Failed back surgery syndrome: Who has failed?

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Rapport : Douleurs lombaires postopératoires

Failed back surgery syndrome: Who has failed? Lombo-radiculalgies postopératoires : d’où vient l’échec? A. Al Kaisy a , D. Pang a , M.J. Desai b , P. Pries c , R. North d , R.S. Taylor e , L. Mc Cracken f , P. Rigoard c,g,∗ a

Pain Management Department, St Thomas & Guy’s Hospital, London, UK International Spine, Pain & Performance Center, Washington DC 20009, USA Spine and Neuromodulation Functional Unit, Poitiers University Hospital, 86000 Poitiers, France d Department of neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA e Institute of Health Research, University of Exeter Medical School, Exeter, UK f Department of Psychology & Behavioural Medicine, King’s College, London, UK g 3 N Lab (Neuromodulation & Neural Networks), Poitiers University Hospital, 86000 Poitiers, France b c

a r t i c l e

i n f o

Article history: Received 17 September 2013 Received in revised form 24 July 2014 Accepted 18 October 2014 Available online xxx Keywords: Failed back surgery syndrome Spinal cord stimulation Spine Chronic pain Back pain Surgery

a b s t r a c t Introduction. – Failed back surgery syndrome (FBSS) results from a cascade of medical and surgical events that lead to or leave the patient with chronic back and radicular pain. This concept is extremely difficult to understand, both for the patient and for the therapist. The difficulty is related to the connotations of failure and blame directly associated with this term. The perception of the medical situation varies enormously according to the background and medical education of the clinician who manages this type of patient. Eight health system experts (2 pain physicians, 1 orthopaedic spine surgeon, 1 neuro spine surgeon, 1 functional neurosurgeon, 1 physiatrist, 1 psychologist and one health-economic expert) were asked to define and share their specialist point of view concerning the management of postoperative back and radicular pain. Ideally, it could be proposed that the patient would derive optimal benefit from systematic confrontation of these various points of view in order to propose the best treatment option at a given point in time to achieve the best possible care pathway. Conclusion. – The initial pejorative connotation of FBSS suggesting failure or blame must now be replaced to direct the patient and therapists towards a temporal concept focusing on the future rather than the past. In addition to the redefinition of an optimised care pathway, a consensus based on consultation would allow redefinition and renaming of this syndrome in order to ensure a more positive approach centered on the patient. © 2014 Elsevier Masson SAS. All rights reserved.

r é s u m é Mots clés : Lombo-radiculalgies postopératoires Stimulation médullaire épidurale Rachis Douleurs chroniques Douleurs du dos Chirurgie

Introduction. – Les lombo-radiculalgies postopératoires (LRPO) résultent d’une cascade d’évènements médicaux et chirurgicaux, ayant conduit ou laissé le patient avec des douleurs persistantes chroniques du dos et des membres inférieurs. Ce concept est extrêmement difficile à saisir, tant pour le patient que son thérapeute. La principale difficulté est en relation avec les connotations d’échec et de blâme qui sont associées directement à ce terme. La perception de la situation médicale varie énormément en fonction de la culture et de l’éducation médicale du clinicien qui prend en charge ce type de patient. Huit experts du système de soins (deux médecins de la douleur, un chirurgien du rachis orthopédiste, un chirurgien du rachis neurochirurgien, un neurochirurgien fonctionnel, un médecin de rééducation, un psychologue et un expert médico-économique) ont été sollicités pour définir et partager leur point de vue de spécialiste concernant le management de la douleur postopératoire lombo-radiculaire. Dans l’idéal, il pourrait être proposé au patient une confrontation systématique de ces différents points de vue afin d’optimiser sa prise en charge et proposer les meilleures alternatives thérapeutiques possibles, à un moment donné, dans son parcours de soins.

∗ Corresponding author at: Corresponding author. Unité rachis et neurostimulation, service de neurochirurgie, 2, rue de la Milétrie, BP 577, 86021 Poitiers cedex, France. E-mail address: [email protected] (P. Rigoard). http://dx.doi.org/10.1016/j.neuchi.2014.10.107 0028-3770/© 2014 Elsevier Masson SAS. All rights reserved.

Please cite this article in press as: Al Kaisy A, et al. Failed back surgery syndrome: Who has failed? Neurochirurgie (2015), http://dx.doi.org/10.1016/j.neuchi.2014.10.107

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Conclusion. – La connotation initiale du FBSS est péjorative parce qu’elle suggère un échec ou un blâme. Elle doit maintenant être remplacée pour guider le patient et ses thérapeutes vers un concept temporel se focalisant sur l’avenir plutôt que sur le passé. La redéfinition d’un algorithme de prise en charge optimisé serait un bon début mais il faudra en plus un consensus basé sur l’échange de points de vue pour redéfinir et renommer ce syndrome afin qu’une approche plus positive s’en dégage et reste finalement centrée sur le patient. © 2014 Elsevier Masson SAS. Tous droits réservés.

1. Introduction Failed back surgery syndrome (FBSS) is a diverse and complex array of symptoms involving persistent or recurrent, chronic pain after one or more surgical procedures on the spine. Commonly this results in functional failure of the spine, as opposed to failure of treatment or surgery, although these may also occur [1]. In the United States, where spine surgery exceeds 300,000 operations per year, 10–40% of lumbar spine operations result in FBSS [1]. Patients with FBSS are a heterogeneous group, with complex and varied aetiologies [2]. Patients typically present with chronic back or extremity pain, often both. Back pain is described as diffuse, dull, or aching; extremity pain as sharp, pricking, or stabbing. FBSS patients might also experience weakness and spasm in the limbs, numbness and, possibly, bladder and bowel difficulties [2]. Patients with FBSS have a low quality of life (QoL) and high psychological morbidity and are frequent users of health services [3–5]. The term “FBSS” does not identify a cause or provide guidance to appropriate management [6]. Further, such a term may leave the impression of a lack of precision in diagnosis and treatment [7]. 1.1. FBSS: two-sided failure The concept of failed back surgery syndrome is extremely difficult to understand, both for the patient and for the therapist and this difficulty is related to the connotations of failure and blame directly associated with this term. Patient may find that it is difficult to accept upon agreeing to a proposed treatment, designed to treat and relieve pain, his or her life is transformed into a state of permanent, severe chronic pain after one or several surgical procedures. The patient’s personal perception and everyday experience may associate both technical failure and psychological failure related to impairment of quality of life as a result of the pain or the surgical procedure. The therapist may consider that the situation corresponds to a technical failure or a poor indication [8], however, aggression to the nervous system by the underlying spinal disease can per se lead to postoperative persistence or recurrence of pain, despite a clearly defined indication or a technically satisfactory procedure. 1.2. The medical community’s perception The perception and assessment of the medical situation in this context of failure vary enormously according to the background and medical education of the clinician who manages this type of patient. Spine surgeons tend to adopt an anatomical and biomechanical vision of pain. The advantage of this approach is that it might avoid missing indications for repeated surgery in this setting. However, a possible disadvantage of this approach might be a more singular focus of mechanistic aetiologies while ignoring the pathophysiology and the characteristics of the pain itself, as well as its neuropsychological impact. Without incorporating these

various elements into the evaluation of the patient, failure may result despite a technically justified surgical indication. Pain physicians tend to focus on symptom management based on a multidimensional approach. Ideally, the advantage of this management strategy is that it might limit the invasiveness and determine the order of priority of the techniques proposed; it takes into account the psychological dimension of the problem, related to the patient’s perception and mental acceptance of pain, and finally, it allows a diversity of medical techniques to be proposed to the patient. The disadvantages of this approach are related to the limitations of some pain physician’s in their degree of competence with relation to anatomical or radiological assessment of any mechanical conflicts that would partly account for the pain and that would be eligible for a more aggressive curative procedure or a singular focus on palliative or interventional procedures without the hope for resolution.

1.3. Health system constraints The particularly difficult economic context in European countries is currently responsible for a paradox concerning the use of medical technologies: on the one hand, there is a rapid growth of the potential indications for new electronic medical devices, such as neurostimulation techniques, but, on the other hand, the inevitable restrictive policy related to excess costs induced by health systems for the community is designed to limit excessive diffusion of these expensive devices or erratic practices without any multidisciplinary consensus, and can therefore constitute a major obstacle to the potential benefit that patients could derive from these new technologies. However, the health system is designed to avoid excessive use of technological equipment in all of these patients before the efficacy and cost-effectiveness ratio of these devices have been clearly demonstrated. The purpose of this article is to compare the points of view of the various therapists involved in the care pathway of these patients.

2. Expert point of views Eight health system experts were asked to define and share their specialist point of view concerning the management of postoperative back and radicular pain. Doctor Al Kaisy is the Director of the Pain Management Department at St Thomas & Guy’s Hospital, London, UK. As an anaesthetist, he is specialised in the non-invasive, medical management of chronic pain patients. However, his world-recognized experience in spinal cord stimulation and peripheral nerve stimulation has given him particular insight into what can be considered to be broad, global management of this disease. Doctor Pang is a consultant in the same department and is particularly specialised in semi-invasive analgesic procedures, such as spinal infiltration, radiofrequency techniques, and autonomic nervous system blocks.

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Doctor Desai is trained in physical medicine & rehabilitation as well as pain medicine. He is decided to the comprehensive management of spinal disorders, incorporating pharmaceutical options, invasive pain management, percutaneous implant techniques for spinal cord stimulation and novel rehabilitative and physiotherapeutic technique. He maintains the importance of integrating physiotherapy into the chronic pain patient’s pathway. This unusual career gave him the opportunity to offer his patients a very interesting and global view with their care, taking into account not only pain relief but functional improvement as well. He is the director of Spine, Pain Medicine & Research department at Metro Orthopedics & Sports Therapy centre. Professor Pries is an orthopaedic surgeon specialised in the management of juvenile scoliosis. He has been a full time spinal surgeon from 1987. His main clinical interests have included paediatric spinal deformity and reconstructive adult spinal surgery. He is now committed to assessment and holistic care for low back, and other spine pain. He provides definitive assessment and diagnosis of all spine conditions, and has developed a range of non- and surgical treatment programmes. He teaches worldwide, and publishes on basic and clinical science in relation to spinal conditions Doctor Rigoard is a neurosurgeon specialised in the management of spinal surgical diseases and neurostimulation techniques. He founded the Spine and Neurostimulation Functional Unit with Prof. Pries at Poitiers University Hospital in France, in which orthopaedic surgeons and neurosurgeons work in close collaboration, hand in hand. Professor North is Professor Emeritus of Neurosurgery and Anaesthesiology at the J. Hopkins University of Baltimore, USA, and one of the pioneers of spinal cord stimulation and worldwide diffusion of this technique. He is the author of numerous publications and of two randomized prospective studies that compared success rates of repeat spinal surgery versus spinal cord stimulation. Professor Taylor is Professor Health Services Research at the University of Exeter, UK and has particular interest in international systems for the valuation and reimbursement of health technologies and contributed to the design and statistical analysis of some of the key studies on spinal cord stimulation and failed back surgery syndrome. Over the last 15 years, he contributed to the work of the National Institute for Health and Social Excellence (NICE), the UK agency responsible for coverage decisions for medical devices. Professor Mc Cracken is currently professor of Behavioural Medicine at King’s College London, in the Health Psychology Section, Psychology Department, within the Institute of Psychiatry. He is active in clinical services at INPUT Pain Management at Guys’ and St Thomas’ Hospitals NHS Foundation Trust, London. There, he is a Consultant Clinical Psychologist and Lead Psychologist. His research focuses on development of treatment for chronic pain, psychological flexiblity, and acceptance and commitment therapy (ACT). 2.1. A pain physician’s point of view Dr Adnan Al Kaisy, Dr David Pang (St Thomas Hospital, Pain Management Dept, London, UK). A large number of medical, behavioral and structural factors may contribute to surgical failure in spinal surgery. There is a significant proportion of patients with persistent and disabling pain despite surgery that is technically correct and targeted at their concordant pathology. This challenging situation leaves both the patient and their clinicians puzzled and it is important for both parties to understand the various factors that might contribute to this occurrence. Investigation of structural and biomechanical abnormalities is only a part of the overall management of such patients. Even once these are discovered and treated, it does not guarantee good outcomes. Non-surgical factors that influence outcomes are becoming

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increasingly mentioned in the literature and the evidence underlying them is growing rapidly. Spinal surgery is not unique in having patients that continue with painful symptoms. Chronic pain is increasingly recognized after almost all types of surgery. The first publication in 1998 [9] shows that medical practitioners have been slow to recognize that the problem could exist but the large number of subsequent publications have increased awareness of this condition [10–12]. An example of where pathology may not correlate with clinical symptomatology lies in the use of MRI in spinal pain. Imaging of the spine is amongst the most common medical investigation conducted yet the evidence that it improves outcomes is far from certain. A randomized trial of surgery in 267 patients with sciatica secondary to herniated discs demonstrated that after surgery, the presence of herniated discs or nerve root compression did not correlate with outcomes at 1 year [13]. This suggests that these structural pathologies may not be causal. In an older publication, completely normal discs are found in only 36% of asymptomatic adults and a meta-analysis of randomized trials failed to show that imaging affected outcomes in low-risk back pain [14]. Thus, there must be other factors that contribute to a successful outcome in spinal surgery. Kehlet et al. in 2006 proposed that three factors could be responsible for persistent pain [10]: • iatrogenic neuropathic pain; • persistent sensitization of acute pain; • genetic makeup that predisposes to persistent pain. Iatrogenic neuropathic pain might occur from direct nerve injury during surgery, spinal cord ischaemia or postoperative scar tissue and epidural fibrosis. It is possible that neuropathic pain will occur as a direct result of any trauma, similar to the phenomenon seen in complex regional pain syndrome after innocuous extremity trauma. Although the full changes in symptoms and signs of CRPS are not seen in the low back, neuropathic features have been demonstrated in studies using quantitative sensory testing. Certain patients with specific neuropathic changes respond well to treatments that target neuropathic pain, such as spinal cord stimulation. The presence of epidural fibrosis is an important cause of neuropathic pain post-spinal surgery. A study of 78 patients with FBSS using epiduroscopy demonstrated that 91% had significant fibrosis. This was even higher in cases where surgery was more extensive [15]. Magnetic resonance imaging only demonstrated this fibrosis in 16.1% of the patients. This adds further evidence against the oveereliance on imaging modalities for clinical decision-making. Persistent sensitization of acute pain and neural plasticity of the central and peripheral nervous system provides another explanation of why structural pathology may not fully respond to surgical means [16]. Peripheral sensitization occurs when inflammatory mediators act on peripheral nociceptive nerve fibres and receptors to reduce activation thresholds and increase excitability. This leads to hyperalgesia so that lower levels of peripheral nociceptive stimuli are needed to activate a pain response. Once tissue healing is complete and inflammation subsides, this peripheral sensitization typically resolves. In addition to peripheral sensitization, another mechanism to amplify nociceptive effects occurs when persistent painful stimuli leads to changes in neuronal plasticity at the level of the central nervous system [17]. These changes lead to hyperalgesia and increases sensitivity to painful stimuli. As the neuronal changes occur at the central nervous system, it is termed central sensitization. Chronic and persistent noxious stimulus leads to changes in intracellular protein synthesis at the dorsal horns of the spinal cord and alterations in ion channels and membrane receptors. Loss of inhibitory interneuronal activity is also observed and plays an important contributing factor. The net result is both increased sensitivity to

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nociceptive stimuli and in severe cases, normal non-painful stimuli become perceived as painful. This leads to sensitivity in a larger area that is affected by injury and is termed secondary hyperalgesia. This phenomenon explains why surgery for chronic painful conditions may be unsuccessful. Many studies have shown that severe and chronic pain preceding surgery leads to increased risk of chronic postoperative pain [18–23]. As these changes occur at the molecular level and are mediated by gene transcription, it is no surprise that much research is involved in determining such genetic factors that will predispose to chronic pain. Chronic pain states such as fibromyalgia shows polymorphisms of genes affecting serotoinergic, catecholamine and dopaminergic systems that play a role in the pathogenesis of chronic pain. In a twin study of low back pain comparing 2108 mono- and dizygotic twins suggested that a small genetic contributor might play a role in men but not in women. A study of 258 patients with lumbar disc herniation suggested that the A118G gene might play a role in postoperative pain [24]. Psychological and social factors have been studied as important factors that influence outcome from spinal surgery. It is increasingly recognized that these psychosocial attributes also affect other surgical procedures as well. Psychosocial factors were demonstrated to be more predictive of negative outcomes than structural abnormalities [20]. The presence of litigation was also strongly associated with negative outcomes [25,26]. The main psychological that are specific to poor outcomes are depression, anxiety, poor coping, somatization and hyperchondriasis [23,23,27]. Therefore, all of the above provide a possible mechanism of pain that is initiated acutely and propagated towards a chronic phase. From nerve sensitization to psychosocial perpetuation, these contributing mechanisms must be assessed and looked for if any success is to be expected in managing these patients. 2.1.1. Pain medicine assessment It is important to understand the pathology that initially leads to a patient having spine surgery. Ideally, this would have been thoroughly assessed and managed by the patient’s spine surgeon but to assume that the initial diagnosis is always correct or remains correct would do our patients a disservice. Providing an alternate perspective may be useful in this setting. A recent article on diagnostic errors in medicine has shown that large numbers of cognitive errors can influence diagnostic decision-making and these biases can affect even the most expert physician [28]. When assessing the pain itself the clinician must establish whether the pain is new or is it the same prior to surgery. New pain would infer a possible iatrogenic causes but if the pain is similar to the symptoms experienced prior to surgery then it could be either the surgery was not at the underlying cause or it was not sufficient to treat that cause. The distribution of pain is critical as axial pain usually implies a different diagnosis than that of radicular limb pain. The area of pain will affect what modalities would be suitable as the therapeutic approach differs between generalized pains versus localized pain. Factors that exacerbate the pain and the episodic pattern of pain are necessary as these will help individualize treatment. The progression of symptom severity may suggest either disease progression or poor coping mechanisms. It is important to look for both. The clinician must look for features that may suggest neuropathic pain. This is assessed clinically as there are no gold standard diagnostic investigations. Symptoms include spontaneous paroxysmal pain, shooting, shock-like pains, burning, tingling or crawling sensations, sensory loss with pain and pain following non-painful stimuli, such as light touch. Signs, such as hyperalgesia, allodynia and neurological abnormality add weight to the diagnosis of neuropathic pain. Screening tools, such as pain DETECT, LANSS and DN4 can help but the sensitivitiy and specificity range between

approximately 80–90% and are useful as screening tools rather than a means of making a diagnosis [29]. Simultaneous to a physical assessment, a behavioral evaluation should also be conducted. These psychological and social issues may perpetuate the symptoms or form barriers to therapy. There are a number of “yellow flags” that represent psychosocial factors that are associated with barriers to treatment. These factors are a belief that the pain is harmful, a passive rather than active approach to pain management, fear avoidance behavior, low mood and social withdrawal. Ongoing litigation can pose a problem as can secondary gain. Alcohol and drug misuse is another barrier to rehabilitation and treatment. 2.1.2. So what can we do? As there are a number of factors that can perpetuate the pain in FBSS, it is logical that a multidisciplinary approach is critical to successful long-term management. Patients must have realistic expectations and goals in seeking treatment and these should be discussed and agreed upon with the treatment team. Expecting a complete resolution of symptoms via a single clinician may be a course of action doomed to failure. Involving a team of pain and spinal physicians, specialist pain nurses, physiotherapists, occupational therapists and psychologists who specialize in pain is the optimal approach. Treatment aims to educate patients in their condition and improves their understanding so that realistic goals can be met; pain-relieving therapies to reduce the symptom burden, physical and occupational therapies to improve function and psychological therapies to address negative pain behaviors and to provide strategies to manage their pain are all a part of this strategy. Pharmacological therapies are the most common medical approach to pain relief and consist of both conventional analgesics and anti-neuropathic medications, such as the gabapentinoids and tricyclic antidepressants. These should be used in the context to helping patients manage their pain and are not agents that should be used alone in the long-term as tolerance and side effects are common. Interventional pain therapies, such as epidural steroid injection, radiofrequency denervation, trigger point injections and epidural adhesiolysis are frequently used but the evidence for their efficacy in FBSS is weak [6,30]. Neuromodulation, such as spinal cord stimulation for FBSS has amongst the highest grade of evidence in pain-relieving treatments. The two high quality randomized trials show that this approach is superior to conventional medical management and repeat surgery [7,31]. It involves implanting an electrode into the epidural space that generates an electrical field to stimulate the dorsal columns of the spinal cord. This generates a pleasant feeling of parasthesia that can prevent the perception of pain. The mechanism of action is based on the gate theory by Wall and Melzack but the exact mechanisms are still under study [32,33]. Many studies have demonstrated the efficacy and health-economic value of spinal cord stimulation (SCS) for chronic neuropathic radicular pain over recent decades [6,7,31,34–38]. However, the back pain component of FBSS remains a challenge for neurostimulation [37]. This treatment has an advantage of safety, reversibility and a trial period to determine efficacy using temporary electrodes prior to permanent implantation. Again, all these pain-relieving procedures should be used in the context of multidisciplinary care with the overall aim of providing the patient with tools to manage their pain with physical and psychological rehabilitation. It is of note that a large trail in primary care of non-specific low back pain showed that stratifying patients into groups depending on their potential for chronic disability demonstrated better outcomes than treating them as a single group [39]. This shows the effectiveness of a multidisciplinary approach. Caution must be made before generalizing this

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to FBSS as these patients had non-specific low back pain and not FBSS. 2.2. A spine surgeon’s point of view Prof. Pries and Dr. Rigoard (Spine and Neuromodulation Functional Unit, Poitiers, France) Pooling of spine and neuromodulation skills within a single clinical unit? Collaboration between orthopaedic surgeons and neurosurgeons in a common entity “spine surgeons”? A continuum of care for patients? Spine surgeons tend to have a big ego, which, behind their technician’s mask, enables them to deal with various planned or unexpected difficult situations in the operating room. However, their ego can also be a drawback when it comes to accepting failure. Despite the efforts and the clinical skills deployed by spine surgeons and despite their demonstrated technical capacities, and their scrupulous and almost obsessive desire to restore abnormal anatomy, the notion of failure characterising FBSS is two-sided, except for surgeons who renounce their humanity and who behave like machines, devoid of any affect or empathy towards their patients. The lack of cohesion sometimes observed between the various successive medical personnel is an intrinsic aspect of the complementarity, borders and limits of the various fields of competence. The frequent limit of functional neurosurgeons is that they do not like screws and the frequent limit of biomechanical surgeons is that they do not like chronic pain patients. Does the solution consist of confrontation? Avoidance? We believe that a better solution would consist of joining forces. 2.2.1. A joint physical platform At Poitiers University Hospital, we have proposed the formation of a clinical unit combining orthopaedic surgeons and neurosurgeons, working hand in hand, in order to provide the most adapted solution and follow-up for patients with a spinal problem, particularly FBSS. Within this spine and neurostimulation clinical unit, eight surgeons, four orthopaedic surgeons and four neurosurgeons work together to ensure a continuum of care for patients with a spinal problem at all stages of the patient’s disease (from initial admission to the emergency department for a cauda equina syndrome secondary to stenotic disc hernia, for example, to supportive care for permanent disability, pain or residual deficit resulting from the initial lesion). 2.2.2. Individual specialists seeking complementarity The range of pooled skills is based on the fact that all surgeons of this unit must be able to propose, according to each surgical indication, endoscopic, percutaneous and minimally invasive spinal surgery techniques for traumatic, neoplastic or degenerative indications. Three of these surgeons are specialized in spinal deformity surgery and complex spinal instrumentation. Three surgeons are specialized in spinal cord stimulation, peripheral nerve stimulation and motor cortex stimulation implantation techniques, in addition to their spine surgery activity. Two surgeons of the unit (an orthopaedic surgeon and a neurosurgeon) ensure disability surgery. 2.2.3. A regional network structure Several multidisciplinary consultation meetings are held each week and some regional multidisciplinary visits are held each month: • a weekly spinal tumour multidisciplinary consultation meeting; • a local and regional low back pain management multidisciplinary consultation meeting;

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• two regional low back pain clinics at Poitiers university hospital and in a peripheral centre (Niort); • three monthly pain clinics in a pain management centre, two of which are held in peripheral hospitals (Niort and La Rochelle); • three monthly disability clinics, two of which are held in peripheral rehabilitation centres (Niort and La Rochelle). A research unit devoted to neurostimulation (N3 Lab for Neuromodulation and Neural Networks Lab) and a Biomechanics research unit located in the anatomy laboratory of the morphological department of the Poitiers Faculty of Medicine also work in close collaboration with the clinical unit. 2.2.4. Our approach The goal of this multidisciplinary approach was to accompany each patient from the time of his or her first visit until medical and/or surgical management of all potential consequences of the patient’s spinal disease, particularly chronic pain or possible disability. The objective was to create a platform, centralizing orthopaedic and neurosurgical skills by trying to ensure convergence of all of the various specialties involved IN varying degrees in the management of spinal diseases: neurologists, rheumatologists, oncologists, pain physicians, psychiatrists and rehabilitation physicians. This process was developed at Poitiers University Hospital, but also within a pain management network and a regional disability management network. The ultimate ambition of this project is to ensure that the patient finds the most appropriate healthcare professional at each stage of his/her disease and our desire for the surgical community would be to identify a new generation of spine surgeons able to deal with mechanical problems as well as the problem of chronic pain. Acceptance of complementarity between two populations of surgeons with different backgrounds remains an essential pre-requisite to build the future. 2.3. A functional neurosurgeon’s point of view Prof. Richard North (Baltimore, US). Functional neurosurgery versus reconstructive spine surgery for failed back surgery syndrome: An evidence-based approach. Pain is normally a biologically useful sensation, signaling actual or impending tissue damage, and so persistent pain after lumbosacral spine surgery might reflect persistent pathology, which can be addressed by further surgery. Alternatively, persistent pain might reflect established injury, in particular to the nervous system, i.e., neuropathic pain, for which different treatment would be appropriate. Neurosurgical procedures for pain may be categorized as anatomic, ablative or augmentative. If an anatomic problem amenable to decompression, stabilization or other reconstructive surgery is competent to explain a patient’s pain, then repeated surgery is indicated. This is particularly straightforward if a patient’s prior surgery was similarly and clearly indicated, but its technical goals were not achieved, or some complication supervened. All too often, however, (in a majority of cases, some say [40]), the original indications for surgery are obscure, and so further surgery is all the more difficult to justify. Indeed, repeated lumbosacral spine surgery yields diminishing returns, as it is well known [41]. Absent a clear-cut anatomic basis for a complaint of pain, the neurosurgeon’s perspective should be functional. In fact, even in the presence of obvious anatomic abnormalities (viz., degenerative lumbosacral spine disease is ubiquitous), if a satisfactory functional outcome is achieved (relief of pain, without potentially disabling or progressive neurologic deficit), then, the anatomic abnormality need not be corrected. If a patient fails conservative, non-operative

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treatment and is referred for neurosurgical evaluation, a full range of procedures – not just anatomic reconstruction – should be considered. Among functional procedures for failed back surgery syndrome, spinal cord stimulation (SCS) is well established; it is performed not only by functional neurosurgeons but also by interventional pain specialists. SCS is minimally invasive and reversible, and (unlike repeated reconstructive surgery) it is amenable to a therapeutic trial with a temporary system, to establish its efficacy before a commitment is made to the definitive procedure. SCS compares favorably with repeated surgery by virtue of higher yield with lower morbidity and greater cost-effectiveness. A single-center RCT of SCS vs. reoperation for FBSS demonstrated significantly better clinical outcomes [42] and greater cost-effectiveness [43] for SCS in patients with prominent radicular pain. A multi-centre RCT comparing SCS with conservative medical management reached similar conclusions [6]. This is consistent with the non-randomized studies that comprise the rest of the evidence base [44]. A multi-centre RCT of SCS vs. reoperation, incorporating the latest techniques and equipment for each, was undertaken in 2010 [38]. A review of the evidence comparing SCS with surgical and medical alternatives could clarify future study design issues and objectives. SCS treatment success depends upon proper patient selection, equipment choice, and physician training. Studies of SCS must include protocols to protect patient safety, including careful patient selection criteria. SCS studies must also rely on appropriate outcome measures to determine treatment success. Additional outcomes can and should be collected but pain relief should be the primary outcome. SCS studies must follow accepted standards regarding patient selection, sample size calculation, group comparability, standardized group treatment during data collection, reduction of bias, data analytical methods, and appropriate followup methods, including basing intervals on intervention dates (instead of study entry). Data reporting should include raw figures as well as percentages and information on all sub-group outcomes. The best evidence to date indicates that SCS, a functional procedure, is superior to reconstructive spine surgery in selected cases.

2.4. A physiatrist’s point of view Dr Mehul J. Desai (Washington, DC, US). Rehabilitation perspective Increasingly, patients with FBSS present not only with chronic and persistent pain but also functional impairment, these issues often interact in a complex fashion to prevent clinical improvement. Furthermore, in the US and other jurisdictions, functional outcomes to treatment are progressively scrutinized as important outcome measures. There are numerous physiotherapy protocols employed towards the treatment of FBSS, most commonly lumbar stabilization-based treatment algorithms. Unfortunately, most of these approaches have not been studied rigorously in a controlled fashion. Various prospective clinical trials focused on pain relief have also demonstrated improved function when integrating neuromodulatory techniques and physiotherapy as compared to therapy alone. Additionally, decreased medication usage has also been reported. It goes to follow that judiciously assimilating well-delineated physiotherapy approaches in conjunction with medical and interventional treatments may optimize outcomes, certainly these options deserve further investigation. It is quite likely that despite our efforts to employ technologically sophisticated interventions to FBSS, in the absence of a thorough understanding of the underlying aetiologies and without an integrated rehabilitation and behavioural component, success will remain fleeting.

2.5. An health system expert’s point of view Prof. Rod Taylor (Exeter, UK). At a time of unprecedented global financial austerity, health care providers and purchasers have never been under greater pressure to control their spending. Faced with static (or even, falling) budgets, yet rising healthcare costs, due to changing population demographics, increased costs of technology, and increasing public expectations, so providers and payers need to ensure the value of every healthcare dollar, euro or yen spent. So what will convince providers and purchasers on the value of spending for FBSS? The simple answer is “the right sort of evidence”. That evidence essentially needs to be in two forms: (1) evidence of the burden of FBSS; (2) evidence of the value for money (or “costeffectiveness”) of medical technologies to manage FBSS. We have a growing body of this evidence that FBSS is disabling and can have a negative impact on a patient’s health-related quality of life, well-being, and productivity [5,45]. For example, we found in our systematic review in neuropathic pain that FBSS patients experience a particular poorer level of health-related quality of life compared with other neuropathic pain conditions (e.g. diabetic polyneuropathy) and a number of chronic diseases (e.g. heart failure, type 2 diabetes) [45]. This data points to the fact that FBSS has high burden on patients and is therefore potentially an important area for health spending and investment. A number of published studies support the cost-effectiveness of spinal cord stimulation (SCS) for FBSS. The analysis by North et al. of a randomised controlled trial at 3-year follow-up found SCS to be a “dominant” economic option (was less costly and more effective) compared to reoperation [43]. Simpson et al. [46] and Taylor et al. [37] both report a cost-effectiveness ratio (ICER) for SCS of under £10,000 per quality adjusted life year (QALY). As this data shows a cost-effectiveness ratio well below the normal maximal willing to pay threshold of £20,000 to £30,000 per QALY, one most renowned international technology assessment agencies (National Institute for Health and Care Excellence [NICE]) in 2008 concluded that SCS was a good value for money and recommended the UK National Health Services use the treatment for chronic neuropathic pain, including FBSS [47]. In conclusion, we do have “valu” evidence of the FBSS burden and cost-effectiveness of SCS to make the case to purchasers and payers to invest in FBSS. However, we need more – better quality data on FBSS epidemiology (incidence and prevalence), the impact of FBSS on patients on medical and social care systems, and further economic evaluation evidence for additional neuromodulatory solutions for FBSS. 2.6. A psychologists point of view Prof. Mc Cracken (London, UK). Clearly there are people with the same identified spinal pathology who have pain and others who do not [14]. Likewise, there are those with back pain who seek treatment and those who do not [48], and from those who seek treatment for ostensibly the same conditions, some experience treatment failure and some experience success [49,50]. This must mean that it is not only the underlying pathology nor the surface condition, such as the pattern of symptoms that determines failure or success. Other factors are at play. A complete or helpful view of the problem of back pain must accommodate these factors. From a psychological point of view, many of these factors happen to be psychological. It is only natural that a person with pain will want it to stop and that those who seek to help them will agree with this desired outcome and seek to achieve it. In fact, this focus on pain reduction as outcome, on the part of both the person with pain and the treatment provider, is the same behavior patterns. We might call

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the pattern “identify an undesirable experience and eliminate it” or “find a problem and fix it”. As we say, this is an entirely natural, often effective, and even evolutionally adaptive behavior pattern, except that it does not always work. In the case of some back pain, this pattern is not the road to success – it is a trap. It is a trap in part because it can narrow the focus of action on eliminating a problem rather than, for example, on building opportunities for positive goals. To focus on a surgical operation to eliminate pain so that a person can function better, and achieve a higher quality of life, can include restricting a person means for achieving this quality of life. To avoid this restriction, one would need to apply methods designed specifically to widen the range of available means. It is easy for pain and related thoughts and feelings to become the dominating concerns in a person’s life. They are there when they lay down in bed, there when they wake, when they move, when they make plans, and when they consider their future. When pain and its related thoughts and feelings dominate in experience they also dominate in actions taken. And it is rather difficult for a person to break out of this cycle of feeling frightened, depressed, and miserable, attempting to find solutions to this, analyzing and ruminating over these, and seeking in one’s actions to avoid or escape this situation [51]. The trouble is that avoidance and escape are not a way out of the cycle, they are a part of the cycle itself. One problem with the fact that pain and wanting to be rid of pain become the dominate experiences is that this puts the patient in a risky and vulnerable situation. The story that pain needs to be fixed for life is a very coherent one – it makes sense. As we say, however, it is also a limited one. Without access to other points of view, the patient is constrained. From here, they “must!” have an operation if it might help. Unless another option can be seen, they will be unable to refuse the procedure. The desperation and fear that fuel this are potentially potent influences that cannot be easily neutralized [52]. This is the sense in which they are vulnerable. In this position, where they are essentially not free to say no, we may deem them less responsible when failure happens. People with pain can learn to function well and achieve a good quality of life without pain reduction [53,54]. Comprehensive psychologically based treatment approaches that focus on change in cognitive, emotional, and behavioral processes are considered the most clinically effective and cost-effective approaches to chronic pain [55]. Numerous systematic reviews support the claim for the effectiveness of psychological approaches [56], including analyses of low back pain alone [57]. Although the focus of psychological treatment can differ from somewhat centre-to-centre, predominantly the focus is not on eliminating pain but on improving daily functioning. In the ideal, even if pain is a part of the focus, it is not the exclusive or primary focus. There are psychological factors that impact on the experience of pain. Indeed, psychological factors are inherent to the experience of pain. And, these same types of psychological factors might be seen as responsible when surgical operations for back pain do achieve their intended results. At the same time, the psychologist’s perspective, at its best, is wider than this. From this perspective, complaints of back pain, patterns of seeking (or persistently seeking) care, agreeing to a procedure, and patterns of daily emotional, physical and social functioning are not merely reflections of pain but are foremost patterns of behavior. As these are patterns of behavior, the psychologist’s perspective asks us to look at any identified influences on these patterns that can be altered, especially by means that are as direct as possible. The surgeon’s scalpel can eventually create impacts on these but the primary mechanism of impact is somewhat a narrow one and not the most direct. As to “who’s failure” is failure following surgery, this answer depends on the purpose of the question. If the purpose is to place blame, it seems not very useful, and to keep within a theme of this section, it seems very narrow. A psychologist’s point of view

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on surgical failure is most explicitly one that asks for a breadth of perspective: broad in outcomes, in influences on these outcomes, and in the range of methods that might be applied to achieve them.

3. Discussion The management objectives of chronic pain following spinal surgery must remain focused on the patient. The reader must therefore consider each point of view expressed in this article not in opposition to the previous or following point of view, but as simply one particular aspect of a continuum of care, which must be integrated into a more global analysis. These complementary views should be combined to solve “The puzzle of Pain”, as suggested by Ronald Melzack in the title of his book [58]. Ideally, it would be suggested that the patient would derive optimal benefit from systematic confrontation of these various points of view in order to propose the best treatment options at a given point in time to achieve the best possible care pathway. A strictly medical view of FBSS without taking into account the spine surgeon’s view could miss certain indications for repeat surgery, which, in highly selected cases, may resolve the patient’s pain by treating the underlying cause. This approach may facilitate the resolution of FBSS and thereafter be considered a positive outcome of surgery. By contrast, systematic repeated mechanical surgery in a patient presenting with plastic adaptation of the nervous system in response to chronic pain will likely lead to complete failure and even recurrent pain at the site of surgery or multiplication of painful sites in high-risk patients. Spine surgeons must be familiarised with the concepts of chronic pain. It is proposed that an exchange of information based on sharing of opinions between experienced physicians at scientific meetings, congresses or round tables would be beneficial to the evolution of management of FBSS and chronic pain. Chronic pain should also be part of the initial training of future spine surgeons, encouraging them to adopt a comprehensive approach to each patient undergoing spine surgery, from initial surgery to management of residual pain. The concepts of “failure” or “blame” would then be somewhat reconciled and only be considered if the patient was abandoned at some point during management. Consultation of the various specialists involved in this type of management is now essential in order to redefine this care pathway, by attempting to optimize the quality of life of these complex patients in whom limited treatment options are available. One might even propose a “gatekeeper” concept, helmed by a physician well versed in both the mechanical and inflammatory indications for initial and repeated surgery and the mechanisms of chronic pain and functional impairment. Whatever the approach, we must also try to limit the high costs of these patients to health systems related to the chronic nature of their pain. A joint reflection on the care pathway must therefore define a flow-chart of the various types of management, not only in terms of efficacy, benefits, efficacy/invasiveness ratio, but also in terms of cost-effectiveness ratio and value, as ultimate objectives. The title of this article and the very name of failed back surgery syndrome could tempt us to look for and identify the individual responsibility of a healthcare professional in relation to this failure, but this approach would be purely artificial. In fact, this term probably needs to be changed to a less pejorative term, indicating the need for ongoing management of these patients and in some instances, the incapacity of medicine to ensure the cure of all ills despite recent technological progress. “The soul and body rive not more in parting. Than greatness going off.”

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« L’âme ne se sépare pas du corps avec plus de douleur que l’homme de sa grandeur. » William Shakespeare, Antony and Cleopatra. 4. Conclusion “Failed Back Surgery Syndrome” results from a cascade of medical and surgical events that had led to or left the patient with chronic back and radicular pain. This pain often remains refractory to the various available management strategies for a considerable proportion of these patients. This initial pejorative connotation, suggesting failure or blame, must now be replaced by a global and multidisciplinary approach to this difficult disease state in order to direct the patient and therapists towards a temporal concept focusing on: (1) the future rather than the past (2) a transition from a mechanical problem to a chronic disease. In addition to redefinition of an optimised care pathway, a consensus based on consultation would allow redefinition and renaming of this syndrome in order to ensure a more positive approach to the future. Disclosure of interest Dr. Al Kaisy received fees related to the presentation of study results at scientific congresses from Nevro Corp. Dr. Desai is a consultant for Medtronic, Inc and Kimberly-Clark Medical. Prof. Pries is a consultant for Alphatec Spine. Prof. North is a consultant for Algostim, LLC and Stimwave, Inc, received research grants from Boston Scientific Corp., Medtronic, Inc and St Jude Medical, Inc. Prof. Taylor is a consultant for Medtronic Inc. Dr. Rigoard is a consultant for Medtronic Inc. and received honoraria for medical training from St Jude Medical, research grants from Medtronic Inc & St Jude Medical. All other authors reported no conflict of interest for this study. Acknowledgements We would like to thank Lolita Ichoutine for typing the manuscript, Anthony Saul for his editorial support, the N3 Lab for his technical help, and the direction of research department of Poitiers University Hospital, represented by Mrs. Guyon and Mr. De Bideran for their support. References [1] Saravanakumar K. Bonica’s Management of Pain. 4th edn. Anaesthesia; 2010. [2] Tharmanathan P, Adamson J, Ashby R, Eldabe S. Diagnosis and treatment of failed back surgery syndrome in the UK: mapping of practice using a crosssectional survey. Br J Pain 2012;6(4):142–52. [3] Talbot L. Failed back surgery syndrome. BMJ 2003 Oct 25;327(7421):985–6. [4] McDermott AM, Toelle TR, Rowbotham DJ, Schaefer CP, Dukes EM. The burden of neuropathic pain: results from a cross-sectional survey. Eur J Pain 2006;10(2):127–35. [5] Manca A, Eldabe S, Buchser E, Kumar K, Taylor RS. Relationship between health-related quality of life, pain, and functional disability in neuropathic pain patients with failed back surgery syndrome. Value Health 2010;13(1):95–102. [6] Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, et al. Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome. Pain 2007;132(1–2):179–88. [7] Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, et al. The effects of spinal cord stimulation in neuropathic pain are sustained: a 24month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation. Neurosurgery 2008;63(4):770 [762–70; discussion]. [8] Mehul J, Desai, Rod S, Taylor, Philippe Rigoard. Optimized medical management of failed back surgery syndrome. A transatlantic critical overview of the literature. Neurochirurgie 2014 [Submitted for publication (Hors-série)]. [9] Crombie IK, Davies HT, Macrae WA. Cut and thrust: antecedent surgery and trauma among patients attending a chronic pain clinic. Pain 1998;76(1–2):167–71.

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