Medical Journal Articles

Following are abstracts and summaries of articles about PLDD and Dr. Choy that have appeared in professional journals.

The full articles are available by request from the Laser Spine Center.

Techniques in Regional Anesthesia, Vol. 9, No. 1, January 2005, pgs. 50-55, “Percutaneous Laser Disc Decompression: History and Scientific Rationale,” Daniel S.J. Choy, M.D.

Photomedicine & Laser Surgery, Vol. 22, No. 5, pgs. 423-425, Arpad Fejos, M.D.

• Abstract: This 10-year follow-up study reports that 86% of patients who underwent the PLDD treatment were still pain-free.

Medical Laser Application, 16:59 and 16:61-64 (2001), "From the Editors" and "History of Percutaneous Laser Disc Decompression (PLDD)," Daniel S. J. Choy.

Journal of Clinical Laser Medicine & Surgery, Vol. 19, No. 1, 2001, pgs. 1-2, "Editorial: Percutaneous Laser Disc Decompression, A First Line Treatment for Herniated Discs."

SPINE, Vol. 17, No. 8, August 1992, "Percutaneous Laser Disc Decompression: A New Therapeutic Modality," Dr. Daniel S. J. Choy, M. D., et. al.

• Abstract: The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was good to fair response in 261 patients (78.4%) and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.

The New England Journal of Medicine, Vol. 317, No. 12, Sept. 17, 1987, Correspondence: "Percutaneous Laser Nucleolysis of Lumbar Disks," Daniel S. J. Choy, M. D., et. al.

Journal of Clinical Laser Medicine & Surgery, Vol. 14, No. 1, 1996, pgs. 13-15, "Rapid Correction of Neurologic Deficits by Percutaneous Laser Disc Decompression (PLDD)," D.S.J. Choy, M.D., F.A.C.P

• Abstract : Immediate correction of neurologic deficits due to herniated disc disease following percutaneous laser disc decompression (PLDD) has not previously been reported. In a review of 182 cases of herniated intervertebral disc disease with radicular pain syndromes, the author observed a high percentage of return of absent ankle and knee jerk reflexes, return of straight leg raising to normal, and a change of the characteristic rolling to one side, bending the knees, and propping up with the hands as the usual maneuver to change from a supine to a sitting position ("Choy sign") to an ability to sit up directly by trunk flexion, immediately, and at 1 day after PLDD. The neurophysiologic implications are discussed.

The New England Journal of Medicine, Vol. 337, No. 19, Nov. 6, 1997, Correspondence: "Positive and Negative Gravitational Forces and Herniated-Disk Sciatic Pain," Daniel S. J. Choy, M. D.

Journal of Clinical Laser Medicine & Surgery, Vol. 15, No. 2, 1997, pgs. 71-73, "Magnetic Resonance Imaging of the Lumbosacral Spine Under Compression," Daniel S. J. Choy, M. D.

• Abstract: Object: This study was undertaken to duplicate the more physiological imaging of lumbar disk herniation possible with the "sitting magnetic resonance imaging (MRI)" that exists at Harvard and Zurich. Method: A compression frame was constructed of plywood that would fit into a standard MRI machine. A patient lying in the frame, on expending the bent knees, would experience a compressive force on his lumbar and thoracic spine, thus duplicating the higher intradiscal pressures found in the sitting position. Results: It was found that in 50% of patients so studied there was reduction of their pain syndromes as well as augmentation of disk herniation by MRI. Conclusion: The compression frame used during MRI of the spine results in a more physiological representation of herniated disks seen in the erect position.

Journal of Clinical Laser Medicine & Surgery, Vol. 16, No. 2, 1998, pgs. 123-125, "Percutaneous Laser Disc Decompression in Spinal Stenosis", Daniel S. J. Choy, M.D., F.A.C.P. and Jeffrey Ngeow, M.D.

• Abstract: Objective: The authors determined whether percutaneous laser disc decompression (PLDD) is an effective treatment for spinal stenosis where bulging or protruding discs are a contributing factor. Summary Background Data: Spinal stenosis is associated primarily with the middle-aged and elderly patients, its chief symptom being low back and/or radicular pain worsened by walking. The condition is particularly resistant to conservative measures and to open surgery. PLDD is a minimally invasive treatment for intervertebral disc protrusions with low morbidity and a high success rate. Methods: This unblinded study was undertaken to determine whether PLDD would alleviate the pain of spinal stenosis in patients who also had protruding lumbar discs. Thirty-five patients of both sexes and all ages with MRI-documented lumbar spinal stenosis associated with bulging or protruding discs were treated with PLDD on an outpatient basis. Pain relief was the only parameter followed. Patients were asked to rate their pain immediately after treatment, one day later, four weeks later, and at a follow-up ranging from five to forty-nine months later. Pain was quantified on a scale of 0-10, with 0 being a total absence of pain and 10 being severe pain. A score of 0-2 was considered excellent, 3-5 good, and 6-10 poor. Results: Excellent results were seen in 69% of cases, good in 9% and poor in 22%. Pain relief immediately after treatment always continued through the four weeks and five to forty-nine month follow-ups. Conclusions: It was our conclusion that PLDD compares favorably with open surgery in the treatment of lumbar spinal stenosis that is partially or completely due to bulging or protruding discs.

Journal of Clinical Laser Medicine & Surgery, Vol. 16, No. 6, 1998, pgs. 325-331, "Percutaneous Laser Disc Decompression (PLDD): Twelve Years' Experience with 752 Procedures in 518 Patients", Daniel S.J. Choy, M.D.

• Abstract: Background and Objective: Percutaneous laser disc decompression (PLDD) is a procedure in which herniated intervertebral discs are treated by reduction of intradiscal pressure through laser energy. This is introduced by a needle inserted into the nucleus pulposus under local anesthesia and fluoroscopic monitoring. The small volume of nucleus vaporized results in a sharp fall of intradiscal pressure, with consequent migration of the herniation away from the nerve root. First proposed by the author in 1984, this concept was validated by 2 years of in vitro experiments. Out aim was to apply this concept to a large series of patients with herniated disc disease. Study design/materials and methods: A nonrandomized, nonblinded study was conducted in male and female patients with symptomatic, image-documented intervertebral herniated discs in a 12-year period using PLDD as the only treatment modality. Results: The author's own series consists of 752 intervertebral discs in 518 patients over a period of 12 years. The overall success rate ranged from 75% to 89% with a complication rate of less that 1%. Conclusion: PLDD has proven to be safe and effective. It is minimally invasive, is performed in an outpatient setting, requires no general anesthesia, results in no scarring or spinal instability, reduces rehabilitation time, is repeatable, and does not preclude open surgery should that become necessary.

Journal of Clinical Laser Medicine & Surgery, Vol. 17, No. 1, 1999, pgs. 25-27, "Early Relief of Erectile Dysfunction after Laser Decompression of Herniated Lumbar Disc", Daniel S.J. Choy, M.D.

• Abstract: Objective: The use of percutaneous laser disc decompression (PLDD) for the treatment of erectile dysfunction caused by herniated disc disease is described. Summary Background Data: Disc herniation is often overlooked as a cause of erectile dysfunction, with few cases reported in the literature. Methods: Two patients with erectile dysfunction were treated with PLDD as outpatients. Results: In addition to the early return of erectile function in both cases, immediate pain relief was achieved in the second case. Follow-up visits confirmed continued normal sexual function and lack of pain. Conclusions: The literature now includes 23 well-documented cases of erectile dysfunction caused by spinal cord disc herniation. PLDD is a minimally invasive procedure that can be used to treat herniation of intervertebral discs, which has been found to cause erectile dysfunction.

Journal of Clinical Laser Medicine & Surgery, Vol. 17, No. 6, 1999, pg. 239, "Editorial Note: New CPT for Percutaneous Laser Disc Decompression Awarded by American Medical Association."

Journal of Clinical Laser Medicine & Surgery, Vol. 18, No. 1, 2000, pgs. 29-32, "Familial Incidence of Intervertebral Disc Herniation: An Hypothesis Suggesting That Laminectomy and Discectomy May Be Counterproductive", Daniel S. J. Choy, M. D.

• Abstract: Objective: To determine (1) if familial and genetic factors play a role in the genesis of disc herniation, (2) the incidence of multiple disc herniations, (3) the incidence of disc reherniation in patients treated with standard laminectomy and discectomy, and (4) to construct an hypothesis that best explains all three. Summary Background Data: It is known that there is a substantial incidence of disc herniation in first order relatives of patients with herniated nucleus pulposa (HNP), that multiple disc herniations are not uncommon, and that disc reherniations and repeat operations after laminectomy and discectomy range from 5 to 37%. Also, there is a recent report of a genetic defect leading to defective cross-linkage of collagen strands in patients with HNP. Methods: Using the questionnaire method, a group of the author's patients with documented HNP treated with percutaneous laser disc decompression (PLDD) was surveyed as to the existence of known disc herniations among first order relatives. Analysis of the author's series of 621 patients with HNP disclosed the incidence of multiple disc herniations. A comprehensive literature search provided data on reherniations and reoperations following laminectomy and discectomy. Results: In 174 respondents, the number with first order relatives who had HNP was 74 (or 43%). This compares with the national incidence of HNP of 1.7%. The statistical significance yields a P=0.0001. In the 621 patients with known HNP, the number who had more than one herniated disc was 236 (or 38%). In multiple reports in the literature, the incidence of reherniation after laminectomy and discectomy ranged from 5 to 37%. Conclusions: The simplest hypothesis explaining all of the above is that intervertebral disc herniation is due to an acute or subacute increase of intradiscal pressure acting against a congenitally weak annulus fibrosus and posterior longitudinal ligament, and therefore laminectomy and discectomy, by further weakening these structures, may be counterproductive.

Journal of Clinical Laser Medicine & Surgery, Vol. 19, No. 1, 2001, pgs. 15-20, "Response of Extruded Intervertebral Herniated Discs to Percutaneous Laser Disc Decompression", Daniel S. J. Choy, M. D.

• Abstract: Objective: To describe the clinical features of 21 patients with extruded (but nonsequestered) herniated intervertebral discs before and after treatment with percutaneous laser disc decompression (PLDD). Background Data: PLDD was introduced in February, 1986, by Choy and Ascher. This relatively noninvasive technique for the treatment of herniated intervertebral discs has been extensively described elsewhere. Previously, only uncomplicated disc herniations were treated with PLDD, with a success rate according to the MacNab criteria of 89% and a complication rate of 0.4 to 1.0%. Until 1998, the author and others adhered to strict criteria of patient selection to produce "clean" data that could be analyzed without complications. However, after 12 years of accumulating clinical data, it became feasible and desirable to "expand the envelope" and attempt treatment of more complicated cases. Methods: Twenty-one patients with magnetic resonance imaging (MRI)-documented extruded, but nonsequestered, herniated discs with appropriate pain syndromes were treated with PLDD. Results: Eighteen of the 21 patients treated achieved the top category of the MacNab criteria, with good pain relief, and in some instances, reversal of neurological deficits. Conclusions: Patients with extruded but nonsequestered disc herniations may now be included in the group selected for PLDD.

Journal of Clinical Laser Medicine & Surgery, Vol. 20, No. 1, 2002, pg. 15, "Editorial Comment."

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