Prospective,Two-part Study of the Interaction Between Spinal Cord Stimulation and Peripheral Nerve Field Stimulation in Patients with Low Back Pain: Development of a New Spinal-Peripheral Neurostimulation Method

Objective: The goal of the study was to assess the efficacy of interaction between spinal cord stimulation (SCS) and peripheral nerve field stimulation (PNFS) and to evaluate a new spinal‐peripheral neuromodulation method for low back pain. Materials and Methods: The prospective two‐part study included patients with low back pain due to failed back surgery syndrome and/or spinal stenosis. In the first part 20 patients were implanted with SCS and PNFS. They selected the best program out of three: SCS alone, PNFS alone, or both together. In the second part another 20 patients with the same implanted leads were selecting between three programs: SCS and PNFS separately, SCS as anode and PNFS as cathode, or in reverse. Results: In the first part 79% of the patients selected simultaneous use of SCS and PNFS. The overall success of the trials was 85%. In the second part communication between SCS and PNFS provided wider coverage of axial pain. The overall success of the trials was 90%. Conclusion: Simultaneous use of SCS and PNFS increase efficacy of both methods for axial back pain. The new SPN method showed great potential in providing coverage for back pain.     

Peripheral Nerve Field Stimulation in the Treatment of Postlaminectomy Syndrome after Multilevel Spinal Surgeries

Introduction: Chronic low back pain in patients with postlaminectomy syndrome (PLS) is challenging to treat, especially for patients who have undergone multilevel surgical procedures. Despite conservative therapy and available interventional pain procedures including spinal cord stimulation (SCS) and intrathecal therapies, patients may continue with intractable low back pain. Peripheral nerve field stimulation (PNFS) may represent an effective alternative treatment option for these patients when conventional treatments do not provide adequate relief of intractable low back pain. Methods: Eighteen patients underwent an uneventful PNFS trial with percutaneous placement of four temporary quadripolar leads (Medtronic, Inc., Minneapolis, MN, USA) placed subcutaneously over the lumbar or thoraco‐lumbar area. Results: After experiencing excellent pain relief over the next two days, temporary leads were removed. The patients were implanted with permanent leads and rechargeable or non‐rechargeable generator two to four weeks after temporary lead removal. All patients reported sustained pain relief 12 months after implantation. Discussion: PNFS with use of four vertically orientated leads provides an effective treatment option for patients with PLS after multilevel surgical procedures with intractable low back pain who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and interventional treatments including SCS and intrathecal therapy. Conclusion: PNFS may be more effective in treating intractable low back pain than SCS in patients with PLS after multilevel spinal surgeries.     

Spinal Cord Stimulation as Alternative Treatment for Chronic Post‐Herniorrhaphy Pain

Objective: Our goal was to determine the efficacy of spinal cord stimulation for patients with intractable post‐herniorrhaphy pain which conventional treatment failed to ameliorate. Procedure: The patients underwent an uneventful spinal cord stimulator (SCS) trial with percutaneous placement of two eight‐electrode epidural leads (Medtronic Inc, Minneapolis, MN, USA) to level T7‐T8‐T9. Results: Upon experiencing excellent pain relief over the next two days during the trial, the patients were implanted with permanent leads and rechargeable or non‐rechargeable generators two to four weeks later and reported sustained pain relief during following 12 months after implantation. Conclusion: We conclude that SCS offers an alternative treatment option for intractable post‐herniorrhaphy pain. This type of treatment should be considered for use in a select group of patients when all conventional treatments failed.     

Subcutaneous Stimulation as Add-on Therapy to Spinal Cord Stimulation in Patients With Persistent Spinal Pain Syndrome Significantly Increases the Total Electrical Charge per Second: Aspects on Stimulation Parameters and Energy Requirements of the Implanted Neurostimulators

ObjectiveIn our previous multicenter randomized controlled trial, we demonstrated the clinical effectiveness of peripheral nerve field stimulation (PNFS) as add-on therapy to spinal cord stimulation (SCS) for the treatment of chronic back pain in patients with persistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS). To our knowledge, no previous study has investigated the effect of PNFS as an add-on to SCS on the energy consumption of the implanted neurostimulators. Therefore, in this study, we compared the specific stimulation parameters and energy requirements of a previously unreported group of patients with only SCS with those of a group of patients with SCS and add-on PNFS. We also investigated differences that might explain the need for PNFS in the treatment of chronic low back pain.Materials and MethodsWe analyzed 75 patients with complete sets of stimulation parameters, with 21 patients in the SCS-only group and 54 patients in the SCS + PNFS group. Outcome measures were average visual analog scale score, SCS parameters (voltage, frequency, and pulse width), SCS charge per second, and total charge per second. We analyzed baseline characteristics and differences between and within groups over time.ResultsBoth groups had comparable patient characteristics at baseline and showed a significant decrease in back and leg pain. SCS charge per second did not significantly differ between the groups at baseline or at 12 months. The total charge per second was significantly higher in the active SCS + PNFS group than in the SCS-only group at baseline; in the SCS + PNFS group, this persisted for up to 12 months, and the SCS charge per second and total charge per second increased significantly over time.ConclusionsOur results show that add-on PNFS increases the total charge per second compared with SCS alone, as expected. However, further research is needed because our results do not directly explain why some patients require add-on PNFS to treat low back pain.     

Successful Peripheral Nerve Field Stimulation for Thoracic Radiculitis Following Brown-Sequard Syndrome

Objective: The objective of this study is to present a novel approach to the treatment of thoracic radiculitis following Brown‐Sequard syndrome with peripheral nerve field stimulation (PNFS). Furthermore, we endeavor to discuss the role of PNFS in the management of refractory neuropathic pain conditions including post‐traumatic and post‐surgical neuropathy particularly with regards to the post‐surgical spine. Materials and Methods: Presented is a 57‐year‐old man with history of thoracic microdiscectomy resulting in Brown‐Sequard syndrome presented with chronic post‐operative thoracic radicular pain radiating to the abdomen, refractory to conservative management. The patient underwent three intercostal nerve blocks from T7 to T9 with transient symptomatic relief. The patient's options were limited to chemomodulation, neuromodulation, or selective intercostal nerve surgical neurectomy. He subsequently underwent a PNFS trial and reported >75% pain reduction. Permanent percutaneous PNFS electrodes were implanted subcutaneously over the right T7 and T9 intercostal nerves and replicated the trial results. Results: Neuromodulation produced pain relief with >90% improvement in pain compared with baseline both during the trial and following permanent implantation of the PNFS system. Conclusion: Chronic radicular pain may be difficult to manage in the post‐surgical patient and often requires the use of multiple therapeutic modalities. In this case, we successfully utilized PNFS as it demonstrated greater technical feasibility when compared with dorsal column stimulation and repeat surgery; therefore, it may be considered for the management of post‐surgical neuropathy. Further controlled studies are needed to evaluate the efficacy of PNFS as a treatment option.     

Spinal Cord Stimulation With Additional Peripheral Nerve/Field Stimulation Versus Spinal Cord Stimulation Alone on Back Pain and Quality of Life in Patients With Persistent Spinal Pain Syndrome

IntroductionPersistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS) refers to new or persistent pain following spinal surgery for back or leg pain in a subset of patients. Spinal cord stimulation (SCS) is a neuromodulation technique that can be considered in patients with predominant leg pain refractory to conservative treatment. Patients with predominant low back pain benefit less from SCS. Another neuromodulation technique for treatment of chronic low back pain is subcutaneous stimulation or peripheral nerve field stimulation (PNFS). We investigated the effect of SCS with additional PNFS on pain and quality of life of patients with PSPS compared with that of SCS alone after 12 months.Materials and MethodsThis is a comparative study of patients with PSPS who responded to treatment with either SCS + PNFS or SCS only following a multicenter randomized clinical trial protocol. In total, 75 patients completed the 12-month follow-up: 21 in the SCS-only group and 54 in the SCS + PNFS group. Outcome measures were pain (visual analog scale), quality of life (36-Item Short Form Survey [SF-36]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), overall health (EuroQol Five-Dimension [EQ-5D]), disability (Oswestry Disability Index [ODI]), and pain assessed by the McGill questionnaire.ResultsThere were no significant differences in baseline characteristics between the two groups. Both groups showed a significant reduction in back and leg pain at 12 months compared with baseline measurements. No significant differences were found between the groups in effect on both primary (pain) and secondary parameters (SF-36, HADS, EQ-5D, ODI, and McGill pain).ConclusionIn a subgroup of patients with chronic back and leg pain, SCS alone provided similar long-term pain relief and quality-of-life improvement as PNFS in addition to SCS. In patients with refractory low back pain not responding to SCS alone, adding PNFS should be recommended.Clinical Trial RegistrationThe Clinicaltrials.gov registration number for the study is NCT01776749.     

Treatment of Chronic Intractable Hip Pain After Iliac Crest Bone Graft Harvest Using Peripheral Nerve Field Stimulation

Introduction: Autologous iliac crest bone graft (ICBG) harvest is a common procedure performed at the time of many spinal surgical procedures and associated with morbidity incurred at the harvest site, the most troublesome being chronic donor site pain. Methods: The patient underwent an uneventful peripheral nerve field stimulation (PNFS) trial with percutaneous placement of two temporary eight‐electrode leads (Medtronic Inc., Minneapolis, MN, USA) placed in epifascial plane over the left ICBG harvest site. Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and generator two weeks later and reported sustained pain relief at 12‐month follow‐up visit. Discussion: Peripheral nerve field stimulation provides an effective treatment option for patients suffering from chronic hip pain after ICBG harvest who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and more invasive techniques. Conclusion: Peripheral nerve field stimulation offers an alternative treatment option for select patients with chronic hip pain after ICBG harvest.     

Spinal Cord Stimulation in Conjunction With Peripheral Nerve Field Stimulation for the Treatment of Low Back and Leg Pain: A Case Series

Background. The treatment of chronic low back and leg pain remains a difficult medical challenge, particularly for patients with postlaminectomy syndrome. While spinal cord stimulation (SCS) has been a significant addition to the available options, it is often inadequate in relieving both the back and leg pain components. We hypothesized that for some patients the combination of SCS with peripheral nerve field stimulation (PNFS) would be a safe, effective alternative that would be more effective than either modality alone. Objective. Our objective was to demonstrate the efficacy of PNFS used in combination with SCS for the treatment of chronic pain syndromes involving the lower back and legs. Study Design. Case series. Methods. A total of 20 patients with chronic low back and leg pain syndromes who had failed conventional therapies underwent implantation of a combination of traditional SCS and PNFS. Leads were placed in the epidural space, as well as superficially in the subcutaneous tissues of the lower back, directly in the region of maximum pain. Patients initially underwent a trial of stimulation to assess response, and a permanent system was implanted if patients reported greater than 50% pain relief during the trial. For some patients, a combination was used at the time of the initial trial. In other cases, the decision to proceed with the combination was made later, either at the time of permanent implant, or later on, after SCS alone failed to adequately control pain. Results. In each case, PNFS was used in combination with traditional SCS for patients with chronic lower back and lower extremity pain. While not all of these patients ultimately proceeded with the combination of SCS and PNFS to control their pain, the majority of patients found the combination better in controlling their overall pain than either modality alone. In addition, using a combined approach at the time of trial provided a noninvasive and effective method of comparing the efficacy of each method, allowing patients to identify the best form of neuromodulation for their particular pain. Conclusions. Due to the availability of 16 contact capacity generators, neurostimulation with multiple leads in various combinations—including both epidural and peripheral nerve field stimulation simultaneously—can be applied safely and effectively. The availability of this combined approach for a trial of stimulation prior to implant allows patients to compare SCS to PNFS and to indicate a preference for one over the other or for the combination. We conclude that PNFS may be used in combination with SCS as a safe and effective alternative treatment for patients with chronic low back and leg pain, and further suggest that the combined approach should be considered as a treatment option for this population.     

Efficacy of Peripheral Nerve Field Stimulation for the Management of Chronic Low Back Pain and Persistent Spinal Pain Syndrome: A Narrative Review

ObjectivesVarious approaches have been developed with a view to treating the back pain component in patients with chronic low back pain (CLBP) and persistent spinal pain syndrome (PSPS). Emerging evidence shows that peripheral nerve field stimulation (PNFS) may be an efficacious therapeutic modality against axial low back pain. Hence, the aim of the review was to evaluate the analgesic efficacy and safety of PNFS, when used alone or as an adjunct to spinal cord stimulation (SCS), for managing CLBP and PSPS.Materials and MethodsA comprehensive search for clinical studies on PNFS and PNFS + SCS used for the management of CLBP and/or PSPS was performed using PubMed, EMBASE, MEDLINE via Proquest, and Web of Science.ResultsA total of 15 studies were included, of which four were randomized controlled trials (RCTs), nine were observational studies, and two were case series. For patients receiving PNFS, a significant decrease in back pain intensity and analgesic consumption, together with a significant improvement in physical functioning, was observed upon implant of the permanent system. Meanwhile, the addition of PNFS to SCS in refractory cases was associated with a significant reduction in back and leg pain, respectively.ConclusionsThis review suggests that PNFS, when used alone or in combination with SCS, appears to be effective in managing back pain. However, high-quality evidence that supports the long-term analgesic efficacy and safety is still lacking. Hence, RCTs with a larger patient population and of a longer follow-up duration are warranted.     

Treatment of Multifocal Pain with Spinal Cord Stimulation

Introduction: We report a retrospective case study of combined treatment of cancer‐related pain and chronic low back and lower extremity pain related to postlaminectomy syndrome (PLS) with one spinal cord stimulation (SCS) system. Methods: The patient underwent an uneventful SCS trial with percutaneous placement of two temporary eight‐electrode leads (Medtronic Inc., Minneapolis, MN) placed at the level of T8‐T9‐T10 and T5‐T6‐T7. Results: After successful trial, he was implanted with permanent leads and generator, reporting sustained pain relief at 12‐month follow‐up visit. Discussion: SCS is a trialable, reversible, and interactive therapy permitting patients to control the level of stimulation they feel based on their degree of pain. Conclusion: SCS provides an effective, alternative treatment for select patients with cancer‐related chest wall pain and pain related to PLS who have failed conservative treatment.     

Spinal Cord Stimulation and Thalamic Pain: Long‐term Results of Eight Cases

Objectives. We submit a retrospective analysis of results of eight patients suffering from intractable pain of established or suspected thalamic origin. These patients were treated with spinal cord stimulation (SCS) in the cervical or dorsal cord. No patient was suffering pain from a complete hemibody or facial area. Material and Methods. Five men and three women aged 27–67 years were treated in the Pain Unit of our institution between April 1993 and January 2006. The cause of pain in five cases was stroke (plus one suspected). Multiple sclerosis was responsible for pain in two cases. An upper or lower extremity was affected in six cases. Extension to adjacent trunk was common. Exclusive trunk pain was treated in two cases. Results. The follow‐up period was 36–149 months. Two patients were not battery‐implanted because pain relief was insufficient during the trial phase. Two patients had a further stroke: One died and one was cured from pain. Good‐to‐excellent results were attained in six patients; long‐term good‐to‐excellent results were maintained in three patients. Conclusions. Despite previous adverse reports, certain cases of thalamic pain can be effectively alleviated through SCS.     

A Prospective,Open‐Label,Multicenter Study to Assess the Efficacy of Spinal Cord Stimulation and Identify Patients Who Would Benefit

Objective: To identify patients likely to benefit from spinal cord stimulation (SCS). Materials and Methods: This multicenter, prospective, open‐label study included medical centers experienced in SCS therapy, carried out in 13 physicians in seven centers. We recruited 55 patients with complex regional pain syndrome, failed back surgery syndrome, or peripheral vascular disease. Neurostimulators were implanted in 34 patients found to respond to SCS in a preliminary test, who were then followed for six months. Thirty‐four patients scored their pain on a visual analog scale (VAS) and completed the EuroQol‐5D questionnaire before and after test stimulation and after one and six months. Results: During test stimulation, the mean VAS and quality of life (QOL) scores improved from 74.0 to 23.4 and from 0.430 to 0.664, respectively, in the 34 patients. At six months, the mean VAS score was 29.7 in 29 patients and the mean QOL score was 0.661 in 31 patients. Conclusion: SCS may improve pain management and QOL.     

Subcutaneous Stimulation as an Additional Therapy to Spinal Cord Stimulation for the Treatment of Lower Limb Pain and/or Back Pain: A Feasibility Study

Objective: The objective of this study was to demonstrate the efficacy of subcutaneous stimulation (SubQ) as an additional therapy in patients with failed back surgery syndrome (FBSS) with chronic refractory pain, for whom spinal cord stimulation (SCS) was unsuccessful in treating low back pain. Study Design: Case series. Materials and Methods: FBSS patients with chronic limb and/or low back pain whose conventional therapies had failed received a combination of SCS (8‐contact Octad lead) and/or SubQ (4‐contact Quad Plus lead(s)). Initially leads were placed in the epidural space for SCS for a trial stimulation to assess response to suppression of limb and low back pain. Where SCS alone was insufficient in treating lower back pain, leads were placed superficially in the subcutaneous tissue of the lower back, directly in the middle of the pain area. A pulse generator was implanted if patients reported more than 50% pain relief during the trial period. Pain intensity for limb and lower back pain was scored separately, using visual analog scale (VAS). Pain and Quebec Back Pain Disability Scale (QBPDS) after 12‐month treatment were compared with pain and QBPDS at baseline. Results: Eleven FBSS patients, five male and six female (age: 51 ± 8 years; mean ± SD), in whom SCS alone was insufficient in treating lower back pain, were included. In nine cases, SubQ was used in combination with SCS to treat chronic lower back and lower extremity pain. In two cases only SubQ was used to treat lower back pain. SCS significantly reduced limb pain after 12 months (VAS_bl: 62 ± 14 vs. VAS_12m: 20 ± 11; p= 0.001, N= 8). SubQ stimulation significantly reduced low back pain after 12 months (VAS_bl: 62 ± 13.0 vs. VAS_12m: 32 ± 16; p= 0.0002, N= 10). Overall pain medication was reduced by more than 70%. QBPDS improved from 61 ± 15 to 49 ± 12 (p= 0.046, N= 10). Furthermore, we observed that two patients returned to work. Conclusion: SubQ may be an effective additional treatment for chronic low back pain in patients with FBSS for whom SCS alone is insufficient in alleviating their pain symptoms.     

Analysis of Failed Spinal Cord Stimulation Trials in the Treatment of Intractable Chronic Pain

Objective

The purpose of this study is to identify the factors affecting the failure of trials (<50% pain reduction in pain for trial period) to improve success rate of spinal cord stimulation (SCS) trial.

Methods

A retrospective review of the failed trials (44 patients, 36.1%) among the patients (n=122) who underwent SCS trial between January 1990 and December 1998 was conducted. We reviewed the causes of failed trial stimulation, age, sex, etiology of pain, type of electrode, and third party support.

Results

Of the 44 patients, 65.9% showed unacceptable pain relief in spite of sufficient paresthesia on the pain area with trial stimulation. Four of six patients felt insufficient paresthesia with stimulation had the lesions of the spinal cord. Seventy five percent of the patients experienced unpleasant or painful sensation during stimulation had allodynia dominant pain. Third-party involvement, sex, age and electrode type had no influence on the outcome.

Conclusion

We conclude that SCS trial is less effective for patients with neuropathic pain of cord lesions, postherpetic neuropathy or post-amputation state. Further, patients with allodynia dominant pain can feel unpleasant or painful during trial stimulation.     

Peripheral Subcutaneous Neurostimulation in the Management of Neuropathic Pain: Five Case Reports

Introduction. Spinal cord stimulation (SCS) is an effective treatment option for neuropathic pain. However, because of the obvious procedural issues, SCS is unable to reach certain areas, such as the face, thorax, coccyx, the cervico‐dorsal and lumbar areas, and the sacral, abdominal, and inguinal regions. On the other hand, these areas are easily reached by subcutaneous field stimulation. Methodology. We report the analgesic results, using a visual analog scale (VAS), of five patients with neuropathic pain treated with subcutaneous field stimulation to the area. We also discuss the probable mechanism of action, and highlight the technical issues inherent to this approach. Results. Significant pain reduction and reduction in analgesic medication were reported in all patients during the study period, with VAS scores consistently lowered by more than 50% from baseline levels. As a result of pain reduction, the patients’ quality of life improved. There were no adverse events reported except for early electrode array displacement in two of our patients. Conclusion. When SCS is not appropriate for certain neuropathic pain syndromes, subcutaneous field stimulation may be used with some degree of efficacy.     

Treatment of Chronic Chest Wall Pain in a Patient With Loeys-Dietz Syndrome Using Spinal Cord Stimulation

Objective: Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable pain including chronic chest pain. Methods: The patient with a history of Loeys‐Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain underwent an uneventful SCS trial with percutaneous epidural placement of two temporary eight‐electrode leads placed at the level of T3‐T4‐T5. Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and rechargeable generator four weeks later and reported sustained pain relief at 12‐month follow‐up visit. Conclusion: SCS provides an effective, alternative treatment option for select patients with Loeys‐Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain who have failed conservative treatment. SCS may provide pain relief with advantages over conservative treatments and more invasive techniques.     

Spinal Cord Stimulation for Intractable Visceral Pain due to Chronic Pancreatitis

Pain caused by chronic pancreatitis is medically intractable and resistant to conventional interventional or surgical treatment. We report a case of spinal cord stimulation (SCS) for intractable pain due to chronic pancreatitis. The patient had a history of nonalcoholic chronic pancreatitis and multiple emergency room visits as well as repeated hospitalization including multiple nerve block and morphine injection for 3 years. We implanted surgical lead at T6-8 level on this patient after successful trial of percutaneous electrode. The patient experienced a decreased visual analog scale (VAS) scores for pain intensity and amount of opioid intake. The patient was followed for more than 14 months with good outcome and no further hospitalization. From our clinical case, spinal cord stimulation on intractable pain due to chronic pancreatitis revealed moderate pain control outcome. We suggest that SCS is an effective, noninvasive treatment option for abdominal visceral pain. Further studies and long term follow-up are needed to fully understand the effect of SCS on abdominal visceral pain.     

Subcutaneous Peripheral Nerve Stimulation with Inter‐lead Stimulation for Axial Neck and Low Back Pain: Case Series and Review of the Literature

Objectives: While pain in the extremities often responds to treatment using spinal cord stimulation (SCS), axial pain is notoriously refractory to SCS. Interest in subcutaneous peripheral nerve stimulation (SQ PNS) as an alternative to SCS has emerged, but the most appropriate electrode locations and neurostimulator programming techniques are not yet clear. Methods: A retrospective review was conducted of consecutive patients evaluated from August 2009 to December 2010 who had undergone trial of SQ PNS with inter‐lead stimulation for axial spine pain. Patients proceeding to implant were followed postoperatively with routine clinical visits and a survey form at last follow‐up. Ultrasound was used intraoperatively to ensure placement of electrodes at the appropriate depth in patients with larger body mass index. Primary outcome was patient‐reported pain relief at last follow‐up. Literature review was conducted by searching MEDLINE (1948–present) and through an unstructured review by the authors. Results: Ten patients underwent trial of SQ PNS and six proceeded to permanent implantation. Fifty percent (3/6) of implanted patients preferred neurostimulation programming that included inter‐lead stimulation (“cross‐talk”). Average duration of postoperative follow‐up was 4.5 months (range 2–9 months). Average patient‐reported pain relief at last follow‐up was 45% (range 20–80%). One patient required re‐operation for migration. Patients not proceeding to implant had paresthesia coverage but no analgesia. Conclusion: SQ PNS is a promising therapy for axial neck and back pain based on a small cohort of patients. Ultrasound was useful to assist with electrode placement at the most appropriate depth beneath the skin. While inter‐lead stimulation has been preferred by patients in published reports, we did not find it clearly influenced pain relief. Future investigations should include a randomized, controlled study design, as well as defined implantation technique and neurostimulator programming algorithms.     

Spinal Cord Stimulation for Visceral Pain From Chronic Pancreatitis

Background and Objectives: Spinal cord stimulation (SCS) may reduce pain scores and improve function in patients with various chronic abdominal pain syndromes including chronic pancreatitis. Here described is a large clinical experience in SCS for severe chronic pancreatitis. Methods: SCS was trialed in 30 patients with chronic pancreatitis. SCS trials lasted 7–14 days (median 9 days). SCS lead tips were mostly positioned at the T5 (N= 10) or T6 (N= 10) vertebral level. Results: Twenty‐four patients (80%) reported at least 50% pain relief on completion of the trial. Among these, pre‐trial visual analog scale (VAS) pain scores averaged 8 ± 1.6 (standard deviation) and opioid use averaged 165 ± 120 mg morphine sulfate equivalents. During the trial, VAS pain scores decreased to 3.67 ± 2 cm (p < 0.001, Mann–Whitney Rank Sum Test) and opioid use decreased to 105 ± 101 mg morphine equivalent a day. Six patients failed the trial; one was lost to follow‐up; in three patients after the implantation, the system had to be removed due to infection or lead migration; and 20 were followed for the whole year. For 20 patients followed for the whole year, VAS pain scores remained low (3.6 ± 2 cm; p < 0.001) at one year, as did opioid use (48.6 ± 58 mg morphine equivalents). Conclusions: SCS may be a useful therapeutic option for patients with severe visceral pain from chronic pancreatitis. Prospective trial is warranted.     

Spinal Cord Stimulation Has Proven Benefit on Pain and Quality of Life in Patients With Angina Pectoris When Less Invasive Therapies Have Failed

Background. Since 1988, spinal cord stimulation (SCS) has been used at Odense University Hospital for patients with refractory angina pectoris. The aim of our prospective study was to evaluate the long‐term effects of SCS on pain, activities of daily living (ADLs), quality of life (QOL), sleep hygiene, and physical functioning for patients with angina pectoris. Methods. Before and after placement of SCS for patients with intractable angina pectoris, we performed structured telephone interviews questioning for pain relief, ADLs (Nottingham Health Profile), physical functioning (Seattle Angina Questionnaire) and sleep hygiene. Results. Out of 150 patients with SCS over 15 years, 41 patients had died, 46 patients had their devices explanted, and four patients did not participate or could not be reached. Three patients had less than 6 months of follow‐up and were therefore not included in our analysis. The beneficial effects of SCS treatment for intractable angina pectoris were reduction in pain and improvement in QOL. Sleep pattern and physical functioning were not improved to the same extent as reduction in pain or improvement in QOL. Almost all of our SCS‐treated patients did recommend SCS for intractable angina pectoris. About 30% of patients discontinued treatment, the most common cause being electrode displacement and malfunction of the system. Other reasons for discontinued therapy were the evolvement of invasive treatment options such as coronary artery bypass graft and PTCA and use of such options in some patients during our prolonged observation period. Conclusion. This survey shows that SCS leads to a 70–80% improvement in pain, which, in turn, leads to improvement in QOL, whereas, physical condition and sleep pattern did not improve to the same extent.