Percutaneous trial lead placement for failed back surgery syndrome

Scenario

A 57-year-old female with a history of L4-L5 and L5-S1 laminectomy and fusion presents with persistent axial back and left leg pain. She has been diagnosed with failed back surgery syndrome (FBSS). She has trialed several medial branch blocks and lumbar epidural steroid injections with minimal relief. She is currently taking gabapentin 300 mg three times daily and has participated in several courses of physical therapy with minimal benefit. She is anxious that no solutions will be found for her chronic pain and seems willing to try alternative therapies. Discussion takes place to consider spinal cord stimulation and the possibility of performing a trial of the stimulation to see if it can help her. She expresses interest in proceeding and is given some literature to review on the therapy.

• Variation : Conservative multimodal management has not been trialed -- Spinal cord stimulation is generally considered after patients have failed more conservative management with medication, physical therapy, or other less invasive interventional techniques, although this is not necessarily required. Placement of SCS should not be viewed as a replacement or contraindication to multimodal analgesia, especially considering that patients often have multiple pain generators and pain is often multifactorial. In many cases, patients will continue taking adjuvant medications and pursuing physical therapy. However, there should be an effort to reduce opioid consumption, and a plan for opioid reduction should be discussed with the patient as part of preoperative planning.

• Variation : The patient has had multiple surgeries at different levels -- It is important to confirm the level of a patient's prior surgeries as this may interfere with safe placement of percutaneous leads. Laminectomies will result in a disrupted ligamentum flavum, while fusion hardware may interfere with imaging. Prior surgery can result in epidural scarring that extends beyond the level of surgery. This can interfere with the loss of resistance technique and pose difficulty threading leads. Severe central canal stenosis may be a contraindication for an SCS as placement of a space-occupying lead may cause myelopathy. Although this is of greater concern in cervical SCS placement, it should be considered at all levels. Before SCS implant, patients with FBSS should be reevaluated by their surgeon to ensure there are no structural issues that would require further surgery. It is also valuable to obtain updated imaging with contrast to assess for new or worsening pathology. Thoracic spine magnetic resonance imaging (MRI) can also be included as part of preoperative planning for thoracic SCS placement.

• Variation : The patient is elderly and has mild cognitive impairment but good family support -- Although family members help the patient to remember and effectively communicate at visits, using the device and communicating eventual needs for reprogramming and functional improvements may be hampered. At times, the patient's underlying pain state or comorbidities may influence the surgeon's choice of SCS manufacturer. Device selection is a complex process taking into account the characteristics of the patient's pain, surgeon's preference, and patient's ability to communicate. Patients with anxiety disorders or difficulty describing their pain may benefit from placement of a device that does not require extensive intraoperative mapping and patient cooperation, such as high-frequency 10 kHz. All elderly patients should go through psychiatric evaluation as standard of care, not necessarily to rule out placement but to find ways to optimize the patient for a better outcome.

• Variation : The patient has a history of breast cancer that has been in remission for 2 years -- Patients with medical conditions requiring frequent MRI imaging, such as cancer, may influence the choice of SCS device. Some SCS devices are fully MRI compatible, some are conditionally compatible, while some are not compatible at all. A full discussion with the patient's oncologist or other relevant providers regarding the likely need for future MRI imaging should occur before SCS placement. Similarly, there may be less utility in selecting an MRI-compatible device for patients who already have a contraindication to MRI, such as those with non–MRI-compatible pacemakers or deep-brain stimulators. Other patients who may have an increased need for MRI imaging include those with a concern for intracranial pathology, such as patients with a history of seizures or headache, as well as patients with multiple joint complaints or surgeries.