Laminectomy

Unfortunately this operation isn’t always successful. Laminectomy is very effective in decreasing the pain and improving the function in patients with lumbarspinalstenosis, a condition that primarily afflicts elderly patients, and is caused by degenerative changes that result in enlargement of the facet joints. The enlarged joints then place pressure on the nerves which can be effectively relieved with a lumbar laminectomy.

Anatomy of the back

Human spine is made up of individual bones called vertebrae, which are stacked on top of each other and are grouped into four regions:

1.    the cervical spine or neck (made up of 7 vertebrae)
2.    the thoracic spine or chest area (made up of 12 vertebrae)
3.    the lumbar spine or low back (made up of 5 vertebrae)
4.    the sacrum or pelvis area (made up of 5 fused, non-separated vertebrae)

The vertebrae are separated from one another by soft pads called intervertebral discs, which prevent the vertebrae from rubbing against each other. Each disc is made up of two parts, a soft center called the nucleus and a tough outer band called the annulus. Inside the spine is a central tube, surrounded by bone and discs, called the spinal canal which is filled with spinal cord, the cauda equina, and spinal nerves. 

The most common cause – herniated intervertebral disc

One of the most common reasons for laminectomy is a prolapsed or herniated intervertebral disc.

This happens when disc comes out from its normal localization and causes pressure on spinal cord or surrounding nerves. Consequences are different depending on the localization of herniation. If the herniated disc is in the lumbar region, this can cause:

• sharp and continuing back pain
• a weakening of the muscles in the leg
• some loss of sensation in the leg and foot
• difficulties to raise your leg when it is held in a straight position

A herniated disc in the neck region can cause symptoms including:

• pain in arm or shoulder
• numbness and weakness in the arm

A herniated disc may be triggered by, for example, twisting your back while lifting something heavy.

Spinal stenosis

Spinal stenosis is a specific condition characterized by a narrowing of spaces in the spine which is often resolved by laminectomy. This narrowing results in pressure on the spinal cord and nerve roots which can lead to a number of problems, depending on which nerves are affected. In great majority of patients, spinal stenosis is accompanied with cramping, pain or numbness in legs, back, neck, shoulders or arms; a loss of sensation in extremities; and sometimes problems with bladder or bowel function. In most cases mild symptoms of spinal stenosis are removed by pain relievers, physical therapy or a supportive brace. However, if we talk about some more serious cases of spinal stenosis, doctors may recommend surgery.

Before the operation

The doctor should run some tests prior to surgery to aid diagnosis and to be sure what structures are involved. These tests may include:

• Spinal x-ray
• Myelogram
• Computerized tomography (CT) scan
• Magnetic resonance imaging (MRI) scan

A few days before the surgery, the patient should meet with the anesthesiologist to discuss whether to have general anesthesia or spinal anesthesia. Age should not be a factor in deciding whether to have laminectomy. However, if patient has other medical conditions that might make this procedure less successful, surgery should be avoided.

The operation procedure

In most cases, patient is placed in a kneeling position to reduce the weight of abdomen on spine. Many people think that laminectomy and microdiscectomy are two same things. Lumbar laminectomy differs from microdiscectomy in that the incision is longer and there is more muscle stripping. The back is approached through a 2-5 inch long incision in the midline of the back. The left and right back muscles are dissected off the lamina on both sides and at multiple levels. Then doctor removes the ligament joining the vertebrae along with all or part of the lamina. The goal is to see the involved nerve root. After the spine is approached, the lamina is removed which allows visualization of the nerve roots. The doctor pulls the nerve root back toward the center of spinal column and removes the disk or part of the disk. Although the surgery takes 1-3 hours, patients lose very little blood.

Post – operative care

Patients usually stay in the hospital for one to three days but the patient's return to normal activity is largely dependent on his or her pre-operative condition and age. In the first few days after the procedure anything harder then walking is not recommended. Excessive bending, lifting or twisting is forbidden for six weeks in order to avoid pulling on the suture line before it heals. Muscle spasms are quite common following laminectomy. Pain relief is ordered and given regularly.

Possible post-op pain

It is completely normal to have some pain after operation. This is caused by swelling of the previously compressed nerve as well as from surgery itself. There may also be some muscle spasms across the back and down the legs. 

Laminectomy success rate

The success rate of a laminectomy is good and approximately 70% to 80% of patients will have significant improvement. Laminectomy results are much better for relief of leg pain then for relief of lower back pain. Unfortunately, the symptoms may recur after several years as the degenerative process that originally produced the spinal stenosis continues. Another operation that could be helpful is fusing the joint. Fusing the joint prevents the spinal stenosis from recurring and can help eliminate pain from an unstable segment. Fusion surgery is especially useful if there is a degenerative spondylolisthesis associated with the stenosis. 

Possible complications of laminectomy

Like with any other operation, complications from spinal stenosis surgery are possible and may result from other existing medical problems or can be caused by the severity of the spinal problem. These complications may be more serious in an older adult.

• Nerve root damage
• Bowel or bladder incontinence
• Paralysis : Paraplegia or quadriplegia
• Cerebrospinal fluid leak may be encountered if the dural sac is breached
• Infections happen in about 1% of any elective cases
• Bleeding is an uncommon complication as there are no major blood vessels in the area
• Postoperative instability of the operated level can be encountered
• Splitting open of the wound
• Injury to the spinal cord
• Death (rare) related to major surgery
• A deep infection in the surgical wound
• An unstable spine which is more common after multiple laminectomies
• Tears in the fibrous tissue that covers the spinal cord and the nerve near the spinal cord, sometimes requiring re-operation

Long term outlook

A regular exercise program following surgery increases spinal muscle strength and flexibility. It will also protect the spine against future injury. Patients should be aware of the fact that sometimes, the operation doesn't work and the original symptoms remain, but even when this happens it probably won’t make the symptoms worse. Some patients may develop chronic back pain after laminectomy, a medical condition known as postlaminectomy syndrome. Some alternative techniques for decompressing spinal nerves with less disruption of spinal stability have been developed and include laminotomy and microsurgical lumbar laminoplasty. 

Other forms of treatment

Alternative treatment to surgery isn’t always possible, but generally should be tried first. This may include:

• Stabilization exercises
• Stretching and strengthening exercises
• Training on how to safely use the back (such as proper lifting techniques)
• Chiropractic
• Osteopathy
• Switching to ergonomic furniture.

Discectomy without laminectomy may also be an option, and this can often be done as day surgery using arthroscopic microscopic discectomy.