To decompress the L4-L5 level in an open procedure, the incision inevitably extends across spinal levels above and below the level needing the surgery.

Traditionally lumbar (low back) spine surgery has been performed “open”. This means that a fairly long incision (multiple inches) is made along the middle of the spine. This inevitably extends above and below the intended level(s) to be operated.

  • The muscles of the spine are elevated off the spinal bones, injuring the blood supply to the muscles, which can lead to permanent damage to the muscle and pain. The surgeon needs to do this to see the spine and perform the procedure. Unfortunately this muscle injury and soft tissue injury can also increase blood loss and risk of infection.
  • Additionally, as the muscles are elevated off and detached from the bone, the joints of the spine (facets) can be damaged, potentially leading to more spine pain or lead for additional surgery later.

Click images to enlarge. Images taken and modified from Medtronic.

Minimally invasive surgery (MIS) for the lumbar spine has been developed to avoid much of the complications of low back surgery.  Everyone knows someone who has undergone an unsuccessful spine surgery and either has continued pain and problems or required more surgery.  This is what has given spine surgery a poor reputation.

  • Specifically, the tubular MIS procedure involves making a significantly smaller incision(s) only over the intended operative level(s). Using a series of tubular dilators to spread the muscle with minimal irritation MIS also preserves the adjacent spine levels and joints.
  • Through a small tube, the same decompression procedure can be performed as with the traditional “open” approach. After the procedure, the tubular retractor is removed and the muscles return to normal.

Usage/insertion of the tubular retractor.

Muscles returning to normal position as the tubular retractor is removed.

Open VS Tubular Minimally Invasive Surgery (MIS)
  • Typically, tubular MIS procedures result in less pain, lower complications, smaller scar, and faster recovery from surgery.
What type of procedure can be performed MIS?

Decompression procedures (laminectomy or discectomy) involve drilling off bone and other tissue, which may be pressing on the nerves. It may or may not involve removing a bone spur (osteophyte), a disc herniation or a cyst.

MIS procedures are most commonly used for decompressions. A series of dilator tubes spread the muscles off the bone and a tubular retractor is placed. The bone (lamina) is drilled and the nerves are decompressed.

Advantages to a MIS decompression:

  • Smaller surgical scar
  • Less disruption of tissues
  • Potentially less pain
  • Outpatient surgery
  • Lower infection rate
  • Less postoperative instability
  • Lower risk of future fusion

Fusion procedures (transforaminal lumbar interbody fusion- TLIF) involves drilling off more bone than in just a decompression, removing the spine joints (facet joints), placing a cage device in the disc space, and securing with screws and rods. This also removes bone spurs (osteophytes), a disc herniation or a cyst. This is usually used to treat a spondylolisthesis, or slippage of one vertebra over another.

Tubular MIS fusion potentially has the most advantages of the tubular MIS techniques.

A series of dilator tubes spread the muscles off the bone and a tubular retractor is placed.

Through the tubular retractor, the nerves are decompressed, the facet joints are removed, a cage is placed in the disc space and screws/rods are placed.

The above and below joints are not damaged, leading a lower adjacent level disease.

Advantages to a MIS TLIF:

  • Smaller surgical scar
  • Less disruption of tissues
  • Less blood loss
  • Shorter hospital stay
  • Lower complications
  • More pain improvement
  • Muscle preservation
  • Lower adjacent level disease
  • All risks even lower in the obese

Tumor Resection
At Rocky Mountain Brain & Spine Institute, we have performed the first two spine tumor resections in Colorado. The first resection was a lumbar ependymoma tumor and the second was a high thoracic schwannoma.

By using a 22 millimeter tubular retractor, a tumor can be removed from the spine and avoid fusion. In both of our surgeries, patients were discharged from the hospital less than 24 hours after surgery with minimal pain. In standard spine tumor resections, patients are admitted to the hospital for multiple days.

Scoliosis correction
Using tubular minimally invasive surgery techniques, certain scoliosis conditions can be corrected.

What is and what is not MIS surgery?

In our opinion, minimally invasive surgery on the spine involves tubular retractors. This provides a smaller incision, less damage to muscle and soft tissues, lower complications and better results in our hands.

A “smaller incision” does not necessarily mean a procedure is minimally invasive. Some surgeons can make a slightly smaller scar, but do not use a tubular retractor to spread the muscle. These surgeons still detach the muscle from the bone causing muscle damage and potentially facet joint injury.

Stem cell therapy image and Information from

Anterior and lateral surgical approaches can be used in spine fusions and artificial discs, but this also does not necessarily mean a procedure is minimally invasive. Anterior and lateral approaches may avoid damaging the back muscles, however they still risk damage to abdominal organs, large blood vessels and possibly anterior spine muscles. In comparing anterior fusion to tubular minimally invasive fusion:

  1. Infection and blood clots may be increased in anterior approach patients
  2. There tends to be a longer hospital stay in anterior approach patients
  3. There tends to be increased blood loss from major blood vessel injury in anterior approach patients
  4. Readmission (admitted back to the hospital) odds may be increased in anterior approach patients
  5. Cost may be higher in anterior approach patients

Mid and low back fusion procedures can be performed now using a robot such as the Mazor. This type of robot may be used along with tubular minimally invasive procedures, but using the robot by itself does not necessarily mean the procedure is minimally invasive. Additionally, major nerve and spine injuries have been reported in using the robot due to errors in technology.

Stem cells treatment is not necessarily a minimally invasive technique. Stem cell procedures are not thought to be effective currently. They are not FDA approved and commonly require cash payment.

Laser spine procedures can be performed using minimally invasive techniques, but minimally invasive spine surgery may be more effectively performed without a laser.

  • Lasers are straight beams which do not work well around corners
  • Lasers emit heat
  • Lasers cannot easily control depth
  • The reoperation rate with lasers is reported to be higher than with traditional minimally invasive surgery
  • Laser treatment tends to require cash payment.

Our surgeons at Rocky Mountain Brain & Spine institute are BOARD CERTIFIED and perform tubular minimally invasive spine procedures.