Spinal Cord Stimulation for Failed Back Surgery Syndrome

Objective. The purpose of this study is to evaluate the effectiveness of modern spinal cord stimulation (SCS) for the treatment of failed back surgery syndrome (FBSS). Materials and Methods. Thirty patients were treated with SCS between December 1992 and January 1998 for low back and radicular pain after multiple failed back surgeries. Permanent systems were implanted if trial stimulation led to > 50% pain reduction. Median long‐term follow‐up was 34 months (range, 6–66 months). Severity of pain was determined postoperatively by a disinterested third party. Results. Overall, 12 of the 16 patients (75%) who received permanent implants continued to report at least 50% relief of pain at follow‐up. All six patients who underwent placement of laminectomy‐styled electrode for SCS in the thoracic region had > 50% pain relief at long‐term follow‐up. Visual analog scores decreased an average of 3.2 (from 8.6 preoperatively to 5.4 postoperatively). Patients undergoing SCS placement via laminectomy in the thoracic region experienced an average decrease of 4.9 in VAS, whereas those who underwent percutaneous placement of thoracic leads had an average decrease of 2.5. Conclusions. SCS is an effective treatment for chronic low back and lower extremity pain which is refractory to conservative therapy and which is not amenable to corrective anatomic surgery. Though our patient population is small, our results imply that the laminectomy‐style electrodes in the thoracic region achieve better long‐term effectiveness than percutaneous leads.     

Hardware Failures in Spinal Cord Stimulation for Failed Back Surgery Syndrome

Spinal cord stimulation (SCS) is an efficient means for treatment of the postsurgical lumbar spine condition known as failed back surgery syndrome (FBSS). Although the devices and the implantation techniques are well established and the technology is sophisticated, there are some complications caused by hardware failures. This study was aimed at identifying the most frequent types of hardware failures and their causes in FBSS patients treated with SCS. In a retrospective analysis, a group of 42 FBSS patients using single lead SCS for 6–74 months was evaluated. Only hardware failures were considered in the analysis, and parameters such as occurrence of failure after primary implantation of the device, frequency and site of failure, stimulation time to failure (TF), and overall time of SCS usage were recorded. In the patient group studied, 12 surgical corrections of the hardware were carried out in 10 patients. In eight patients there was a single corrective procedure, in two additional cases there were two surgically corrected hardware failures each. The most often encountered type of hardware failure was lead breakage or disruption of insulation (percutaneously placed Quad leads only) leading to short circuiting and dysfunction (n= 8). Second in frequency were receiver (model 3470) failures due to insulation leakage at the plug connection site (n= 2). In one case, extension cable breakage caused dysfunction of the system, and another dysfunction was caused by distal extension cable disconnection. In conclusion, SCS is a low‐complication procedure for treatment of benign low‐back pain, but seems to be prone to lead and insulation failures.     

Spontaneous Resolution of Nausea Induced by Spinal Cord Stimulation for Failed Back Surgery Syndrome

Introduction: Spinal cord stimulation (SCS) is used for treatment of pain arising from a variety of pathologies. Reported side‐effects related to SCS are most commonly technical complications including malfunction, lead migration, or severance. Up to date, only a few cases of gastrointestinal side‐effects have been reported. Materials and Methods: A 54‐year‐old man with a 20‐year history of low back pain developed persistent and refractory nausea following spinal cord stimulator implantation. Results: The nausea resolved spontaneously within eight weeks allowing continued use of the spinal cord stimulator. Conclusions: In this case report, we described the uncommon side‐effect of nausea because of SCS that resolved over time allowing continued neurostimulation therapy in a patient with arachnoiditis and failed lumbar back surgery syndrome. We encourage other providers to report similar cases to help elucidate the mechanism of these seemingly underreported side‐effects to allow continuation of the therapeutic effects of SCS.     

Spinal Cord Stimulation in Failed Back Surgery Syndrome: An Integrative Review of Quantitative and Qualitative Studies

BackgroundSpinal cord stimulation (SCS) is an established therapy of failed back surgery syndrome (FBSS), although the effects on daily functioning, quality of life (QoL), and patients’ expectations, experiences, and satisfaction remain elusive. The current integrative review aimed to summarize the overall effects of SCS in patients with FBSS on pain relief, health-related QoL, and daily activities.Materials and MethodsPubMed, CINAHL, Embase, ClinicalTrials.gov, gray literature, and reference lists of relevant articles were searched for additional papers. All included studies were assessed for risk of bias using the Mixed Methods Appraisal Tool. Following the methods of Whittemore and Knafl, an integrative review and a meta-analysis were performed.ResultsIn total, 16 articles were included; 11 articles presented quantitative outcomes, and five articles presented qualitative data. Lower back pain, leg pain, overall pain, Oswestry Disability Index, EuroQol Five Dimensions Health Questionnaire three-level/five-level, and the physical component score of Short Form Health Survey (SF-36) significantly improved during all follow-up moments. Only the mental component score of the SF-36 did not significantly improve, compared with baseline. Heterogeneity was diversely present among the studies. Patients’ expectations and goals were disparate, although patients seemed to desire a return to their pre-FBSS state. Experiences with regard to the outcomes showed that patients largely recuperated after SCS, although limitations were still present. Patients also expressed inconvenience with regard to the trial period, implantation location, and recharging of the implantable pulse generator.ConclusionsSCS showed beneficial effects on different domains of life in patients with FBSS. The quantitative analyses suggest an overall improvement in most domains, although patients’ experiences show that limitations in daily life and living with the SCS system persist. Multiple extensive preoperative counseling sessions and discussions with patients are deemed necessary to improve patient satisfaction and meet their expectations. Shared decision-making and provision of complete information are key factors for success.     

Treatment of Failed Back Surgery Syndrome

Objectives. To evaluate the long‐term results of different therapies for failed back surgery syndrome (FBSS). Materials and Methods. From 1992 to 1997, 49 patients were treated for FBSS. Twenty patients were treated medically. Twenty‐four patients, who did not respond to medical therapy, underwent spinal cord stimulator (SCS) implant and five underwent further spine surgery. All patients were evaluated by VAS, PDI, and the Oswestry Scales before treatment and at follow‐up. Leg pain, back pain, work status or daily activities, drug side effects, and use of analgesic medications after implantation were examined. Follow‐up ranged from 24 to 84 months (mean 42 months). Results. At last follow‐up, the patients treated medically demonstrated good results on leg and low back pain in eight cases; in other cases, good results were transitory and several therapeutic courses were necessary to control the pain. Two patients treated medically had substantial side effects. All but two patients treated with SCS demonstrated good results for their leg pain; whereas those treated for back pain with SCS had poor results. Two patients still needed continuous drug administration. Conclusions. Medical therapy is effective for leg and back pain; nevertheless, several courses of therapy may be necessary. SCS is an effective treatment for leg pain, however, its effectiveness on back pain appears to be inadequate.     

Spinal Cord Stimulation vs. Conventional Medical Management: A Prospective,Randomized, Controlled,Multicenter Study of Patients with Failed Back Surgery Syndrome (PROCESS Study)

Introduction. Since its first application in 1967, numerous case series indicate that spinal cord stimulation (SCS) is an effective treatment for the management of failed back surgery syndrome (FBSS). However, only one randomized controlled trial has demonstrated that SCS provides more effective pain relief than re‐operation and conventional medical management. The PROCESS randomized, controlled, multicenter trial aims to assess the clinical effectiveness and cost‐effectiveness of SCS when added to conventional medical management compared to conventional medical management alone in patients with FBSS. Methods/Design. A total of 100 FBSS patients with predominantly neuropathic leg pain will be recruited from 12 centers and randomized to receive either conventional medical management alone or in combination with SCS for a period of 24 months. Patients will be evaluated at 1, 3, 6, 9, 12, 18, and 24 months. At the 6‐month visit, patients will be classified as successful (≥  50% pain relief in the legs) or unsuccessful (< 50% pain relief in the legs). If the results of the randomized treatment are unsuccessful, patients can cross over to the alternative treatment arm. Discussion. This paper highlights the rationale, design, methods, and challenges of an ongoing prospective, randomized, controlled, multicenter clinical trial that has been undertaken to obtain conclusive evidence of the clinical efficacy and cost‐effectiveness of an SCS system in patients with FBSS.     

An Analysis of the Components of Pain,Function, and Health‐Related Quality of Life in Patients with Failed Back Surgery Syndrome Treated with Spinal Cord Stimulation or Conventional Medical Management

Objectives: Failed back surgery syndrome (FBSS) patients experience pain, functional disability, and reduced health‐related quality of life (HRQoL) despite anatomically successful surgery. Examining sub‐dimensions of health outcomes measures provides insight into patient well‐being. Materials and Methods: The international multicenter PROCESS trial collected detailed HRQoL (EuroQol‐5D; Short‐Form 36) and function (Oswestry Disability Index) information on 100 FBSS patients. Results: At baseline, patients reported moderate‐to‐severe leg and back pain adversely affecting all dimensions of function and HRQoL. Compared with conventional medical management alone, patients also receiving spinal cord stimulation (SCS) reported superior pain relief, function, and HRQoL at six months on overall and most sub‐component scores. The majority of these improvements with SCS were sustained at 24 months. Nonetheless, 36–40% of patients experienced ongoing marked disability (standing, lifting) and HRQoL problems (pain/discomfort). Conclusions: Longer‐term patient management and research must focus on these refractory FBSS patients with persisting poor function and HRQoL outcomes.     

Higher Preimplantation Opioid Doses Associated With Long‐Term Spinal Cord Stimulation Failure in 211 Patients With Failed Back Surgery Syndrome

ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.