Jonathan Richardson

Spinal cord stimulation versus conventional medical management for neuropathic pain: A multicentre randomised controlled trial in patients with failed back surgery syndrome

Abstract Patients with neuropathic pain secondary to failed back surgery syndrome (FBSS) typically experience persistent pain, disability, and reduced quality of life. We hypothesised that spinal cord stimulation (SCS) is an effective therapy in addition to conventional medical management (CMM) in this patient population. We randomised 100 FBSS patients with predominant leg pain of neuropathic radicular origin to receive spinal cord stimulation plus conventional medical management (SCS group) or conventional medical management alone (CMM group) for at least 6 months. The primary outcome was the proportion of patients achieving 50% or more pain relief in the legs. Secondary outcomes were improvement in back and leg pain, health‐related quality of life, functional capacity, use of pain medication and non‐drug pain treatment, level of patient satisfaction, and incidence of complications and adverse effects. Crossover after the 6‐months visit was permitted, and all patients were followed up to 1 year. In the intention‐to‐treat analysis at 6 months, 24 SCS patients (48%) and 4 CMM patients (9%) (p < 0.001) achieved the primary outcome. Compared with the CMM group, the SCS group experienced improved leg and back pain relief, quality of life, and functional capacity, as well as greater treatment satisfaction (p ⩽ 0.05 for all comparisons). Between 6 and 12 months, 5 SCS patients crossed to CMM, and 32 CMM patients crossed to SCS. At 12 months, 27 SCS patients (32%) had experienced device‐related complications. In selected patients with FBSS, SCS provides better pain relief and improves health‐related quality of life and functional capacity compared with CMM alone.

The effects of spinal cord stimulation in neuropathic pain are sustained: a 24-month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation

OBJECTIVEAfter randomizing 100 failed back surgery syndrome patients to receive spinal cord stimulation (SCS) plus conventional medical management (CMM) or CMM alone, the results of the 6-month Prospective Randomized Controlled Multicenter Trial of the Effectiveness of Spinal Cord Stimulation (i.e., PROCESS) showed that SCS offered superior pain relief, health-related quality of life, and functional capacity. Because the rate of crossover favoring SCS beyond 6 months would bias a long-term randomized group comparison, we present all outcomes in patients who continued SCS from randomization to 24 months and, for illustrative purposes, the primary outcome (>50% leg pain relief) per randomization and final treatment. METHODSPatients provided data on pain, quality of life, function, pain medication use, treatment satisfaction, and employment status. Investigators documented adverse events. Data analysis included inferential comparisons and multivariate regression analyses. RESULTSThe 42 patients continuing SCS (of 52 randomized to SCS) reported significantly improved leg pain relief (P < 0.0001), quality of life (P ≤ 0.01), and functional capacity (P = 0.0002); and 13 patients (31%) required a device-related surgical revision. At 24 months, of 46 of 52 patients randomized to SCS and 41 of 48 randomized to CMM who were available, the primary outcome was achieved by 17 (37%) randomized to SCS versus 1 (2%) to CMM (P = 0.003) and by 34 (47%) of 72 patients who received SCS as final treatment versus 1 (7%) of 15 for CMM (P = 0.02). CONCLUSIONAt 24 months of SCS treatment, selected failed back surgery syndrome patients reported sustained pain relief, clinically important improvements in functional capacity and health-related quality of life, and satisfaction with treatment.

Quality of life, resource consumption and costs of spinal cord stimulation versus conventional medical management in neuropathic pain patients with failed back surgery syndrome (PROCESS trial)

Background: Chronic back and leg pain conditions result in patients’ loss of function, reduced quality of life and increased costs to the society.

A thermographic study of paravertebral analgesia

Six patients undergoing paravertebral blocks for chronically painful conditions of the chest wall were thermographically imaged so that the extent of cutaneous vasodilatation and hence sympathetic block could be correlated with the distribution of the somatic block. All blocks were performed by a single experienced operator, with a single percutaneous entry, using 15ml of 0.5% bupivacaine at a mean level of T9–10 (range T7–8‐T10–11), with radiological confirmation of correct needle placement. There was a mean distribution of the somatic block of five dermatomes (range 1–8), as evidenced by loss of pinprick sensation, with upper and lower limits of T6 and L3. The mean distribution of the sympathetic block was eight dermatomes (range 6–10), as evidenced by ipsilateral skin warming (p = 0.0005‐0.001), with upper and lower limits of T5 and L3. No bilateral spread was observed. No significant postural changes in blood pressures were seen, although there was a small but significant decrease in supine heart rate (p = 0.05). This study demonstrates that a large unilateral somatic and sympathetic block is obtainable with a single thoracic percutaneous paravertebral injection. It challenges the suggestions that this method of analgesia is ineffective and hazardous, that a sympathetic component is a rare accompaniment and that the lumbar nerve roots are spared.

Targeted methylprednisolone acetate/hyaluronidase/clonidine injection after diagnostic epiduroscopy for chronic sciatica: A prospective, 1-year follow-up study

Background and Objectives It has been claimed that epiduroscopy offers an ideal combination of diagnostic and therapeutic interventions in one session. We prospectively evaluated whether abnormalities at the lumbar level as diagnosed by magnetic resonance imaging (MRI) are confirmed by epiduroscopy, and assessed if targeted epidural injection of medication alleviates sciatic pain. Methods A flexible, 0.9-mm fiberoptic endoscope was introduced through a disposable steering shaft into the caudal epidural space and advanced until the targeted spinal nerve was identified. Adhesions were mechanically mobilized under direct vision, and a mixture of 120 mg methylprednisolone acetate, 600 IU hyaluronidase, and 150 μg clonidine was applied locally. Pain scores were measured by visual analog scale (VAS) and global subjective efficacy rating. Results Nineteen of 20 patients studied showed adhesions via epiduroscopy. In 8 patients, 6 of whom had never undergone surgery, these were not detected with earlier magnetic resonance imaging. Six patients showed concomitant signs of active root inflammation. Of 20 patients treated with a targeted epidural injection, 11 patients (55%) experienced significant pain relief at 3 months. This was maintained at 6, 9, and 12 months for 8 (40%), 7 (35%), and 7 (35%) patients, respectively. Mean VAS at 3 months was significantly reduced (n = 20; ΔVAS = 3.55; P < .0001), and this persisted at 12 months (ΔVAS = 1.99, P = .0073). Conclusions Epiduroscopy is of value in the diagnosis of spinal root pathology. In sciatica, adhesions unreported by MRI can be identified. Targeted epidural medication, administered near the compromised spinal nerve, results in substantial and prolonged pain relief.

Bilateral thoracic paravertebral block: potential and practice

Paravertebral nerve blocks (PVBs) can provide excellent intraoperative anaesthetic and postoperative analgesic conditions with less adverse effects and fewer contraindications than central neural blocks. Most published data are related to unilateral PVB, but its potential as a bilateral technique has been demonstrated. Bilateral PVB has been used successfully in the thoracic, abdominal, and pelvic regions, sometimes obviating the need for general anaesthesia. We have reviewed the use of bilateral PVB in association with surgery and chronic pain therapy. This covers 12 published studies with a total of 538 patients, and with varied methods and outcome measures. Despite the need for relatively large doses of local anaesthetics, there are no reports of systemic toxicity. The incidence of complications such as pneumothorax and hypotension is low. More studies on the use of bilateral PVB are required.

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.

Continuous intercostal nerve block versus epidural morphine for postthoracotomy analgesia

Twenty patients undergoing elective thoracotomy were randomized into two groups, receiving either lumbar epidural morphine (n = 10) or continuous extrapleural intercostal nerve block (n = 10). Subjective pain relief was assessed on a linear visual analogue scale. Pulmonary function (peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity) was measured on the day before operation and daily for 4 days after operation. Pulse oximetry monitoring was used to determine the incidence of hypoxemia. No significant difference was observed between the groups concerning pain relief (except at 28 hours, in favor of the intercostal nerve block group), respiratory performance, or arterial oxygen saturation. Vomiting, pruritus, and urinary retention occurred only in the epidural group, whereas nausea occurred significantly less frequently in the extrapleural group. We conclude that after thoracotomy continuous extrapleural intercostal nerve block is as effective as lumbar epidural morphine in reducing postoperative pain and restoring pulmonary mechanics. Because of the significantly lower complication rates we favor continuous extrapleural intercostal nerve block for postthoracotomy analgesia.

Bilateral paravertebral analgesia for major abdominal vascular surgery: a preliminary report

Paravertebral analgesia is highly effective in blocking unilateral afferent input from the trunk, but its bilateral use does not appear to have been described. Eight patients undergoing major abdominal vascular surgery had pre‐operative bilateral paravertebral catheters inserted. A dose of 25 ml of bupivacaine 0.5% divided between the two catheters provided the basis of an effective intra‐operative analgesic regimen which was continued postoperatively by infusion of bupivacaine for 4 days. Diclofenac and morphine completed a balanced analgesic regimen which was started pre‐operatively and continued for 5 and 3 days respectively. Cardiovascular stability was notable throughout surgery, even with aortic clamping and all patients were extubated at the end of surgery. Good quality analgesia was obtained as assessed by low postoperative pain scores at rest and on movement. Three patients were not admitted to the intensive care unit, where mean stays for the group was 10 h (range 0‐24 h) and mean hospital stay was 10 days (range 7–14). There were no additional demands made on the nursing staff and no postoperative pain‐related complications occurred. We conclude that bilateral paravertebral analgesia, as part of a balanced analgesic technique, is an alternative method of providing effective afferent blockage for major abdominal surgery.

The Management of Postsurgical Pain in the Elderly Population

It is likely that the trend towards ever more aggressive surgery in elderly and possibly frail patients will continue, with the lifting of traditional age limits. Recent evidence has shown that surgical trauma induces processes of nervous system sensitisation that contributes to and enhances postoperative pain and leads to chronic pain. This knowledge provides a rational basis for pro-active, pre-operative and post-operative analgesic strategies which can reduce the neuronal barrage associated with tissue damage. As well as a reduction or elimination of post-operative pain, an improvement in physiological variables, such as neu-roendocrine stress responses and post-operative pulmonary function can be expected. Complete pain control cannot be achieved with a single agent or technique without significant serious adverse effects, a problem which is compounded in the elderly patient due to a combination of slower drug metabolism, decreased organ function and physiological changes in cardiovascular and respiratory reserves. A balanced analgesic regimen that includes an effective afferent block (regional analgesia) is more appropriate. By preventing postoperative pain and its associated neuroendocrine sequelae, major surgical procedures in traditionally unsuitable patients can be seriously considered.