Many people develop spinal narrowing within the lumbar spine (low back), which presses on the nerves inside the spinal canal. This pressure often causes pain in the legs, often with walking or other activities, as well as back pain. Oftentimes, a decompression surgery achieves remarkable improvement in function and relief of pain. However, some surgeons recommend fusion surgery instead.
An endoscope drastically reduces the invasiveness of surgery to decompress the nerves. By causing less harm to the spine, patients often have better outcomes with regard to postoperative pain, quicker recovery, quicker return to activities, less postoperative pain medication use, as well as reduced risks. Dr. Mahan has published and taught extensively on this subject
https://pubmed.ncbi.nlm.nih.gov/?term=mahan+ma+%5Bau%5D&sort=pubdate
Causes of lumbar spine narrowing (stenosis)
With age, the disc between the spinal bones (vertebral bodies) wears down. Age-related disc collapse leads to height loss (as most people are not as tall at age 90 as they were at age 19). This settling of the spine often causes narrowing:
- The disc gets wider – think of an elephants paw spreading out as it puts weight on it
- The stretchy ligament (ligamentum flavum) in the back also settles (think of a curtain folding up at the floor after the performance)
These two processes lead to narrowing (stenosis) around the nerves of the spinal canal (cauda equina). Pressure on these nerves is uncomfortable, particularly with walking, standing, and other activities, and oftentimes alleviated with bending forward, such as the so-called “shopping cart sign” or needing to sit intermittently while walking longer distances. However, individual symptoms are often unique. So, symptoms cannot perfectly diagnose the problem. It requires a combination of symptoms, an MRI, and oftentimes other diagnostic tests
In severe cases, stenosis can not only cause pain and discomfort, but weakness, numbness, and in rare circumstances, problems with bowel and bladder function. As you would expect, the more severe the problem, and the longer duration of the problem, the greater likelihood that surgical decompression cannot reverse deficits. Therefore, we strongly recommend that you consider treatment, before it becomes a permanent problem.
Surgical treatment of narrowing (stenosis)
If the symptoms are not too severe, we recommend that individuals try nonsurgical management first. This may include things like physical therapy, yoga, stretching, and other forms of exercise. When the narrowing is severe on MRI (or CT myelogram) and the symptoms appear to arise from that narrowing, we often recommend surgery to open the space for the nerves.
Unfortunately, this is typically a one-way process, and neglecting it does not lead to improvement.
For open surgeries, this is typically referred to as a laminectomy (lamina = shingle of the spine). The muscles are scraped or burnt off of the lamina and retractors are used to compress the muscles outward so the surgeon can look inside. This causes a loss of blood flow (ischemia) to the muscles, often leading to irreversible muscle loss. The lamina is removed entirely, which also removes the attachment spot for the back muscles.
With endoscopic surgery, we do not remove the entire lamina, as those are important attachment spots for the spinal muscles. Dr. Mahan calls this surgery an interlaminar decompression, indicating that we are preserving the lamina. Other endoscopic surgeons may call this a ULBD, which stands for unilateral laminotomy and bilateral decompression. The goal of the surgery is to remove the portion of the ligamentum flavum (which is not a structural ligament, but rather more of a flexible membrane) and underside of the lamina, leading to decompression of the nerves. In endoscopic decompression, the only goal is to remove the parts that are causing the narrowing, not the entire spinal lamina.
What is Endoscopic Decompression?
Endoscopic decompression is a cutting-edge surgical technique aimed at removing narrowing from inside the spinal canal. The endoscopic technique is fundamentally different than open surgical techniques. Endoscopic surgery works inside the spinal canal to decompress from within; whereas open surgery removes bone from the outside in order to decompress inside. The procedure involves the use of an endoscope, a thin tube equipped with a light and camera, which is inserted through a small incision to access the narrowed spinal levels. We remove the thickened ligamentum flavum, remove the underside of the lamina, and, occasionally, sometimes disc fragments, relieving pressure on the spinal nerves and alleviating pain, weakness, or numbness.
Surgical Approach
The endoscopic discectomy is typically performed under local anesthesia and sedation. Here’s a breakdown of the surgical process:
Preparation: You are positioned comfortably, most commonly lying face down. Imaging, which refers to X-rays or fluoroscopy, is used to correctly locate the spinal level (vertebrae) where the stenosis is located. Because the endoscopic approach solely focuses on the problem (and is not exploratory), we are ultra-precise in planning.
Incision: A small incision (about 6-7 mm, for approximately width of your pinky fingernail) is made in the skin at the level of the affected spinal level. A tube is inserted through this incision, and the endoscope is carefully navigated to the narrowed spinal level.
Visualization: The endoscope provides beautiful images of the spinal elements, including the nerves, joints, ligamentum flavum and lamina. The ligamentum flavum is carefully sculpted away from the lamina using a very small drill. Once the ligamentum flavum is detached from it bone anchors, it is carefully removed from the spine.
Benefits of Endoscopic Decompression
Ultra-minimal approach: The small incision and small tools reduces trauma to the spinal muscles, which is the most common and obvious source for surgery-related pain. Recent literature demonstrates reduced muscle breakdown, as measured by muscle proteins in the blood, when an endoscopic technique is utilized1 . The reduction in muscle breakdown is better than other minimally invasive approaches, like open or tubular microdiscectomy.
Reduced Risks: The minimized opening of the body and use of constant irrigation has been shown to reduce several risks, including infection2 , bleeding, dural tear (spinal fluid leak)3 , as well as risk of postoperative pain medications and their side effects4 . Stronger pain medications, i.e., opioids / narcotics, have more side effects, such as constipation and urinary retention, addiction, and, according to the US CDC, opioids increase all-cause mortality. Approximately 98% of our patients not on narcotics will not start a narcotic for this surgery.
Less Pain: most patients experience less postoperative pain compared to open procedures, when compared in head-to-head research trials. Most patients only need a combination of ibuprofen (Advil™ or Motrin™) and acetaminophen (Tylenol™) for managing the incisional discomfort after surgery.
Faster Recovery: Many patients can return to their normal activities within weeks, as opposed to months with more invasive surgeries.
Shorter Hospital Stay: Most patients undergo endoscopic discectomy on an outpatient basis, meaning they can go home the same day or after a short observation period.
However, because of the technical complexity of the surgery, many surgeons do not offer this option.
Risks and Potential Complications
Like any surgical procedure, endoscopic decompression carries risks, though these are generally lower than those associated with open surgery. Some of the potential complications include:
Incomplete relief of symptoms: Sometimes, particularly with large disc fragments and severe nerve compression or longstanding disc herniations, the spinal nerve does not recover perfectly. This can lead to a disappointing resolution of pain, weakness, or numbness.
Need for revision surgery: Sometimes, particularly if there is a slipped disc (spondylolisthesis), patients find that the decompression alone is insufficient and they may require a fusion surgery to restore height between the vertebral bodies and/or to correct the slip between the vertebral bodies. We discussed this risk upfront, as every patient is unique. Generally, we strive to preserve individual’s spine flexibility; recommending fusions only when necessary to treat a different problem.
Infection: Although rare, infection at the incision site or deeper in the spine can occur. In our series, only 1 patient of approximately 1,200 patients had an infection2 , which occurred after swimming. We therefore recommend avoiding submersion, including pools, hot tubs, and bathtubs, until 1 month after surgery
Bleeding: While the endoscopic approach minimizes bleeding3 , there is still a small risk of bleeding after the surgery -which may also require revision surgery.
Dural tear: The use of irrigation and endoscopy reduces the incidence (frequency of occurrence) of inadvertent tears of the spinal fluid membrane, also known as dura mater. In certain cases, there are adhesions to the dura, such as facet cysts, which greatly increases the likelihood of an unavoidable and unintentional tearing of the dura (incidental durotomy). Because the tools are smaller with an endoscopic approach, durotomies tend to be smaller. Thus, they are frequently managed less aggressively than those caused in open surgeries. For example, lumbar drains are more frequently used in management of dural tears from open surgery , but rarely in endoscopic surgery
Nerve Injury: Because this is a technically complex surgery, there is a slight risk of damaging nearby nerves during the surgery, which could result in weakness, numbness and/or new pain. Fortunately, in most cases, any worsening in function usually recovers with time.
Anesthesia-related complications: Adverse reactions to the anesthesia. The risks of your anesthesia are reviewed with you by our anesthesia team immediately prior to surgery. In some cases, when individuals have multiple medical problems, we may ask you to see our anesthesiologists prior to surgery to make the best plans.
Need for Conversion to Another Surgery: In unforeseen circumstances, our team may need to convert to a traditional open surgical approach during the procedure. This is exceptionally rare.
Medical complications: These are problems that are independent of the surgery, but may occur because in association with surgery. For example, blood clot may form in the legs (deep vein thrombosis – DVT) or lungs (pulmonary embolism – PE) if you are not moving much after surgery. Other examples include: opioid or other pain medication problems, such as drug dependence or addiction, bowel obstruction, etc.
It is important to understand risk factors are often patient-specific, and that we will provide our best estimate of your risks – not generalized estimates.
What to Expect After Surgery
After the procedure, you will spend a short period in a recovery area to allow the sedating medications to wear off, and most can go home the same day.
Postoperative Care: You may experience mild discomfort or soreness at the incision site, which is typically managed with anti-inflammatory pain medications.
Activity Restrictions: Initially, you may be advised to avoid strenuous activities, such as lifting heavy objects or bending excessively, for a few weeks to allow your body to heal.
Physical Therapy: A physical therapy program may be recommended to strengthen the muscles around the spine and improve mobility. Everyone tends to do well with a coach helping them out to achieve their goals.
Follow-up Appointments: a 6 week follow-up appointment is set prior to surgery. Additional follow-up appointments are established to assess the success of the surgery, additional needs or other considerations. Imaging tests, such as MRI or X-rays, may be used to confirm that the stenosis has been adequately removed and that no further issues are present.
Recovery and Long-Term Outlook
Recovery from endoscopic decompression is typically quicker compared to traditional open spinal surgery. Many patients report a significant reduction in pain and an improved ability to perform daily activities within a few weeks. However, full recovery may take several months as the body continues to heal.
While most patients achieve lasting relief, it’s important to maintain a healthy lifestyle, engage in regular exercise, and avoid activities that could strain the spine to reduce the risk of future problems.
- Akçakaya, M. O. et al. Serum creatine phosphokinase levels as an indicator of muscle injury following lumbar disc surgery: Comparison of fully endoscopic discectomy and microdiscectomy. Clin. Neurol. Neurosurg. 145, 74–78 (2016).
- Mahan, M. A. et al. Full-endoscopic spine surgery diminishes surgical site infections – a propensity score-matched analysis. Spine J 23, 695–702 (2023).
- Chin, B. Z. et al. Full-endoscopic versus microscopic spinal decompression for lumbar spinal stenosis: a systematic review & meta-analysis. Spine J. 24, 1022–1033 (2024).
- Tong, Y., Ezeonu, S., Kim, Y. H. & Fischer, C. R. Single-Level Unilateral Biportal Endoscopic versus Tubular Microdiscectomy: Comparing Surgical Outcomes and Opioid Consumption. World Neurosurg. 190, e754–e761 (2024).
