Minimally Invasive Spine Surgery

Spine surgery is traditionally done as "open surgery," meaning the area being operated on is opened with a long incision to allow the surgeon to view and access the anatomy. In recent years, however, technological advances have allowed more back and neck conditions to be treated with a minimally invasive surgical technique.

Becauseminimally invasive spine surgery (MISS), does not involve a long incision, itavoids significant damage to the muscles surrounding the spine. In most cases,this results in less pain after surgery and a faster recovery.

Spinesurgery is typically recommended only when a period of nonsurgical treatment —such as medications and physical therapy — has not relieved the painfulsymptoms caused by your back problem. In addition, surgery is only consideredif your doctor can pinpoint the exact source of your pain, such as a herniateddisk or spinal stenosis.

Minimallyinvasive techniques are beginning to be used for a wider range of spineprocedures, and have been used for common procedures like decompression andspinal fusion since the 1990s. Decompression relieves pressure put on spinalnerves by removing portions of bone or a herniated disk. Spinal fusion correctsproblems with the small bones of the spine (vertebrae). The basic idea is tofuse together the painful vertebrae so that they heal into a single, solidbone.

Description

Thisillustration shows the incision site in the lower back that is used for sometraditional spine surgeries.

Minimallyinvasive spine surgery (MISS) is sometimes called less invasive spine surgery.In these procedures, doctors use specialized instruments to access the spinethrough small incisions.

In atraditional, open surgery, the doctor makes an incision that is 5 to 6 in. longand moves the muscles to the side in order to see the spine. With the musclespulled to the side, the surgeon can access the spine to remove diseased anddamaged bone or intevertebral disks. The surgeon can also easily see to placescrews, cages, and any bone graft materials necessary to stabilize the spinalbones and promote healing.

One of themajor drawbacks of open surgery is that the pulling or "retraction"of the muscle can damage the soft tissue. Although the goal of muscleretraction is to help the surgeon see the problem area, it typically affectsmore anatomy than the surgeon requires. As a result, there is greater potentialfor muscle injury, and patients may have pain after surgery that is differentfrom the back pain felt before surgery. This can lead to a lengthier recoveryperiod.

Minimallyinvasive spine surgery was developed to treat spine problems with less injuryto the muscles and other normal structures in the spine. It also helps thesurgeon to see only where the problem exists in the spine. Other advantages toMISS include smaller incisions, less bleeding, and shorter stays in thehospital. 

(Left) Inopen surgery, muscles surrounding the spine are pulled back to reveal thebones. (Right) After removing portions of the bone (a decompression procedurecalled laminectomy), bone graft material and screws are placed along the sidesof the vertebrae. 

AlthoughMISS holds advantages for many patients, it is important to note that some backand neck problems cannot yet be treated effectively with minimally invasivemethods. In general, MISS procedures take less time than open procedures,however, depending upon patient needs, MISS may take longer to perform andrequire several incisions.

Procedure 

A tubularretractor is used to create a passageway for the surgeon to reach the problemarea of the lower back.

MISS fusionsand decompression procedures (such as diskectomy and laminectomy) are performedwith special tools called tubular retractors. During the procedure, a smallincision is made and the tubular retractor is inserted through the skin andsoft tissues down to the spinal column. This creates a tunnel to the small areawhere the problem exists in the spine. The tubular retractor holds the musclesopen and is kept in place throughout the procedure. 

The surgeonaccesses the spine using small instruments that fit through the center of thetubular retractor. Any bone or disk material that is removed exits through theretractor, and any devices necessary for fusion — such as screws or rods — areinserted through the retractor. Some surgeries require more than one retractor. 

In order tosee where to place the incision and insert the retractor, the surgeon is guidedby fluoroscopy. This method displays real-time x-ray images of the patient'sspine on a screen throughout the surgery. The surgeon also uses an operatingmicroscope to magnify the view through the retractor. 

An operatingmicroscope provides excellent illumination and magnification during minimallyinvasive spine procedures.

At the endof the procedure, the tubular retractor is removed and the muscles return tooriginal position. This limits the muscle damage that is more commonly seen inopen surgeries. 

(Left) Anillustration showing a cross-section view of a healthy intevertebral disk.(Right) A cross-section magnetic resonance imaging (MRI) scan of the anatomysurrounding an intevertebral disk. The solid red rectangle shows the placementof the tubular retractor through the muscle and the dotted lines indicate thepositioning of small surgical

The mostcommon types of anesthesia used for MISS are general (you are asleep for theentire operation) and regional (you may be awake but have no feeling from yourwaist down). 

CommonMinimally Invasive Spine Surgeries

MIS LumbarDiscectomy

A herniateddisk in the lower back that pinches a nerve may cause severe leg pain,numbness, or weakness. To surgically relieve these symptoms, the disk isremoved. This procedure is called a diskectomy. 

For thesurgery, the patient is positioned face-down and a small incision (sometimesless than 1 in.) is made over the location of the herniated disk. The surgeoninserts the retractor and removes a small amount of the lamina bone. Thisprovides the surgeon with a view of the spinal nerve and the disk. The surgeoncarefully retracts the nerve, removes the damaged disk, and replaces it withbone graft material.

 

Thisminimally invasive technique can also be used for herniated disks in the neck.The procedure is done through the back of the neck and called an MIS posteriorcervical diskectomy. 

MIS LumbarFusion

A standard,open lumbar fusion may be performed from the back, through the abdomen, or fromthe side. Minimally invasive lumbar fusions can be done the same way. 

A commonMISS fusion is the transforaminal lumbar interbody fusion (TLIF) Using thistechnique, the surgeon approaches the spine a little bit from the side, whichreduces how much the spinal nerve must be moved. 

In an MISTLIF, the patient is positioned face-down and the surgeon places one retractoron either side of the spine. This approach prevents disruption of the midlineligaments and bone. Using the two retractors, the surgeon can remove the laminaand the disk, place the bone graft into the disk space, and place screws orrods to provide additional support. 

Approachingthe spine slightly from the side does not provide the surgeon with a full viewand it is often a challenge to remove the disk completely. This may make fusionhealing more difficult. Sometimes the surgeon will use additional bone graftbesides the patient's own bone to improve the likelihood of healing. 

In the MISTLIF procedure, a retractor is placed on either side of the spine.

A smallinstrument is inserted through the tubular retractor to remove a herniateddisk. Screws to support the fusion are placed in the bone through bothretractors. 

Minimallyinvasive spinal fusion is also commonly performed from the side. There are twoprocedures that use a side approach: extreme lateral interbody fusion (XLIF)and direct lateral interbody fusion (DLIF). The benefits of these lateralfusion surgeries are that they do not injure the muscles in the back and theydo not tug or pull on the nerves in the spinal canal.

Recovery

Minimallyinvasive procedures canshorten hospital stays. The exact length of time neededin the hospital willvary with each patient and individual procedure, butgenerally, MISS patientsgo home in 2 to 3 days. 

Becauseminimally invasive techniquesdo not disrupt muscles and soft tissues, it isbelieved that post-operativepain is less than pain after traditional, openprocedures. You should stillexpect to feel some discomfort, however,advancements in pain control now makeit easier for your doctor to manage andrelieve pain. 

To help youregain strength and speedyour recovery, your doctor may recommend physicaltherapy. This will depend onthe procedure you have had and your generalphysical condition. Specificexercises will help you become strong enough to returnto work and dailyactivities.

If you havehad a fusion procedure, itmay be several months before the bone is solid,although your comfort levelwill often improve much faster. During this healingtime, the fused spine mustbe kept in proper alignment. You will be taught howto move properly,reposition, sit, stand, and walk. 

How long itwill take to return to yourdaily activities after MISS depends upon yourindividual procedure andcondition. Your doctor will evaluate you after yoursurgery to make sure thatyour recovery is progressing as expected.


  (0)   Comment