What is Lateral Recess Stenosis?
In medical terms, Stenosis is a ‘narrowing’ of any tubular vessel or structural passageway within the body. Lateral Recess Stenosis is a condition where the narrowing reduces the available space within the exit doorway (foramen) of the spinal canal. This may be caused by arthritic overgrowth of the facet joints, degeneration of the disc with loss of disc height and overriding of the facet joints with consequent bulging of the disc. This resultant loss of space in the foramen can cause squeezing or pinching of the nerve roots as they exit the spine through the doorway.
What are the symptoms?
The typical pattern is that of progressively worsening pain in the leg(s) although the causal problems occur within the spinal region. The symptoms may include heaviness, leadenness or weakness affecting one or both legs so that the sufferer may believe the problems are muscle-related. Specifically, weakness in the thighs, hamstrings or calves, weakness on push off and ‘foot drop’ may be experienced and the condition can progress to wasting of the legs. Furthermore, the walking distance can be reduced in a process known as ‘Claudication’ caused by starvation of blood supply to the nerves. When walking ceases, the blood supply recovers and the symptoms subside.
What is wrong with conventional diagnosis?
The main difficulty in diagnosing this condition is that many features are misleading. Indeed, Lateral Recess Stenosis and Axial Stenosis (see appropriate page) are related conditions and may occur in combination. It is important to distinguish between the two at an early stage because the treatment pathway can be different. In fact Axial Stenosis is generally over-diagnosed, because the pathology can be more readily seen on MRI and CAT scans. Lateral Recess Stenosis can be present on the scans for many years in the absence of symptoms. Similarly, in the experience of The Spinal Foundation, Axial Stenosis may be present within the spine but at a level that is not causal of the symptoms. In short, Axial Stenosis may be a prominent feature on the scans, but it may be less contributory of the presenting symptoms than Lateral Recess Stenosis.
Is a more accurate diagnosis possible?
It is important to remember that Lateral Recess Stenosis and Axial Stenosis are related conditions. Lateral Recess Stenosis commonly occurs in the lumbar spine region of the lower back at vertebral levels L4/5 & L5/S1, and in the neck at vertebral levels C5/6 & C6/7. Axial Stenosis however commonly occurs in the lumbar spine region of the lower back at vertebral levels L2/3 & L3/4 and in the neck at vertebral levels C4/5 & C5/6. The significant benefit offered by aware state diagnosis (see below) is that it enables the surgeon to accurately target the problem area and thus deliver specific treatment focused only upon that problem area.
Can the diagnosis be confirmed?
This can be achieved by the use of spinal probing of the nerve, contents of the foramen and epidural space to determine contributory levels. Hydraulic discography can be used to determine levels causing compression of the nerve exiting the spinal space. This procedure enables the surgeon to re-tension the disc and ligaments, restore disc height, realign the facet joints and restore the volume of the foramen at the suspected level. These techniques, which include the injection of an X-ray visible liquid into the disc, open up the ‘Foramen’ or spinal spaces and effectively liberate the nerve temporarily. Where pain rather than compression is the predominant symptom then insertion of anaesthetic or steroid in to the disc (Differential Discography) can be used to distinguish the role played by each level in the symptom complex. If these studies transiently reverse the symptoms, then the specific causal segment can be identified without having to open the back at several levels. This will demonstrate whether or not the original surgery addressed the causal segment in the first instance or whether it addressed the correct level but failed to correct the effects of the pathology at the operated level.
What is wrong with conventional surgery?
Conventional surgical treatments encompass a wide range of possibilities; all of which have a place but are not necessarily efficacious. Please note however that this is a general guide and that individual cases should be correctly assessed by a competent surgeon in order to decide upon the most appropriate treatment. The following brief guide is included so that the lay person may gain a basic understanding of the conventional options they may be offered:
- Laminectomy is the removal of substantial areas of bone from the ‘Lamina’ or vertebral arch. It releases space within the spinal column but also removes muscle purchase points and can lead to extensive scarring on local and related tissues within the spine. In many cases, it can also lead to increased spinal instability and the need for spinal fusion at a later date. Laminoplasty is a process whereby the Lamina arch is split apart to increase the volume of available space. The resultant gap or split is maintained by bone grafting or by the insertion of tissue or implants. These techniques fail to provide sufficient access & liberation of the nerves laterally through the foramen.
- Medial Facetectomy is the removal of the inner part of the joint on either side of the vertebrae to preserve as much of the Lamina arch as possible. Endoscopic Medial Facetectomy is a similar process, but is facilitated by the insertion of a telescope. However it offers only limited access and can only be used to treat a small area. These techniques fail to provide sufficient access & liberation of the nerves laterally through the foramen.
- Inter-spinous spacers can be inserted using keyhole surgery at the ‘posterior’ or back of the spine between the spinous processes in order to restore some of the original posterior spacing of the vertebrae in cases where disc height has been lost through degeneration. Often, these spacers take the form of a cushion or a metal implant. By spreading the spinous processes this attempts to restore some segmental height, re-tension the spine and enlarge the foramen. The outcome depends in part upon the amount of residual disc that is present and may alter the posture of the lower lumbar spine and can not be applied at the L5/S1 level. The technique will fail to ease symptoms if the nerve is significantly tethered in the foramen.
All of the above are ‘posterior’ approaches in the sense that surgery is carried out from the back of the spine. The major problem with these techniques (with the exception of the interspinous spacers) is that they cannot adequately clear the ‘Foramen’ or spaces within the spinal column as they only permit removal of material from inner areas of the foramen and it is within the lateral areas that the greatest need exists. This means that the surgeon may address too many levels in an ‘overkill’ operation and still not adequately solve the problem.
What is aware state diagnosis?
Conventionally the cause of the pain is diagnosed from the pattern of the pain and MRI scans but these techniques are inaccurate. However, the causal pain sources can now be accurately defined through aware state surgical examination, during which the surgeon seeks to replicate the pain by spinal probing. When this provokes a response, the patient, who is protected by circulating intravenous pain killers, offers feedback to the surgeon regarding the type and distribution of the pain produced. Sometimes, when the response is only partially akin to the presenting symptoms or when the response is at more than one spinal level, additional techniques such as Differential Discography are used. These techniques enable the surgeon to determine the relative importance of each site in the totality of the patient’s pain and condition, and that the symptoms can be modified by Endoscopic Minimally Invasive Spine Surgery.
Why is this better than conventional diagnosis?
This ‘live’ approach to diagnosis means that causes of pain can be defined and ultimately confirmed and also that misdiagnosis due to strange nerve anatomy can be avoided. Subsequent endoscopic examination with the patient awake then leads the surgeon to the precise source of pain at the specified intervertebral level. This is in complete contrast to conventional diagnostic techniques which rely upon pre-operative ‘guesstimation’ based upon X-rays, MRI scans and CAT scans and often results in the “overkill” of multiple level surgery performed to attempt a treatment “catch all”.
How is Lateral Recess Stenosis treated minimally invasively?
Following aware state diagnosis, the patient is treated using Transforaminal Endoscopic Lumbar Decompression & Foraminoplasty. This facilitates the accurate clearance of scarring around the nerves in the foramen. At the same time, the nerve can be liberated from tethering to the disc, the facet joint margin and specific ligaments (Superior Foraminal Ligament) and from bone spurs arising from the facet joint margin or vertebral body margin by lasing. After this, any bulging disc areas can be removed. This enables the surgeon to open up the doorway by using core boring tools and thus the nerves are mobilised. At the same time, the surgeon can seal leaks and tears in the disc wall which may be contributing to the irritation of the nerve in the foramen.
Why is this better than conventional surgery?
The benefit of Endoscopic Minimally Invasive Spine Surgery is that it enables the surgeon to treat the condition specifically, precisely and with minimum collateral damage to tissues, reduced risk to the patient and enhanced long-term outcome. This is in contrast to conventional surgery, especially where multi-level conditions are suspected. Under these circumstances, the surgeon will treat all the involved levels using ‘overkill’ multi-level surgery with its problems including blood loss, potential nerve and tissue damage, extended post-operative care and unnecessarily operating on non-causal levels. Minimally invasive techniques can be used in all age groups but offer treatment for the frail, the infirm and the elderly because they avoid the use of General Anaesthesia. They also open up the opportunity to treat long term symptoms where the diagnosis is in question to the conventional surgeon and where the patient would otherwise be referred for palliative Chronic Pain Management.
What proof is there of successful treatment?
Aware State Diagnosis and ELDF Surgery are delivering encouraging results in well over 80% of patients when reviewed 2-4 years later, and 70% at 10 years later.