Peripheral Nerve Stimulation in the Treatment of Chronic Pain Syndromes From Nerve Injury: A Multicenter Observational Study.

INTRODUCTION: Assessing the feasibility, technical implications, and clinical benefits of peripheral nerve stimulation (PNS) performed by an implantable pulse generator (IPG) located close to the stimulation site. MATERIALS AND METHODS: Selected patients were affected by neuropathic pain associated with a documented peripheral nerve lesion, refractory to conventional surgical or pharmacological treatment. A PNS system specifically designed for peripheral placement (Neurimpulse, Padova, Italy) was implanted and followed for six months, recording the degree of patient's satisfaction (PGI-I questionnaire), the pain numerical rating scale (NRS) and the quality of life (SF36 questionnaire), as well as any change in drug regimen and work capability. The statistical significance of differences was determined by the paired Student's t-test. RESULTS: A total of 58 patients were referred to permanent IPG implantation. Stimulation failure due to lead damage or dislocation was noticed in two cases (3.4%) in six months. At the follow-up end, the relative NRS reduction averaged -58 ± 30% (p < 10-6 ) and was greater than 50% in 69% of the cases. Quality-of-life physical and mental indices were increased by 18% (p < 0.005) and 29% (p < 0.0005), respectively. The administration of antalgic drugs was stopped in 55% and reduced in 16% of the patients. Low-energy stimulation was possible in most cases, resulting in an IPG estimated life of 80 ± 35 months. CONCLUSIONS: Successful PNS was achieved with a stimulation system designed for peripheral location. This new technology reduced the incidence of lead-related adverse events and the energy cost of the treatment.

Spinal cord stimulation: predictive parameters of outcome in patients suffering from critical lower limb ischemia. A preliminary study.

INTRODUCTION: The aim of our study is to identify the assessment of metabolic and dynamic capillaroscopy parameters that may be predictive of the outcome of spinal cord stimulation in patients affected with non-revascularisable chronic critical limb ischemia. MATERIALS AND METHODS: Forty patients, 16 female and 24 male, average age 69 ± 8, underwent microcirculatory screening with transcutaneous oximetry and dynamic capillaroscopy. Microcirculatory assessment was performed before temporary implantation of the spinal cord stimulation stimulator and after one month. The following metabolic parameters were considered: TcPO2-TcPCO2 and with dependent limb, difference between dependent limb and supine values (Δ TcPO2, Δ TcPCO2), change in TcPO2-TcPCO2 after stimulation. Dynamic capillaroscopy parameters were recorded. Follow-up visits were scheduled at three, six, and twelve months after implantation. The procedure was performed placing an Octrode (St. Jude Medical, St. Paul, MN, USA) on the dorsal columns of the spinal cord. RESULTS: Two groups were identified on the basis of transcutaneous oximetry measurements: group A (22 patients) and group B (18 patients), responding differently to the postural test. After one month of home testing period, there was an improvement in metabolic parameters, differing from one group to the other. The morphofunctional data provided by capillaroscopy highlighted the percentage of open capillaries poststimulation as being a significant parameter, although not mentioned in previous studies. CONCLUSIONS: Spinal neuromodulation is an effective therapy option in the management of patients affected by non-reconstructable chronic critical limb ischemia.