Dr. Allan Dyer has a Bachelor of Science degree in Pharmacy and is a doctor of Internal Medicine. He was also awarded a Ph.D. for his graduate studies and pioneer work in Transthoracic Cardiac Defibrillation.
During his career as a senior administrator and Deputy Minister of Health, he instituted the hospital services quality assessment, generic drug substitution program, prescription drug benefit, emergency air ambulance and paramedic programs for the government of Ontario.
On retirement from government service, he pursued research leading to the development of spinal decompression technology
He coined the term Vertebral Axial Decompression and registered the first medical device to administer this procedure with the Food and Drug Administration. He has been awarded three US patents on the equipment and the procedure for non-surgical spinal decompression .
In an interview with The American Chiropractor (TAC), Dr. Dyer….
TAC: Could you tell our readers about the VAX-D table. How did the idea evolve?
Dyer: The recognition that chiropractic manipulation does help relieve low back pain coupled with the fact that research had shown discogenic lesions to be the main pain generator led to investigation to develop technology that could be programmed to modulate intervertebral discs beyond that possible with manual methods.
Many years ago, a pioneer in the back pain field named Cyriax hypothesized that, if we could find a method to distract the spine that would not elicit trunk muscles’ contraction, we should be able to produce negative intradiscal pressure, which, if strong enough, could suck a herniated disc back in.
We started the search with standard traction devices like the Tru-Trac device, but found that linear traction (whether applied statically or intermittently) did not bypass trunk muscle contraction.
We discovered that tension applied to the spinal column using a logarithmic time force curve bypassed the muscle guarding reflex, and lowered the disc pressure to negative levels.
Recently, we have made significant advances in motion control technology that incorporates physiological biofeedback to control and perfect the decompression procedure.
TAC: There are a certain amount of doctors out there that would say there is no difference between decompression and traction. How would you respond to this assertion?
Dyer: Because there are commonalities with traction superficially, some people equate the procedures. The same superficial attitude would state that a CT scan is nothing more than an X-ray. The difference in both cases is the inclusion of computer technology that significantly impacts the outcome of the procedure.
Traction has been in use for many years as an unsupervised physical therapy modality. Traction has not been shown to lower intradiscal pressures, and has had a dismal track record with chronic low back pain. Anderson and Nachemson placed pressure transducers in four subjects in the lumbar spine during traction procedures. They found that the intradiscal pressures went up dramatically in both cases. They concluded that at no time was negative intradiscal pressure observed and, therefore, the disc could not be sucked back in as proposed by Cyriax. They suggested that, in order to produce a relative reduction in disc pressure, traction must be administered in such a way as to allow trunk muscle relaxation. Traction can be expected to increase intradiscal pressure and can, therefore, aggravate a protruded, herniated or extruded disc. It is, therefore, contra-indicated for patients with herniated discs.
Technological advances, along with our research, led to the development of VAX-D Treatment. The computer control of the equipment allows controllable, effective axial distraction to be applied to the lumbar vertebral column without eliciting trunk muscle contraction. We found that distractive forces must be applied and released in a progressive logarithmic fashion.
TAC: Can you please explain what is meant when you say that it is a logarithmic pull pattern?
Dyer: VAX-D incorporates computer programmed technology that applies the tension according to a logarithmic curve. Essentially, as tension is increased, the time function is progressively slowed. This is a critical difference between VAX-D and traction and is the reason VAX-D was issued a US patent #6,039,7376. This patent describes the complex computer program and illustrates the logarithmic time/tension curve.
Traction applies tension on a linear time rate; e.g., if you plot the strength of tension (lbs.) vs. time (secs.), the plot is a straight line. The biological response to traction causes reflex muscle guarding. This is a homeostatic protective response that prevents traction from decompressing discs. When the procedure is governed by a logarithmic time rate, reflex guarding is averted, and the disc pressure can be decreased to negative levels.
TAC: What would you say is the percentage of tables sold to chiropractors versus those sold to other professions?
Dyer: About 65 percent of our devices are utilized by MD’s and DO’s. The remainder are used by chiropractors and PT’s.
TAC: What kind of research has been done on the VAX-D and/or decompression in general?
Dyer: It should be noted that VAX-D is the only device proven to achieve spinal decompression through direct recording of negative pressures in intervertebral discs in living subjects. No other device has been shown to lower the disc pressure. In addition, independent clinical research has demonstrated neurodecompression following VAX-D. No other product has ever published comparable research studies. Therefore, practitioners using any other devices cannot legally substantiate spinal decompression claims.
VAX-D also has a number of clinical studies that have demonstrated significant efficacy. That fact that these clinical studies have shown consistent levels of success also provides practitioners with research evidence of efficacy.
In a recent internet search (January 2008) using PubMed, Medline, and Embase, we could not find any clinical research on any of the other so called decompression tables published in "peer reviewed" medical journals. Yet they all claim success rates in excess of 85 percent.
TAC: What is the biggest difference between the way the way MD’s approach the use of the decompression, versus how a DC initially approaches it? Is it any different to that of a DO?
Dyer: MD’ and DO’s are able to utilize the complete VAX-D protocol in the treatment of back and neck pain. Many patients have a large inflammatory component to their spinal disorder. The VAX-D protocol includes the use of certain prescription pharmaceutical agents in conjunction with the mechanical therapy. In addition, particular diagnosis, such as Internal Disc Disruption, require the concomitant use of Matrix Metalloproteinase Inhibitors (MMPI’s) along with an oral steroid such as methylprednisolone.
DC’s and PT’s are unable to prescribe so they are not able to take advantage of all of the treatment adjuncts unless associated with a multi disciplinary practice.
Also, many DC’s (and some DO’s) add spinal manipulation to the procedure. We caution all practioners not to add any adjunct that has the potential to increase the intradiscal pressure.
TAC: Are there any threats to the use of this technology as a form of improving low back pain in the future?
Dyer: There are several unrelated answers to this question. One threat has been the use of fraudulent and illegal marketing techniques. Some practitioners have already been subject to fines for making false claims.
The other threat to the availability of the treatment is improper denial of claims for the service by insurance providers and third party payers. The treatment is often denied on the basis that the treatment is "investigational and experimental" in nature. In fact, the treatment does not have an investigational regulatory status with the US Food and Drug Administration, whose mandate is to make such determinations. Investigation devices must be utilized under an Investigational Device Exemption.
Several landmark class action lawsuits against a number of managed care companies have concluded that they have engaged in a conspiracy to improperly deny and delay claims, in whole or in part, and/or reduce payment to physicians based upon improper use of definitions of Experimental and Investigational status of treatments.
We believe that "evidence based medicine" should be a determining factor in whether a drug or device should be recognized and reimbursed by the health insurance industry.
VAX-D is the only device with a long history of studies published in peer reviewed journals, including a recent study, in February 2008, that showed short- and long-term outcomes after VAX-D treatment in a large sample of patients with activity-limiting low back pain that had failed at least two previous, non-surgical treatments. The study showed that patients had significantly improved pain and disability scores at end of treatment, at 30 days and at 180 days post-discharge.
TAC: Can you tell our readers about the cervical component? What kind of conditions have demonstrated improvement?
Dyer: Anatomical differences and enhanced proprioceptor reflex sensitivity, compared to the lumbar spine, dictate the use of higher precision and special adaptations to successfully treat discogenic lesions in the cervical spine.
Research found that the application of tension needed to be strictly controlled in the horizontal plane and the vertical plane in order to avoid triggering muscle guarding and spasm in the cervical spine. The cervical collar component is also critical for distracting the head and neck, because it allows the required mobility of a circumferential lift system, while providing the necessary support and immobilization for patients in the post treatment period when the muscle guarding reflexes have been reduced. Without the protection of the collar, head and neck movements will trigger muscle spasm, increased intradiscal pressure and neck pain.
We have many of the new Genesis Cervical systems in the field now, and they all report success with herniated and degenerative disc disease cases. We will need to do properly designed clinical studies in order to determine the overall success rates with different conditions.
TAC: How do post surgical patients respond to decompression?
Dyer: Post surgical patients respond positively to VAX-D treatment, although the reported success rate in the literature is lower. An outcome study on 778 patients wrote: "Thirty-one patients had previous lumbar disc surgery. Eighty-four percent of this group’s pain scores, 71 percent of their mobility scores and 61 percent of their activity scores improved by one unit or more with therapy, and 65 percent of their pain scores were reduced to 0 or 1. Vertebral axial decompression was well tolerated."
TAC: While there are many different types of decompression tables available with varying degrees of research to support it, what’s your advice to our readers who may be using any type of "decompression" table in their practice?
Dyer: Look to purchase equipment that has clinical support published in peer reviewed medical journals. Don’t base the purchase on marketing hype. Look for at least Level II evidence of efficacy.
TAC: Is there an issue that doctors using decompression along with cash prepayment plans should be aware of? (Ie, Is the patient paying for something that they’re not getting??) Can you explain this concern?
Dyer: Yes, there is an issue when a practitioner is charging a patient for decompression, using a traction device. In addition, a patient should be treated with equipment that has clinical support for its efficacy.
TAC: When it comes to decompression, there are many concerns and/or rumors about the government or insurance companies giving doctors problems when utilizing this new technology. Who are these people/organizations? And why do you think they are giving doctors such a hard time?
Dyer: The Department of Justice has an obligation to protect the public against false advertising. The DOJ and some insurance companies have initiated investigations into fraudulent claims made by decompression device manufacturers, and then repeated by practitioners in promoting the service. Patients cannot be induced to take a treatment based upon fraudulent claims.
The spinal decompression industry is full of misinformation, unsubstantiated claims and marketing hype. Many manufacturers have been quoting research done on VAX -D as though it applies to their device. That is illegal. It is disconcerting that the industry has grown so large, when a search of the medical literature reveals there are no studies published in peer-reviewed medical journals on devices other than VAX-D.
Many device manufacturers claim that their equipment will lower the intradiscal pressure. To this day, VAX-D is the ONLY device shown in clinical research to decompress the disc to negative levels (Ramos & Martin, Journal of Neurosurgery).
TAC: Any final words for our readers?
Dyer: We at VAX-D have always been more interested in the outcome for the patient, rather than the marketability of the equipment. One of our mottos is, "Real Science, Real Studies, Real Results".
I would advise purchasers to make their decisions on clinical evidence rather than on marketing hype, and to make sure that they can substantiate any claims that they make regarding the treatment and its success rates.