My Spine World

What is an intervertebral disc?

Let’s find out what is an intervertebral disc and what is discectomy.Your spine is made up of 33 bones, called vertebrae, that are stacked on top of one another. These bones connect to create a canal that protects the spinal cord.

Five vertebrae

make up the lower back. This area is called your lumbar spine

 In between your vertebrae are flexible intervertebral disks. These disks are flat and round, and about a half inch thick.

Spinal discs separate each individual vertebra and soak up shock. Without them, the bones in your spine would grind against each another, and you’d be unable to absorb the impact of trauma and body weight.

 More than just protective, these cushions also give the spine flexibility, making movements such as twisting and bending possible.

Like  a coin has 2 sides, discs  have a both soft and hard component at once. There’s a tough outer layer, called annulus fibrosus, and a soft, gel-like center, called nucleus pulposus. Fibres on the outside of each disc helps them attach to vertebrae and stay in place. Similar it to a hot lava cake!

If the strong outer layer of the disc ruptures, the gel-like center can “leak” into the spinal canal: the passage that contains the spinal cord and spinal fluid. This is called a disc prolapse or disc herniation. Other term sometimes used to describe this condition is ‘slipped disc’.

The result can be intense pain in your back, along with weakness in an arm or leg. Numbness can also occur, since the nerve signals are being blocked. Making it all more troublesome is the fact that the gel can release a chemical irritant that may contribute to nerve inflammation and pain.

How big a problem is it?

The incidence of a herniated disc is about 5 to 20 cases per 1000 adults annually and is most common in people in their third to the fifth decade of life, with a male to female ratio of 2:1. The estimated prevalence of symptomatic herniated disc of the lumbar spine is about 1-3 percent of patients.  The prevalence is most significant among 30-50-year-olds. The patient’s between 25-55 years old have an approximately 95 percent chance of herniated discs occurring either at L4-L5 or L5-S1.

Does it require surgery?

 There are enough studies out there  to suggest that  pain and discomfort from disc  herniation  resolves in 90 %of individuals within 2 – months and the  prolapsed disc can regress.

The rate of spontaneous regression was found to be 96% for disc sequestration, 70% for disc extrusion, 41% for disc protrusion, and 13% for disc bulging. The rate of complete resolution of disc herniation was 43% for sequestrated discs and 15% for extruded discs.

Most people who have herniated discs respond well to conservative treatment or non-operative and do not require surgery.

If you’ve tried non-surgical strategies and you still have symptoms after 8 weeks , surgery may be a good option. 

Here we are going to understand lumbar disc prolapse and lumbar discectomy surgery

WHAT IS DISCECTOMY ?

 It is a surgery  performed to remove the herniated portion of the lumbar disc. It has a high success rate, especially in relieving leg pain (or sciatica), caused by the herniated portion of the disc pressing against the lumbar nerve/nerves.

Here I will be discussing about different methods of doing a lumbar discectomy.

1. Open laminectomy and discectomy

This was the traditional method of doing a discectomy by removing the lamina from the back and accessing the disc and then performing discectomy. Open classical laminectomy and discectomy used to be widely accepted surgical procedure for lumbar disc prolapse.

Now with advances in surgical techniques and use of microscopes and endoscopes, surgeons have moved away from the classical laminectomy and discectomy approach.

 While this surgery led to a significant improvement of nerve root compression signs, patient satisfaction was impaired by symptoms which were due to the collateral damage the surgeon had produced with regards to more muscle injury and removal of bone.

 Also the return to normal activities were delayed and inpatient stay after surgery was also longer. The problem of postoperative back pain and rapid progression of disc degeneration due to aggressive disc removal affected the clinical outcomes. Hence this approach has become outdated in most centres.

2. Microdiscectomy

 

The reduction of collateral damage was the driving force for the two pioneers of lumbar microsurgery. In the year 1977 Yasargil and Caspar described independently a microsurgical interlaminar approach. One year later, it was “Tex” Williams who was the first surgeon to perform this approach in the US. The pioneering work of JA McCulloch made this approach popular in the 90s of the last century and it still remains arguably  the “gold standard” in the spine surgery community worldwide.

Using modern microdiscectomy techniques, the surgeon is able to minimize the extent of the operation and potential for tissue damage by using a standard incision of 1 to 1.5 inches and focusing the tissue dissection on spreading the muscles and ligaments rather than cutting them.

Targeting techniques using fluoroscopic guidance minimize the incision necessary to gain a direct view of the surgical field. Magnification allows improved visualization of the nerve sac and the disc herniation. Bayoneted instruments allow precision manipulation of tissues without obstructing the direct view.

Due to minimal dissection of the muscles and other soft tissues, post-operative pain is tolerable. By removing the portion of the disc that is irritating the nerve, usually the pre-operative radiculopathy pain would have  diminished or resolved, and many patients would  feel immediate improvement in their leg pain when they wake up from the surgery. Patients are typically encouraged to walk within a few hours of the surgery.

Patients typically stay in the surgery centre or hospital for a few hours after surgery before being released to return home. Depending on the patient’s condition, one overnight stay in the hospital may be recommended.

Following the operation, patients may return to a relatively normal level of activities quickly.

3. Tubular Microdiscectomy

By minimizing incision size and sparing paraspinal structures using a smaller, more targeted surgical exposure than traditional open discectomy, microdiscectomy served the rationale of lowering surgical approach–related morbidity, thus attempting to improve patient outcomes while retaining surgical efficacy. These principles remain the goals of all minimally invasive spine surgery. In an attempt to further these principles, tubular microdiscectomy was developed.

How is it performed?

 This technique made use of a small-diameter tubular retractor (14 mm) that was placed over sequential dilators that created a surgical pathway to the lumbar spine in between fascicles of the lumbar paraspinous muscles, avoiding the traditional detachment of the multifidus muscles from the spine that is common to open discectomy and microdiscectomy.

To maintain the position of the tubular retractor and free the surgeon’s hands, the tube was supported by an articulated, repositionable arm that was secured to the operating table.

The tube diameter was also large enough to allow 2 or 3 microsurgical instruments to be used in the surgical field simultaneously (e.g., a high-speed drill, a suction device, and a nerve root retractor).

Originally, the tubular retractor was coupled with an endoscope to provide visualization. Subsequently, the operating microscope was used with the tubular retractor. Whether one uses an endoscope or a microscope for visualization, tubular microdiscectomy involves similar retractors and similar principles.

Benefits include:

• Even Smaller incision(s) than microdiscectomy  (1 inch)
• Less blood loss
• Lower risk of muscle and soft tissue damage
• Lower risk of infection
• Reduced postoperative pain
• Reduced pain medication use
• Faster recovery

Patients who undergo this surgery in an outpatient setting report a more comfortable experience that allows them to go home the same day or the next day of surgery and begin recovery sooner at home.

4. Endoscopic Discectomy

The aim of minimally invasive surgery is to achieve the objective of surgery (discectomy) and leave minimum foot print at the surgical field as possible.

Endoscopic discectomy is  as minimalistic as it gets and the most advanced minimally invasive surgery in spine available today.

Endoscopic Spine Surgery is a surgical procedure using micro-sized incisions (less than 1-inch) and small tubular systems in combination with an endoscope to visualize the surgical field.

While endoscopic surgical approaches are commonly used to treat other areas of the body (e.g., gastrointestinal), advances in optics, visualization of tissues, and spinal imaging make Endoscopic Spine Surgery (endoscopic discectomy ) a surgical treatment choice for many patients.

It is an advanced, state-of-the-art form of minimally invasive spine surgery designed to provide the patient a quicker recovery time and less recurring pain than traditional spine surgery methods.

It can also can help preserve normal range of spine mobility post-operatively. In some cases, the procedure can be performed using regional anesthesia instead of general anesthesia, decreasing overall medical risks in patients who are older and/or have co-existing medical disorders that may increase surgical risk.

How is Endoscopic Spine Surgery Performed?

A 1-inch or smaller skin incision is made and a tubular trocar (about the width of a pencil) is inserted. Depending on the patient’s specific diagnosis, the endoscopic technique may access the spine using one of two approaches: either an intralaminar (from the back of the spine between two laminae) or transforaminal (from the back/side of the spine into the neuroforamen )approach.

Next, a tiny camera is inserted through the trocar to the targeted area of the spine. Throughout ESS, the camera captures and projects real-time images of the operative site onto a monitor in the surgeon’s direct view. The endoscopic camera assists and guides the surgeon during the surgical procedure.

When the operation has concluded (discectomy), the endoscopic camera and trocar are gently removed and the small incision is closed with a suture and small dressing.

Advantages

Endoscopic discectomy require less use of anesthesia, less risk of infection and bleeding, least muscle injury  and less recovery time,. This means that you can get results quicker than almost any other herniated disc pain relief treatment. Furthermore, because the incision is so small and precise, the scar, if any, will be ¼ of an inch or less, practically unheard of in the industry.

You can get back to your normal activities quicker than was ever possible before.

These  “keyhole techniques” in effect provide a larger body of “tools” in the armamentarium that is available to the spinal surgeon these days to address the patients’ pathology.

 The utility of the “tool” is highly dependent on the skills and preferences of the artisan with respect to the use of the tool and his or her ability to deliver the intended results based on their mastery of the tools.

As always, surgery will remain an art as well as a science with its greatest accomplishment, perhaps being able to know when not to operate apart from knowing how to operate and who to operate upon.

Take guidance from your doctor/ surgeon and see you soon with some more spine tips in My Spine World. Remember, we got your back!