Abstract】Objective To introduce the treatment of cervical spondylosis with low-temperature plasma nucleus pulposus ablation and to explore the clinical application value of low-temperature plasma. Methods Eighty-six patients aged 16 to 82 years who were diagnosed with cervical spondylosis by MRI and clinical manifestations were treated with percutaneous plasma nucleus pulposus ablation, and their efficacy was observed and analyzed by using visual analog scoring (VAS) and Macnab scoring. Results All patients in this group were followed up from 3 months to 18 months, with an average of 10 months. 86 patients had different degrees of symptom improvement, and the total effective rate was 86.7%. The mean preoperative VAS score was (6.11±0.32), and the mean postoperative VAS score from 3 months to 18 months was (1.71±0.52). According to the modified Macnab efficacy assessment criteria, the treatment effect was excellent in 55 cases, good in 9 cases, acceptable in 10 cases, and poor in 12 cases, with an effective rate of 86.7%. None of the cases had serious complications. Conclusion Under strict control of its indications, plasma nucleus pulposus ablation is an effective minimally invasive interventional procedure for the treatment of cervical spondylosis with the characteristics of simple operation, safety, small trauma and excellent recent efficacy.
【Key words】myeloablation; cervical spondylosis; minimally invasive
Cervical spondylosis is a disease with neck pain and stiffness as the main clinical symptoms. The traditional treatment method is intervertebral disc removal, but this procedure is open surgery, which is highly invasive and often results in complications such as nerve root injury, dural sac injury, cerebrospinal fluid leakage, intervertebral discitis, large vessel injury, postoperative back pain, etc. The risk is high. In the last decade, percutaneous disc decompression has been considered a safe and reliable minimally invasive method for treating herniated discs. Cryogenic plasma nucleus pulposus ablation is a kind of disc decompression surgery, which is another minimally invasive surgical method for treating herniated discs after percutaneous disc aspiration and laser vaporization decompression of the nucleus pulposus. In October 2001, we applied this technique to perform nucleoplasty for cervical disc herniation and obtained satisfactory results. This procedure is particularly suitable for patients with cervical, radicular and sympathetic cervical spondylosis who have poor results with conservative treatment and whose indications for surgery are not obvious or who are unwilling to undergo surgery. Eighty-six patients aged 16 to 82 years with cervical spondylosis treated with nucleus pulposus cryoablation from April 2010 to August 2011 were followed up and observed, and the initial satisfactory clinical results were achieved, which are reported below.
1.Objects and methods
(1) Clinical data
There were 86 patients in this group, 54 males and 32 females; age ranged from 16 to 82 years old, average 45 years old; disease duration ranged from 3 months to 10 years; average 36 months. Those who had poor results after three months of conservative treatment were included in this study. Simple vertigo, headache and neck soreness were found in 20 cases; severe neck and shoulder stiffness, pain and upper limb soreness, burning pain and numbness of the radiculopathy were the main cases; 39 cases were accompanied by prolonged dizziness and headache; 10 cases had severe headache. There were no signs and symptoms of severe cervical spinal cord compression.
(2) Surgical instruments
ArthroCare 2002 tissue vaporizer, C-arm X-ray machine, puncture needle.
(3) Surgical procedure
Surgical puncture access and needle approach: ①Patient in supine position with a soft pillow on the neck to stretch the neck back and keep the muscles relaxed; ②Localize the lesioned intervertebral space under C-arm X-ray machine fluoroscopy, mark the puncture site, and routinely disinfect and lay the towel; ③Local infiltration of about 5 ml of 1% lidocaine into the puncture site and the prevertebral fascia; ④Into the arterial and visceral sheaths under X-ray machine guidance, and place the special puncture needle in the middle of the lesioned intervertebral disc. The puncture needle was placed in the middle of the diseased disc, with the midpoint in the orthogonal fluoroscopy and the posterior edge of the disc in the lateral fluoroscopy. The puncture needle core is withdrawn and the cold ablation tip attached to the ablation mainframe is placed under x-ray guidance. Make sure the position of the tip is accurate (about 3mm from the posterior edge of the disc), set the energy level to 3, step on the thermal coagulation button for 0.5~1 second, stop immediately if there is obvious irritation, and reset the tip. If there is no obvious irritation, step on the ablation button for 10-15 seconds, while rotating the tip slowly at a constant speed of 360 to perform gasification and ablation, and counterclockwise to perform gasification and thermal coagulation. Pull out the knife head together with the trocar needle for 3 mm, retreat to the center of the disc, and ablate again in the same way. Finally, the patient is asked for autonomic sensation and a second disc ablation can be performed if needed. After rotating out the tip, the puncture needle was withdrawn, the field was cleaned and disinfected, and a dressing was applied.
(4) Postoperative precautions and care
Wear a neck brace for two weeks after surgery, and take oral antibiotics routinely for one day (dexamethasone 50mg/d for three days if the pain is severe). Some patients may have slight neck discomfort on the postoperative day, so avoid activities and pay attention to the clean care of the neck wound. Three days after the operation, functional exercises of neck health care gymnastics were performed.
2.Efficacy and evaluation
(1) Efficacy assessment criteria
(1) Visual analogue score (VAS) of pain was used before surgery, 3 days after surgery and 3 months after surgery: 0 indicated no pain, 10 indicated the most painful; 1~3 mild pain, 4~6 moderate pain, 7~10 moderate pain. ②Efficacy evaluation was performed by the modified Macnab scale at 3 days and 3 months after surgery, respectively, and the main judgment criteria were based on the improvement of clinical symptoms. Excellent: pain disappeared, no activity dysfunction, resumed normal work and activity; Good: pain disappeared, able to engage in light work; OK: symptoms improved, still have pain, unable to work; Poor: nerve compression performance, need to perform surgery. The results were recorded at the postoperative and follow-up periods, and the excellent rate of efficacy was counted.
Statistical methods Data were processed by statistical criteria; mean ± standard deviation, using statistical correlation software, and tested by paired t-test for before and after control, and P < 0.05 was considered significant.
(2) Results
The VAS pain score was (2.40 ± 0.87) at three days after treatment, and the mean VAS score was (1.71 ± 0.52) from 3 months to 18 months after surgery and (6.11 ± 0.32) before treatment, which was significantly lower after surgery compared with the preoperative period. the efficacy of Macnab score at 3 days after surgery was rated as excellent in 70 cases, good in 5 cases, acceptable in 5 cases and poor in 6 cases. The excellent rate was 81.3%, and the effective rate was 93.3%. At postoperative follow-up from 3 months to 18 months, the average treatment effect was excellent in 55 cases, good in 9 cases, acceptable in 10 cases, and poor in 12 cases, with an excellent rate of 63.9% and an effective rate of 86.7%.
3.Discussion
(1) Mechanism of cervical intervertebral disc herniation
The intervertebral disc is composed of cartilage end plate, fibrous ring and nucleus pulposus, of which the nucleus pulposus is mainly composed of collagen and proteoglycan, while the intervertebral disc cells rely on the periphery of the fibrous ring and the vascular supply in the vertebral body. When the disc degenerates, the pressure inside the disc can reach 24.07kpa, which affects the blood supply from the annulus fibrosus to the central part of the disc, making the intervertebral disc cells and matrix nutrition interrupted, the nucleus pulposus dehydrated and fragmented, while the tissue dehydration and fragmentation form a fissure, which becomes a channel for the protrusion of the nucleus pulposus. Thus, the nucleus pulposus protrudes backward to compress the spinal cord and nerves. The compression of the nerve root by the herniated disc and the consequent inflammatory reaction such as edema and exudation of the nerve root are the main reasons for the main clinical symptoms such as shoulder, neck, arm pain and numbness of the lower back and leg pain. Therefore, relieving the compression and removing the pain-causing medium around the nerve root or improving local microcirculation become the key to treating nerve root cervical spondylosis.
(2) Rationale of low-temperature plasma nucleus pulposus ablation
Cryogenic plasma radiofrequency nucleus pulposus ablation combines tissue ablation and radiofrequency thermal coagulation to reduce the pressure in the intervertebral disc by ablating and vaporizing the nucleus pulposus tissue, thereby relieving pain. The main principle of action is that the application of 100kHz radiofrequency causes ions (K+, Na+, etc.) in the tissue to form plasma and accelerates it. The accelerated plasma breaks the peptide bonds in the nucleus pulposus tissue and forms elemental molecules and low molecular gases (O2, H2, CO2), which escape through the puncture channels, thus relieving the pressure on the dura and nerve roots for therapeutic purposes. This is why radiofrequency is also called plasma knife. The plasma tip reaches the target tissue of the disc nucleus pulposus through the puncture needle, which allows the nucleus pulposus to achieve decompression and decompression, a small pressure reduction that will significantly reduce the irritation of the lesion on the nerve root or nerve endings, thus relieving the symptoms as well. In addition, some of the nucleus pulposus tissue is removed and the remodeling of the nucleus pulposus tissue within the disc is completed; at the same time, radiofrequency thermal coagulation causes the collagen of the nucleus pulposus tissue to contract and solidify. Compared with other internal decompression procedures, its characteristics are simple operation (puncture under local anesthesia through the C-arm X-ray machine guidance); small trauma (the diameter of the puncture hole is only 1mm); safety (the instrument only produces a temperature of 40 ℃ when working, and 70 ℃ when heating, the temperature range of 40 ℃ ~ 70 ℃, in a small heat penetration and tissue necrosis, only on the surrounding 2mm range of tissue (effect); low-temperature plasma nucleus pulposus ablation only interrupts the molecular structure and alters the biochemical state of the disc, rather than direct thermal denaturation of the disc. In a cadaveric study [16], it was found that myeloplasty decompresses the nucleus pulposus without causing necrosis and that tissue vapor coagulation is confined to the nucleus pulposus, leaving the annulus fibrosus, endplate, and vertebral body unaffected; myeloplasty achieves volumetric removal of the disc without significant thermal or structural damage to the surrounding tissue. There is also no effect on the stability of the spine.
(3) Indications
Compared with other minimally invasive procedures, cryogenic plasma nucleus pulposus ablation is less invasive, more complete and more effective. The temperature is lower, and there is no thermal damage to the surrounding tissues under the correct operation. The entire procedure is guided by a C-arm X-ray machine, and the entry point is between the carotid sheath and the trachea and esophagus, where there are no major blood vessels or nerve tissue. This method has been proven to be safe in practice. For patients with cervical spondylosis for which conservative treatment is ineffective and surgery is not appropriate, cervical disc myeloablation is an excellent minimally invasive method. It is suitable for nerve root type, vertebral artery type, sympathetic type cervical spondylosis. MRI and neurological examination is consistent, the fibrous ring is intact, and the onset of the disease is more than 3 months as the first choice. Conservative treatment within 3 months of the first onset is done as the first choice. In case of recurrence, it is the target of treatment.
Good indications are as follows: (1) discogenic pain and contained disc herniation; (2) shoulder and neck pain and heaviness with obvious upper limb soreness, burning pain and numbness; (3) simple cervical disc herniation; (4) unilateral disc herniation confirmed by MRI if conservative treatment is not effective for three months; (5) those presenting unilateral type of nerve root symptoms with mild cervical spine osteophytes and degeneration.
(4) Contraindications
(1) extra-cervical lesions, such as combined frozen shoulder, oblique angle muscle syndrome; (2) serious ankylosing spondylitis, rheumatoid arthritis; (3) combined with serious primary diseases such as cardiovascular, cerebrovascular, liver, kidney and hematopoietic system. ④ nucleus pulposus free in the spinal canal, disc infection, vertebral fracture or tumor; ⑤ severe bony spinal stenosis, calcification of the posterior longitudinal ligament or herniated disc; ⑥ those with spinal cord compression degeneration and cone fasciculation sign. (7) Those with a 2/3 reduction in disc height or severe degeneration or vacuum; (8) Those with significant psychological disorders, pregnant women, etc.
(5) Complications
In general, cryo-plasma nucleus pulposus ablation is a safe and minimally invasive procedure. Only a few scholars have reported cases of postoperative bacterial discitis, and dural fibrosis. If the puncture process causes transient radiating pain in the upper extremity, the needle needs to be slightly withdrawn and the direction and angle of needle entry changed, and the operation can be continued. A few people reported intraoperative tip fracture, but the fracture rate is not high. It is considered to be related to the following factors: (1) the diameter of the cervical tip joint is thin about 1 mm, which is not strong enough; (2) the intensity of repeated puncture is reduced because of incorrect puncture route; (3) the patient swallows frequently during the operation, which has a squeezing effect on the tip; (4) the tip is used for several times.
(6) Precautions
① Strict case selection is a prerequisite for successful surgery, except for the previously discharged factors, and cases with severe disc degeneration shown by MRI should also be discharged. Although the disc height is still normal, the ablation effect is not very satisfactory, which may be related to the decrease of disc water and degeneration in such patients, thus reducing the ablation effect of low-temperature plasma. ②In addition to preoperative instructions, good communication with the patient, intraoperative cooperation between the operator and the patient is necessary to complete the surgery. The patient should be instructed not to swallow as much as possible during the operation to avoid damage to the surrounding important tissues and blood vessels. ③The solid anatomical knowledge and standardized operation of the operator is the key to improve the efficacy and reduce complications. Since there are many important structures in the neck and the operation space is relatively limited, the operator is required to have a very clear understanding of the adjacent relationships of important structures in the neck in order to improve the success rate.
Cryogenic plasma nucleus ablation is performed under local anesthesia, which is fast, safe and effective. Compared with other minimally invasive procedures, this procedure has a small puncture hole, the puncture channel is basically bloodless, and the channel is significantly smaller compared with percutaneous puncture and aspiration, and the incision and aspiration are highly injurious and require a week of postoperative bed rest; compared with laser treatment, this procedure has a low local temperature (about 40℃～70℃), little thermal damage, and mild pain, while the laser has a high local temperature (about 300℃～600℃), much thermal damage, and significant pain. The laser has high local temperature (about 300℃～600℃), high thermal damage and significant pain. The whole procedure of low temperature plasma nucleus pulposus ablation only takes about 5-10min, and there are no complications such as spinal cord, nerve and blood vessel damage after the operation, and it is highly efficient to strictly grasp the indications, so it can be carried out in outpatient treatment, and it can be a positive choice in the treatment of cervical disc herniation in the ladder treatment.