Instrumented fusions: a need for guidelines and research

Management of patients with neuropathic pain

Background: Neuropathic pain diseases commonly treated with pain medicine are postherpetic neuralgia (PHN), diabetic peripheral neuropathy (DPNP), complex regional pain syndrome (CRPS), and chronic pain after spinal surgery. Diagnosis and treatment of these neuropathic pain diseases is an arduous task, and there is a need to improve the understanding of these entities.Current Concepts: PHN is diagnosed when pain persists for more than 3 months after the healing of herpes zoster rashes, and this disease is commonly encountered in the elderly population. The pathophysiology of DPNP is ischemia of nerve tissue due to microvascular damage. In addition to sensory nerves, DPNP can also result in changes in motor and autonomic nerves. CRPS is a chronic intractable pain disorder, and is classified into types 1 and 2. Type 1 CRPS is diagnosed when there is no evidence of nerve damage while type 2 CRPS shows evidence of nerve damage. However, the signs and symptoms do not differ depending on the type. Chronic pain after spinal surgery is characterized by persistent back pain even after one or more spinal surgeries. This neuropathic pain occurs in the lower back or leg region.Discussion and Conclusion: The most crucial step in the management of patients with neuropathic pain is to suspect and diagnose if the pain has the characteristics of any pain-related disease. Although the etiology and pathophysiology may differ, the treatment of neuropathic pain remains the same and includes both conservative and interventional approaches. Neuropathic pain diseases often become chronic in nature, and thus, it is important to establish a treatment plan which aims at decreasing pain, improving patient’s functionality and attaining an acceptable quality of life.

The incidence of failed back surgery syndrome varies between clinical setting and procedure type

BACKGROUND

Failed back surgery syndrome (FBSS) is a significant cause of lumbar disability and is associated with severe patient morbidity. As the etiology of FBSS is not completely elucidated, the risk factors and evaluation of patients with FBSS remains challenging. Our analysis of a wide variety of operation types, clinical setting, and their correlation to FBSS seeks to allow fellow clinicians to be aware of the potential risk factors that leads to this devastating diagnosis.

METHODS

Data were obtained for patients undergoing anterior lumbar fusion, posterior lumbar fusion, or decompression procedures from January 2010 to December 2017 from the Mariner insurance database. Rates of FBSS at six- and twelve-months post-surgery were determined for patients undergoing single/multilevel procedures according to place of service, and approach/procedure type.

RESULTS

From 2010 to 2017, 102,047 patients underwent lumbar fusion or decompression surgery (54% decompression procedures, 36% posterior fusions, and 8.9% anterior fusions).5.4% of patients were diagnosed with FBSS within six months of the index procedure, and 8.4% were diagnosed with FBSS within twelve months. FBSS was higher in the inpatient (6.0%) vs. outpatient (4.3%) cohort. Among the surgical techniques, multi-level procedures had significantly higher rates of FBSS than single-level procedures, the highest being 10% in multi-level inpatient decompression procedures (p < 0.05).

CONCLUSION

The highest rates of FBSS occurred in in the elderly (age group 70-74), for those patients whose index procedure was received in an inpatient setting, as well as for those receiving a multi-level surgery.

Spinal Cord Stimulation in Failed Back Surgery Syndrome: Review of Clinical Use, Quality of Life and Cost-Effectiveness

Failed back surgery syndrome (FBSS) is complex and recurrent chronic pain after spinal surgery. Several important patient and surgery related risk factors play roles in development of FBSS. Inadequate selection of the candidates for the spinal surgeries is one of the most crucial causes. The guidelines suggest that conservative management featuring pharmacologic approaches and rehabilitation should be introduced first. For therapy-refractory FBSS, spinal cord stimulation (SCS) is recommended in selected patients. Treatment efficacy for FBSS has increased over the years with the majority of patients experiencing pain relief and reduced medicinal load. Improved quality of life can also be achieved using SCS. Cost-effectiveness of SCS still remains unclear. However evidence for SCS role in FBSS is controversial, SCS can be beneficial for carefully classified patients.

Multi-target neurostimulation for adequate long-term relief of neuropathic and nociceptive chronic pain components

Successful treatment of chronic pain for patients with failed back surgery syndrome can be extremely complicated. These patients require careful and individualized clinical assessment, as they often present with mixed pain syndromes that involve both neuropathic and nociceptive components. The distinct types of pain involved in such cases may require combined treatments from individual interventions that are analgesically independent and specific for each type of pain involved. Neuromodulation by electric stimulation at appropriately chosen targets and combinations may be an important option to consider for such patients. We present a case of combined debilitating axial nociceptive spinal pain and bilateral neuropathic leg pain in a patient after 14 failed back operations. A combination of spinal cord stimulation (SCS) and deep brain stimulation in the periventricular gray (PVG) have successfully provided the patient with complete relief of both components of his chronic pain condition, after all other pain management options had been exhausted. By alternating activation of each implanted stimulator separately and in conjunction, we were able to demonstrate a clinically independent analgesic character for each stimulation system, each specific to a particular type of pain. The SCS provided complete relief of the neuropathic pain component, without affecting the nociceptive component at all. The PVG stimulation provided complete relief of the nociceptive component, without affecting the neuropathic component at all. In combination, there was complete relief of the total chronic pain condition. There appeared to be no overlapping or synergistic effect between the two neuromodulation systems in the patient. The patient has had prolonged complete relief from his chronic pain condition with the combined neuromodulation intervention over 22 years of follow-up.