What are Vagal Nerve Stimulator Placement and Battery Exchanges?
Vagal nerve stimulator (VNS) placement and battery exchanges refer to a minimally invasive procedure in which a pulse generator device similar to a pacemaker is inserted in your neck to treat certain forms of epilepsy (seizure disorder) and depression. The device functions by sending electrical impulses to the brain through the vagus nerve.
The vagus nerve stimulator device or implant is a round, flat chunk of metal that measures about 4 cm or 1.5 inches across and 10 to 13 mm in thickness. It consists of a battery that can last from 1 to 15 years. When the battery reaches the end of battery life (EOBL), the device will no longer deliver any stimulation. When a fresh battery is needed, the entire device is replaced to avoid opening the hermetically sealed metal case and to prevent contact between generator components and body fluids with the risk of prompting a rejection reaction.
Indications for Vagal Nerve Stimulator Placement
The vagus nerve is the longest cranial nerve in the body. It consists of both motor and sensory nerve fibers. It is responsible for involuntary functions such as control of the body’s heart rate, blood pressure, and digestive tract. The nerve runs from the lower part of the brain, through the neck, to various organs in the chest and abdomen, on both sides of your body. Damage or compression of the vagus nerve can lead to many conditions. Vagus nerve stimulator placement has been recommended for the treatment of depression and epilepsy, especially partial seizures (limited to a part of the brain), when medications have been ineffective.
Preparation for Vagal Nerve Stimulator Placement and Batter Exchanges
Pre-procedure preparation for vagal nerve stimulator placement generally involves the following steps:
- A thorough examination is performed by your doctor to check for any medical issues that need to be addressed prior to surgery.
- Depending on your medical history, social history, and age, you may need to undergo tests such as blood work and imaging to help detect any abnormalities that could threaten the safety of the procedure.
- You will be asked if you have allergies to medications, anesthesia, or latex.
- You should inform your doctor of any medications, vitamins, or supplements that you are taking.
- You may need to refrain from supplements or medications such as blood-thinners or anti-inflammatories a week or two prior to surgery.
- You should refrain from alcohol or tobacco at least a week before surgery.
- You should not consume any solids or liquids at least 8 hours prior to surgery.
- Arrange for someone to drive you home after surgery.
- A written consent will be obtained from you after the surgical procedure has been explained in detail.
Procedure for Vagal Nerve Stimulator Placement
Vagus nerve stimulator placement may take about 2 hours and is done under local or general anesthesia. Two incisions are made, one in your neck and the other in your chest. A pulse generator device is implanted in the left side of your chest and connected to the vagus nerve in your neck through a lead wire which passes under the skin. A few weeks after surgery, your doctor programs the generator to send electrical pulses at regular intervals and currents to your vagus nerve. With the help of a hand-held magnetic device, you will be able to turn on or off the generator when you think you are going to have a seizure.
VNS placement does not cure seizures but can reduce the intensity and number of attacks by as much as 30 to 50%. You may also recover much sooner from a seizure and experience better quality of life. It can also improve mood and overall well-being, which is specifically crucial for individuals with recurrent or treatment-resistant depression.
Over time, when the battery of the device wears out, the stimulator is replaced with a less invasive procedure by opening only the chest wall incision.
Postoperative Care and Recovery
Postoperative care instructions and recovery after vagal nerve stimulator placement generally involves the following steps:
- You will be transferred to the recovery area where your nurse will closely observe you for any allergic/anesthetic reactions and monitor your vital signs as you recover.
- Most patients can go home the same day of the surgery. However, some may require an overnight hospital stay.
- Your device will be calibrated by your neurologist to the appropriate settings before leaving.
- You may experience pain, inflammation, and discomfort in the operated area. Medications are provided as needed.
- Application of cold and heat therapy on the operated area is also recommended to reduce inflammation and pain.
- Instructions on surgical site care and bathing will be provided.
- A periodic follow-up appointment will be scheduled to monitor your progress.
Risks and Complications
Vagal nerve stimulator placement is a relatively safe procedure; however, as with any surgery, some risks and complications may occur.
General risks of any surgery include:
- Blood clots
- Blood loss
- General pain
- Anesthetic reactions
Risks and complications specific to vagal nerve stimulator placement include:
- Difficulty swallowing
- Difficulty breathing
- Device malfunction
- Tingling or prickling of the skin