Bill Klaproth (Host): This is The Healing Podcast, brought to you by MarinHealth. I'm Bill Klaproth. And with me is Dr. Akash Shah, a spine surgeon at MarinHealth Spine Institute, a UCSF Health Clinic. And today, we're going to delve into the topic of lumbar stenosis. Dr. Shah, welcome.

Dr. Akash Shah: Hey, Bill, thanks so much for having me on. It's a super important and common topic. So, I'm really happy that we have a chance to talk about it.

Host: Yeah. This is a common topic. Many, many, many people suffer with low back issues. So really glad to talk with you today, Dr. Shah. So, let's start with the basics. What exactly is lumbar spinal stenosis and how common is it?

Dr. Akash Shah: So, lumbar stenosis just very simply is a narrowing of the lumbar spinal canal, and that results in compression of the nerves that run through your spine, right? So, the spine is comprised of bones and discs, and ligaments, all of which surround a canal through which our nerves travel. And typically, it starts with your brain, kind of exits the skull, goes into your neck, continues on through your mid-back and thoracic spine, and then it transitions into nerve roots once it enters the lumbar spine or the lower back. And these nerves exit the spine at each level. They give us sensation and strength to the entire lower half of the body. And when that canal narrows, those nerves get compressed, right?

So, I mean, I'm from Los Angeles originally, so my analogy for this is unsurprisingly highway-related. You think of your lumbar canal as like a four-lane freeway, right, through which the nerves travel unimpeded without traffic. But if that freeway has a lane closure or two, the space for your nerves decreases, right? And the speed at which information can travel through those nerves slows as well. Traffic builds up, the cars get backed up. And, you know, that traffic jam in the lumbar spine results in nerves getting irritated. And so, that results in the symptoms that we'll talk about later, right? Like back pain and leg pain and numbness.

With respect to how common it is, it's unfortunately very common, especially as we age, right? Worldwide, I think, the most reliable estimate suggests that well over a hundred million people have symptomatic lumbar stenosis. And between 10-15% of older adults in this country have it. And so, as we grow older and live longer, just the number of people with lumbar stenosis is, unfortunately, only going to increase.

Host: Wow. A hundred million people. That's a lot of people. Quick question for you, Dr. Shah. You said this is a narrowing of the spinal canal. Why does the spine narrow as you age?

Dr. Akash Shah: The most common answer to this is wear and tear, right? So, the spine, like we talked about a little bit, it's comprised of these intervertebral discs between each bone in the spine, they act as shock absorbers. There are joints that allow for motion, and then there are ligaments that provide stability. And so, in a healthy spine, the discs, the bones, joints, ligaments, they all work together to maintain normal motion and stability in the spine. And all of these structures surround the nerves.

But as we age, each of these structures degenerates. So, our discs lose water and height over time. As they flatten, they can bulge backwards and compress nerves. And then, as the discs degenerate, this also puts added stress on the joints, which then causes them to get arthritis. And then, as those joints become arthritic, they get swollen and they grow larger, and they develop bone spurs. And then, these bone spurs and bigger joints also lead to less space available for the nerves. Then, the spinal canal also has a ligament that runs along the back of the canal, just behind the nerves. And this ligament can also grow thicker and stiffer with degeneration, and it can buckle and also compress nerves. You can also have abnormal motion of the spine that can lead to nerve compression.

As our joints degenerate through the process that we talked about, they can actually cause some instability in the spine that causes one vertebra to slip back and forth. And this slipping and sliding can also repeatedly compress nerves. And then, there's a very small percentage of people who are just born with very narrow canals. But the vast majority of patients who develop lumbar stenosis, it's from the causes that I mentioned, right? And the key point is that it's not usually caused by any one structure. It's just typically a combination of degenerative changes that just gradually reduce the space available for the nerves.

Host: So, you mentioned before this compression of the nerves causes the pain that we feel. What are some of the most common symptoms then people experience?

Dr. Akash Shah: The most common symptoms are, unsurprisingly, back pain as well as leg pain and occasionally numbness. But the actual combination of these can be pretty variable. And I think it's important to recognize that they're usually due to different things. So, back pain, the low back pain is usually due to arthritis and disc disease. There can be occasional muscle spasms as well, just from the inflammation of these structures.

Leg pain, on the other hand, is because of the nerves. So, one or both legs can be involved depending on whether the right side or the left side is more compressed than the other. In that situation, the patients would have shooting pain down their buttocks and their legs, and this is something called lumbar radiculopathy. In cases of more severe compression that's compressing multiple nerves, patients have a little bit of a different symptom complex. They may have an aching or cramping pain in their buttocks, thighs, or calves that gets worse with activity and standing, but gets better with sitting or bending forward.

And then, in addition to the pain, there is numbness and tingling that may also be involved. At times, folks may start noticing that they can't walk more than a short distance before they have to stop, leaning on a shopping cart when you're in the grocery store or sitting down or bending forward opens up the canal slightly so that the symptoms improve. And so, that particular pattern-- activity-dependent leg pain or numbness that resolves with rest-- is pretty characteristic of severe lumbar stenosis.

Host: Is this where sciatica comes in as well?

Dr. Akash Shah: Yeah. Yeah. That's exactly right. So, we talked about-- the term I used lumbar radiculopathy. I think the term that we most commonly use is sciatica, right? I mean, it kind of comes from symptoms from inflammation of the sciatic nerve. But all of the lumbar or many of the lumbar spinal nerves contribute to that particular nerve, the sciatic nerve. And so, kind of shooting pain down the leg is like sciatica-type pain. And so, that's what that is exactly.

Host: While I would say lumbar radiculopathy is ridiculous, I'm sure that's what a lot of people say. So, how do you diagnose this? How do you figure this out? Some people probably just have aches and pains from overdoing it. And then, there's people that have this chronic condition. How do you diagnose it, and what kind of imaging or testing is usually involved?

Dr. Akash Shah: Yeah. You know, it's something that you can't necessarily clinch the diagnosis with just one type of test, right? So, we usually diagnose lumbar stenosis with a combination of hearing the patient's story, what their exam is like, and then imaging. So actually, I don't make it a requirement for folks to have MRIs before they see me. So honestly, a lot of the diagnosis comes from the story that patients tell me. If they describe a pattern of symptoms, like what we talked about, leg pain or heaviness with walking, relief when sitting or bending forward, that's a big clue for me that we might have a lumbar stenosis picture.

Next, you just examine the patient, right? I'll check for changes in their sensation or changes in strength in specific muscle groups that may clue us into which nerves are affected. I like to watch patients walk as well. Sometimes I'll ask them to arch their back backwards to see if that reproduces any of their symptoms. We also kind of have to think about whether or not there's any vascular issues, right? So, sometimes sort of affected blood flow can have similar leg symptoms to lumbar stenosis. And so, I always check their pulses and look at their legs to make sure there isn't a vascular issue instead.

Then, of course, imaging is what we do to confirm the diagnosis. And MRI is the gold standard because it lets us see the nerves themselves as well as the discs and the joints and the ligaments. And it can show us exactly where the compression is and how tight the canal is at that level. There are more and more people who are unable to have an MRI and maybe that's because of metal in their body or a pacemaker. If that's the case, we can get a special kind of CT scan as well. It's called a CT myelogram. You inject contrast dye around the nerves to just make it easier to visualize.

In addition to that advanced imaging, I also think that plain old fashioned x-rays are incredibly important since we can use them to look for alignment issues or instability that could potentially influence a possible surgical plan. But something I tell my patients is I don't treat MRIs, right? I treat the people in front of me. And so, the most important thing is whether the patient's symptoms correlate with what we see on imaging. If the patient has severe compression on an MRI, but minimal symptoms, well then, there's not really a point in me sticking a knife in their back.

Host: Yep, that makes sense. Okay. So, there are non-surgical treatment options, as you said, before surgery. So, how are those considerations made and how might non-surgical treatment options help?

Dr. Akash Shah: Yeah, you're absolutely right. The first line of treatment for lumbar stenosis is non-operative. Only in the setting of rapidly progressive weakness would the recommendation be surgery first, but that's almost never the case with degenerative lumbar stenosis. And so, non-invasive treatments would consist of the following: so physical therapy, activity modification, weight loss, and oral medications. And so, we can kind of explain how each of them would help separately. So, physical therapy sometimes feels like something the doctor throws at you to delay surgery, but really nothing can be further from the truth. A targeted physical therapy program strengthens your core muscles and paraspinal muscles and improves your posture.

We talked about all the structures in the spine, but what I didn't mention are the paraspinal muscles that run on either side of the spine. They do an incredibly important job in stabilizing the spine. Strong core and paraspinal muscles takes pressure off of the discs and the joints, and it reduces the pain that comes from these structures, and it often slows the progression of stenosis.

Kind of along these same lines, weight loss can also reduce the amount of stress and strain on those structures. Activity modification is like a fancy word that just means making slight changes to how you perform the activities that normally cause pain. Avoiding long periods of standing or taking breaks during walking, they may head off stenosis symptoms before they occur. Similarly, learning to use, say, a slightly bent forward posture when your symptoms flare up can be helpful. If running or prolonged walking causes too much pain to exercise, then sometimes folks will transition to exercises that are less likely to result in nerve symptoms, like using the bike since you're usually bent forward when you're on a bicycle.

Then, finally, moving on to just oral pain medications, right? Anti-inflammatory medications like ibuprofen or naproxen can reduce inflammation around the irritated nerves and joints as well. Sometimes medications like gabapentin or pregabalin can also lessen the severity of nerve-related pain or numbness, but none of these treatment options reverse lumbar stenosis because they can't change the anatomy. But by reducing the strain on the spine, improving biomechanics and reducing inflammation, it can go a pretty long way to making the symptoms tolerable.

Host: Absolutely. So, I know some people then in potentially conjunction with physical therapy and non-operative methods also get an epidural steroid injection as a treatment option. How do those help and when are they appropriate in the treatment mix?

Dr. Akash Shah: Yeah. So, I mean, next in the ladder of invasiveness is an epidural steroid injection, just like you mentioned. Steroids are powerful anti-inflammatory drugs. If there is a specific nerve or nerves that are compressed, we can place steroid medication directly around those nerves and pinpoint them. Compressed nerves are inflamed, red and swollen. And a targeted steroid injection just around those nerves can calm that down considerably.

And while it is temporary relief, it can last anywhere from weeks to multiple months. These injections tend to be more useful for patients with radiculopathy, the sciatica-type pain. It's a little bit less reliable in patients that have severe compression of multiple nerves centrally. And, you know, of course, we want these injections to be therapeutic, that is to make people feel better. But they're also useful in cases that are a little bit tougher diagnostically. And so, if a patient gets response from an epidural, that tells us that the area that we injected is likely responsible for a large part of their symptoms.

Host: How long can someone be on an epidural steroid? As long as it's working and helping that person manage the pain?

Dr. Akash Shah: Yeah. It's an area of a little bit of debate. I think in our practice, we try not to do more than three or four in a year, just due to a variety of issues. The first one is just diminishing returns. By and large, the injection that is going to give you the most relief is the first injection that you get. And after that, subsequent injections tend to provide less and less relief.

Additionally, there's some evidence that repeated steroid injections in the same area can cause local areas of decreased bone mineral density or kind of osteoporosis or osteopenia in those areas. So, we try to limit how many we do.

Host: And then, at what point do you start considering surgery for a lumbar stenosis? What factors would go into that decision?

Dr. Akash Shah: Most patients do perfectly fine with the non-operative treatments that we talked about, but if they have persistent symptoms that they are limited by, despite at least three months of non-operative treatment, is when I start having a discussion on whether surgery can give them relief. When they have failed non-operative management and their symptoms become intolerable to them is kind of when I think we start to discuss what surgery would look like, right? If a patient is unable to tolerate walking for even a short period of time or have a difficult time with normal activities of daily life, shopping, walking the dog, going on short walks. If you're not able to work or enjoy retired life or do the things that you love, right? It's no way to live life, and we need to find a solution.

If we have neurologic deterioration like progressive leg weakness or numbness or, in very rare cases, chronic compression that starts to affect bowel or bladder function, then that also clues us into moving a little bit more expeditiously with surgery. But surgery isn't benign, right? These operations require general anesthesia, and we have to make sure that someone is healthy enough to undergo surgery. And if they're not, we have to work with our anesthesiologists and primary care doctors and cardiologists to optimize them as best as we can. And if we're unable to optimize them, we have to have a hard discussion on the risks and benefits of surgery and whether the risks outweigh those benefits.

Host: And then, can you walk us through the main types of surgeries used to treat lumbar stenosis, such as laminectomy, laminotomy, and spinal fusion? And then, how do you decide which approach is best for a patient?

Dr. Akash Shah: Yeah. So when a surgery is needed, the first question always has to be, what exactly are we addressing? As spine surgeons, 99% of the time we decompress what is compressed and fuse whatever is unstable. A laminectomy is the most common surgery for lumbar stenosis. The lamina is the back part of the vertebra that forms a roof over the spinal canal.

And, as structures start to crowd the canal and compress the nerves through the processes that we talked about earlier, we have to find a way to create more room for the nerves. In a laminectomy, we just remove that roof to fully open the canal. And this is the standard procedure that we do when there is multi-level stenosis or when there's severe compression that requires us to have a, like wide decompression.

A laminotomy is a smaller, more targeted version of a laminectomy. Instead of removing that entire roof, we just remove a window of bone on one or both sides, just the part under which there is compression. A fusion, on the other hand, is different, right? It's not done to create space, but rather to stabilize an unstable spine. And that spine is either already unstable, like if one vertebra is slipping in front of the other, or we can make it unstable by having to remove so much bone to adequately decompress the nerves.

And so, therem are, you know, usually three ways that we fuse this spine. The first and most common is with screws and rods. The second is to remove the disc and place a metal cage between the two vertebra as well as screws and rods. This is called an interbody fusion, and the third and least commonly performed is a non-instrumented fusion where you don't place any metal and you just use bone graft instead. This is a little bit less robust, but it is a reasonable option in older patients that have poor bone quality.

So to kind of go back through a laminotomy, it's a small and focused opening. A laminectomy is a wider opening for more severe stenosis, and a fusion is added on when the spine is unstable or if it could become unstable after the decompression.

Host: Yeah, I'm just, thinking about this a little bit, with all these options here, we do hear about minimally invasive spine surgery. What does that really mean then, and how is it different from traditional open surgery for lumbar stenosis?

Dr. Akash Shah: Yeah. So, great question. The goals of traditional open versus minimally invasive surgery are the same: to take pressure off the nerves. The only difference is how to get down to the spine, right? Minimally invasive surgery, unsurprisingly, tries to minimize the collateral damage to the spine done in order to accomplish the surgery.

Usually, it involves smaller incisions, avoiding stripping muscle off bone, using tubes or small retractors that split rather than cut muscle, and microscopes or endoscopes to help visualize better as well as special instruments that are designed to work through these neuro corridors. And by keeping muscle dissection limited, patients tend to have improved postoperative pain and quicker recovery.

But not every case is ideal for a minimally invasive approach. For example, if you have multi-level compression, so you need to do surgery on multiple levels. If you have revision surgeries that have a ton of scar tissue, significant deformity, that requires many bone cuts, these are all cases where sometimes open surgery would be safest and quickest.

There isn't necessarily a neat dictionary definition of minimally invasive spine surgery, and I think it's as much a philosophy as it is an actual type of surgery. The aim ought to be to do the smallest amount of dissection and disruption possible to effectively address the problem. But that last part's key, right? There's no point in doing a surgery where you keep the incision one centimeter long, but you don't accomplish the goals of surgery. So, the question isn't necessarily whether minimally invasive or open surgery is more effective or better. I think they both have their place depending on the problem that we're addressing.

Host: Right. For that specific patient.

Dr. Akash Shah: Exactly.

Host: Yeah, that makes sense. You were mentioning new techniques, robotics. Can you talk about that a little bit, new technologies or approaches like robotics or advanced imaging that are changing how spine surgery is performed today and helps you as a surgeon?

Dr. Akash Shah: Absolutely. This is a huge part of why I became a spine surgeon. Innovation and technology in spine surgery have moved quite fast in the past decade. And I'm very excited about where things are going. We have fantastic tools both inside and outside the operating room that make surgery safer, more precise, and often less invasive.

So, intraoperative navigation is a fantastic tool. We take a three-dimensional CT scan in the operating room and map out the patient's anatomy in real time. The surgical instruments that we use are tracked on a screen so that we know exactly where we are in three-dimensional space. This is very helpful for when we're putting in screws to make sure that they're in the ideal position and a safe trajectory, as well as planning out the right diameter and length.

It's great for minimally invasive fusions, because you don't have to dissect as much to see the anatomic landmarks. Navigation tells us exactly where we are. And it's also very helpful for challenging deformity, or repeat surgery cases where the normal anatomy is distorted. Robotic-assisted spine surgery is also becoming more popular. In this case, we can upload a CT scan before the patient even gets into the room, and the robot can help keep a steady trajectory for when we put our screws in to allow us to put those screws with great accuracy. This improves precision, and it can also help reduce radiation exposure during surgery, because you're not taking as many x-ray shots while the patient's asleep.

And even outside the operating room, right? There are a growing number of data-driven and AI-assisted planning softwares, especially for when we do fusion surgeries where we're trying to improve the patient's alignment. We can plan out things like how to bend the rods and where to make certain bony cuts, et cetera. This is still an evolving space. But all of these tools enhance the ability of the surgeon to more predictably accomplish the goals of surgery. I want to leave as few things up to chance as possible, right? If surgery, unexpected things happen, and everyone in there is well-trained to address those things if they were to happen, but it would be a lot better if we minimize the number of variables in a surgery.

Host: And it sounds like that's what these tools do. So, the improved imaging is like seeing inside the body. Is that right? Where you couldn't ordinarily see. Through the imaging, you really know where you're going. Is that right?

Dr. Akash Shah: Yeah, exactly. So, normally, when we put screws in, we're trained to kind of know which anatomic landmarks to look for in order to kind of put these screws in the right place in the spine. That's because we can't really dissect the entirety of the spine, right? That would be rather morbid and a ton of blood loss and a ton of pain.

And so, we understand the anatomy of the spine. But even then, we have to dissect quite a bit more than you would have to with this sort of image-guided, or rather CT-guided navigation. And it essentially minimizes the amount of dissection that you have to do, and you get to see the bony anatomy right there on a screen in front of you.

Host: It's just amazing. And then, the robotics, as you said, really kind of helps you work with precision. I would take really that really steady hand. So, this all sounds like it would help the recovery process. So, what is the typical recovery process like after lumbar stenosis surgery, and what can patients expect in terms of outcomes?

Dr. Akash Shah: A lot of it depends on how many levels we've decompressed, whether there was a fusion, and if this was more of an open versus minimally invasive surgery. But for most people, it is a steady and predictable process. The timeline might vary depending on the exact surgery, but here is what you typically expect.

The first is the perioperative phase, like the first few days after surgery. Most patients are up and walking the same day or the next morning. If they're admitted, we have them work with physical therapy as well. And they usually require narcotics for a few days after surgery. There is typically some soreness in the back that's completely expected. Most patients go home.

Over the first six weeks after surgery, patients will gradually start to walk more. We had them limit deep bending or twisting or lifting heavy items, but we encourage them to get back to normal activities around the house. And by this mark, the pain should be significantly improving, and most people at this time don't need narcotics anymore.

This is also at the time when most patients feel that their leg symptoms are better because the nerves are decompressed, but the muscle discomfort and soreness can take a little longer to recover. At the six-week mark, usually, you have patients work with physical therapy to rebuild strength and improve their mobility. And by the three-month mark, patients usually feel that they're much more mobile with more endurance.

Now, the timeline is often a little bit delayed in fusion surgery because the bone has to heal, but the pattern overall is similar. Leg pain, heaviness, fatigue, that usually gets significantly better pretty quickly. Some people feel relief immediately, and it takes a couple of weeks in others. Numbness and weakness though if they were present before surgery are more variable. Numbness and tingling can often take months to improve because nerves take a long time to regenerate. And if there was weakness that was present before surgery, it definitely can improve. But it depends on how weak the muscles were beforehand and how long the nerve was compressed for. It can take up to 12 to 18 months to see the full degree of nerve recovery.

But I love doing surgery for lumbar stenosis, because it is one of the more reliable operations that we do. Most people get significantly better with improvement in their functionality. They get back to walking, hiking, traveling, playing with their grandkids, just whatever activities they enjoy.

Host: And that is definitely the good news on that. So, we all know people with back pain and sometimes you hear, "I can't take it. I want to go in and just have surgery." And some people are like, "I'm putting it off. I don't want to go in. I don't want to go in for a surgery." But you said basically that decision rests on if the persistent symptoms become intolerable. When a person reaches that point, that's when you start to consider surgery. Is that right?

Dr. Akash Shah: That's exactly right. There are very few things in the degenerative kind of spine world that need surgery, right? There's a handful. But at least when it comes to lumbar stenosis, you don't ever need surgery, right? It is more a matter of are the symptoms of this nerve compression preventing you from doing the things that you want to do, and have we exhausted everything short of surgery? I think those are the patients in whom they're more likely to be successful.

Host: Right. That makes a lot of sense. If your quality of life is definitely impacted and you can't do the things you want to do and the pain is intolerable, then it seems like it's time. Otherwise, if you can live with that pain, it sounds like there are ways to manage this through as you've been talking about, Dr. Shah.

Dr. Akash Shah: Absolutely. Yeah, there are.

Host: This has really been fascinating. I know a lot of people, as you said before, a hundred million people deal with this. So, really important topic. I'm so glad you spent some time with us today, Dr. Shah. Before we wrap up, is there anything else you want to add? Anything else we should know about this?

Dr. Akash Shah: No, you know, I think these are all great questions. This is probably 99% of what folks ought to know about lumbar stenosis, and it very much kind of covers what I tend to talk about in clinic with my patients whenever they have this diagnosis.

Host: And I know a lot of people live with back pain. It sounds like if you're suffering from back pain, it just makes sense to go see a spinal surgeon or go see your physician and get it checked out right away instead of just trying to live through the pain. I'm going to just power through it. It makes sense to go and see someone too, right? Because you might find that, hey, with some physical therapy, you'll be able to manage these symptoms and get that quality of life that you've lost back instead of just trying to, "I'm going to power through and I'm just going to keep taking aspirin." Would that be good thought on that?

Dr. Akash Shah: I totally agree with you. There's no reason to be a hero when it comes to your lower back if you're having back pain. And the best time to come see a specialist is before things get intolerable, because we can intervene with these non-operative treatment options that may make it so you don't progress to having intolerable symptoms. Or if you are going to progress that way, at the very least, to slow the progression of it

Host: Right. That's such a good point. No reason to be a hero. I love how you said that. And the best time to get this checked out is before it becomes intolerable. That's when you really have some movement and some leeway to try to correct this then.

Dr. Akash Shah: Exactly.

Host: Absolutely. Dr. Shah, this has been fascinating. Thank you so much. Would love to have you back on again. Thank you so much for your time. This has been great.

Dr. Akash Shah: Absolutely. It was my pleasure. Thank you for having me on.

Host: Absolutely. And once again, that is Dr. Akash Shah. And for more information, just go to mymarinhealth.org. And if you enjoyed this podcast, please share it on your social channels and check out the entire podcast library for topics of interest to you. I'm Bill Klaproth. This is The Healing Podcast, brought to you by MarinHealth. Thanks for listening.