1. Aetna considers dorsal column stimulators (DCS) medically necessary durable medical equipment (DME) for the management of members with chronic pain due to: (i) failed back surgery syndrome with low back pain and significant radicular pain, (ii) complex regional pain syndrome (also known as reflex sympathetic dystrophy), or (iii) inoperable chronic ischemic limb pain secondary to peripheral vascular disease and the member meets all of the following criteria:
   
   
   1. There is documented pathology, i.e., an objective basis for the pain complaint, and 
   2. Other more conservative methods of pain management have been tried and failed, and 
   3. Member does not have any untreated existing drug addiction problems (per American Society of Addiction Medicine (ASAM) guidelines), and 
   4. Member has obtained psychiatric clearance, and 
   5. Member has predominantly radiating extremity pain, and 
   6. Member experienced significant pain reduction (50% or more) with a 3- to 7-day trial of percutaneous spinal stimulation.  (A trial of percutaneous spinal stimulation is considered medically necessary for members who meet the above-listed criteria, in order to predict whether a dorsal column stimulator will induce significant pain relief.)

2. Aetna considers DCS experimental and investigational for the management of members with chronic, malignant pain, other chronic non-malignant pain (e.g., headache, cephalgia, occipital neuralgia, intercostal neuralgia, trigeminal neuralgia, phantom limb syndrome, inguinal pain, and post-herpetic neuralgia), or spasticity  because its effectiveness for these indications has not been established.

3. Aetna considers the use of cervical spinal cord stimulation for the treatment of members with cervical trauma or disc herniation, presenting with arm pain, neck pain, or cervicogenic headache, as experimental and investigational because its effectiveness for these indications has not been established.

4. Aetna considers DCS medically necessary DME for the management of intractable angina in members who are not surgical candidates and whose pain is unresponsive to all standard therapies when all of the following criteria are met:
   1. Member has angiographically documented significant coronary artery disease and is not a suitable candidate for revascularization procedures such as coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), and
   2. Member’s angina pectoris is New York Heart Association (NYHA) Functional Class III (patients are comfortable at rest; less than ordinary physical activity causes fatigue, palpitation, dyspnea, or anginal pain) or Class IV (symptoms of cardiac insufficiency or angina are present at rest; symptoms are increased with physical activity), and
   3. Reversible ischemia is documented by symptom-limited treadmill exercise test, and
   4. Member has had optimal pharmacotherapy for at least one month.  Optimal pharmacotherapy includes the maximal tolerated dosages of at least two of the following anti-anginal medications: long-acting nitrates, beta-adrenergic blockers, or calcium channel antagonists; and
   5. Member experienced significant pain reduction (50% or more) with a 3- to 7-day trial of percutaneous spinal stimulation. (A trial of percutaneous spinal stimulation is considered medically necessary for members who meet the above-listed criteria, in order to predict whether a dorsal column stimulator will induce significant pain relief.)

   Contraindications to dorsal column stimulation for intractable angina are presented in an appendix to the Background section of this CPB.

5. Aetna considers dorsal column stimulation experimental and investigational for all other indications.

See also CPB 362 - Spasticity Management

Dorsal Column Stimulation for Chronic Pain:

Dorsal column stimulators (DCS), also known as spinal cord stimulators, are most commonly used for the management of failed back surgery syndrome.  The use of DCS for controlling chronic low back pain is a non-destructive, reversible procedure, thus, it is an attractive alternative for patients who may be facing or have already experienced neuroablative procedures, or habituating opioid medications.  The failure in earlier trials of spinal stimulation pointed to the importance of carefully selected patients in the success of this procedure.  Today, a patient should meet the following criteria (Kumar et al, 1986) before permanent implantation of a DCS is considered: (i) other more conservative methods of pain management have been tried and failed; (ii) the patient has exhausted all surgical options; (iii) the patient has predominantly radiating extremity pain; and (iv) the patient experienced significant pain reduction with trial percutaneous spinal stimulation.

DCS is a therapy for chronic pain with organic origins and has not been shown to benefit problems which are largely behavioral or psychiatric. There is evidence that outcomes of DCS are improved if candidates are subject to psychological clearance to exclude from surgery persons with serious mental disabilities, psychiatric disturbances, or poor personality factors that are associated with poor outcomes. The literature supporting presurgical psychological clearance for DCS has been reviewed by a number of authors (see, e.g., Heckler, et al., 2007; van Dorsten, 2006).

There is sufficient evidence of the effectiveness of dorsal column stimulation in pain management. Shatin, et al. (1986) published the findings of a multi-center clinical study of DCS for treatment of chronic, intractable pain of the low back and/or legs.  Ninety patients were available for follow-up which averaged 14.5 months.  Seventy percent of the subjects experienced excellent (75 to 100%) or good (50 to 74%) analgesia.  In addition, 28% of all subjects at last follow-up used opioid medications, compared to 40% of all subjects before implantation of the DCS.  North et al (1991b) reviewed the long-term results of 50 patients with failed back surgery syndrome who had received implantable DCS.  Successful outcome, as judged by at least 50% sustained analgesia and patient satisfaction with the result, was recorded in 53% of patients at 2.2 years and 47% of patients at 5.0 years.  Eighty three percent of the subjects continued to use their stimulators at the 5-year follow-up.  At the time of follow-up, only 12% of patients were using analgesic medications with half of them at reduced dosage, compared with 74% before the commencement of DCS therapy.  Moreover, most patients reported an improvement in ability to perform daily activities.  In another report that examined 5-year follow-up in 102 patients with failed back surgery syndrome undergoing repeated operation, North et al (1991a) found that most of these patients reported no change in their abilities to carry out activities of daily living.

Ohnmeiss, et al. (1996) concluded that spinal cord stimulation can result in improved physical function and reduced pain in selected patients with intractable leg pain.  Furthermore, Bell et al (1997) as well as Devulder et al (1997) reported that spinal cord stimulation is cost-effective in treating patients with chronic failed back surgery syndrome.

Turner, et al. (2004) conducted a systematic review on the effectiveness of DCS in relieving pain and improving functioning for patients with failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS).  These authors concluded with suggestions for methodologically stronger studies to provide more definitive data regarding the effectiveness of DCS in relieving pain and improving functioning, short-term and long-term, among patients with chronic pain syndromes.  Taylor, et al. (2005) assessed the safety and effectiveness of DCS for the treatment of chronic back and leg pain and FBSS and concluded that there is moderate evidence for the effectiveness of DSC for these indications.  Furthermore, a recent Cochrane review (Mailis-Gagnon, et al., 2004) concluded that although there is limited evidence in favor of DCS for FBSS and CRPS, more research is needed to confirm whether DCS is an effective treatment for certain types of chronic pain.  This is in agreement with the findings of a recent assessment on spinal cord stimulation for the management of neuropathic pain by the Ontario Ministry of Health and Long Term Care (2005).  This report stated that FBSS and CRPS are the two most common indications for DCS.  North, et al. (2005) also reported that DCS provided adequate pain relief in patients with FBSS with predominant low back pain and secondary radicular pain.  Harney, et al. (2005) stated that there is now a significant body of evidence to support the utilization of DCS in the management of CRPS.

A Cochrane review (Ubbink and Vermeulen, 2003) stated that there is evidence to favor DCS over standard conservative treatment to improve limb salvage and clinical situation in patients with inoperable chronic critical leg ischemia.  This is in agreement with the findings of Carter (2004) who noted that though limited in quantity and quality, better evidence exists for the use of DCS in neuropathic pain, CRPS, angina pectoris and critical limb ischemia, as well as Cameron (2004) who stated that DCS had a positive, symptomatic, long-term effect in cases of refractory angina pain, severe ischemic limb pain secondary to peripheral vascular disease, peripheral neuropathic pain, and chronic low-back pain.

Dorsal Column Stimulation for Angina Pectoris:

Dorsal column stimulators have also been shown to be effective in the treatment of patients with angina pectoris patients who fail to respond to standard pharmacotherapies and are not candidates for surgical interventions.  Patients should undergo a screening trial of percutaneous DCS of 3 to 7 days.  If they achieve significant pain reduction (more than 50%), the system is then implanted permanently.  For this procedure, epidural electrodes are generally placed at an upper thoracic or lower cervical spinal level.  Although the exact mode of action of DCS in alleviating anginal pain is unclear, it has been suggested that its beneficial effects are achieved through an increase in oxygen supply to the myocardium in addition to its analgesic effect.

Gonzalez-Dader, et al. (1991) reported their findings of DCS on 12 patients with established angina at rest or with minimum effort, who are unresponsive to the maximum tolerable pharmacotherapies, and there was a contraindication for revascularization surgery or intraluminal angioplasty.  After a mean follow-up of 9.8 months, there was a significant decrease in the number of angina attacks (30.9 to 9.6 attacks per week) and a significant improvement in the treadmill ergometric test.  The authors concluded that DCS is a very low-risk technique that significantly enhances the quality of life of patients with unstable angina.  Similarly, Sanderson, et al. (1992) noted that in 14 patients with severe intractable angina pectoris unresponsive to conventional therapies including bypass grafting, DCS resulted in a significant improvement of symptoms and a marked decrease in glycerol trinitrate consumption.  These benefits persisted in some patients for over 2 years without any apparent adverse sequelae.  It was concluded that DCS is a useful technique for patients with severe intractable angina who have failed to respond to standard therapies.

In a randomized controlled study with a 1-year follow-up (n = 22), de Jongste and Staal (1993) found that DCS improved both the quality of life and cardiac parameters of patients with refractory angina pectoris.  Mannheimer, et al. (1993) examined the effects of DCS on myocardial ischemia, coronary blood flow, and myocardial oxygen consumption in angina pectoris induced by atrial pacing (n = 20).  Fifteen subjects had recurrent angina following a previous coronary bypass procedure and 5 subjects were considered unsuitable for bypass surgery.  It was concluded that DCS has an anti-anginal and an anti-ischemic effect in severe coronary artery disease.  Moreover, myocardial ischemia during treatment (spinal cord stimulation) results in anginal pain.  Thus, DCS does not deprive these patients of a warning signal.  This observation was supported by the findings of Anderson, et al. (1994) as well as Eliasson, et al. (1994).  In a prospective study (n = 50), Anderson and co-workers investigated whether DCS employed for relief of refractory angina can mask acute myocardial infarction.  These investigators found no evidence that DCS concealed acute myocardial infarction.  Eliasson and colleagues evaluated the safety aspects of DCS in patients (n = 19) with severe angina pectoris by means of repeated long-term electrocardiograph recordings.  There were no increases in the frequency of ischemic attacks, the total ischemic burden, or the number of arrhythmic episodes during treatment with DCS.

In a prospective randomized controlled clinical trial, de Jongste, et al. (1994) studied the effects of DCS on quality of life and exercise capacity in patients with intractable angina.  Patient inclusion criteria were as follows: (i) angiographically documented significant coronary artery disease not suitable for revascularization procedures such as CABG or PTCA, (ii) New York Heart Association Functional Class III or IV angina pectoris, (iii) reversible ischemia documented at least by a symptom-limited treadmill exercise test, and (iv) pharmacologically optimal drug treatment for at least 1 month.  Optimal pharmacotherapy included the maximal tolerated dosages of at least 2 of the following anti-anginal medications -- long-acting nitrates, beta-adrenergic blockers, or calcium channel antagonists.  Exclusion criteria included myocardial infarction or unstable angina in the last 3 months; significant valve abnormalities as demonstrated by echocardiography; and somatic disorders of the spine leading to insurmountable technical problems in treatment.  Seventeen patients were randomly assigned to one of the two groups: (i) treatment (implantation within 2 weeks, n = 8), and (ii) control (implantation after 8 weeks, n = 9).  Quality of life was assessed by daily and social activity scores and recording sublingual glyceryl trinitrate consumption and angina pectoris episodes in a diary.  Exercise capacity was evaluated by means of treadmill exercise testing.  All subjects were followed up for 1 year.  The authors found that DCS significantly improved quality of life and exercise capacity in these patients and that the beneficial effects of DCS may be mediated via an improvement of oxygen supply to the heart in addition to an analgesic effect.

Sanderson, et al. (1994) reported the long-term clinical outcome of 23 patients with intractable angina treated with DCS.  They were followed up for 21 to 62 months.  Three patients died during the course of the study.  None of the deaths was sudden or unexplained; and this mortality rate was acceptable for such patients.  Two subjects had a myocardial infarction which was associated with typical pain, and not concealed by DCS.  The authors concluded that DCS is an effective and safe treatment for patients whose angina is unresponsive to conventional therapies.

An AHRQ evidence-based guideline on management of cancer pain concluded that dorsal column stimulators have not been shown to be effective for treatment of refractory cancer pain.  The assessment states: "Percutaneous electrical stimulation for the relief of otherwise refractory cancer pain has likewise not yet been evaluated in controlled trials.  Case reports -- limited essentially to the percutaneous insertion of spinal cord electrodes for dorsal column stimulation -- tend to focus on details of the method, to use non-uniform patient selection criteria, and to use heterogeneous pain assessment methods and follow-up duration.  Not all experience is favorable.  Hence, as Miles and colleagues wrote nearly 20 years ago, ‘At this stage it seems sensible to concentrate effort on evaluating the method rather than on encouraging widespread and possibly indiscriminate use of what is an expensive use and relatively unproven technique.’"

Cervical Spinal Cord Stimulation:

Cervical spinal cord stimulation (SCS) has been used to treat patients with cervical trauma/disc herniation presenting with arm pain, neck pain, and/or cervicogenic headache.  However, there is insufficient evidence that cervical SCS is effective for these indications. 

Garcia-March, et al. (1987) reported the use of SCS in 6 patients with total or partial brachial plexus avulsion.  Two patients had had amputation of the arm and suffered from phantom limb and stump pain.  After a mean follow-up of 14 months, 2 patients were pain-free, 1 had partial relief and required analgesics, and in 3 patients there was no effect.  Robaina, et al. (1989) studied the use of SCS for relief of chronic pain in vasospastic disorders of the upper limbs.  A total of 11 patients with chronic pain due to severe vasospastic disorders in the upper limbs were treated with cervical SCS.  In 8 patients the pain was due to reflex sympathetic dystrophy (RSD) in the late stage of the disease, and 3 patients had severe idiopathic Raynaud's disease.  The mean follow-up for both groups was 27 months.  A total of 10 patients (91%) had good or excellent results.  In the RSD group, the amount of pain relief achieved enabled most patients to undergo subsequent physiotherapy and rehabilitation.  These investigators concluded that in severe cases of RSD and idiopathic Raynaud's disease, SCS is an alternative treatment that can be used as primary therapy or as secondary therapy after unsuccessful sympathectomy or sympathetic blocks.

Simpson, et al. (2003) reported on the use of cervical SCS for the management of patients with chronic pain syndromes affecting the upper limb and face (n = 41).  Follow-up ranged from 5 months to 11 years and 3 months (median of 4 years and 7 months).  Overall, 68% obtained sustained pain relief, rated as significant in 51% of total.  Patients with facial pain did not respond, while those with ischemic syndromes responded well.  The major drawback of this study was that it was a retrospective uncontrolled study.

In a review on the treatment of cervicogenic headache (Martelletti and van SuijlekomIn, 2004), cervical SCS was not listed as one of the therapeutic approaches that include drug-based therapies (e.g., paracetamol and non-steroidal anti-inflammatory drugs), manual modalities, transcutaneous electrical nerve stimulation, local injection of anesthetic or corticosteroids, and invasive surgical therapies.  In addition, in a review on the safety and effectiveness of SCS for the treatment of chronic pain, Cameron (2004) stated that SCS had a positive, symptomatic, long-term effect in cases of refractory angina pain, severe ischemic limb pain secondary to peripheral vascular disease, peripheral neuropathic pain, and chronic low-back pain.  Spinal cord stimulation for the treatment of cervical trauma with disc herniation presenting with arm pain, neck pain, and/or cervicogenic headache was not discussed in the review.  The clinical value of cervical SCS for these indications needs to be investigated by well-designed randomized controlled studies.

Appendix

DCS for intractable angina pectoris is contraindicated in any of the following conditions:

• Myocardial infarction or unstable angina in the previous 3 months, or
• Significant valve abnormalities as demonstrated by echocardiography, or 
• Somatic disorders of the spine leading to insurmountable technical problems in treatment with DCS.