Spinal cord stimulator

Overview

Spinal cord stimulators comprise slender wires (electrodes) and a small battery pack (generator) resembling a pacemaker. Electrodes are positioned in the epidural space between the spinal cord and vertebrae, while the generator is implanted under the skin, typically near the buttocks or abdomen. These stimulators enable patients to transmit electrical impulses externally via a remote control to alleviate pain. It’s important to note that the exact mechanisms of spinal cord stimulation are not fully understood, but it may impact multiple muscle groups along the spine and modify pain perception in the brain.

Traditional stimulators create a tingling sensation known as paresthesia to replace pain, but newer devices offer “sub-perception” stimulation that is not felt by the patient. Specialized physicians in interventional pain management, using X-ray and/or ultrasound guidance, typically implant these advanced devices.

Reasons of the procedure

Spinal cord stimulation is a treatment often considered when other non-surgical pain relief methods haven’t worked effectively. This approach involves using specialized devices called spinal cord stimulators to address various chronic pain conditions, such as:

• Persistent back pain: Particularly when it persists after surgery, known as failed back surgery syndrome.
• Post-surgical pain: For pain that lingers after surgical procedures.
• Arachnoiditis: This condition involves painful inflammation of the arachnoid, a thin membrane covering the brain and spinal cord.
• Unmanageable heart pain (Angina): In cases where other treatments are ineffective.
• Spinal cord injuries: For managing pain resulting from injuries to the spinal cord.
• Nerve-Related Pain: Including severe diabetic neuropathy and neuropathy caused by cancer treatments like radiation, surgery, or chemotherapy.
• Peripheral vascular disease: For individuals suffering from this circulatory condition.
• Complex regional pain syndrome: A disorder characterized by severe and chronic pain.
• Pain Following Amputation: To alleviate pain experienced after limb removal.
• Visceral abdominal and perineal pain: Addressing pain originating from the internal abdominal organs or the perineal area.

The use of spinal cord stimulation can lead to improvements in overall quality of life and better sleep, reducing the need for pain medications. It is typically employed in conjunction with other pain management approaches, such as medications, exercise, physical therapy, and relaxation techniques.

Risk

Spinal cord surgery is generally considered a secondary option due to potential complications and risks, which include:

• Infection risk: Inserting a device into the body for spinal cord stimulation can lead to infections around the implant, potentially necessitating surgical intervention for treatment or removal.
• Lead displacement: Advances in medical technology have reduced the risk, but there’s still a chance of leads moving out of place; however, anchoring devices help minimize this risk.
• Lead breakage or malfunction: The rigidity of leads may not always match the spine’s flexibility, possibly resulting in leads breaking or malfunctioning, requiring corrective surgery.
• Injuries from lead issues: Broken or displaced leads can harm the spinal cord or surrounding tissues, leading to rare but severe permanent injuries.
• Generator malfunction: The pulse generator used in spinal cord stimulation has a limited lifespan, requiring surgical replacement of batteries or generators in case of failure.
• Gradual loss of pain relief.

Potential side effects, depending on the stimulator type and location, such as tingling or numbness, which may be uncomfortable for some individuals.

Before the procedure

Spinal cord stimulation is usually considered after other treatments like physical therapy and medication injections have been tried without success. Before undergoing this surgery, a series of tests and consultations are necessary to ensure your suitability and rule out any contraindications.

You will need to consult with several healthcare professionals:

• Neurologist: These specialists diagnose the underlying condition causing your pain and determining the need for spinal cord stimulation.
• Pain management specialist: They assess whether less invasive treatments have been ineffective or if there are specific reasons preventing other treatments.
• Neurosurgeon: The neurosurgeon performs the surgery to implant the spinal cord stimulator. In some cases, you might have seen them for prior treatments.
• Psychiatrist or psychologist: Mental health evaluation is essential, as chronic pain can lead to conditions like anxiety and depression. These conditions can impact the effectiveness of spinal cord stimulation and require treatment.
• Anesthesiologist: Since the procedure involves general anesthesia, the anesthesiologist will discuss your medical history and any factors that might affect anesthesia.

Once cleared for surgery, you will receive instructions on how to prepare:

• Medications: Inform your healthcare provider about all medications, including vitamins and supplements. Adjustments may be necessary, such as discontinuing blood thinners, but always consult your provider before stopping any medication.
• Hygiene: Your provider will provide guidance on pre-surgery bathing and grooming, which may include using special hygiene products.
• Fasting: Due to general anesthesia, fasting is required. This means no solid food for at least eight hours before the procedure and no liquids for at least two hours before.

During the procedure

Spinal cord stimulator implantation is a two-step process comprising a trial procedure followed by implantation surgery.

• Trial Procedure:
  • Initial sedation is administered.
  • A specialized needle is introduced through a small incision into the epidural space.
  • Temporary leads are carefully threaded into position and connected to an external pulse generator.
  • The functionality of the stimulator is evaluated over a period ranging from a few days to several weeks.
  • Success is defined as achieving a minimum of a 50% reduction in pain, prompting progression to the next step.
• Implantation Surgery:
  • General anesthesia is administered.
  • Permanent leads are placed in the same location as in the trial phase.
  • In cases involving paddle electrodes, necessary adjustments to muscle tissue are made to accommodate them.
  • The electrode end of the leads is securely anchored, and a designated pocket is created for the pulse generator.
  • The precise location for the generator implantation is determined based on factors such as accessibility for future adjustments or recharging.
  • Closure of incisions is achieved using sutures or staples.
  • Programming of the generator can occur during or after the surgery, with subsequent fine-tuning conducted during follow-up appointments.

After the procedure

After the trial procedure, you’ll likely be discharged on the same day or the following day. Following the generator implantation surgery, in most cases, individuals can return home within one to two days. Your healthcare provider will provide you with detailed instructions for caring for the procedure site after the trial lead placement and the generator implantation. Typically, this involves tending to the surgical wound by keeping it clean and changing the bandages for a period of seven to 10 days. About 10 to 14 days after the generator implantation surgery, you will have a follow-up appointment during which your provider will remove any staples and/or stitches.

Outcome

Following the implantation of trial stimulator leads, most patients can return home either on the same day or the day after the procedure. During this initial recovery phase, it’s important to take it easy and avoid activities like bending, stretching, and lifting to get accustomed to the stimulator leads’ effects. On the other hand, the generator implantation surgery is a more complex procedure, requiring a longer recovery period. Patients typically go home the day after this surgery but must limit physical activity for around four to six weeks. This helps the pocket around the implanted generator heal and allows the body to adapt to the stimulation leads. For personalized recovery guidance, it’s essential to consult with your healthcare provider, who can offer specific recommendations based on your unique situation.

Following your generator implantation surgery, your healthcare provider will schedule regular follow-up appointments. It’s crucial to adhere to these appointments as they facilitate adjustments to the electrical stimulation provided by your device. If you observe an increase in pain levels or the gradual emergence of side effects, it is advisable to promptly contact your healthcare provider.

Possible complications to be aware of include:

• Persistent headache: Should you experience a persistent headache upon sitting or standing, which subsides when lying down, this may signify a cerebrospinal fluid (CSF) leak. Such a leak can occur if a lead damages the dura mater, allowing CSF to escape.
• Signs of infection: Monitor the surgical sites for indications of infection, including erythema, edema, discomfort, or discharge, particularly if accompanied by malodorous characteristics.

Immediate medical attention: should be sought if any of the following symptoms arise:

• Sudden onset of numbness, tingling, or muscle weakness: The sudden appearance of these sensations below the lead’s location could indicate a lead position shift, potentially causing damage to the spinal cord or nearby nerves. It is advisable to consult your provider to differentiate between normal sensations and potential warning signs.
• Symptoms of sepsis: The presence of symptoms indicative of a widespread infection, such as a high fever, rapid heart rate, confusion, or severe weakness, may signal sepsis, a life-threatening condition. Urgent medical assistance is imperative as sepsis necessitates immediate treatment to prevent severe complications or fatalities.