Overview of Lumbar Sympatholysis
Lumbar sympathetic blocks, which are like a particular kind of pain management treatment, have been around since the early 1900s. They’ve been most notably used for a variety of chronic pain conditions. The first time this treatment was written about and used was in the 1920s. It has been especially effective in treating a condition called complex regional pain syndrome, which affects the lower part of the body (this used to be called RSD or causalgia).
It’s also been used for different painful conditions that cause problems with blood circulating properly in the lower part of the body. This includes Buerger’s disease, blockages caused by blood clots, frostbite, diseases causing spasms in the blood vessels, and peripheral arterial disease, which is a condition that affects the arteries away from the heart. Some other conditions that may also benefit from this treatment are phantom limb pain, excessive sweating, and pain after shingles (known as postherpetic neuralgia).
Nowadays, the techniques used in this procedure have evolved and may include using X-rays (fluoroscopy) to guide the procedure, applying chemicals to destroy problematic nerve tissue (chemical neurolysis), and using heat to damage the tissue (radiofrequency thermocoagulation).
There are also surgical methods available, although they are not as common. Knowing the anatomy, physiology, indications, contraindications, possible complications, and technical details of the procedure can contribute to better results.
When we talk about this treatment, it is essential to distinguish two terms. The “lumbar sympatholysis” seeks to cause a more long-lasting or even permanent disruption of the nervous system in the lower part of the body. On the other hand, the “lumbar sympathetic block” typically only uses local anesthetics. It is often useful for determining if a patient would benefit from a lumbar sympatholysis, providing more long-term treatment.
Anatomy and Physiology of Lumbar Sympatholysis
The sympathetic chain, also known as the sympathetic trunk, is a pair of nerve bundles that run from the neck all the way down to the tailbone area. These nerves are an important part of your body’s autonomic nervous system, which controls functions you don’t think about, like your heartbeat and digestion. These nerves are divided into different sections based on where they’re located: in the neck (cervical), chest (thoracic), lower back (lumbar), and tailbone area (sacral).
The majority of nerve signals sent to your legs by the sympathetic chain are located in the upper part of your lower back. These signals arise from the front-middle part of your spinal cord and move towards your spinal nerves; here, they connect to the appropriate nerve bundles. These nerve bundles then send out these nerve signals to your legs.
The part of the sympathetic chain that sends signals to your legs is located on the front-side of your lower back, typically at the levels of L2 through L4. These are located near the edge of the large muscles on either side of your spine (the psoas muscles). There’s a big blood vessel (the aorta) directly in front of and to the side of the left side of your lower back’s sympathetic chain, while a large vein (the inferior vena cava) is in front of the right side of it. Sometimes, the location, size and number of these nerve bundle can vary. They can be between 2 and 5 in total, and average at about 3. These nerve bundles can appear as separate bundles or may be fused together as one piece. Often, there’s no nerve bundle connected to the L1 level, which is the first section of your lower back.
Medical operations can be performed to disrupt these nerve bundles, specifically at the levels of L2-L4. This can result in reduced muscle tightness and decreased pain signals in the legs. This is why patients usually feel relief after having this treatment done. This procedure also often leads to increased blood flow in the foot, most likely due to the blood vessels getting wider and more blood being able to move through the tiny blood vessels present in your skin.
Why do People Need Lumbar Sympatholysis
Lumbar sympathetic neurolysis is a procedure used to treat a variety of problems that affect the lower part of the body. These problems can range from complex regional pain syndrome (a condition causing chronic pain after an injury), postherpetic neuralgia (pain following shingles), and phantom limb pain (pain felt in an area where a limb has been amputated). This procedure can also help people who have severe leg pain because of poor blood supply and cannot undergo surgery to improve circulation.
This procedure is usually considered when people’s quality of life is significantly affected by their symptoms and other treatments, like medications, have not been effective.
Moreover, people with chronic pain in the abdomen making surgery impossible could also benefit from this procedure. This includes pain associated with areas such as the lower part of the large intestine, the kidneys, parts of the bladder, and ovaries. Other uses of this procedure include the treatment of excessive sweat secretion in the soles of the feet.
While it’s beneficial for these conditions, lumbar sympathetic neurolysis has been largely replaced in today’s practice by spinal cord stimulation for many chronic pain conditions. This is a type of therapy that uses electrical signals to mask pain signals before they reach the brain.
When a Person Should Avoid Lumbar Sympatholysis
There are certain circumstances where a procedure shouldn’t be performed. These include:
If the patient hasn’t been properly informed about the procedure and given their consent. It’s really important that people understand what’s going to happen during any medical procedure, and agree to it.
If there’s an infection at the site where the procedure will take place, it’s usually not safe to proceed.
There are also conditions that might mean the procedure isn’t a good idea, but it’s not an absolute no. These include:
If the patient has problems with their blood clotting (coagulation abnormalities), or issues with their blood vessels (bleeding dyscrasias) including problems with the function of platelets, which are components of the blood that help it clot.
If the patient has cancer near the treatment site, there could be increased risks.
If the patient has a whole body infection (systemic infection), bacteria in the blood (bacteremia), or severe heart or lung disease, the procedure could be too risky.
Equipment used for Lumbar Sympatholysis
Fluoroscopic guidance, a technique often used in medical procedures, usually involves the use of a C-arm, a specialised table that can be seen under X-rays (fluoroscopy-compatible table), as well as the necessary needles and medications. The C-arm is a critical piece of medical equipment that provides live, real-time X-ray images to help guide the doctor throughout the procedure. It’s pretty much like a map that ensures the doctor is heading in the right direction. The table used is carefully designed to offer clear imaging, and of course, the specific needles and medications vary based on the procedure being performed.
How is Lumbar Sympatholysis performed
Lumbar sympatholysis, a treatment procedure to relieve pain, can be executed through burning (radiofrequency ablation), chemical agents, or rarely by surgery. Here’s a quick overview, primarily focusing on the burning and chemical methods. X-ray imaging (fluoroscopy) guides the procedure, helping the doctor navigate through the bones and observe the injected dye.
For this process, you will lie on your stomach on the fluoroscopy bed. You’ll be attached to monitors, and calming (anxiolytic) drugs can be given if needed. Preventive antibiotics are not typically required. There is a standard pre-surgery check (surgical time-out) to ensure the right patient and procedure. The lower back area (lumbar region) is then disinfected. The doctor then uses fluoroscopy to spot the target areas between your second to the fourth lumbar vertebrae (L2-L4). Local anesthesia is applied at the site where the needle will enter, avoiding discomfort. Your skin temperature in the lower extremities of both legs is recorded before and after to check if the treatment was successful.
Chemical Neurolysis
In this procedure, a long and slim needle is inserted under the horizontal part of the vertebra (transverse process). The needle is slowly moved forward, guided by fluoroscopy, until it reaches the front edge of the vertebra. The needle entry point is about 7 cm away (laterally) from the midline of your back. The procedure might require the needle to be shifted sideways and forward when it hits your vertebra. Once in place, a dye is injected, and they will look for its movement in the space alongside the vertebra. When the correct site is confirmed, a drug (bupivacaine) is injected to numb the nerve root before injecting the chemical (usually alcohol) that breaks down the nerve. The drug choices can vary based on your condition and the doctor’s preference, but they usually include local anesthetics like lidocaine and nerve breaking chemicals like phenol.
There are various ways to conduct chemical neurolysis, but using three needles has proved to be better in terms of effectiveness and lesser chemical volume usage. If using this method, it’s vital to confirm all levels and check for no blood return before injecting the chemical.
Radiofrequency Thermocoagulation
This method involves damaging the nerve using heat produced by high-frequency radio waves, or radiofrequency (RF) ablation. The initial setup and target positions are more or less the same as in chemical neurolysis. However, specialized needles and radiofrequency probes generate heat at the targets. A radiofrequency generator produces a high-frequency current that breaks down the nerve when applied. Some important factors that affect this technique include the size of the electrode, the duration of the lesion-creating process, and the temperature of the tissue.
Surgical Sympathectomy
Cutting or clipping the nerve chain usually realizes surgical methods. The operation is generally done at or below the second lumbar vertebra (L2) to reduce the risk of sexual dysfunction – a complication more commonly observed when performed in the chest area. It’s important to note that the effects of lumbar sympatholysis aren’t permanent. Nerve-breaking methods using radiofrequency or chemicals typically last up to six months before nerve regeneration. On the other hand, surgical lumbar sympatholysis can have effects lasting up to few years.
Possible Complications of Lumbar Sympatholysis
Some risks or complications can sometimes happen following a procedure known as lumbar sympatholytic, which lowers the function of the sympathetic nervous system. These might include bleeding, infection, injection into the neural area (nervous system), injection into a blood vessel, nerve pain in the thigh and genital area, damage to nerve roots, and rarely, injury to structures around the bladder and kidneys.
The most common complication is genitofemoral neuralgia; a type of nerve pain that affects the inner thigh or genital area. It occurs in about 5 to 7% of patients following the chemical lumbar sympathectomy. Some facts suggest it happens more often when using alcohol instead of phenol as a neurolytic agent, which are chemicals used to damage the nerves to block pain. Usually, these symptoms come and go and often improve within 4 to 6 weeks. The risk of getting this pain can be lowered by avoiding injecting medications into certain muscles in the lower back, specifically levels L3 and L4.
There are also cases of persistent pain after the sympathectomy procedure, which is often described more as a dull ache. The exact reason behind this feeling is not completely clear.
An accidental injection into the nervous system can lead to severe outcomes like paralysis and even death. Injecting a neurolytic agent into the spine can cause temporary weakness and paralysis, with some cases lasting permanently.
Accidentally injecting a neurolytic agent into a blood vessel can also happen due to the close relation of the sympathetic chain to main blood vessels like the aorta and the inferior vena cava, a large vein that carries deoxygenated blood to the heart. Variances in blood vessel anatomy can also contribute to accidental intravascular injection, which can result in direct toxic or ischemic injury to the spinal cord, where blood flow is blocked and tissue is starved of oxygen. That’s why it’s crucial to draw back on the needle before injecting to ensure the injection doesn’t end up in a blood vessel.
What Else Should I Know About Lumbar Sympatholysis?
If you have long-lasting, severe pain in your legs that is not improving, due to conditions like complex regional pain syndrome, post-herpetic neuralgia (nerve pain after shingles), inoperable peripheral arterial disease (a circulation issue), phantom limb pain, erythromelalgia (a rare condition causing burning pain), or hyperhidrosis (excessive sweating), there is a treatment that might help you. This treatment is called lumbar sympatholysis.
Lumbar sympatholysis involves breaking down a group of nerves in your lower back known as the lumbar sympathetic chain. These nerves contribute to pain signals being sent to your legs and their removal can provide relief from your symptoms. The relief can potentially last for several years.
There are several ways to deliver this treatment, including using chemicals, heat from radiofrequency energy, or surgery.
Healthcare providers need to know all about these methods, and when and for whom they are suitable, to provide good pain relief while keeping risks low. They also need to know about contraindications, which are situations when this treatment should not be used, as well as its possible side effects and complications, to ensure your safety.
