Nucleus: The inner portion of the disc which has a gel-like consistency composed mostly of water and is surrounded by the annulus fibrosus (collagen) the tyre and tube construct.
WHAT IS SED / Endoscopic Discectomy?
Selective Endoscopic Discectomy (SED™) is a minimally invasive spine surgery technique that utilizes an endoscope to treat herniated, protruded, extruded or degenerative discs that are a contributing factor to leg and back pain. The endoscope allows the surgeon to use a keyhole incision to access the herniated disc. Muscle and tissue are dilated rather than being cut when accessing the disc.
This leads to less tissue destruction, less postoperative pain, quicker recovery times, earlier rehabilitation, and avoidance of general anesthesia or regional anesthesia. The excellent visualization via the endoscope permits the surgeon to selectively remove a portion of the herniated nucleus pulposus that is contributing to the patient's leg and back pain.
This Surgery is performed with a patient awake and aware in an operating room set up as a daycare / overnight procedure. Surgery time is approximately 30-45 minutes per disc. A small 1/4 inch incision is made on the back to the side of the spine. The entry point is precisely calculated by fluoroscopic intraoperative measurements. Sedation and local anesthesia are provided. The aesthetic will allow the patient to be comfortable during the procedure but will leave enough feeling in the nerves so the patient can actually tell when the nerve is being stimulated or when pressure is taken away from the nerve.
The instrument placement is performed under fluoroscopic or x-ray guidance. A conical probe (obturator) with a side hole for palpating structures and for anesthetizing painful structures is used to dilate a path to the disc. After determining that the probe is in the safe triangular zone between the traversing and exiting spinal nerves, the disc is entered by bluntly penetrating the annular fibers with the probe in case of Intradiscal pathologies. In case of extruded herniations, a targeted epidural approach is preferred using Hand drills & reamers enlarging the foramen and directly accessing the herniation.
If there is an unusual amount of pain with the docking of the blunt probe on the annulus, the surgeon can opt to visualize the outer aspect of the disc before entering the disc. Anomalous nerves and branches of spinal and autonomic nerves have been visualized and documented as contributing causes of back and leg pain that are currently not recognized by traditional surgeons. This area in the foraminal and extra-foraminal zone has been termed the hidden zone by surgeons Ian MacNab and John McCullouch.
The presence of these anomalous nerves and the ingrowth of nerves from an inflammatory membrane that forms over the sensitive disc annulus is responsible for the pain that is out of proportion to what the MRI shows. This phenomenon is not yet completely understood, but good results have been obtained by identification and ablation of these nerves, and by elimination of the condition causing the inflammation.
The procedure proceeds by a cannula being passed over the blunt obturator followed by insertion of the endoscope and operating instruments. The two spinal nerves are protected by the cannula and only the part of the disc needing surgery will be exposed to the operating instruments. The endoscope is inserted into the cannula and degenerated nucleus pulposus is visualized and selectively removed from the herniation site in the posterior portion of the disc. When treating annular tears a small amount of nuclear tissue is removed from underneath the tear. Often, some of this nuclear tissue is seen interposed within the tear preventing it from healing.
The advanced endoscope has integrated multichannel irrigation channels allowing for continuous cool saline irrigation similar to knee arthroscopy. A radio frequency electrode is used to help control bleeding, shrink the disc tissue or shrink the annulus, and ablate ingrown inflammatory/granulation tissue. Heat from the radio frequency probe may also help depopulate and ablate the pain fibers in the annulus.
Advanced endoscopic techniques will also allow the experienced endoscopic spine surgeon the ability to routinely visualize the exiting nerve root, a nerve that is rarely visualized by traditional spine surgeons when they remove herniated discs. Lateral or foraminal stenosis contributing to back pain& Leg pain can also be treated with this procedure. Overgrown bone and soft tissue compressing the Nerve in the spinal canal & Foramen can be incrementally removed using advanced tools like Motorised Burr, Radiofrequency, Motorised shavers & Holmium YAG Laser.Decompression of the nerves can be confirmed & documented during the procedure. The procedure is performed in a setting where a single day hospitalization is needed.
The goal of this procedure is to provide relief of leg pain and prevent further neurologic injury. Back pain is frequently relieved but may persist because of arthritis or other sources of back pain not coming from the disc. Success rates are similar to the published results of standard microscopic discectomy, but with less recovery time and quicker rehabilitation due to the more minimally invasive nature of the surgery.
There may be some discomfort in the surgical area. Other light activity is resumed on the evening of surgery and is gradually increased at home. Leg pain may subside immediately, or after several months. Your pre-operative pain may temporarily increase or change in character. On infrequent instances, if your pain persists, or if it returns, further tests may be needed to look for other causes of your pain, so it is imperative that you keep in contact with Dr. Varun Agarwal after your surgery for up to a year, then on a yearly basis.
Follow-up in the Hospital will occur 6 weeks after surgery depending on the patient's location and situation. One can expect to return to work in 3 to 4 weeks (or earlier if ready) depending on the job demands. Out-of-town patients are usually seen 1-2 days postoperatively to determine whether they can travel home the next day.
Although complications are rare, they can occur. Complications are similar to traditional surgery, which may include death and paralysis. Nerve injury, dysesthesia, complex regional pain syndrome, dural tears, bowel injury, psoas haematoma, epidural haematoma, and segmental instability are complications that may occur and may require additional treatment or surgery to resolve. You may have anomalous nerves in the foramen that can cause increased pain before your original pain subsides.
Because we are dealing with a deteriorating spine, the degenerative and aging process cannot be reversed, so one of the goals is to make the degenerative process less painful, but it will never-the-less still progress or accelerate. Your pain, therefore, in severe degeneration, may persist or return to its pre-operative level and in some cases may even worsen. In that case, alternatives such as fusion is still possible.
One unavoidable consequence of any surgery is scar tissue. Although it is minimized in Transforaminal Endoscopic surgery, its presence is variable and may be responsible for residual leg pain. The overall serious complication rate causing permanent residual Symptoms is less than 1-2%.
The most common side effect that may not be deemed a complication is the feeling of numbness or hypersensitivity (dysesthesia) in your leg after surgery. It can occur immediately after surgery or days and weeks later. Dysesthesia cannot be completely eliminated and its causes are still not completely understood. It is sometimes explained by a nerve that has been numb for a long time from prolonged pressure suddenly becoming decompressed and receiving new blood supply.
It is also similar to the phantom limb phenomenon experienced by some patients who had a limb amputated. Since one of the goals of surgery is to depopulate and ablate the sensitized nerves in the disc to relieve pain, the process of thermal modulation may cause dysesthesia. The actual cause is still speculative, as it can occur even when neuromonitoring does not demonstrate any irritation of the nerve during surgery. When this occurs, it is almost always temporary, but may need nerve blocks and medication to desensitize the nerves.
When your disc becomes hypersensitive to everyday stresses, this can be due to new nerves and blood vessels growing into your degenerating discs. An inflammatory membrane form, along with a process called angiogenesis and neurogenesis. Ablation of this inflammatory membrane is associated with an increased incidence of dysesthesia, but ablation also increases the chance of pain relief. There are also anomalous nerve branches that connect spinal nerves to each other and form in the fat over the annulus.
These nerves are called furcal or "forked" nerves, and not usually seen by the traditional spine surgeon, but can be visualized endoscopically in the area of the foramen and in the triangular zone where the endoscopic instruments must pass. Removal of some of these tiny nerves that are not part of the normal nerve may not be able to be avoided, and can even be found in the surgical specimen.
Communication is very important. Your decision to have Transforaminal Endoscopic Surgery must be made only after you assure yourself that you are fully informed, and any concerns you have must be brought to your surgeon's attention and discussed in detail to your satisfaction. Because this is a new advanced procedure, non-endoscopic surgeons and endoscopic surgeons not familiar with this technique may give you a different opinion that is based on their own experience or with their familiarity with the literature.
Some surgeons unfamiliar with the technique may even argue against it. Any concerns brought up by a second opinion should be brought to Dr. Varun Agarwals attention so that we can communicate with your surgeon if you or he desires. Dr. Varun Agarwal believes that you should have the freedom to make an informed shared decision about your care. After you have made the decision to have Transforaminal Endoscopic Surgery, if you have any problems related to your surgery, it is imperative that you call Dr. Varun Agarwal and notify us about any problems. Most complications can be resolved with proper intervention, but unwarranted delay may jeopardize your surgical result.
Plain x-rays of your spine may be necessary at the time of your preoperative appointments. This will help with preoperative planning.
Blood work and urinalysis, medical clearance, and psychiatric evaluation (In some) may be necessary for certain circumstances if your medical history dictates the need.
Stop all aspirin, non-steroidal anti-inflammatory medications, and alcohol two weeks prior to the procedure or as directed. If you need to continue your medication, ask Dr. Varun Agarwal about the medication. If you need the anticoagulant effect of aspirin for a heart condition or thrombophlebitis, please inform Dr. Varun Agarwal.
Report any concerns about your health that may affect the decision for surgery.
Do not eat or drink anything after midnight or eight hours before the procedure. This includes water, coffee, and juice. If you take medication regularly, ask Dr. Varun Agarwal whether you can take the medication with a sip of water.
Post Operative Instructions
There may be discomfort in the surgical area. Oral analgesics, muscle relaxants, and non-steroidal anti-inflammatory medications may be used as prescribed by your physician. Routine postoperative use of long-acting opioids, augmented by short-acting medication will help with your post-operative recovery. You may feel transient numbness and weakness in your leg from the local anesthetic used during surgery. This will usually start improving the first post op day.
Occasionally, when the feeling comes back you will feel pain in the same or different area when the anesthetic wears off. Report this to us, and we will monitor it. Depending on your surgical findings, there may be some expected nerve discomfort, especially if the herniated disc had to be freed from the irritated nerve, or if an inflammatory membrane was ablated. You may experience the post-op muscle spasm. This can be treated with medication or spinal blocks. Dysesthesia, if it occurs, will usually go away in one week to several months. Rarely, it may be longer. How aggressively it is treated depends on its severity. If severe, it is usually treated aggressively with foraminal epidural blocks, sympathetic blocks, and medication. It is imperative that you contact Dr. Varun Agarwal if this occurs so it can be treated and resolved optimally.
Not Needed in Majority and for 01 Day in a few, You will remain in the recovery room until you are alert enough to leave. Have someone available to drive you home. Under certain rare circumstances, you may be advised to stay overnight in the hospital. You should be able to rest comfortably at home or in your hotel. If you are from out of town, it is usually safe to travel one or two days after surgery, but an overnight stay is recommended.
- Follow your regular diet. You may eat after leaving the surgical facility.
- Avoid straining to have a bowel movement; a laxative may be used if needed, especially if you are taking opiod analgesics.
- You may shower 7 days after your surgery.
- No tub baths or hot tubs for about one week or until the wound is dry and healed.
- Activities of Daily Living
- Light activities may be resumed the evening of surgery.
- Assistance may be needed the first few days with food preparation, lifting, and cleaning.
First Postoperative Week
- Moderate activities with rest periods as needed.
- No sexual relations until you are well on your way to recovery.
- No lifting, bending, or twisting.
- No lifting of more than 5 to 15 pounds after 1 week; no lifting over 25 pounds for 6 weeks.
- You may return to work within 1 to 4 weeks after surgery or as able.
- You may resume driving 4 weeks after surgery or sooner if you are able to do so safely-remember to maintain neutral positioning- #do not slouch.
Important to maintain a neutral spine position with all postures and positions. Bend at the hips, knees, and ankles while keeping your back in neutral. Do not twist or forward bend at the waist.
- Coughing or excessive strain on your back in the first 3 months may result in recurrence of your leg pain from a recurrent herniation.
- Standing - weight evenly distributed on feet, keep knees soft, tighten buttock muscles.
- Standing to sitting - bend at hips and use a step position.
- Sitting -feet flat on the floor, weight through your sitting bones, and back straight. Avoid sitting for more than 40 minutes at a time without a break.
- Sitting to side lying - no twisting, lower to side, and brace with abdominals.
- Side lying to back lying - brace with abdominals and log roll.
Strenuous exercise, such as tennis or skiing, may be resumed when indicated by your treating Doctor.
Walking - Week 1: 10 minutes - 3 times/day Week 2: 15 minutes - 3 times/day Week 3: 20 minutes - 3 times/day
These are walking guidelines only - you may walk as much as tolerated as long as your pain is not increased by walking. #Abdominal Bracing Gluteal Sets
- Partial Sit-Ups Hamstring Stretch Quadriceps Sets
- Side lying Quad Stretch Sit to Stand Transfers Calf Stretch
- Swimming may be resumed 7 to 10 days after your procedure.
4-6 weeks after surgery, a formal program emphasising lumbar stabilisation followed by Mckenzie type extension exercises is recommended for maximum benefit. If your surgery involves multiple levels or if it is primarily for discogenic pain, it is recommended that physical activity be restricted for 4-6 weeks to allow the annulus to heal and strengthen.
There will be tape strips across the incision which will fall off after several days. There will be a small dressing that may be removed the 7 days after your procedure. Sutures are not necessary. Have someone check your wound site for increase in redness, drainage or swelling. Monitor your temperature -if your temperature rises above 100 degrees or any of the above wound changes occur, contact Dr. Varun Agarwal. A follow-up appointment will be scheduled for you at one or two weeks postoperative with your surgeon.
In general, your choice of an endoscopic approach to your back problem is similar to choosing an arthroscopic approach to the knee or shoulder compared to the open approach. The results are similar, but the surgical morbidity is much less. You are encouraged to discuss all alternative approaches for your condition with your physician. It is hoped that this information will allow you and your physician to make the choice that is best for you.
Recent advances in endoscopic surgical technique has allowed for successful endoscopic treatment of conditions such as Failed Back Surgery Syndrome caused by recurrent disc herniation, lateral recess stenosis, foraminal osteophytes, facet cysts, and many degenerative conditions of the lumbar spine such as degenerative and isthmic spondylolisthesis. Where the patho-anatomy can be accessed through the foraminal approach, treatment options may be possible. Biologics are also being considered for tissue healing and regeneration.
This approach is also possible for nucleus replacement or fusion. Advancements are being made yearly, and more alternatives to fusion will be available for painful degenerative conditions of the lumbar spine each year.
The ability to treat painful degenerative conditions of the lumbar spine continues to improve and evolve as the patho-anatomy and patho-physiology of back and leg pain are further elucidated with continued experience with the technique for selective endoscopic discectomyTM. In highly selected patients, we have successfully treated many patients with degenerative conditions such as central and lateral spinal stenosis, degenerative spondylolisthesis, and failed back surgery syndrome from recurrent disc herniations or lateral recess stenosis.
Evolving Foraminal Endoscopic Surgical Techniques and New Instrumentation
The original technique has been modified to approach the foramen using a more lateral approach to allow greater access to the epidural space and to enter a plane between the longissimus muscle and the psoas muscle. The advantage is that this plane avoids dilation of muscle and makes the procedure even less invasive. Approaching the foramen far laterally is also the same approach used for diagnostic and therapeutic injections that can be performed prior to the actual surgery to provide additional information and to give a more accurate prognosis for treatment of a wider spectrum of painful degenerative conditions of the lumbar spine.
Incorporating Diagnostic and Therapeutic Injection Techniques: YESS Approach
These degenerative spinal conditions are first evaluated by transforaminal epidural injections using a non-ionic contrast agent such as Iohexol to outline the foraminal anatomy, then therapeutically injecting a steroid mixed with local anaesthetic. If the surgeon can determine the probable cause of your pain and also determine that it is feasible to safely enter the foramen with the Endoscopic surgical system to surgically address the condition, he may then be able to offer alternatives to more invasive surgical treatment, non surgical treatment, pain management treatment, traditional decompression and fusion, or dynamic stabilisation that is available through most pain management and traditionally trained spine surgeons. As an alternative to decompression and fusion, we perform a minimally invasive endoscopic foraminal decompression of the lateral facet, the foraminal osteophytes or the soft tissue like the ligamentum flavum contributing to the impingement on your traversing and exiting nerve. In chronic back pain, some of the nerves to the facet and disc annulus are also ablated, thus giving relief for back pain. This procedure can be compared to an arthroscopic debridement of a degenerative knee joint for pain relief before the joint wears out to the point of a knee replacement. Ultimately, as we age, a nucleus, facet, disc replacement, or even fusion may still be needed.
Possible Adverse Events and Complications
In the process of performing the foraminal decompression, we have also found anomalous nerve branches in the foramen called furcal nerves. We have even found sympathetic nerve trunks in the foramen. If this is contributing to your pain syndrome, the surgical result is less predictable, and it is possible that these nerves will continue to give you the same, worse, or may create a different pain that is described as a dysesthetic pain. Most dysesthetic pain is relieved with time, and lessened if treated with transforaminal epidural steroid injections and sympathetic lumbar injections.
It is not possible to avoid these nerves completely in foraminal decompression. If ablated, it can provide pain relief, dysesthesia, delayed dysesthesia, weakness, or numbness. Most of these symptoms resolve, but permanent persistence is also a risk of surgery.
This technique of Transforaminal Endoscopic Spine Surgery or Selective Endoscopic Discectomy™ is also not the same as the other endoscopic techniques described by others on the internet unless the surgeon is Specifically trained in this technique and the surgeon uses all the equipments described above.