Vertebral Column Resection (VCR) in Pediatric Spinal Deformity

4-18-2021

 

What is a Vertebral Column Resection (VCR)?

A VCR is complete surgical removal of one, or more, vertebra.  It is always combined with posterior spinal fusion and instrumentation.  This means screws, rods, and possibly cages are used to hold the spine in the new alignment while the spine undergoes bony fusion. Example C below.

A VCR is also called a Three-Column Osteotomy or a Corpectomy.

 

When is a VCR needed?

A VCR may be needed when a severe, rigid spinal deformity is to be corrected. It can be used to treat hyperkyphosis (abnormal forward curvature of the spine) or scoliosis (abnormal side curvature of the spine).

 

Why would more than 1 vertebra be removed?

Removal of a single vertebra can permit 80+ degrees of correction.  Despite this fact a 2^nd vertebra may also need to be removed to achieve the desired correction safely.

 

What happens to the gap between the vertebra after a VCR?

After a VCR the two ends of the spine can be moved in space to correct the spine deformity.  Ideally there is no gap, and the vertebra can be moved so that there is bone-on-bone contact.  However, at times there is a gap after the spine deformity is corrected.  The presence of a gap or hole is dependent upon the type and severity of the spinal deformity. If there is a gap a “cage” is placed which struts from the upper vertebra to the lower vertebra. 

 

Why is a “cage” sometimes placed?

A “cage” strengthens the surgery, by providing a strut from vertebra to vertebra on the front side of the spinal cord.  The usual spinal instrumentation is placed in the back of the spinal cord.  So a “cage” gives 2 areas of stabilization for the spine.  This can increase the likelihood the instrumentation holding the spine and a successful fusion of the surgery.

 

Below is a 10 year old female with Neurofibromatosis Type 1 and a progressive kyphosis.  On the left x-ray the vertebra with the red arrow pointing to it was removed.  On the right, the blue arrow points to the “cage” which was placed at the defect site, to support the spinal column in front of the spinal cord.

Next week we will go over how we do this surgery.

 

https://rdcu.be/cizNe

 

Blog Topic:  “How much correction of the scoliosis did you get during surgery?”

 

This is a common question asked after spinal deformity surgery.

Parents and caregivers are interested in how close their child’s spine was able to be returned to a “normal” alignment on x-ray.  It is a very reasonable question.  I would probably ask a similar question if my child was having scoliosis surgery.  As a parent, I would want my child’s spine to be as close to “normal” as possible.  At first glance it would appear to make sense that the closer the spine correction was to 100%, the better the person will look, the less pain they will have in their back and the better they will function now, and for the long-term.  This however is not often true.  To explain why this is the case, a few important facts/points must be first presented:

 

#1           Scoliosis is a 3-dimensional spine deformity.  The spine twists as it turns, much like a water slide that banks when the slide turns side-to-side.  For a more detailed explanation of this please go to the blog post on 6-6-2020.

 

#2           The x-rays we take of the spine can only easily document 2 of the 3 planes of the scoliosis (coronal and sagittal plane, see below).  The third plane is the axial or transverse plan, which is the “twisting” of the spine.  Sometimes there is a lot of twist in a scoliosis, and sometimes there is not much twist.  Each child and scoliosis is different.  It is hard to measure the twisting of the plane on the x-rays.

              

We can more easily measure the amount of twist or rotation of the spine in the office using the scoliometer (see below).

 

#3           When we talk about how much the scoliosis changes the body, from the patient’s perspective, we really are trying to assess how much different the right side is from the left side of the body.  How asymmetric is the body side-to-side.

#4           The outward changes to each person’s body, by the scoliosis, is unique.  For example, two people could have a 60-degree scoliosis, with one person having a lot of changes to their body, while other person has very little obvious asymmetry.

As a surgeon, we often try to achieve maximal 3-dimensional correction (see the below radiographs).  It is important to note the x-ray which shows the scoliosis is the view from the front/back of the patient, and is only in a single plane (coronal plane).  However, scoliosis is a 3-dimensional problem, as I explained in a previous blog post when I talked about the abnormal rotation of the spine and how we can correct this in surgery.  Sometimes the transverse plane or axial plane, which is what cause the rib prominence and asymmetry, may be the most aesthetically important part of the deformity.

So when the surgeon answers the parent/caregiver’s question and says “80%” they are only referring to correction in only one plane of a 3 plane problem (coronal plane).  However, as a surgeon I know that maximally correcting a scoliosis is not always desirable, or safe. If you make the spine completely straight over the areas you operate, the spine above and below the surgical area may suffer secondarily and then cause pain, spinal instability and need further surgery.

 

The next blog post the reason why we don’t always want 100%, or even 90% of the spine deformity, will be presented.

 

Blog Topic:  Surgeon Recommendations after surgery

Sometimes our precious patients listen to us and other times…………………………………………not so much.

 

Blog Topic: Severe, complex congenital scoliosis cases using Shilla procedures

Over the last 6 Blog posts congenital scoliosis has been exhaustively presented and explained.  Most cases of congenital scoliosis are mild and do not require surgery.  Of those that do need surgery there are several well-accepted techniques for improvement and control of the scoliosis: distraction constructs (traditional growing rods, magnetically-controlled growing rods, VEPTR), resection with short/long fusion, fusion without resection, and resection with Shilla procedure.

This post will finish the postings on congenital scoliosis.

The last case which will be posted is a severe, complex type congenital scoliosis.  The major problem for this young patient (4 years old) who has two adjacent hemivertebra which is at the junction of the thoracic spine (chest) and the lumbar spine. These two hemivertebra cause an acute, severe deformity.

 

The management of this problem involved resection of both of the hemivertebra and fusion over the severely involved section of the spine.  Though there is instrumentation which goes high and low in the spine, these screws are Shilla screws, so they are not fused and will slide up and down the spine as the patient grows.

If there are questions about congenital scoliosis or any other post, please let me know…I am happy to answer all inquiries.

 

Blog Topic: Surgical Treatment of Congenital Scoliosis

 

As previously mentioned congenital scoliosis comes in a wide range of types, locations, and complexity. 

This means surgeons caring for this group of patients needs to have multiple surgical treatment options to optimally care for this potentially challenging deformities, from simple hemivertebra resections to complex vertebral column resections and Shilla constructs. The below three cases demonstrate the progression from simple to complex, both in terms of the deformity and the required surgery.

 

Simple: 7 year old male with a single hemivertebra treated with resection and short fusion

Moderate: 13 year old female with previously operated (outside hospital) on lumbosacral hemivertebra with continued worsening of deformity.  Underwent hemivertebra resection and longer fusion.

 

 

Complex: 8 year old male with Prune Belly syndrome.  Treated with vertebral column resection (VCR) at T10, and Shilla construct T4-L4.

 

On the more complicated end of the congenital scoliosis spectrum (i.e. mixed-type), the simple resection and short fusion may not be the best option.  This is due to the possible presence of adjacent areas of involvement which may induce increasing curves above or below the surgical site.  In the past if this was a concern after surgery, the patient may be placed into a brace, which often is less than ideal as these patients may need to wear a brace for many, many years. 

 

Shilla treatment of congenital scoliosis

The “complex” case above was treated with a VCR and a Shilla procedure.  However performing a Shilla procedure in less severe cases can be optimal.  The below case is a 4 year old male with two areas of congenital deformity (one higher and 31.5 degrees, and one lower and 46.8 degrees). 

CASE 1

 

Because of the upper deformity was congenital and more stiff (see below slide), a simple hemivertebra resection will not be able to control the upper curve.

So, at the time of surgery the left T10 hemivertebra (the lower curve) underwent a VCR (complete removal of the vertebra), and then Shilla T4-L4

The arrow on the below slide shows the closure of the gap when the T10 hemivertebra was resected.

Here is the 6 months after surgery follow-up.  His body shift to the left is significantly improved.  The only levels of fusion are within the white box (below).  The remaining vertebra above and below this white boxed area will be able to grow vertically along the Shilla rods.

The next Blog post will demonstrate complex congenital scoliosis cases using Shilla procedures

 

Blog Topic: Surgical Treatment of Congenital Scoliosis

 

When is surgery necessary?

               This is not a simple answer, mainly because there is a wide spectrum of deformities, from number of areas involved, type of problems, location, magnitude, progression, and age of patient, to name a few of the considerations.  Each patient is unique, so the decision of when surgery is a reasonable option is also unique.  Small magnitude, non-progressive deformities usually don’t require surgery, whereas large magnitude, progressive deformities more typically require surgery.

Small deformity                    Large deformity

No surgery needed                 Surgery needed

 

 

The basic concepts of surgical treatment of congenital scoliosis:

1.      Delay surgery as long as possible to permit vertical growth of the spine.  This can minimize the number of surgeries needed by the end of growth.  In addition, we like to avoid surgery, if possible, until after 4-5 years of age, at a minimum.

2.      Identify the areas of concerns and quantify the problem

3.      Only address the problem area(s).  This means to resect, fuse, and control the problem area(s) only.

4.      Fuse as few vertebra as necessary: this again permits more vertical growth

What are accepted treatments for congenital scoliosis?

1.      Distraction constructs or Growing Rods, both traditional and magnetically-controlled

               Distraction constructs are used occasionally in congenital scoliosis.  Very young patients, multiple problem areas, unknown progression can be factors in which a distraction construct may be used as a temporary method of treatment.

 

2.      Short fusion

12 year old male                      5 years after hemivertebra resection and fusion

1 hemivertebra

 

               A short fusion can work very well when there is a single area of problem.  In the above case the hemivertebra was resected, the defect was closed down…..and fused, which prevents this area from growing crooked.

 

 

Diagram 1                                Diagram 2

Diagram 3

Diagram 1 demonstrates an isolated, single hemivertebra (triangle).  Resection (diagram 2) creates a triangular defect which is then closed down, straightening the deformity (diagram 3).  For this to be successful treatment the spine above and below has to be fairly straight.

 

3.      Short fusion and growth guidance (Shilla)

We will present this surgical treatment next week……..