Spinal cord stimulation for patients with chronic critical leg ischaemia who cannot have blood vessel surgery

Peripheral arterial disease is relatively common, particularly in late middle age. Blockages in the leg arteries can reduce blood flow in the legs enough to cause fatigue and pain in the muscles when walking (called intermittent claudication). This can become severe and cause critical limb ischaemia which can result in rest pain, leg ulceration, and gangrene that requires amputation. Surgery may improve blood flow but is not possible for everybody. Drugs may be used to relieve pain, improve leg circulation, and treat infection. Another option for patients who cannot have surgery is spinal cord stimulation (SCS). This involves stimulating nerves in the spine to help reduce pain and increase healing of ulcers by improving the local blood circulation in the affected leg. The review authors included five randomised and one controlled clinical trial involving a total of nearly 450 patients. In general the quality of the studies was good. Amputation after 12 months was required less often when SCS was added to standard care. Significant pain relief occurred with and without SCS but patients in the SCS group required fewer pain killers. Overall there was no difference on ulcer healing rates between the two treatment groups. Complications of SCS treatment consisted of problems with initially implanting the electrodes, in 8% of patients, and the need for repeat surgery because of electrode or lead failures in 12% of patients; infections occurred less frequently (3%). The average overall costs at two years were calculated in one study and found to be EUR 36,500 in the SCS group and EUR 28,600 in the conservative treatment alone group.

 

Authors' conclusions: 

There is evidence to favour SCS over standard conservative treatment alone to improve limb salvage and clinical situations in patients with NR-CCLI. The benefits of SCS must be considered against the possible harm of relatively mild complications and the costs.

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Background: 

Patients suffering from inoperable chronic critical leg ischaemia (NR-CCLI) face amputation of the leg. Spinal cord stimulation (SCS) has been proposed as a helpful treatment in addition to standard conservative treatment.

Objectives: 

To find evidence for an improvement on limb salvage, pain relief, and the clinical situation using SCS compared to conservative treatment alone.

Search strategy: 

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched January 2013) and CENTRAL (2012, Issue 12).

Selection criteria: 

Controlled studies comparing the addition of SCS with any form of conservative treatment to conservative treatment alone in patients with NR-CCLI.

Data collection and analysis: 

Both authors independently assessed the quality of the studies and extracted data.

Main results: 

Six studies comprising nearly 450 patients were included. In general the quality of the studies was good. No study was blinded due to the type of intervention.

Limb salvage after 12 months was significantly higher in the SCS group (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.56 to 0.90; risk difference (RD) -0.11, 95% CI -0.20 to -0.02). Significant pain relief occurred in both treatment groups, but was more prominent in the SCS group where the patients required significantly less analgesics. In the SCS group, significantly more patients reached Fontaine stage II than in the conservative group (RR 4.9, 95% CI 2.0 to 11.9; RD 0.33, 95% CI 0.19 to 0.47). Overall, no significantly different effect on ulcer healing was observed with the two treatments.

Complications of SCS treatment consisted of implantation problems (9%, 95% CI 4 to 15%) and changes in stimulation requiring re-intervention (15%, 95% CI 10 to 20%). Infections of the lead or pulse generator pocket occurred less frequently (3%, 95% CI 0 to 6%). Overall risk of complications with additional SCS treatment was 17% (95% CI 12 to 22%), indicating a number needed to harm of 6 (95% CI 5 to 8).

Average overall costs (one study) at two years were EUR 36,500 (SCS group) and EUR 28,600 (conservative group). The difference (EUR 7900) was significant (P < 0.009).