanted. Successful spinal cord stimulation may require extensive programming of the
neurostimulators in order to identify the optimal electrode combinations and stimulation channels.
Computer controlled programs are often used to assist the physician in studying the numerous
programming options when complex systems are used.

Spinal cord stimulation has been used in a variety of chronic refractory pain conditions, including pain
associated with cancer, failed back syndromes, arachnoiditis, visceral pain, and chronic reflex
sympathetic dystrophy. There has also been interest in spinal cord stimulation as a treatment of chronic
refractory angina pectoris and treatment of chronic limb ischemia, primarily in patients who are poor
candidates for revascularization. Spinal cord stimulation is generally not effective in treating
nociceptive pain (resulting from irritation, not damage to the nerves) and central deafferentation pain
(related to central nervous system damage from stroke or spinal cord injury).



MEDICAL POLICY CRITERIA

Note: Deep brain stimulation as a treatment of movement disorders (e.g., Parkinson’s Disease) is
addressed in a separate Regence medical policy, Surgery No. 84.

I.     Patient selection focuses on determining whether or not the patient is refractory to other types of
       treatment. The following considerations apply:

       A.    Spinal cord stimulation may be considered medically necessary for the treatment of
             either of the following conditions and when all patient selection criteria in B. below have
             been met:

             1.     Severe and chronic pain of the trunk or limbs, other than critical limb ischemia, that
                    is refractory to all other pain therapies, or

             2.     Chronic refractory angina pectoris in patients who are not considered candidates for
                    a revascularization procedure.

       B.    All of the following Patient Selection Criteria must be met:

             1.    The treatment is used only as a last resort; other treatment modalities
                   (pharmacological, surgical, psychological, or physical, if applicable) have been tried
                   and failed or are judged to be unsuitable or contraindicated.

             2.    Pain is neuropathic in nature; i.e. resulting from actual damage to the peripheral
                   nerves. Common indications include, but are not limited to failed back syndrome,
                   complex regional pain syndrome (i.e., reflex sympathetic dystrophy), arachnoiditis,
                   radiculopathies, phantom limb/stump pain, and peripheral neuropathy.

             3.    No serious untreated drug habituation exists.



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             4.   Patient has been carefully screened, evaluated and diagnosed by appropriate
                  consultants of different specialties, who document agreement with application of
                  these therapies or, at a minimum, do not object to application of these therapies.

             5.   Pain relief from a temporarily implanted electrode has been demonstrated prior to
                  permanent implantation.

II.   Spinal cord stimulation is considered investigational for all other indications including but not
      limited to treatment of the following:

      A.     Critical limb ischemia as a technique to forestall amputation

      B.     Visceral pain

      C.     Nociceptive pain (resulting from irritation, not damage to the nerves)

      D.     Central deafferentation pain (related to CNS damage from a stroke or spinal cord injury)

      E.     Chronic pelvic pain

      F.     Vulvodynia; vulvar vestibulitis



SCIENTIFIC BACKGROUND

Chronic Back and Extremity Pain

The bulk of published literature regarding spinal cord stimulation (SCS) consists of case series. In a
systematic literature synthesis of these studies, Turner and colleagues reported that in patients with
chronic low back pain, an average of 59% of patients had 50% or greater pain relief with SCS. [1]
Results of a randomized controlled clinical trial reported that a significantly greater proportion of
patients initially randomized to repeat lumbosacral surgery opted to cross over to the spinal cord
stimulation arm of the trial, compared to those initially in the spinal cord stimulation arm of the trial
crossing over to lumbosacral surgery. [2] A prospective multicenter study of spinal cord stimulation in
219 patients with chronic back and extremity pain reported successful management of pain in 55% of
patients. [3] A multicenter randomized trial (the PROCESS study) compared SCS (plus conventional
medical management) with medical management alone in 100 patients with failed back surgery
syndrome (FBSS). [4] Leg pain relief (>50%) at six months was observed in 24 (48%) SCS-treated
patients and four (9%) controls, with an average leg pain visual analog scale (VAS) score of 40 in the
SCS group and 67 in the conventional management control group. Between 6 and 12 months, five (10%)
patients in the SCS group and 32 (73%) patients in the control group crossed over to the other condition.
Of the 84 patients who were implanted with a stimulator over the 12 months of the study, 27 (32%)
experienced device-related complications.

More recently, Kemler and colleagues reported on favorable outcomes of SCS among patients with
chronic reflex sympathetic dystrophy (CRSD) who were randomized to the SCS arm compared to those
treated with physical therapy alone. [5] The favorable outcomes were still present at two years’ follow-
up. [6] Another study reported 5-year outcomes from a randomized trial of 54 patients with CRPS. [7]


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Twenty-four of the 36 patients assigned to SCS and physical therapy were implanted with a permanent
stimulator after successful test stimulation; 18 patients were assigned to physical therapy alone. Five-
year follow-up showed a 2.5 cm change in VAS pain score in the SCS group (n=20), and a 1.0 cm
change for the control group (n=13). Pain relief at 5 years was not significantly different between the
groups; 19 (95%) patients reported that for the same result they would undergo the treatment again. Ten
(42%) patients underwent reoperation due to complications.

An evidence-based review from the American Society of Pain Physicians found the evidence for SCS in
failed back surgery syndrome and complex regional pain syndrome strong for short-term relief and
moderate for long-term relief. [8] Reported complications with spinal cord stimulation ranged from
infection, hematoma, nerve damage, lack of appropriate paraesthesia coverage, paralysis, nerve injury,
and death. Evidence-based guidelines from the European Federation of Neurological Societies found
level B (i.e., at least 1 prospective matched-group cohort study or randomized controlled trial in a
representative population) evidence for the effectiveness of SCS in failed back surgery syndrome and
CRPS I. [9] The task force indicated that implantable stimulators are typically used when all other
treatments have failed, and that this context should be taken into account when making
recommendations.

Chronic Refractory Angina

Several randomized studies were identified which focused on two populations of patients: 1. Patients
who were not considered candidates for a revascularization procedure due to comorbidities or other
factors, where SCS was compared to continued medical management; or 2. Patients who would be
considered candidates for a revascularization procedure for the purpose of symptom relief only, where
SCS was compared to coronary artery bypass grafting. The following results were reported:

1. Spinal Cord Stimulation as an Alternative to Medical Management

   Hautvast and colleagues reported on a study that randomized 25 patients with chronic angina who
   were not considered candidates for surgery to receive either an active or sham SCS. [10] Patients were
   followed for six weeks. Primary outcomes included symptom relief (frequency of angina episodes,
   nitrate use, and self-assessment), ischemic episodes as noted on 24 hour monitoring, and
   improvement in cardiac function as noted on exercise stress test. All outcomes were significantly
   improved in the active treatment group compared to the control group. In another small trial,
   seventeen patients were randomized to receive SCS or continued medical management. [11] After the
   eight-week study period, the control group received a SCS and the entire group was followed for one
   year. Those receiving SCS reported a significant improvement in exercise capacity and quality of
   life.

2. Spinal Cord Stimulation as an Alternative to Coronary Artery Bypass Surgery

   The Electrical Stimulation versus Coronary Bypass (ESBY) study randomized 104 patients with
   chronic refractory angina to SCS or coronary artery bypass grafting (CABG). [12] Patients were
   included in the study only if the CABG was considered solely as a technique for reducing angina
   pain. The primary outcomes, measured after six months, were symptom relief and myocardial
   ischemia (as measured by exercise tests). At six months, both treatments were associated with
   similar improvement in symptom relief. Among those undergoing CABG, there was greater
   improvement in various cardiac function measures, such as exercise capacity and less ST segment
   depression. The lack of improvement of cardiac function measures in the active treatment group


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     contrasts with other trials of SCS. However, in this trial the device was turned off for the 24-hour
     period prior to exercise testing, suggesting that SCS does not have a permanent effect on cardiac
     function.

Limb Ischemia

Critical limb ischemia is described as pain at rest or the presence of ischemic limb lesions. If the patient
is not a suitable candidate for limb revascularization (typically due to insufficient distal run-off), it is
estimated that amputation will be required in 60-80% of these patients within a year. Spinal cord
stimulation has been investigated in this small subset of patients as a technique to relieve pain and
decrease the incidence of amputation. Klomp and colleagues conducted a study that randomized 120
patients with critical limb ischemia not suitable for vascular reconstruction to undergo either best
medical care, or medical care in addition to SCS. [13] The primary endpoint was limb survival at two
years. The difference in amputation rate at 12 months was no longer present at 24 months. The addition
of SCS did not improve amputation-free survival nor was the risk of major amputation significantly
reduced. Both groups also reported similar levels of pain reduction. In both groups, the rates of
amputation were highest within the first three months of the study, reflecting the limitations with both
treatment options.

A 2005 update of a systematic review from the Cochrane group on use of SCS in non-reconstructible
critical leg ischemia included six European studies with a total of 444 patients, including the Klomp
study summarized above. [14] None of the studies were blinded due to the nature of the treatment. One
of the studies was non-randomized and one included only patients with ischemic ulcers. Treatment
groups received SCS along with the same standard nonsurgical treatment as the control groups. At 12,
18 and 24 months follow-up individual studies showed a trend toward a better limb salvage that did not
reach statistical significance. However, when results were pooled, a significant decrease in amputations
was found for the SCS group at 12 months follow-up with a number needed to treat (NNT) of nine.
Outcomes for pain relief and ulcer healing were mixed. Quality of life was unchanged in both control
and treatment groups. The overall risk of complications or additional SCS treatment was 17% with a
number needed to harm (NNH) of six. Although the only statistically significant difference favoring the
SCS group was in the pooled data for limb salvage at 12 months follow-up, the report concluded that
there was “evidence that SCS is better than conservative treatment alone to achieve amputation risk
reduction, pain relief and improvement of the clinical situation” in these patients. This seemingly
incongruous conclusion may be explained by the authors’ conclusion that “The benefits of SCS against
the possible harm of relatively mild complications and costs must be considered.” A potential conflict
of interest was noted for the principal investigator.

Miscellaneous

The use of SCS for other conditions such as visceral pain has been reported, though no randomized
controlled trials have been published. The British Pain Society recommended that its use in this and
other emerging indications be carefully audited. [15]

An updated search of the MEDLINE database through December 15, 2008 did not return any clinical
studies that alter the above conclusions.


REFERENCES

1.      Turner, JA, Loeser, JD, Bell, KG. Spinal cord stimulation for chronic low back pain: a

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      systematic literature synthesis. Neurosurgery. 1995 Dec;37(6):1088-95; discussion 95-6. PMID:
      8584149
2.    Burchiel, KJ, Anderson, VC, Brown, FD, et al. Prospective, multicenter study of spinal cord
      stimulation for relief of chronic back and extremity pain. Spine (Phila Pa 1976). 1996 Dec
      1;21(23):2786-94. PMID: 8979327
3.    North, RB, Kidd, DH, Lee, MS, Piantodosi, S. A prospective, randomized study of spinal cord
      stimulation versus reoperation for failed back surgery syndrome: initial results. Stereotact Funct
      Neurosurg. 1994;62(1-4):267-72. PMID: 7631080
4.    Kumar, K, Taylor, RS, Jacques, L, et al. Spinal cord stimulation versus conventional medical
      management for neuropathic pain: a multicentre randomised controlled trial in patients with
      failed back surgery syndrome. Pain. 2007 Nov;132(1-2):179-88. PMID: 17845835
5.    Kemler, MA, Barendse, GA, van Kleef, M, et al. Spinal cord stimulation in patients with chronic
      reflex sympathetic dystrophy. N Engl J Med. 2000 Aug 31;343(9):618-24. PMID: 10965008
6.    Kemler, MA, De Vet, HC, Barendse, GA, Van Den Wildenberg, FA, Van Kleef, M. The effect
      of spinal cord stimulation in patients with chronic reflex sympathetic dystrophy: two years'
      follow-up of the randomized controlled trial. Ann Neurol. 2004 Jan;55(1):13-8. PMID:
      14705107
7.    Kemler, MA, de Vet, HC, Barendse, GA, van den Wildenberg, FA, van Kleef, M. Effect of
      spinal cord stimulation for chronic complex regional pain syndrome Type I: five-year final
      follow-up of patients in a randomized controlled trial. J Neurosurg. 2008 Feb;108(2):292-8.
      PMID: 18240925
8.    Boswell, MV, Trescot, AM, Datta, S, et al. Interventional techniques: evidence-based practice
      guidelines in the management of chronic spinal pain. Pain Physician. 2007 Jan;10(1):7-111.
      PMID: 17256025
9.    Cruccu, G, Aziz, TZ, Garcia-Larrea, L, et al. EFNS guidelines on neurostimulation therapy for
      neuropathic pain. Eur J Neurol. 2007 Sep;14(9):952-70. PMID: 17718686
10.   Hautvast, RW, DeJongste, MJ, Staal, MJ, van Gilst, WH, Lie, KI. Spinal cord stimulation in
      chronic intractable angina pectoris: a randomized, controlled efficacy study. Am Heart J. 1998
      Dec;136(6):1114-20. PMID: 9842028
11.   de Jongste, MJ, Hautvast, RW, Hillege, HL, Lie, KI. Efficacy of spinal cord stimulation as
      adjuvant therapy for intractable angina pectoris: a prospective, randomized clinical study.
      Working Group on Neurocardiology. J Am Coll Cardiol. 1994 Jun;23(7):1592-7. PMID:
      8195519
12.   Mannheimer, C, Eliasson, T, Augustinsson, LE, et al. Electrical stimulation versus coronary
      artery bypass surgery in severe angina pectoris: the ESBY study. Circulation. 1998 Mar
      31;97(12):1157-63. PMID: 9537342
13.   Klomp, HM, Spincemaille, GH, Steyerberg, EW, Habbema, JD, van Urk, H. Spinal-cord
      stimulation in critical limb ischaemia: a randomised trial. ESES Study Group. Lancet. 1999 Mar
      27;353(9158):1040-4. PMID: 10199350
14.   Ubbink, DT, Vermeulen, H. Spinal cord stimulation for non-reconstructable chronic critical leg
      ischaemia. Cochrane Database Syst Rev. 2005(3):CD004001. PMID: 16034919
15.   The British Pain Society. Spinal cord stimulation for the management of chronic pain;
      Recommendations for best clinical practice. [cited 12/15/2008]; Available from:
      www.britishpainsociety.org/SCS_2005.pdf


CROSS REFERENCES

Percutaneous Electrical Nerve Stimulation (PENS) and Percutaneous Neuromodulation Therapy (PNT),


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Regence Medical Policy Manual, Surgery, Policy No. 44

Deep Brain Stimulation, Regence Medical Policy Manual, Surgery, Policy No. 84


Codes    Number       Description

CPT       63650       Percutaneous implantation of neurostimulator electrode; epidural

          63655       Laminectomy for implantation of neurostimulator electrode plate/paddle;
                      epidural

          63661       Removal of spinal neurostimulator electrode percutaneous array(s), including
                      fluoroscopy, when performed

          63662       Removal of spinal neurostimulator electrode plate/paddle(s) placed via
                      laminotomy or laminectomy, including fluoroscopy, when performed

          63663       Revision including replacement, when performed, of spinal neurostimulator
                      electrode percutaneous array(s), including fluoroscopy, when performed

          63664       Revision including replacement, when performed, of spinal neurostimulator
                      electrode plate/paddle(s) placed via laminotomy or laminectomy, including
                      fluoroscopy, when performed

          63685       Insertion or replacement of spinal neurostimulator pulse generator or receiver,
                      direct or inductive coupling

          95970       Electronic analysis of implanted neurostimulator pulse generator system (e.g.,
                      rate, pulse amplitude and duration, configuration of wave form, battery status,
                      electrode selectability, output modulation, cycling, impedance and patient
                      compliance measurements); simple or complex brain, spinal cord, or peripheral
                      (i.e., cranial nerve, peripheral nerve, autonomic nerve, neuromuscular)
                      neurostimulator pulse generator/transmitter, without reprogramming

          95971              simple spinal cord, or peripheral (ie, peripheral nerve, autonomic nerve,
                             neuromuscular) neurostimulator pulse generator/transmitter, with
                             intraoperative or subsequent programming

          95972              complex spinal cord, or peripheral (except cranial nerve)
                             neurostimulator pulse generator/transmitter, with intraoperative or
                             subsequent programming, first hour

          95973              complex spinal cord, or peripheral (except cranial nerve)
                             neurostimulator pulse generator/transmitter, with intraoperative or
                             subsequent programming, each additional 30 minutes after first hour
                             (List separately in addition to code for primary procedure)

HCPCS     L8680       Implantable neurostimulator electrode (with any number of contact points), each



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L8685   Implantable neurostimulator pulse generator, single array, rechargeable,
        includes extension

L8686   Implantable neurostimulator pulse generator, single array, nonrechargeable,
        includes extension

L8687   Implantable neurostimulator pulse generator, dual array, rechargeable, includes
        extension

L8688   Implantable neurostimulator pulse generator, dual array, nonrechargeable,
        includes extension




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