Percutaneous Laser disc decompression PLDD is a new technique first used by Ascher-choy in 1986 for the treatment of lumbar disc herniation, which has been carried out one after another in recent years at home and abroad and has achieved satisfactory results. In October 2004, our hospital started to apply PLDD technology to treat 32 cases of lumbar disc herniation with satisfactory results. The results are summarized as follows. 1.Clinical data 1.1 General data The 32 cases in this group, 11 men and 21 women, aged 19-56 years old, average 43 years old. All of them were diagnosed with lumbar disc herniation through clinical symptoms, weight and CT and MRI examination. There were 24 cases of single disc protrusion, 8 cases of protrusion of two adjacent segments. 2 cases of L3~4 segmental protrusion, 16 cases of L4~5 segmental protrusion, 6 cases of L5~S1 segmental protrusion, and 8 cases of L4~5 and L5~S1 double segmental protrusion, totaling 40 discs. The duration of the disease ranged from 1 month to 13 years, with an average of 18 months. The results were poor or ineffective after 12 weeks of non-surgical treatment, or recurrent. The clinical symptoms were low back pain combined with lower limb radiating pain. 1.2 Treatment 1.2.1 Apparatus and equipment HOP-100 ND:YAG medical laser [produced by Beijing Long Hui Heng Company], wavelength 810 nm, output power 30 W, emission power 15 J. 400 μm diameter optical fiber, 18 G puncture guide needle, C-arm X-ray machine. 1.2.2 Position and puncture Prone position with pillows on the chest and hips to suspend the abdomen to prevent compression of internal organs. The skin was routinely disinfected and toweled, and the puncture site was positioned under fluoroscopy, 8-10 cm from the spinous process on the affected side. The lumbar disc was punctured with a sheathed 18G needle under X-ray surveillance, and the needle entered at an angle of 45° to 60° from the horizontal. Patients complained of pain when the puncture needle touched the disc tegument and the annulus fibrosus, and the pain disappeared once the needle tip entered the nucleus pulposus. For the L5-S1 disc, because the iliac wing was obstructed, we used a 5-mm diameter bone drill after local anesthesia to punch a hole in the iliac wing in the direction of localized puncture before puncturing. The tip of the puncture needle was located in the central posterior portion of the disc nucleus pulposus about 5-10 mm. After successful puncture, the needle core was withdrawn and a 400-μm inner diameter fiber was used, and the outer layer of the fiber was peeled off so that the laser irradiated a complete circle on the plane. Place the fiber into another puncture needle of the same size to adjust the length so that the fiber exposes the tip of the needle about 3 mm. then insert the fiber into the body to fix. 1.2.3 Laser irradiation and dose The fiber output function is 30W, the irradiation time is 1S, the interval time is 2S, the dose is 15J each time, and the total irradiation is 1,600~2,000J. Multi-point (posterior external part of the affected side of the nucleus pulposus, posterior central part of the nucleus pulposus, posterior external part of the healthy side of the nucleus pulposus, and central anterior part of the nucleus pulposus) energy irradiation is used, specifically: under fluoroscopy let the puncture needle tip reach the posterior external part of the affected side of the nucleus pulposus first. The laser irradiation is about 600J, then continue to puncture with the arc of the puncture needle, advance the tip of the puncture needle to the posterior central part of the nucleus pulposus, the laser irradiation is about 500J, then continue to puncture, advance the tip of the puncture needle to the posterior external part of the healthy side of the nucleus pulposus, the laser irradiation is about 400J; finally, return the puncture needle to the outside of the fiber ring, puncture again, so that the tip of the needle is located in the central anterior part of the nucleus pulposus, the laser irradiation is 400J~600J. Then stop During the irradiation, the patient’s reaction should be closely observed, and the sound of laser vaporization and the nature of the fluid and gas discharged through the needle sheath should be monitored. If there is any abnormality, stop immediately. When the patient has obvious lumbar distension and pain, pull out the fiber and use negative pressure injection suction, 3~5 times per interval. 1.2.4 Postoperative treatment After termination of irradiation, pull out the optical fiber and the puncture needle, and apply a band-aid to the needle eye. Stay in bed on the same day and wear a waist brace for activity the next day. Antibiotics and dexamethasone were administered intravenously for 2-3 d. The patient could return to work 1 week after surgery. 2. Results 2.1 The efficacy assessment criteria were mainly based on the degree of remission of clinical symptoms and signs, with reference to the Williams’ efficacy assessment criteria [1]. Excellent: Symptoms and weight completely disappeared and normal work and activities were resumed. Good: The main symptoms and signs disappeared, and the patient was able to perform his or her original work. Possible: individual symptoms disappeared, still affecting work and life. Poor: symptoms and signs do not improve, or even worsen, and need further treatment. 2.2 Evaluation of efficacy The group received regular follow-up after surgery, with the follow-up time ranging from 6 to 18 months, and the average was 10 months. The results were evaluated at 6 months after surgery according to the above-mentioned efficacy evaluation criteria, and the results were excellent in 25 cases (80%), good in 2 cases (6%), acceptable in 3 cases (9%), and poor in 2 cases (6%). The success rate was 94%, and the excellent rate was 86%. 2.3 Postoperative reactions and complications Ten patients had low back pain on the second postoperative day, which lasted for several days and gradually relieved and disappeared after local physiotherapy. There was no vascular, nerve root and spinal cord injury and no intervertebral disc infection and other complications in this group. Two cases with poor outcome were treated with open surgery. 3, discussion 3.1 PLDD principle ① nucleus pulposus retraction decompression theory: the intervertebral disc is a dense structure composed of the fibrous ring surrounding the nucleus pulposus and cartilage plate. choy] et al. found through animal experimental research that a small change in the volume of the disc can cause significant changes in the internal pressure of the disc, after laser irradiation, the nucleus pulposus vaporization can cause a significant decrease in the internal pressure of the disc, while the protruding nucleus pulposus tissue retraction occurs, relieving the The nerve root compression was relieved and the nerve symptoms were relieved. Qi Qiang et al. demonstrated that after laser vaporization, the intradiscal pressure could be reduced by more than 50%. Wang [5] et al. suggested that during laser vaporization of the nucleus pulposus, the nucleus pulposus could be continuously aspirated with an empty needle, and negative pressure was formed in the nucleus pulposus, which caused the surrounding nucleus pulposus tissue to contract centripetally, thus reducing the nerve compression and achieving the purpose of treatment. (②The view that the direction of the herniated nucleus pulposus is changed: Yang Jun et al [6] believed that this surgical procedure is to open a small hole on the lateral posterior side of the lumbar disc, artificially changing the direction of the herniated nucleus pulposus and reducing the possibility of the nucleus pulposus re-projecting to the posterior side. (3) Gap stenosis hypothesis: David LS et al [7] suggested that there is a possibility of gap stenosis after laser disc decompression, and the narrowing of the gap at the herniated disc shortens the passage through which the nerve roots pass, relieves the tension of the nerve roots under pressure due to the herniated disc, and plays a role in eliminating neurological symptoms. 3.2 Indications for surgery The correct grasp of the indications for surgery is an important aspect of obtaining good results. the indications for PLDD surgery are relatively limited: ① bulging and herniated discs compressing the spinal cord or cauda equina nerve roots, with no significant improvement after 8 weeks of non-surgical treatment. ②Younger patients with a herniated or bulging disc that has not been in pain for a long time are the best indications. ③Patients with mild to moderate spinal stenosis, calcification of the posterior longitudinal ligament and other spinal surgeries are relative indications as long as the current symptoms are mainly caused by the herniated disc, while there are mild to severe changes in symptoms. 3.3 Laser energy size and multi-point irradiation According to the conventional lumbar disc herniation treatment, the energy per disc is generally about 800~1500J. Experimental studies have confirmed that the laser can vaporize the disc, and the size of the vaporization cavity is proportional to the energy size, but the vaporization reaches a certain level and has a “saturation tendency”, even if the laser energy is increased again, it cannot significantly change the size of the vaporization cavity. The size of the vaporization cavity is directly proportional to the energy level. We have changed the traditional PLDD procedure from single-point irradiation to multi-point low-energy irradiation, which can enlarge the vaporization cavity and avoid the possibility of thermal damage. Whenever adjusting the direction and position of the needle tip, the fiber must be pulled out first, and the puncture needle must be adjusted to confirm satisfaction before inserting the fiber to avoid breaking the fiber tip. The thermal effect is the stimulation response of the heat energy diffusion of the laser vaporizing the medullary tissue to the surrounding tissues, and most patients have a response process with increasing irradiation time and dose. When the patient complains of heat, soreness and slight pain in the back and legs, the irradiation can be suspended and the fiber can be removed to dissipate heat in the disc, or the fluid and gas in the disc can be aspirated with a syringe, or the needle tip can be moved slightly before irradiation. After removing the puncture guide needle, press the eye of the needle for 3~5 minutes to prevent the occurrence of hematoma. 3.4 Modified L5~S1 intervertebral space puncture method Due to the obstruction of the iliac wing, it is very difficult to puncture all single points with the 18G puncture needle, and it is almost impossible to adjust the aspect of the needle more often. For this reason, we used a local anesthesia to puncture the L5/S1 intervertebral space with a 5mm diameter bone drill at the localization point of the iliac wing, with a success rate of 100% and an accuracy rate of over 90%. In order to reduce pain and enhance the effect of local anesthesia, Dulcolax 100mg can be injected intramuscularly 5min before perforation. 4.Efficacy Conventional PLDD technique for the treatment of lumbar disc herniation has the advantages of simple operation, surgery under local anesthesia, short time consuming, minimally invasive, less patient pain, short hospital stay, fast recovery, not passing through the spinal canal, avoiding the spinal cord and nerve roots, high safety and does not affect It has the advantages of not going through the spinal canal, avoiding the spinal cord and nerve roots, being safe and not affecting the stability of the lumbar spine, having few complications, being able to perform multiple lesions of the disc at the same time or repeat treatment, and being easily accepted by patients. It can avoid complications such as open surgery bleeding, scar formation of paravertebral tissue, postoperative lumbar instability, nerve damage, and retroperitoneal tissue damage. The size of the surgical cost is less than that of conventional open surgery. Efficacy: Choy [9] et al. performed 518 cases of PLDD with 752 intervertebral discs from 1986 to 1999, with a success rate of 85%. The total effective rate reported from home and abroad is between 72.8% and 76.5%. complications of PLDD are rare. However, if the operation is not performed properly, it can lead to nerve and vascular injury or infection. 333 cases of PLDD with 752 segments reported by Choy in his early years had only 1 case of complication of discitis. Other complications such as postoperative fever, infection, ureteral injury, lumbar muscle hematoma, and vertebral lamina injury were rare. In actual clinical work, there are many methods of treatment for disc herniation, and various methods have relatively superior therapeutic ranges, and PLDD requires strict mastery of surgical indications to maximize efficiency.