Performing Minimally Invasive Surgery for Adult Scoliosis: Q&A With Dr. Neel Anand of Cedars-Sinai Medical Center in Los AngelesWritten by Laura Miller | January 04, 2011
Neel Anand, MD, is the director of orthopedic spine surgery at The Spine center at Cedars-Sinai Medical Center in Los Angeles and has pioneered a combination of procedures to correct adult lumbar degenerative scoliosis using minimally invasive techniques. The correction involves using three-minimally invasive procedures using technology that helps him perform the procedures less invasively than open corrections.
Dr. Anand takes these steps to perform the correction:
1. Extreme lateral interbody fusion or direct lateral interbody fusion (XLIF/DLIF). During this step of the process, the surgeon makes a small incision in the patient's side and works through a tube to access the discs in front of the patient's spine. The damaged disc material is cleared out and replaced with bone and protein filled spacers to promote the fusion.
2. AxiaLIF procedure. The AxiaLIF procedure is performed in patients whose scoliosis affects the area between the lower end of the lumbar spine and the top of the sacral spine because that area cannot be accessed from the lateral entry. The AxiaLIF procedure secures the L5-S1 disc with a solid screw.
3. Rod placement on either side of the spine. For the last step of the procedure, surgeons use the CD Horizon Longitude system and percutaneous screws to place rods on the back of the spine. The surgeon uses fluoroscopic guidance and stereotactic navigation to place the screws into the vertebral body and rods are then passed through the skin into position connecting all the screws. The connection of the rods and screws further corrects the spinal curvature, derotating and realigning the spine.
Here he discusses the development of the procedure and how spine surgeons can train to perform it.
Q: What was the process that enabled the development of the procedure for correcting adult lumbar degenerative scoliosis?
Dr. Neel Anand: As the spine degenerates over time, the disc starts collapsing as a car tire would with wear and tear. This results in the spine tilting and rotating as it has lost the support of the discs. This in turn results in scoliosis. The tilt and collapse of the spine compresses the nerves producing leg pain and lack of mechanical support in the spine results in back pain. The primary reason adults seek treatment is pain.
In children, the primary reason for treatment is the progressive cosmetic deformity and rarely pain. Majority of the children can be treated with a brace but the larger curves greater than 50 degrees will need surgery. In adults there are two types of scoliosis, The first kind is the "De-Novo" scoliosis where the spine was normal during childhood and scoliosis develops after the 4th decade due to degeneration of the discs. The second kind is called "Adult Idiopathic Scoliosis" and here the patient has had long standing scoliosis from childhood and now presents with progressive pain and deformity due to increasing degeneration of the spine which presents again around 40 or 50 years of age. Most patients can be treated conservatively initially with many of the non-operative measures including physical therapy, pain medications, and epidural injections to limit the pain but it does not fix the structural problem.
Surgery is the only way to correct and realign the spine to fix the problem and the traditional surgery is an open surgery. Surgeons go into the abdomen through a 6- to 9-inch flank incision moving the abdominal contents to the side and remove the degenerated discs and place spacers followed by turn the patient over and operate on the back to place rods and screws. They have to peel back the muscles to get access to the spine and there is considerable muscle destruction and blood loss. These elderly patients often also have other medical problems, so surgery isn't always an option for them. In the past few years, there have been a lot of technologies coming through for minimally invasive spine surgery, including TLIF and XLIF.
Around 2003-2004 minimally invasive lateral approaches (XLIF/DLIF), were developed where the surgeon drops tubes down the spine through small incisions, elevate the collapsed the disc and realign the spine.
In 2004 technology also recently came through for the minimally invasive procedure for L5-S1 from TranS1 called AxiaLIF. They came out with technology for disc degeneration at the L5-S1. You can't do that procedure from the lateral incision because the pelvis is in the way, so this part of the procedure has to be done separately. With a combination of the lateral approach and the AxiaLIF procedure surgeons can now access all the discs in the spine minimally invasively, elevate them to the correct height and correct the tilt. They can do all of this through tubes and small incisions instead of a large open flank incision.
The final complement to correct scoliosis was the development of the ability to minimally invasively place multiple screws and rods. This allowed for the recreating the structural stability of the spine and obtaining maximal correction and realignment of the spine. Surgeons now could place these screws and rods through small incisions, sparing the muscles instead of stripping and destroying the muscles as is done with traditional open surgery
Hence with the combination of the above technologies, surgeons are now able to treat adult scoliosis comprehensively in a completely minimally invasive manner
Q: What are the advantages of performing this combination of three procedures to the traditional open procedure for adult lumbar degenerative scoliosis?
NA: When we published the first article on the results of this procedure, the biggest thing was the decrease in blood loss among the patients we were treating. The elderly patients were able to deal with that better. They were up and walking around faster and able to recover so much better than patients undergoing the open procedure. That was the first thing we saw. As we went along and got more comfortable with the procedure, we were able to treat 70-90 degree curves minimally invasively. We published our 1-3 year results last year with the statistically significant outcomes in every domain. Now we are looking at the 2-4 year results. We've come a long way and are very comfortable doing these types of operations.
The other big advantage is that normally with deformities we put screws in the pelvis to create the solid foundation at the base of the spine for these long constructs. We npw use the AxialLIF minimally invasive screw, to build this foundation and so we have no need to put these long screws in the pelvis. Twenty-five percent of patients with the long pelvic screws come back for revisions because it breaks down. Now we are avoiding those problems. There are a lot of advantages to performing these types of procedures and a lot of people are slowly getting into it.
Q: How can surgeons implement this procedure in their practice?
NA: There are a lot of courses around the country now being conducted to teach all these technologies. Surgeons can go to these courses and learn about it. I still feel the best way to learn, is to have a one on one visit with an experienced surgeon performing the procedure. The visiting surgeon can then view the experienced surgeon while he or she is actually performing the procedure. They see the procedure performed, understand the indications and can see the results, which gives them a level of comfort. There's a definite learning curve, and this learning curve is one of the biggest among spine surgeries because there are three different technologies the surgeons use. Performing surgery on spinal deformity is a complex procedure already and if the surgeon is not used to treating spinal deformity, the outcome won't be as good. Surgeons also need to pay attention to the indications for the appropriate candidates for surgery. The procedure can definitely be learned, but it isn't for a weekend course. You have to do small cases and learn it step by step, one or two levels at a time.
It is also something that should be done at major centers because these patients are sicker. They have a lot of medical comorbidities, such as diabetes, hypertension, heart and lung disease. The surgeon has to look at everything and see if the patient can take the surgery. It's not a walk in the park; and it's also a big shift from the traditional open surgeries.
Learn more about Dr. Neel Anand.
Read other coverage on spine surgery procedures:
- 6 Things to Know About Endoscopic Cervical Spine Surgery
- Spine Surgery Comparison: Open TLIF Versus Minimal Access TLIF
- Latest Trends in Spine Surgery Techniques: Laser Stem Cell Technology
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