Minimally Invasive Discectomy

Minimally Invasive Discectomy

Is The Scalpel More Potent Than The Needle, Catheter or Endoscope?

The use of the scalpel for the purpose of discectomy has been the surgical standard in the past. With the advent of new and advancing technologies there has been a continuing effort over the latter third of the 20th century to improve patient safety and efficacy as well as decrease procedure cost. How well these varying approaches have been in accomplishing these goals will be reviewed in this section of the Burton Report^®.

The Percutaneous Approach To The Intervertebral Disc

The percutaneous approach to the intervertebral disc has been attractive to many because it seems to be "easy." It is as "easy" as being a circus acrobat appears to be. In other words, for the skilled and experienced professional, this methodology is typically unproblematic.

As shown by the many patient disasters which led to the unfortunate withdrawal of chymopapain for nucleolysis the ability of a carpenter is more important than the nail. This dictum is universally applicable and needs to be carefully considered by any patient considering minimally invasive discectomy. In the following discussions the efficacy of chymopapain (chymo) will be used as a point of reference for the other described procedures.

Automated Percutaneous Lumbar Discectomy (APLD)

Automated percutaneous lumbar discectomy (also referred to as Percutaneous Nuclectomy) was introduced by Gary Onik in 1985 as a means of providing a more safe mechanical means of debulking the interior of a disc.

THis work was influenced by S. Hitikata of Japan who first developed the percutaneous method. APLD was recognized as being helpful in contained disc herniations and contra-indicated in non-contained disc herniations. he good news regarding APLD was its greater overall safety than chymopapain injection. The bad news is that it's efficacy was not, in the Burton Experience, as high as some of the non-invasive therapies and that APLD's cost was high. By year 2000 APLD was rarely performed.

Athroscopic Micro-Discectomy (AMD)

In the early 1970s Parviz Kambin began to perform mechanical nuclectomy at Graduate Hospital in Philadelphia using Craig biopsy instrumentation. Hijikata popularized, in 1975, his version of percutaneousl nucleotomy. By the 1980s, however, Kambin had developed endoscopic instrumentation which allowed the operator to directly visualize the disc annulus and disc fragments in real time. The illustration on the left shows a mono-polar arthroscopic microdiscectomy (AMD) approach. The surgeon has the opportunity to visualize the end of the inserted tube (middle image in blue) and the annulus of the disc (middle image in red) as well as the depths of the interspace. With continued development bi-polar approaches were developed (image right) as well as the beginning of microsurgical discectomy. The good news about AMD is that in the hands of a skilled operator a true minimally invasive procedure was possible. This has been particularly for lateral free-fragment disc herniations which could oftimes be well treated by this technique. The bad news about AMD, according to the Burton Experience, is the fact that many surgeons attempting it simply did not have the skills to do so effectively and safely for the patient. Despite AMD significantly high numbers of patients required additional open surgery to obtain a good result. In addition, the bi-polar approach became, in the Editor's opinion, no longer a "minimally invasive" procedure. It is important to note that for the selected patient and the skilled procedurist AMD can be a highly effective therapy.

Laser Discectomy

Few procedures have matched the media & marketing hype associated with the introduction of chymopapain injection in the 1970s. In the area of "micro-invasive procedures" few have matched the M2H exploitation of the term "laser" in spine therapy.

While there may actually be some skilled practitioners using laser safely and effectively in spine care the Burton Experience has yet to identify many of these practitioners. Through the use of terms such as "thermodiscoplasty, thermoannuloplasty" and "band-aide surgery" laser discectomy has raised to new heights abuse of modern technology and has, in the process, created procedure mills designed primarily for the benefit the procedurists and not the patients.

Nucleoplasty

Nucleoplasty is one of the "new boys on the block" for minimally invasive disc debulking procedures. Nucleoplasty uses a thermal probe (Perc-D Coblation Probe) to "ablate and coagulate" discal tissue by producing a zone of coagulation which is then absorbed by the body. How much of this procedure is M2H and how much is reality remains to be determined.

Images courtesy of Arthrocare Corporation

Anterior Approach Microscopic Discectomy (AAMD)

The anterior approach to the lumbar spine for the purpose of discectomy represents legitimate application of technology whose zenith has not arrived because of the long learning curve required of those who practice it.

The Burton Experience is that the risk factors (i.e. injury to great vessels, ureters, lymphatics, etc.) are still inordinately high but that AAMD will become a valuable technique in the future. It's efficacy will be greatly aided by "real-time" intra-operative monitoring systems presently under development.

Under the title "Fast Relief for Back Pain" (Ian K. Smith, M.D., Time Magazine, September 3, 2001) a "new procedure" referred to as "nucleoplasty" is described. Nucleoplasty is said to show a "70% reduction" in pain and is reported as having an average cost of $5,000 to $7,000. Nucleoplasty involves the use of an intradiscal catheter to heat and "vaporize" the nuclear tissue of the disc in order to "relieve the pressure." This is clearly the latest entry in the M2H sweepstakes in doing poorly something which usually doesn't need to be done at all. Nucleoplasty represents only another means of accomplishing what APLD, AMD and Laser discectomy have attempted to do in the past. These techniques have not yet shown themselves to be cost-effective and there is no reason to believe that this new entry possesses any notable benefit above presently existing totally non-invasive therapy programs.

Summary

Quite frankly the great majority of minimally invasive procedures are "investigative" in the hands of most practitioners. There is, however, a small group of uniquely gifted spine practitioners for whom these are "standard" procedures. Some of these practitioners belong to the International Spinal Injection Society. For the patient lucky enough to get beyond the media & marketing hype (i.e. the "band-aid" surgery bit) and locate a spine care specialist who understands the process of patient selection, and is actually able to make a specific diagnosis, minimally invasive might be a reasonable step forward (but only IF they are utilized when less invasive therapies fail). The Burton Experience suggests, however, that this might be a quest worthy of Diogenes of Sinope's search for an "honest man."

In addition to the above it has been the Burton Experience that about 50% of those having a minimally invasive procedure require additional conventional surgery to fully address the problem. In addition, concurrent pathology, such as lateral spinal stenosis is typically not addressed in a minimally invasive procedure. The patient with a minimally invasive procedure is at significantly higher risk of developing recurrent or other problems. When all is said and done surgical discectomy (microdiscectomy or microsurgical discectomy) remains the "gold standard" of care when performed by a qualified individual (i.e. Board Certified in Spinal Surgery) on a patient who meets the criteria for such. In addition the prudent patient should always perform some "due diligence" in selecting their surgeon.