Laser discectomy. Comparison of systems

Laser Therapy in Lumbar Disc Surgery - A Narrative Review

Introduction: Low back pain is one of the most chronic debilitating conditions involving considerable loss of cash, work, and quality time. Lasers are utilized in different fields of drugs, providing unique advantages. They are useful and advantageous in treating lumbar disc disease. In this research, an attempt is made to examine the role and importance of different lasers in lumbar disc surgeries. Methods: We conducted studies about laser therapy in lumbar disc surgery. Our primary search began with reviewing English-language citations from PubMed and Scopus between 1990 and 2019 using the keywords: (laser therapy) OR (lumbar disc AND disc surgery). The initial search yielded 97 articles. However, about 49 articles were selected and used in the present study. Results: Based on the present study, it can be found that there are several methods of using lasers to treat lumbar disc surgery. These methods all have their strengths and weaknesses. Conclusion: The development of laser lumbar disc surgery can be very helpful due to the reduction of surgical risks and the length of the patients' hospital stay. However, the choice of method used for this type of surgery should be made according to the patient's condition and based on the opinion of the treating physician.

Outcomes with transforaminal endoscopic versus percutaneous laser decompression for contained lumbar herniated disc: a survival analysis of treatment benefit

BACKGROUND

Contained lumbar disc herniations frequently cause back- and leg pain. Clinical outcomes with surgical treatment may be affected by the size and location of the disc herniation. The surgical directly visualized transforaminal endoscopic decompression has gained acceptance and popularity, while the simplified percutaneous laser disc decompression has fallen out of favor in spite of its initial success as a minimally invasive intervention. In an attempt to better understand the durability of both procedures, the authors performed a comparative analysis of clinical outcomes in patients with contained lumbar disc herniations.

METHODS

The study population was comprised 248 patients consisting of 162 patients in the endoscopy group (group 1) and 86 patients in the laser group (group 2). Primary outcome measures were Macnab criteria. Herniations were classified as large or small. Additional parameters of advanced degeneration of the lumbar motion segment including posterior disc- and lateral recess height of <3 mm were recorded. IBM SPSS 25.0 was used for Kaplan-Meier survival analysis and cross-tabulation of these variables with statistical testing for significant associations.

RESULTS

The mean follow-up was 43.5 months. The serial time recorded for Kaplan-Meier analysis ranged from 1.5 to 84 months. The mean age was 53.37 years (standard deviation =14.65 years). The majority of patients had Excellent and Good Macnab outcomes (212/248; 85.5%) regardless of treatment. Fair and Poor results were achieved in another 36 patients (14.5%). There was a higher percentage of Excellent Macnab outcomes in the endoscopy group (94/162; 58.0%) than in the laser group (38/86; 44.2%) at a statistical significant level (P<0.0001). There was a statistically significantly higher percentage of Excellent and Good Macnab outcomes with endoscopic decompression of small paracentral herniations (97.1%; P<0.0001). Percutaneous laser decompression of large central disc herniations was not statistically better than endoscopic surgical decompression (P=0.125). Endoscopic bony and soft tissue decompression was also better than laser at alleviating symptoms in patients with reduced posterior disc- and lateral recess height with 96.7% in patients with reduced disc height of <3 mm and 94% in patients with reduced lateral recess height of <3 mm (P=0.001). Kaplan-Meier (K-M) Survival time showed longer median survival of the treatment benefit for patients who underwent visualized endoscopic surgical decompression (66.0 months) compared to median K-M survival time for percutaneous laser decompression of 17 months (P<0.0001).

CONCLUSIONS

Transforaminal endoscopic decompression for symptomatic herniated disc is an effective and durable surgical treatment to alleviate sciatica-type and back symptoms in the vast majority of patients with good long-term survival of pain relief for up to six years. Interventional percutaneous non-visualized laser decompression for the same condition may provide favorable outcomes in the short-term with soft protrusions. However, the treatment effect deteriorates much faster with a median survival of 17 months.

Current Concepts in Minimally Invasive Discectomy

OBJECTIVE

The purpose of this study was to evaluate the various minimally invasive procedures available for the treatment of lumbar disc disease.

METHODS

A review of the literature, as well as my personal experience with minimally invasive approaches to the lumbar discs, was performed. This review included the percutaneous and open surgical approaches currently available and used for the treatment of lumbar disc disease.

RESULTS

The primary minimally invasive procedures for the treatment of lumbar disc disease include the following: 1) chemonucleolysis, introduced by Lyman Smith in 1964; 2) percutaneous manual nucleotomy, introduced by Hijikata in 1975; 3) microdiscectomy, first performed by Yaşargil in 1968; 4) automated percutaneous lumbar discectomy, introduced by Onik in 1984; 5) laser discectomy, first performed by Ascher and Choy in 1987; 6) endoscopic discectomy, first used by Schreiber and Suezawa in 1986 and improved by Mayer, Brock, and Mathews; 7) microendoscopic discectomy, introduced by Smith and Foley in 1995; and 8) intradiscal electrothermy, first reported by Saal and Saal in 2000.

CONCLUSION

Although all percutaneous techniques have been reported to yield high success rates, to date no studies have demonstrated any of these to be superior to microsurgical discectomy, which continues to be regarded as the standard with which all other techniques must be compared.

A biophysical explanation for Nd:YAG percutaneous laser disc decompression success

OBJECTIVE

To use pre- and postoperative CT density measurements to demonstrate changes achieved by Nd:YAG laser (1,064 nm) in protruded or extruded discs.

BACKGROUND DATA

Nonendoscopic percutaneous laser disc decompression and nucleotomy (PLDN) with the Nd:YAG laser is an established minimal invasive treatment of discogenic pain syndromes in patients with bulging, protruded, or extruded intravertebral discs. Extremely high success rates involving improvement in the flow of cerebrospinal fluid in the dural sac and enhanced venous flow by MRI myelography are 80% lumbar, 86.5% cervical, and 98% thoracic spine. However, verification of reduced intradisc and intraspinal pressure by imaging procedures is difficult.

METHODS

Twenty-one patients, four women and 17 men, with an average age of 43.67 (range, 24-59) were selected. The patients showed lumbar radicular pain syndromes with monosegmental disc protrusion or extrusion, and monoradicular clinical symptoms. Measurements were performed preoperatively and on postoperative day 1.

RESULTS

The preoperative density measurements averaged 83.43, in agreement with the Houndsfield units (HU) described in the literature. Postoperatively, the reduction down to 66.33 HU had a statistical significance of p = 0.001 verified in the t test. Standardizing the measurements prior to laser irradiation to 100% produced an average 20% postoperative density reduction.

CONCLUSION

PLDN with the Nd:YAG laser (1,064 nm) markedly reduces the postoperative density in protrusion and extrusion of intravertebral discs. The excellent therapeutic results achieved with this method in discogenic pain syndromes can be verified by imaging procedures.

Extensive damage to the end-plates as a complication of laser discectomy. An experimental study using an animal model

To date, there have been no reports of experiments demonstrating the effects of neodymium:YAG laser (Nd:YAG laser) on the vertebral end-plates. In this study the effect of Nd:YAG laser on end-plates was examined in 32 guinea pigs which were randomly divided into two groups. The first group was the control group, the second one the Nd:YAG laser group. All animals had experimental disc degeneration at three levels. Re-exploration was performed two months after the surgical ventral disc herniation. In the second group the same procedure was performed but at the end of the re-exploration, Nd:YAG laser irradiation of the degenerated discs was done. The wounds in both groups were closed again. Two months later all animals were sacrificed for histological and biochemical analysis. The cervical spine was excised en bloc and the overlying muscles were removed. Determination of hydroxyproline was done colorimetrically in the specimens harvested from each of these groups. Light microscopy was undertaken to evaluate the extent of morphological changes. The differences observed between the two groups were statistically significant (p < 0.05). From the results of this study, there is the question whether the Nd:YAG laser is a useful instrument in neurosurgery. Therefore, it remains to be proven whether or not this is of real benefit in the treatment of patients with degenerated disc disease.

Effect of Nd:YAG laser on experimental disc degeneration. Part II. Histological and MR imaging findings

The potential advantages of percutaneous procedures over traditional discectomy are multiple, but the use of laser energy to ablate disc tissue appears entirely empirical. To date, no experimental study exists investigating the results of laser on degenerated intervertebral disc. The present study was therefore undertaken to determine the histological and radiological changes induced by neodymium-yttrium-aluminum-garnet (Nd:YAG) laser on such disc tissue. It was shown that the vaporization of disc tissue was caused by Nd:YAG laser in early period, but this was gradually replaced by cartilaginous fibrous tissue at 60 days after laser irradiation as a result of the proliferation of cartilaginous cells and fibrous tissues. Accordingly the magnetic resonance (MR) imaging index histogram moved to the left in the early period, but it moved to the right again at 60 days after laser irradiation. In view of these data, we conclude that the use of laser in degenerated disc disease does not represent an effective treatment as an alternative to conventional surgical methods.

Lasers in neurosurgery

Lasers have been used in neurosurgery for the past 25 years, undergoing modifications to suit the specific needs of this medical discipline. The present report reviews the current use of lasers in neurosurgical practice and examines the pros and cons of lasers in specific neurosurgical applications. In spite of their advantages, laser use is still not widespread in neurosurgery. One reason is the continued lack of complete control over real-time laser interactions with neural tissue. A greater acceptance and use of lasers by neurosurgeons will depend upon automated control over defined specific parameters for laser applications based upon the type of tissue, the desired effect on tissue, and application to the clinical situation without loss of precision and a lot of expense. This will require the integration of newer lasers, computers, robotics, stereotaxy, and concepts of minimally invasive surgery into the routine management of neurosurgical problems.