A spinal cord stimulator (SCS) is a device implanted under the skin that uses mild electrical impulses to interrupt pain signals before they reach the brain. This form of neuromodulation treats chronic pain that has not responded to other treatments like physical therapy or medication. Whether a patient is “put to sleep” for this procedure has a variable answer because SCS implantation is structured in two distinct phases, each requiring different anesthesia. The patient’s need to be responsive during the first phase directly influences the level of sedation used.
The Two Phases of Spinal Cord Stimulator Implantation
The process of receiving a spinal cord stimulator is divided into two stages: the temporary Trial Phase and the Permanent Implant Phase. The Trial Phase determines if the therapy provides sufficient pain relief, typically aiming for at least a 50% reduction in pain scores. During this phase, temporary leads are placed in the epidural space and connected to an external battery worn for three to seven days.
If the trial is successful, the patient proceeds to the Permanent Implant Phase, which is a more involved surgical procedure. This stage includes implanting a permanent pulse generator, or battery, usually in the abdomen or upper buttocks, and connecting it to the permanent leads placed in the spine. The purpose is to internalize the entire system, allowing the patient to manage chronic pain with a fully implanted device. This separation ensures the significant cost and commitment of the permanent device are only undertaken if the trial demonstrates a positive outcome.
Anesthesia Protocols for SCS Surgery
The level of anesthesia depends entirely on the procedure phase and the specific type of lead being placed. The Trial Phase almost always requires the patient to be partially awake and responsive. This is accomplished using Monitored Anesthesia Care (MAC), which involves intravenous sedation combined with local anesthesia at the incision site.
MAC places the patient in conscious sedation, where they are relaxed and groggy but can still respond to verbal commands. This ability to communicate is necessary because the surgeon needs immediate feedback to correctly position the leads and “map” the stimulation area to cover the region of chronic pain. General Anesthesia (GA), which requires breathing support, is typically avoided during the trial as it prevents this crucial patient-surgeon communication.
In the Permanent Implant Phase, the anesthesia protocol is more variable, depending on the complexity of the final device. Procedures involving simple percutaneous leads may still be performed under MAC or heavy sedation, especially if intraoperative testing is required. However, more complex devices, such as paddle leads that require a small opening in the bone (laminotomy) for placement, are often performed under General Anesthesia. The placement of the internal pulse generator, which involves creating a pocket under the skin, is often done with heavier sedation once the leads are secured.
Patient Experience During the Procedure
During the Trial Phase, the patient is awake enough to participate in the placement process, which can cause some anxiety but is necessary for the device’s success. After the local anesthetic is administered, the patient will feel pressure as the leads are advanced into the epidural space, rather than sharp pain. The medical team continuously monitors the patient’s comfort level and adjusts the sedation if needed to ensure the experience is tolerable.
The most important part of the awake experience is the testing or mapping phase, where the surgeon applies a low electrical current to the leads. The patient communicates precisely where they feel the resulting stimulation, often described as a mild tingling sensation called paresthesia. This feedback confirms that the electrical field covers the exact area of the patient’s pain, optimizing the device’s long-term effectiveness. While some patients may not remember parts of the procedure due to the sedative medications, their ability to communicate remains the primary reason for using conscious sedation.
Immediate Post-Operative Expectations
Following either the Trial or Permanent Implant procedure, the patient is transferred to a post-operative recovery area for monitoring. Recovery time is often shorter after Monitored Anesthesia Care compared to General Anesthesia, as the body clears lighter sedative medications more quickly. Patients commonly feel groggy from the sedation and may experience localized discomfort or soreness at the incision site.
Most patients are typically discharged home the same day, provided they are stable, the effects of the sedation have adequately worn off, and they have clear post-operative instructions. Initial post-operative restrictions are immediately enforced to prevent movement of the newly placed leads or disruption of the incision sites.
Post-Operative Restrictions
Restrictions typically include:
- Avoiding bending.
- Lifting anything heavier than five to ten pounds.
- Twisting the back for the initial recovery period.
The medical team ensures the patient understands how to manage the incision site and when to resume light activities like short walks.