Dr. Ruiz-Ocaña is Head of the Neurosurgery Department at Hospital Universitario Quirón Madrid and President of the Spanish Society of Neurosurgery.
What is canal stenosis?
I think the first thing to do is to explain what the spinal canal is. We call the spinal canal the duct located along the entire length of the spine and formed by the vertebrae as they articulate with each other along the medial axis of the spine. The spinal cord descends through this canal from the base of the skull to the last vertebrae. It is also important to know that from the medulla emerge through the lateral face, left and right, the nerves that will transmit the sensitivity and will make possible the movement of the muscles after a brain order, voluntary or reflex.
Stenosis refers to the loss of the diameter of this canal or of the vertebral foramina through which the nerves exit, creating a conflict of space between continent and content. That is, the nerve elements are compressed and with little blood supply. The most frequent area of involvement is the lumbar region.
What symptoms do these patients have?
Basically, patients complain of pain or a tingling sensation in the legs after walking a distance of between 50 and 150 meters, depending on the degree of pathology. Many of these patients have to sit down and rest in order to start walking again. There is usually no pain at rest.
Another type of symptom is pain that radiates, in the form of sciatica to one or both legs even without having started walking and just by standing up. Sometimes there is a combination of these symptoms.
What happens in the 3rd and 4th ages?
Over the years, the joints of the vertebrae degenerate and bony ridges are formed, which contribute to the narrowing of the canal. On the other hand, there is a thickening of a ligament between the vertebrae that also reduces their diameters. As the average lifespan of the human being is prolonged, this pathology is becoming more common in consultations.
Is there a solution and what are the risks of surgery?
The solution is basically decompressive surgery. There is no risk of neurological sequelae and good results reach 80%. The risk is greater due to the patient’s general pathology such as hypertension, diabetes, cardiac alterations or taking frequent anticoagulants at this age than the surgery itself.