What happens during the operation?
Patients are given a general anesthesia to put them to sleep during most spine surgeries. As you sleep, your breathing may be assisted with a ventilator. A ventilator is a device that controls and monitors the flow of air to the lungs.
Some surgeons have begun using spinal anesthesia in place of general anesthesia. Spinal anesthesia is injected in the low back into the space around the spinal cord. This numbs the spine and lower limbs. Patients are also given medicine to keep them sedated during the procedure.
Discectomy surgery is usually done with the patient kneeling face down in a special frame. The frame supports the patient so the abdomen is relaxed and free of pressure. This position lessens blood loss during surgery and gives the surgeon more room to work.
The two main discectomy procedures are
- laminotomy and discectomy
- microdiscectomy
Laminotomy and Discectomy
Laminotomy and discectomy is the traditional method of removing the disc. Laminotomy is taking off part of the lamina bone (the back of the ring over the spinal canal). This allows greater room for the surgeon to take out part of the disc (discectomy).
An incision is made down the middle of the low back. After separating the tissues to expose the bones along the low back, the surgeon takes an X-ray to make sure that the procedure is being performed on the correct disc. A cutting tool is used to remove a small section of the lamina bone.
Next, the surgeon cuts a small opening in the ligamentum flavum, the long ligament between the lamina and the spinal cord. This exposes the nerves inside the spinal canal. The painful nerve root is gently moved aside so the injured disc can be examined. A hole is cut in the outside rim of the disc. Forceps are placed inside the hole in order to clean out disc material within the disc. Then the surgeon carefully looks inside and outside the disc space to locate and remove any additional disc fragments.
Finally, the nerve root is checked for tension. If it doesn't move freely, the surgeon may cut a larger opening in the neural foramen, the nerve passage between the vertebrae.
Before closing and suturing the wound, some surgeons will implant a special foam pad or a piece of fat over the nerve root to keep scar tissue from growing onto the nerve. Some surgeons also insert a small drain tube in the wound.
Microdiscectomy
The surgeon performs microdiscectomy using a surgical microscope. A two-inch incision is made in the low back directly over the problem disc. The skin and soft tissues are separated to expose the bones along the back of the spine. An X-ray of the low back is taken to ensure the surgeon works on the right disc.
A retractor is used to spread apart the lamina bones above and below the disc. Then the surgeon makes a tiny slit in the ligamentum flavum, exposing the spinal nerves. A special hook is placed under the spinal nerve root. The hook is used to lift the nerve root, so the surgeon can see the injured disc.
Next, the annulus (outer ring) of the disc is sliced open. Material from inside the disc is to ensure the disc doesn't herniate again. Since only the injured portion is removed, the disc is left intact and functioning. Then the surgeon inspects the area around the nerve root and removes any loose disc fragments. Finally, the nerve root is gently wiggled to make sure it is free to move. If it can't move, the surgeon also cleans around the neural foramen, the nerve passage between the two vertebrae. When the nerve moves freely, the muscles and soft tissues are put back in place, and the skin is stitched together.