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An example known for everybody since
years ago would be developement of laparoscopy, practiced by almost every general
surgeon; this technique allows to heal abdominal diseases "without opening the
abdomen" as it used to be classically, going through small orifices drilled
on abdomen skin to insert instruments and even a device to watch the operation
through a small specially designed TV camera.
With the developement and improvement of laser in surgery, Americans introduced the application of laser for the treatment of several diseases of human body. This technology still astonish scientifics and doctors day by day by watching the results obtained as the very few complications in operations where laser it's used.
Laser stands for: "light amplification by stimuled radiation emission", and the beginning of its developement was back at the 60's with Maiman, who based in atomic theories that Einstein developed in 1917.
In practice, laser is a concentrated light ray, which by contact with human tissue it trends to be absorbed by such tissue, with the following evaporation or disappearance of the tissue, meaning that a surgeon can, for example, eliminate a tumor without touching it by only pointing a laser ray on tumoral tissue. All this makes unnecessary classic metallic instruments (pincers, etc.) wich are a lot thicker and bigger than a laser fiber, obtaining with the latter a less traumatic surgical intervention and very best results.
Many types of laser have been
developed: Argón, CO2, Neodmium-Yag, etc. (an experimentel comparasion
of CO2, Argon, ND-Yag and HO-Yag láser ablation of intervertebral discs-Lane
et coll. spine) and its application in surgery of discal hernia and other diseases
of nervous system begun long time ago, but results were not encouraging in the
beginning, due to a great inconvenience of laser: by making contact with human
tissue, it evaporated the point where it touched and also generated a surrounding
heat area to that point, wich could produce severe burns beyond the area that
the surgeon wanted to heal.
Investigations continued and nowadays there is a new kind of laser known as "Holmium-Yag" or "contact laser", by which irradiation of heat out the point where the laser is applied is minimal, solving this way the main inconvenience that implied using this kind of technology in precision surgery, as in the treatment of discal hernia.
This "Holmium-Yag" or "contact" laser represents the earliest in biomedical technology terapeutic arsenal, and it has many applications in many specialties: but its cost, due that it's vanguard technology, it's higher than other kinds of laser.
In traumatology it's used for all kinds of artroscopy, even the smaller as wrist articulation, elbow, shoulder and jaw, inclusive (The use of láser in orthopedic procedures-current concepts- review. Sherk).
In urology it transformed prostate and bladder surgery, and makes the so called "intracorporean litho-triptia" or elimination of hughe calculus that cannot be powdered by classic extra-corporean rx or echo litho-triptia devices.
In gynecology and general surgery its applications are so many that they all cannot be enumarated.
In neurosurgery it is used to heal cerebral tumors in the base of the skull, deep tumor, intra-ventricular tumors, marrow tumors, and a very developed application is the US is for the treatment of lumbar discal hernia; Swiss and Korean also use it for cervical discal hernia (Siebert.W-Percutaneous láser disc decompression--The european experience-spine)
Classically, discal hernias were treated by a open surgery procedure, known
as laminectomy, but due that such technique carried
many inconveniences to some patients, they begun to appear percutaneous
techniques (which is, through the skin, by a little hole). First appeared chemonucleolysis
(percutaneous nucleolysis of lumbar discs- Choy- New.Engl.J.Med) or injection
of a substance into the disc to destroy discal tissue, which brought several
problems due that the extension of discal destruction could not be controlled
exactly, so the technique was abandoned.
Then appeared open discal surgery with microscope, same as laminectomy but with a smaller wound. It produced less inconveniences but, as classic laminectomy, sometimes produced the "epidural fibrosis". It's still practiced, but less frequently.
Later it appeared Percutaneous Disectomy (chirurgie percutanne de la hernie discale lumbaire- roy camille, Benazet - Saillant. Enciclop. Med-chirurgicale. París) or eliminations of discal hernia through a little hole made on skin by which there are inserted very thin instruments without touching the spine and extracting that way the damaged discal tissue diminishing the intradiscal pressure, cornerstone in the genesis of the discal hernia. This technique does not produce fibrosis, nor destabilizes spine avoiding the use of screws, plates, hospitalisation (due that it's practiced outpatient) and it's practiced without general anesthesia. Besides, it's cost is infinitely inferior than other techniques.
Nowadays discal herniaes have been treated using Holmium-Yag or "contact" laser
(The ablation capacity of Holmium-Yag láser in lumbar interverbral discs-Leu
et coll-Zurich-Suisse), technique that can be resumed as it follows: A canula
(thinner than a ballpen reserve) is inserted in a percutaneous way, and it includes
a laser fiber, a tiny TV camera, irrigation and aspiration hoses, and besides
it's included a device that allows the tip of the fiber to move forwards and
backwards according to the requirements of the surgeron, allowing him to have
a very precise control over the instrument.
Once inside, the surgeon goes exploring inside the affected disc with the help of the video system, which gives him a clear vision of what the problem is exactly. Applying laser, the surgeon goes disintegrating the damaged parts of the affected disc, reducing discal pressure and providing immediate relief to the patient on the surgery table.
Thanks to the serum irrigation system of this kind of instruments, it's even more guaranteed that the laser ray will never affect beyond required by surgeon, due that a liquid medium created inside the disc maintains intradiscal temperature within a correct range.
This wonderful technology, which seems taken from a sci-fi tale, is the state-of-the-art of medicine in the most developed countries.
Preliminary studies at the US showed that discal hernia surgery with this kind of contact laser or Holmium-Yag did not evidence any severe complication, minimal aggression, simplicity of procedure, vaporization of 51% of initial intradiscal pressure, without loss of discal height with conservation of spine rotation center and its consequent conservation of spinal stability. All this has made that statistics of excelent results for percutaneous disectomy raised from 87% to 92% for the american school.
(results of percutaneous lumbar discectomy with laser-sherk et
coll-state of the art reviews-spine).
What is more important, Holmium-Yag opens the ways of endoscopic exploration inside the medular channel, with the ability to eliminate peridural fibrosis through periduroscopy and foraminoscopy, already in investigation.
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