TREATMENT OF LUMBAR HERNIAS BY ENDOSCOPIC NUCLEOPLASTY WITH RADIOFREQUENCY

Objective: To evaluate the postoperative outcomes of minimally invasive technique for treating lumbar disc herniation in patients undergoing percutaneous endoscopic nucleoplasty with radiofrequency in the center of minimally invasive procedures Veracruz (CEMIVER) of the HRAEV.. Methods: A descriptive, comparative, ambispective and longitudinal study. The clinical records of patients who underwent herniated disc surgery were reviewed from March 2010 to March 2015. Inclusion criteria were individuals of both sexes, aged 18-65 years, with disc herniation diagnosis by MRI, evocative discography (pain) and clinical evaluation. The variables were analyzed by VAS, Oswestry disability index for functional assessment and Macnab criteria for modified retrospective cross clinical classification. Results: 161 patients were included, 81 female and 80 male, aged between 18 and 65 years with severe (83.8%) and moderate (16.2%) disability according to the Oswestry disability index; the total of excellent results was 83.8%, 9.5% were good, 4.8% were median and 1.9% were poor results, according to the Macnab criteria; the average time of surgery was 84 minutes per procedure, and the postoperative average bleeding was 65 ml. Of the total, 87.4% of the patients were on an outpatient basis and 7.6% had a short hospital stay.. Conclusion: It was found that percutaneous endoscopic nucleoplasty with radiofrequency technique is a procedure that offers great benefits for patients with lumbar disc herniation, including performing it under local anesthesia, with clear visualization of the surgical field, minimal pain, little bleeding, shorter operative time, does not cause instability of anatomical structures and has minimal rate of complications.


INTRODUCTION
The intervertebral disc is the anatomical structure that connects the vertebral bodies.Skeletally, three main zones can be differentiated: the cartilaginous plate, which separates the vertebral bodies from the fibrous ring, the fibrous ring, and the nucleus propulsus.
Lumbar pain syndrome (LPS), associated with lumbar disc herniation, is a lesion that presents clinically as low back pain, which irradiates to the gluteal zone, thighs, legs and feet.It may follow a dermatome and can present weakness, numbness and tingling in the lower limbs.In the majority of individuals who have suffered lumbar pain, generally aged between 20 and 60 years, a high percentage of them have to be operated on, as pain is associated with 45% lumbar disc hernias.
Minimally invasive surgery is the current trend for all types of surgery, especially in the vertebral spine, where the surgical focuses and procedures continue to be considered by many as a last-resort treatment, unless there is evidence of progressive neurological lesion.The indecision over whether to perform surgery is partly due to concerns about the morbidity associated with traditional spine surgery, which can damage muscles during the approach to the vertebral spine.Minimally invasive discectomy is considered adequate by the majority of patients, and by many surgeons, for the treatment of lumbar disc hernias; however, the degree of minimum invasiveness various widely among surgeons.
The most common modern adaptation of a technique of this type is described is microlumbar discectomy, which offers various surgical advantages.The use of minimum incisions is made possible using specialized or tubular mini-retractors, which retract the muscle.Many surgeons use an endoscope or a surgical microscope to minimize invasivity, and the muscles are divided to the width of the dilators by small incisions that define the majority of microdiscectomies performed today.Minimally invasive adaptations to standard laminectomy, in discectomy include smaller incisions; therefore, in these surgical techniques, there is less manipulation of the nerve root, as well as fenestration of the annulus, and elimination of only the sequestered fragment, which can be easily extracted through the annular defect. 1 This investigation study begins by giving an overview of the results obtained by various authors, such as the advances in the technique of percutaneous endoscopic nucleoplasty with radiofrequency, with results that enables us to see the benefits obtained in the patients.It also includes the methodological development of the study, through to the final results, which show that the population served at this tertiary hospital, as well as users of the metropolitan area with a diagnosis of herniated discs, will benefit greater from this minimally invasive surgery.
Since earliest times, man has sought ways to alleviate his pain and favorably change the natural course of diseases.In prehistoric times, we have only bone remains in which fractures and dislocations have been found, with signs of bone fusion in the Paleolithic era.One of the first written evidences found dates back to more than 2500 years B.C, in a medical text known as the Edwin Smith papyrus, which refers to traumatic lesions of the spine, giving a clinical description. 2Hippocrates (460-370 B.C.) and Galen (130-201) were the first to link vertebral spine injury to paralysis of the limbs.Galen also performed experiments on animals, demonstrating that disruption of the spinal cord produces paralysis and anesthesia below the level of the lesion. 3But it was not until the mid-eighteenth century that surgical treatments of the spine began to be performed, particularly in the European countries, such as England, Germany and France; at the end of the nineteenth century, specialists began to speculate on the instability generated by laminectomy on the vertical spine, and various osteoplastic laminectomy techniques are described. 4In 1905 Cushing 5 formulated indications and contraindications for spine surgeries, in which he mentions the benefit of decompressing the neural elements crushed by bone fragments or bullets, in patients with incomplete nerve injuries.In 1649, French surgeon Ambroise Paré was the first to propose traction for the treatment of traumatic spine lesions. 6Decompression alone helped improve the neurological symptoms, and until the end of the 20 th century, this procedure was widely used for a wide range of degenerative cervical problems with anterior spinal compression, but it could present complications due to bone collapse and expulsion, pseudoartrosis and morbidity at the site of injection into the iliac crest.Instrumentation of the vertebral spine has grown exponentially since the introduction of the anterior approach to the cervical spine, by Cloward 7 in 1955-1956, by Harrinton 8 in 1973 for the thoracolumbar spine, and by doctor Eduardo Luque Rebollar apud Apostolides et al. 9 who designed bars and transpedicle screws for segment fixation. 7,8,9ince then, the technical aspects have been developed, and the next major breakthrough came in the late 1960s and early 1970s when Caspar began using microsurgery. 10,113][14] Today, changes or transformations have been made to the conventional procedure, such as the use of minimally invasive surgical techniques, which avoids the complications associated with the traditional procedures, which use broader approaches and expose more tissue.Among the new techniques, the endoscopic approach using dilators has enabled multiple surgeries, and new routes and multiple approaches have been developed for the application of endoscopic techniques. 15In recent decades, spine surgery has turned its focus to increasingly less invasive procedures.The universal trend in current surgery is minimum invasion, reducing pain scores, morbidity and postoperative disability.Various works have been published on the treatment of hernias of the nucleus pulposus using the MAST (Minimally Invasive Spinal Technology) system, concluding that: the clinical results are the same as those obtained using classical techniques; the postoperative hospitalization time is significantly shorter, and can be done on an outpatient basis; the time for return to work is significantly shorter; and patient satisfaction is greater.Increased frequency of herniation recurrence has not been shown.The aims of this study are to evaluate the postsurgical results of the minimally invasive technique in the treatment of lumbar disc hernias in patients submitted to percutaneous endoscopic nucleoplasty with radiofrequency, and to establish the functionality and assess the postoperative clinical grading of our patients.

METHODOLOGY
This is a descriptive, comparative, ambispective, longitudinal study conducted at the Hospital de Alta Especialidad de Veracruz (HAEV) and CEMIVER.Approval of the study was obtained from the Research Ethics Committees of both Institutions, and prior informed consent was obtained from the patients.
Clinical records of the traumatology and orthopedic service were used, particularly those of the modular spine surgery unit, for patients diagnosed, clinically and by imaging, with lumbar disc herniation, with discography.Patients were of both sexes, aged 18 to 65 years.Subjects were excluded if they had obesity, sequestrated hernia, hematological diseases, bone marrow syndrome, degenerative congenital bone disorders, instability, degenerative lumbar spondyloysis, spondylolisthesis, infections, and tumors, and those for whom there were no medical records.
Clinical records were used in this study, always protecting the patient's integrity, in order to comply with the rules of respect and confidentiality.In each procedure, basic materials for minor surgery were used in the operating theater, with the use of fluoroscopy and nonionic contrast medium in the trans-surgical, as well as Wolf endoscopy for spine surgery and the Disc-Fx radiofrequency team.
All the patient records that met the inclusion criteria were reviewed in the period March 2010 to March 2015 in the area of traumatology and orthopedics in the modular spine surgery unit.The study variables were also evaluated, and clinically correlated.(Table 1)

ANALYSIS OF THE DATA
The Student t test was used for the descriptive statistics, showing rapid recovery of the patient, and reduced costs and adverse events at the abovementioned hospitals.The variants were measured using the VAS (visual analog scale of pain) scale, the Oswestry disability index for the functional assessment, and the modified Macnab criteria for the clinical grading.The analyses were performed using the software program Microsoft Excel 2010, SPSS 19.

RESULTS
The study, conducted at the Hospital de Alta Especialidad de Veracruz (HAEV) and CEMIVER, included 161 patients, selected based on the inclusion criteria.The subjects were male and female, with a minimum age of 18 years and a maximum age of 65 years.
At the time of diagnosis, all patients were indicated to receive six months of consistent conservative treatment, with administration of anti-inflammatory analgesics, weight control, preventive postural techniques for the spine, and rehabilitation and infiltration.The technique of percutaneous endoscopic nucleothermodiscoplasty was performed in 100% of the patients; 83.8% with severe disability, and 16.2% with moderate disability, according to the Oswestry disability index (Table 2); a total of 83.8 % excellent results was obtained, with 9.5% good results, 4.8% average, and 1.9 % poor, according to the criteria of Macnab; we found a significant decrease in postoperative pain using the VAS scale (Table 3); the average surgery time was 84 minutes per procedure, average postoperative bleeding of 65 ml; 87.4% of the postoperative patients were treated on an outpatient basis, and 7.6% had a short hospital stay.

DISCUSSION
Degenerative disease of the lumbar disc, and in particular, lumbar disc herniation, is a disease that is commonly presented to orthopedic doctors, particularly spine surgeons at the Hospital de Alta Especialidad de Veracruz, where percutaneous endoscopic microdiscectomy with radiofrequency is performed using the posterolateral (PTL), extreme lateral (ETL) and interlaminar (ITL) approaches.It is a minimally invasive technique that enables discectomies to be performed through a small skin incision, with fluoroscopic control.
Nowadays, there is experience in the use of this technique in various parts of the country, but so far, there have been no reported data on this technique in the State of Veracruz.This study performed at the HAEV and CEMIVER found favorable results for the use of percutaneous endoscopic nucleoplasty with radiofrequency for the treatment of lumbar disc herniation, with very similar results to those obtained in Germany and the United States by doctors Sebastian Ruetten 16 , Chiu 17 and Yeung, 18 each with their case series, according to their investigation studies.A study carried out in Colombia by Doctor J.F. Ramírez et al., who obtained favorable preliminary results in a population of 3000 patients in a study performed over fifteen years, is a reference of importance and a pioneering work in the use of these minimally invasive techniques of the vertebral spine in Latin America.That study demonstrated immediate stability, good clinical response, absence of intraoperative morbidity, reduced surgery times and bleeding, and a very short hospital stay, as some of the results of this first series of the technique.This three-year study at this hospital institution is promising, and requires longer follow-up time, as well as inviting other hospitals to conduct multi-center studies to determine its efficacy, motivating spine surgeons to use it, and to learn about these new minimally invasive surgical techniques.

CONCLUSIONS
Nowadays, minimally invasive surgery is still a technique that is little known or practiced in Mexico; to date, and despite some opposition, this new advance in surgical techniques is opening doors and different routes, as the results obtained are successful and have shown great benefits for our population.
The vast majority of surgeons specializing in the vertebral spine continue to perform the conventional procedures described by   the old school.Despite and against the opponents to this new technology and surgical techniques for medicine, particularly spine surgery, we have obtained similar, or in some cases better results, and that may bring satisfactory benefits for our population.Those who know and perform these surgical techniques have studied them abroad, and have gradually opened the way for this new technology called minimally invasive spine surgery.We therefore emphasize and trust, according to our results and benefits in our patients, and described in various studies worldwide, which show that this type of technique used for the treatment of lumbar disc herniation provides great benefits for our patients, such as: it can be performed with local anesthetic, clear visualization of the surgical field through endoscopy, mini-mum pain, little bleeding, shorter surgery times, it does not cause instability of the anatomical structures, less aggression and damage to the tissues, outpatient procedure, low medical cost, more cosmetic procedure among others, and with a lower risk of transand postoperative complications.
Based on our study, we have confidence in the results obtained, therefore we widely recommend these surgical techniques for the patient population of Hospital de Alta Especialidad de Veracruz and the Centro de Mínima Invasión de Veracruz (CEMIVER).
All authors declare no potential conflict of interest concerning this article.

Table 3 .
Comparative data on pre-and postsurgical pain VAS Scale

Table 2 .
Comparative data on pre-and postsurgical functionality.