Open decompression for lumbar spinal stenosis running across several levels. The bone and thickened ligament crowding the nerves are removed level by level under direct view, so the nerves have room again. Where the spine is stable, nothing is fused: the operation makes space and leaves the rest of the anatomy intact.
Laminectomy. Licensed patient-education animation, ViewMedica.
Lumbar stenosis is a narrowing of the space around the nerves. It builds up slowly from several directions at once: the facet joints enlarge as they wear, the ligament along the back of the canal thickens and buckles inward, and the discs bulge from the front. Over time the canal becomes a tight ring around the nerves.
A laminectomy removes the back wall of that ring. The lamina and the thickened ligament are taken away over each narrowed level, and the recesses where the individual nerve roots turn to leave the spine are opened out, giving the nerves room again.
Stenosis at one level and stenosis at four are the same disease but call for quite different operations. When several levels are involved, an open operation is usually a better choice than a tubular one.
Lumbar central stenosis before and after decompression. Axial views at a stenotic level showing hypertrophied facets and buckled ligamentum flavum compressing the thecal sac, alongside the same level after laminectomy with the sac restored to a round profile.
The usual symptom is neurogenic claudication, which has a recognizable pattern: the trouble is mainly in the legs, and it changes with posture.
Relief when leaning forward is an important clue. Bending forward opens the canal a little, which is why someone with stenosis can push a shopping cart much further than they can walk upright, and why a stationary bike is easier than a treadmill.
Dr. Zaidi performs most single and two-level decompressions through a tubular retractor, and for those it is an excellent operation: one small opening, the muscle spread apart without being stripped, and often home the same day.
That changes as levels are added. A tube gives an excellent view of a small area, so covering four levels means several separate openings or repeatedly re-angling one, and by then the access is no smaller than an open exposure. Severe stenosis all the way around the canal, scarring from previous surgery and difficult anatomy also favor an open operation.
The aim is to keep the access as small as the work allows. Beyond a certain amount of work, a direct view gives a safer and more complete decompression. This is explained in more detail in how the approach is chosen.
This is the most important decision in stenosis surgery, and it helps to understand it before your consultation. Removing the back of the canal relieves the nerves, but it does not stabilize anything, and if a lot of the joints has to be removed to free the nerves, a level can be left looser than it was.
So each level is checked for whether it is stable:
Adding a fusion does not make the decompression work better. Where the spine is stable, fusing it adds operating time, blood loss, implants and months of recovery without adding relief, and it shifts load to the neighboring levels. Where there is a slip, or where freeing the nerves means removing the joints that hold a level together, a fusion is what makes the decompression safe, and then it is the right operation.
This is decided on standing and flexion-extension X-rays as well as the MRI, because a slip that only appears when the patient bends will not show on a scan taken lying down.
The patient is positioned face down on a frame that lets the abdomen hang free, because pressure on the abdomen increases bleeding from the veins around the spine.
A midline incision over the levels to be decompressed, and the muscle lifted off the laminae to either side. Imaging confirms the levels before any bone is removed.
The laminae are taken down across the stenotic levels and the thickened ligament beneath is removed from the sac. This is the step that gives the central canal its space back.
Each nerve root is followed out to where it leaves and freed at the lateral recess and foramen. Freeing only the central canal can leave the roots trapped further out, which is a common reason for leg symptoms that persist after surgery.
The facet joints are trimmed from underneath instead of being removed, so the nerves are freed while enough of each joint remains to keep the segment stable. How much can safely be removed decides whether a fusion is needed.
Every root is checked to be loose along its course, bleeding is controlled, and the muscle and fascia are closed in layers over the decompressed canal.
Multilevel lumbar decompression. Laminae removed across several levels, ligamentum flavum lifted off the thecal sac, and each root followed out through an undercut facet into an opened lateral recess.
A decompression is an operation for leg symptoms. It gives the nerves room, so the walking distance, the heaviness and the leg pain are what respond, and they often respond quickly.
Figures are general ranges from the surgical literature and cannot be guaranteed for any one person. Recovery varies with the number of levels decompressed, age, general health and what the nerves looked like at surgery. Always follow the instructions you are given after your own operation.
How many levels are involved, and whether any of them is unstable, decides both the size of the operation and whether a fusion is part of it. Bring any MRI, CT or X-rays you already have.