Radiofrequencies in low back pain PDTA - Pathos

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Radiofrequencies in low back pain PDTA

Clinical report

Pathos 2023; 30, 1. Online 2023, Mar 30
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Damiana Maurogiovanni, Gianpaolo Fortini, Daniele Bertollo
UOC  Terapia del Dolore, CP
ASST Settelaghi, Varese
Direttore: Gianpaolo Fortini
_____________________________________________________________________________________________________


Summary

The authors present the proposal of a specific therapeutic diagnostic pathway; the quality of care and the journey of the citizen/patient affected by low back pain. They also present the results of a retrospective study aimed at verifying the impact that radiofrequency procedures have within this PDTA.

Riassunto

Gli autori presentano in dettaglio la proposta di un progetto mirato a ottimizzare , attraverso un percorso  diagnostico terapeutico specifico, la qualita’ delle cure e il percorso del cittadino/paziente affetto da low back pain. Presentano inoltre i risultati di uno studio retrospettivo mirato a verificare l’impatto che le procedure di radiofrequenze abbiano all’interno di tale PDTA.

Key words

Pain, diagnostic therapeutic pathway (DTP), radiofrequency

Parole chiave

Dolore, percorso diagnostico terapeutico assistenziale (PDTA), radiofrequenza


Introduction

Low back pain is defined as pain, muscle tension or stiffness, located between the 12th rib and gluteal folds, with or without irradiation to the limbs. It includes lumbago (hinge L4-L5), lumbar sciatica (beyond the knee L5/S1) and lumbocruralgia (anterior thigh L3/L4). More than 80% of the world population has suffered from this pathology at least once in their life.1
LBP is a major problem both in terms of treatment costs and the high social costs it entails, as it represents one of the major causes of disability and absenteeism from work, affecting mostly subjects aged 55-60 years . The incidence also seems to be destined to increase in the coming years: among the 25 most common causes of DALY's (disability adjusted life year) worldwide, LBP has moved from fifth place in 2005 to fourth in 2013 and is constantly growing.2 In the United States it is one of the leading causes of disability over 45 years and the second cause of medical consultation.
The diagnosis of LBP is complex and includes both clinical and instrumental diagnostic aspects, but also psycho-social and multidisciplinary ones, since this symptom can subtend to mechanical and non-mechanical causes, but also originating in some cases from pathologies of surgical interest (e.g. FBSS) or internal medicine (visceral causes: abdominal aneurysm, pelvic or renal pathologies).

Definition

The overall diagnostic therapeutic care pathway (PDTA) aims at taking charge of the patient and managing the demand according to a systemic approach to optimize the quality of care and the path of the citizen/patient, determining a significant organizational impact in the company that uses it.
The terms "diagnostic", "therapeutic" and "welfare" contemplate the perspective of an active and total taking charge of the patient, the prevention of rehabilitation, the definition of a shared clinical path and an often multi-professional management which envisages various areas of intervention such as psycho-physical, social, occupational and disability.
The construction of a PDTA defines an all-encompassing road map of objectives, roles and areas of intervention, helps to improve the constancy, reproducibility and uniformity of the services provided, guarantees clarity of the information to the user and of the tasks to the operators and helps to predict and minimize the risks and incidence of extraordinary events, while facilitating flexibility and adaptation.
The objective of the PDTA is the creation of an organizational clinical model that aims at sharing a therapeutic diagnostic path of the patient with LBP pain, aimed at pain diagnosis and shared therapy. This path should include the development of multidisciplinary and local hospital interfaces as well as the implementation of specific research and data collection oriented not only to pharmacological and procedural aspects, but to an overall view, according to the perspective of clinical governance.

Pathophysiology and clinic of LBP

In the construction of the PDTA of the LBP the first step is represented by the correct identification of the pain generator made complex by the wide diversification of the pathologies that can underlie this symptom: protrusions/herniated discs, arthritic facet joint disease, congenital anomalies, static/dynamic imbalances , infections (TB, rheumatism), metabolic osteopathies, vertebral fractures, degenerative disc disease, sacred ileitis. Particular attention should also be paid to the analysis of the patient's remote pathological history which allows the Red Flags to be excluded.3 Serious pathologies known to cause LBP such as tumors, aortic aneurysms and osteomyelitis. Differentiating the types of LBP pain and its specificities is useful, because the goals of care and the therapeutic approach are different depending on the pathology in progress. The adequate knowledge of the pathophysiological mechanisms underlying the manifestation of the pain symptom and the clinic represent a valid aid in the procedure to be followed. (Figure 1)
The current assistance system in Italy is of the sectoral-specialist type, for which each provider (GPs, specialists, hospitals, etc) is qualified to provide assistance with different degrees of clinical assistance complexity. In the event that the patient suffers from pain, various critical issues emerge concerning the diagnostic area, related both to the subdivision of professionals belonging to the various specialist areas that operate in the area of pain and to the use of operational protocols that do not have national origins but often use models that can be correlated to particular healthcare realities. Consequently, it is necessary to consider whether the citizen/patient affected by LBP has been visited by other specialists (primarily any previous evaluations or NCH interventions), whether he has already undertaken a diagnostic process or experimented with therapeutic options and the responses obtained to them.
An adequate and thorough E.O. it allows to distinguish the signs (Delitala, Laségue, Dandy, Valleix, Wasserman) and symptoms of a compression, irritation or interruption syndrome as well as the root territory of localization and possible irradiation of the referred and/or evoked pain. Alteration of reflexes (e.g. Babinsky) and joint tests of the lumbar spine and hip (joint integrity test, Gillet test, Gaenslen test and active and passive physiological movements) complete the semiological evaluation.
Following the numerous diagnostic instrumental techniques allow to further study the alterations of the spine. The pain therapist often finds himself continuing a diagnostic-therapeutic path started by other specialists but in any case there are some instrumental tests that constitute an essential reference both for the diagnosis and for the interventional strategy in the procedures. According to European guidelines, MRI is considered the best imaging test for LBP.1
Rx, although not recommended by the same guidelines for the spine, nevertheless represents the gold standard in spondylolysis, spondylolisthesis and is useful in disc degeneration and vertebral fractures, especially in dynamic modality.
MRI remains the gold standard in disc herniation and canal stenosis, assessing the health of parenchyma and nerve roots, thus constituting the investigation of choice in Red Flags suspicion. Finally, CT remains the technique of choice for studying the spine, providing information even on intra-articular floaters, disc dehydration, canal stenosis, presence of geodes, sclerosis. Although the European guidelines do not recommend the use of EMG, this investigation can sometimes be indispensable to indicate the type and severity of the nerve damage and the nerve root involved. Upon completion, laboratory tests are performed, especially in the case of suspicion of a rheumatological pathology (e.g. ankylosing spondylitis).
It should be remembered that in some specific cases it is also possible to resort to selective epidural injections, diagnostic block of the facet joints or diagnostic block of the sacroiliac joint as maneuvers having diagnostic-therapeutic value.
From the first visit, therefore, a PDTA is assumed which must be confirmed or corrected after the medical therapy or the diagnostic/therapeutic procedure that is considered useful for proceeding. In order to optimize resources, it is proposed to stratify patients into three categories:
  1. Patients (NRS 2-3) not to be taken into care (e.g. elderly people with osteoarthritis who have not already reached the 2nd step of the WHO scale without benefit) but to be referred to the attending physician with an accompanying letter.
  2. Patients (NRS 4-5) to be framed from a diagnostic point of view in which to start with medical therapy (e.g. intravenous cortisone cycle or switch to fixed therapy + as needed; these patients can be re-evaluated for procedures or referred to the doctor.
  3. Patients with acute pain (NRS >6) for which to start immediately with procedures for diagnostic/therapeutic purposes.

If the doctor deems it appropriate to activate the diagnostic/therapeutic procedure, he sets up the procedure, has consent signed and sets the date of the procedure. Whoever performs the first procedure must verify indications, clinic, current therapy, allergies and assumes responsibility for the act, identifies the metamere concerned or type of procedure (e.g. caudal infiltration instead of interlaminar epidural) trying to follow the indications (see specific chapters of the various procedures). You must comply with the agreed protocols, make the surgical file reporting useful data (in the PI non-progression of the m.d.c., pain to direct the 2nd procedure (2nd PI, coblation, RFG, PDS, SCS, referral to neurosurgeon) or the passage to another PDTA It is essential to mark the procedure precisely on the TA folder as recommended by the flow-chart, when possible it is useful to acquire and archive the images.
Those who carry out the first post-procedural check-up evaluate the diagnostic/therapeutic response of the procedure considering the various parameters: pain relief, (NRS, PR) duration over time, quality of life (Oswestry), reduction of drugs and use of rescue dose, leave written documentation indicating the next step to the procedure (another IP, coblation, peridoscopy, SCS, etc.) and program all the subsequent steps. Any subsequent maneuvers must be scheduled after 15-20 days to give the cortisone-deposit time to act. In the operational flow-chart of the LBP we start from procedures of low complexity (IP, block FA) and proceed, based on the response, to procedures of medium complexity or high technology (SCS, PDS). Sometimes patients arrive who have already undergone diagnostic/therapeutic procedures (e.g. intraforaminal by neuroradiologists) so they can go directly to more advanced procedures.
In radiculopathy PDTA, the use of RFG and PDS can potentially give an "intermediate" response compared to SCS, so they can be used in cases where SCS seems disproportionate to the patient's symptoms or clinical conditions (elderly patient, patient with doubtful compliance, in canal stenoses). The use of RF in various applications (disc coblation, RF FA, RF S-J, RFG) can be decisive or in any case long-lasting responses but it is expected that they can be repeated or follow one another because they act on different structures; International data emerge in which procedures with RF or PDS can recover the progressive loss of efficacy also of SCS.

Our case studies lead us to identify 3 types of patients:
  1. Young and working-age patients with acute pain in whom procedures can be curative, rapid intervention is needed using invasive procedures and resources -> low, medium and high complexity procedures.
  2. Older patients (65-75 years) with good quality of life in whom procedures can be performed but due to spinal degeneration and osteoarthritis progression, recur after some time and benefit from further procedures which provide pain responses acute but which then slip towards a chronicity that requires suspension.
  3. Older patient (> 75 years) where a good quality of life does not exclude invasive procedures but giving  preference to medium complexity methods (RFG, PDS), leaving high technology (SCS, intrathecal pumps) to younger patients.

Treatment options

We currently have various therapeutic options available which form an integral part of the PDTA (Figure 2) with the aim of improving the waiting times of the therapeutic diagnostic process, improving the information and communication aspects with the patient/citizen with the guarantee of a plan personalized intervention, optimize and monitor the quality levels of the care provided, promote the active participation of the patient in the management of his/her illness, encourage monitoring and methodical management of the patient by the doctor, optimize and rationalize access to specialist structures, guarantee treatment of any complications with integration of the various skills, improve the user satisfaction for the services received, activate a monitoring system of the operating methods envisaged by the route.
Although from 23 to 48% of patients with lumbosciatica due to herniated disc heal spontaneously, around 70% continue to have symptoms after a year, which is why analgesic therapy is often necessary.4 We must not forget that the first step of a therapeutic approach is the pharmacological one and only after its failure are interventional methods proposed.
The World Health Organization (WHO) in 1996 proposed a pain rating scale (initially only for cancer pain) and subsequently also adopted as a guideline for the treatment of musculoskeletal pain.
The first step in the pharmacological treatment of LBP, as with all musculoskeletal disorders, is to administer paracetamol or NSAIDs. Paracetamol is the active metabolite of phenacetin and appears to inhibit COX-3 present in the central nervous system. This active ingredient is widely used both individually and in association with other molecules (tramadol, codeine or oxycodone). Several Cochrane reviews have instead shown that NSAIDs are no more effective than opioid analgesics and muscle relaxants in relieving pain in patients with LBP. Three studies have documented substantially equal efficacy of NSAIDs and physiotherapy programs, spinal manipulations, or “bed rest” in patients with acute low back pain.5
The second step consists in the prescription of weak opioids such as tramadol or codeine, the latter in Italy is available only in galenic preparations or in oral formulations in association with paracetamol.
Codeine is a prodrug and only 10% of the administered codeine is transformed into morphine, as such it exerts the analgesic effect. The demethylation at the cytochrome level is carried out by the 2D6 -CYP 450 enzyme of which there is a large genetic polymorphism. 7-10% of Caucasian subjects are genetically lacking in this enzyme (called poor metabolizers), in these subjects the drug is practically ineffective due to the lack of transformation into morphine. On the other hand, the opposite situation is recorded in about 15-20 million Europeans where there is a duplication of 2D6 (called ultra rapid metabolizers), therefore acute toxicity effects are possible in these subjects (e.g. nausea, hallucinations, hyperalgesia, etc.) also strict.
Tramadol is an analgesic drug whose mechanism of action is mainly due to an increase in serotonergic neurotransmission in the central nervous system. The pharmacodynamics of tramadol is not limited to an increase in serotonergic neurotransmission, in fact this active principle also acts by inhibiting the reuptake of norepinephrine and interacting with mu-receptors as a weak agonist. The recommended daily dose is between 50-100 mg orally four times a day, but taking into account the dual mechanism of action, careful titration of the drug is suggested to prevent the typical side effects (nausea, vomiting, convulsions.) Given its emetic effect, it is practice the association with an antiemetic and particular attention must be paid to the possible association with the antiemetics metoclopramide and ondasentron.. Ondasetron, being a serotonergic antagonist, may block the analgesic activity of tramadol. Unfortunately, tramadol is the drug most frequently involved in inappropriate or contraindicated drug combinations responsible for adverse drug reactions, even fatal.6
The third step includes drugs such as morphine, oxycodone, buprenorphine, fentanyl and tapentadol and their use is indicated when the pain intensity is severe, at least greater than or equal to 6 on the NRS scale.
The Guidelines on pain management suggest, having verified the intensity of the pain, to start the therapy with the most suitable drug. Therefore, if the patient complains of chronic pain of intensity 8 on the NRS scale, drug therapy must be started from the last step, skipping the second.7 In our experience, when using an opioid it is essential to start from the lowest dosages and increase very gradually, always using prophylaxis for nausea and constipation, as well as accurate information to the patient.
Tapentadol is a recently synthesized molecule, it has affinity on the µ-opioid receptors and simultaneously an inhibition action on the reuptake of norepinephrine and serotonin. Tapentadol exerts its analgesic effects directly without any pharmacologically active metabolites. Patients should start treatment with this drug with the lowest possible dosage and then increase it to the dose that allows you to control the painful symptoms. Treatment is usually started with doses between 50-200 mg/day. It is a very manageable drug that allows its use even in patients with mild-moderate renal insufficiency and mild liver damage. The most frequent side effects consist of nausea, dizziness, headache and constipation and the latter can be combated by taking a laxative together with tapentadol. Withdrawal symptoms may occur following sudden discontinuation of tapentadol treatment and should therefore be discontinued gradually. Several studies support greater or equal clinical efficacy of tapentadol in the treatment of LBP compared to other strong opioids such as oxycodone, and greater or equianalgesia of tapentadol is achieved with an incidence of side effects half that of oxycodone. (better gastrointestinal tolerability).8.9
Before starting treatment with opioid drugs, as well as before applying a patient to variably complex interventional methods (as discussed below), it is necessary to request a psychological evaluation as well as, in some selected cases, to entrust the management of drug therapy to the SERT (drug addiction services). This in order to avoid, in fragile subjects, the phenomenon of addiction. The SERT is a free public service of the NHS in which professionals such as doctors, nurses, educators, social workers and psychologists work. Applicants are required to provide personal data as drugs considered by Italian law as narcotics (buprenorphine, methadone, gamma-hydroxybutyrate) may be dispensed with. At the time of dispensing, a certificate is issued, in the form of a self-adhesive or paper label, which allows possession of the molecule for therapeutic purposes. Some facilities use the recognition of the patient, the prescribing doctor and the drug dispenser through an identification code. The SERTs implement interventions of information, prevention, harm reduction, support, orientation, and treatment of addictions for both patients and their relatives. They ascertain the psychophysical state of health of the subject, defining individual therapeutic programs to be implemented directly or in agreement with social recovery structures, and periodically evaluate the progress and results of treatment and intervention programs on individual drug addicts with reference to clinical aspects psychological and social.
Continuing along the path, followed by the application of low, medium or high complexity methods that allow us to implement the interventional possibilities available to us. Low complexity methods have a low cost compared to medium and high complexity methods even if the benefit is lower both in quantitative and qualitative terms. Epidural space injections of a mixture of anesthetic and cortisone have good scientific evidence in treating LBP caused by herniated discs but poor scientific evidence in treating LBP due to degenerative disc disease. They are very effective in the short term but not in the long term. The facet joint blocks do not have a long-term benefit, however they can be repeated over time if they are effective (good pain relief) without particular complications. Sacroiliac block is the most common therapy in the treatment of LBP due to sacroiliitis.10
Among the methods of medium complexity, radiofrequency consists of high-frequency electromagnetic waves supplied through a needle with a visible tip or with an electrocatheter, which locally generate an electric field with relative heat production. (Figure 3)  Pulsed radiofrequency (RFP) maintains the electrode tip temperature between 40-42°C throughout the procedure, enabling neuromodulation of the dorsal roots and preventing cell destruction. Needle RFP is performed by positioning the needle transforaminal near the nerve root in its post-ganglionic position under radiological control and confirmed by injection of contrast medium. Lead RFP is performed with lead insertion through the hiatus, radiological confirmation, peridurography, and neurostimulation. RFP appears to cause microscopic and intracellular damage (eg, mitochondrial and cytoskeletal edema, microfilament and microtubule disorganization, myelin rearrangement) after applying an electric field to the dorsal ganglion with a mild thermal effect. Furthermore, it would influence in the medium term the gene expression of c-fos, TNF ? and IL-6 involved in the mechanism of neural inflammation and maintenance of nerve root hypersensitivity. The goal is to reduce inflammation and restore nerve function, with benefits that can last for some time depending on the pathology and duration of treatment. It is an outpatient therapy that is performed in day surgery lasts a few minutes and is performed on the patient awake, in the prone position. The RFP is applied in a particular way for some specific pathologies such as: chronic pain in the pelvis-perineal area, LBP especially with irradiation to the lower limbs, arthrosis, some types of disc degeneration and recurrence  after surgery, FBSS, mono or pluriradiculopathies, root canals. Following the therapy, postural gymnastics and/or physiotherapy exercises are usually recommended to obtain even better results.
Radiofrequency of the ganglion (Fig.5) is an interventional technique which consists in "bombarding" the nerve root responsible for the painful symptomatology with radiofrequencies. That is why first it is necessary to understand with certainty which root is responsible for the symptomatology. After local anesthesia, electrodes for radiofrequency are inserted near the root percutaneously under fluoroscopy.
In fact, continuous radiofrequency refers to harmful percutaneous procedures aimed at causing neurolesions at the level of the Central and Peripheral somatosensory (mainly nociceptive) system. Radiofrequencies of clinical interest are 300-500 KHz. The radiofrequency signal is applied through an electrode isolated, except for its distal part called active tip around which the biological effects of interest, induced by the heat, take place. The total current entering the body is equal to the current leaving the body through a dispersion plate. Non-intranervous uses: medial branch sinus nerve neurotomy, sacroiliac joint neurotomy, spinal ganglia thermorhizotomy (not used), gray branch neurotomy (little used), sympathetic ganglia (cervical-lumbar), RF annuloplasty, coblation (RF bipolar). Uses within nervous tissue: trigeminal thermorhizotomy, percutaneous cervical cordotomy.
Radiofrequency of the facet joints (Fig. 6) is an interventional method which consists in the emission of radio frequencies at the level of the posterior primary nerve branches that innervate the zygapophyseal joint. The radiofrequency of the sacroiliac joint (Fig.7) is a procedure similar to the previous ones, only that it intervenes on the sacroiliac joint identified as the cause of the LBP. Through fluoroscopy, the sacral holes S1, S2 and S3 are identified from where the posterior nerves exit and with the needle it reaches between these and the sacroiliac joint. Once the needle touches the sacrum, it is withdrawn approximately 10mm from the lateral edge of the posterior sacral foramen. The lateral projection here is essential to make sure you are in the correct position. The stylet is removed from the introducer and the catheter with the electrodes is inserted in order to carry out the therapy. After the usual stimulation tests you can start with the therapy. After carrying out the radiofrequency, the pharmacological mixture composed of anesthetic and cortisone can be injected through the operating channel.11
Nucleoplasty, the last of the medium complexity methods treated, is a disc decomposition technique which in turn includes various procedures such as laser decompression, nucleotomy and coblation. Nucleoplasty by coblation, is indicated in the treatment of patients suffering from persistent low back pain, with or without a peripheral radicular component, triggered by a contained disc herniation (bulging) and also small or medium hernias. The rational principle of this technique is that by retracting the disc protrusion the symptomatology disappears because the root is no longer compressed on one side and because the degenerated material of the disc nucleus is removed with coblation.
The exclusion criteria of this technique are the loss of 50% of the disc height, completely extruded or sequestered disc herniations, vertebral tumor or fracture, moderate or severe spinal stenosis, laceration of the disc annulus, degenerative instabilities. Coblation (C= controlled + Ablation) uses radiofrequency energy associated with a conductive medium to produce a plasma field made up of highly ionized particles in order to cause the breaking of organic molecular bonds in the tissue. Plasma is essentially a mixture of excited ions. Coblation therefore allows the nuclear material of the disk to be removed and channels to be created in the latter to allow the protrusion to re-enter. Potential complications are nerve injury, hemorrhaging, and discitis.12
The highly complex methods include medullary neurostimulation (SCS) based on selective electrical stimulation of the spinal cord by means of electrocatheters, implanted in the epidural space and connected to a pulse generator, in order to modify the perception of pain in the painful areas. The delivered electrical stimulus translates into the perception of a paresthesia by the patient (sensation similar to a "pins and needles") which replaces the painful sensation.
Epidurolysis consists in the positioning of a transacral peridural catheter armed for the administration of drugs (hyaluronidase, cortisone, local anesthetic and physiological solution) in the epidural space between the dura mater and the yellow ligament covering the internal part of the bone of the spinal canal, in order to obtain a "liberation" of the compressed nerve roots following a previous operation on the spine or due to adhesions formed following inflammatory / degenerative pathologies (post laminectomy syndrome, LBP, herniated discs, spinal stenosis). In fact, scar adhesions can contribute to the onset of radicular pain, by stretching or compressing the nerve roots. To act precisely on the root that causes the pain, it is possible to stimulate it electrically, so as to make the patient feel a tingling in the corresponding area (electroguided peridurolysis). The procedure, for which hospitalization is necessary, takes place in the operating room with sterile technique and under radiographic control (peridurography).
The benefit will appear gradually in the days following the intervention and may continue, depending on the severity of the clinical picture, for 3-6 months. The method can be repeated after at least 3 months. It is indicated to perform it after failure of conservative treatment with physical therapy, chiropractic, drug therapy, and fluoroscopy-guided epidural injections.

Materials and methods

This study retrospectively analyzed some data collected routinely in the standard PDTA of the Pain Therapy Center of Varese and contained in the records of patients who performed medium/high complexity methods (RF and/or ESMT/ESMD implant) between January 2018 and in October 2020 in the Pain Therapy Center of Varese. The patients included in this study are 51, of which 21 males and 30 females, they are all adults (mean age 67±2.55) and 22 out of 51 patients are of working age (conventionally considered under 65 years). They are all patients diagnosed with LBP for at least 3 months and in whom conservative pharmacological therapy and low-complexity methods have failed to manage the symptoms. FBSS was diagnosed in 16 patients. In 80% of patients treated with medium/high complexity methods there were simultaneously several possible factors implicated in the genesis of LBP. Unlike other studies, patients diagnosed with depression were not excluded, who represent 3.4% of patients in our study. On the other hand, patients affected by LBP of tumor pathogenesis, nor patients undergoing ESM implantation with a diagnosis of vascular pathology/AOAI, were not considered. All interventional procedures of medium/high complexity were performed in Day Surgery at the Ospedale del Circolo in Varese.  Of these 51 patients, 14 had RF FA, 2 RF SJ, 11 coblation and 13 RF GAG, 11 had an ESM implanted. The latter underwent a clinical psychological evaluation before the operation. Finally, 2 patients are affected by multiple sclerosis and 1 only by post herpetic neuralgia. All the patients who underwent the procedure had to suspend their pre-operative anticoagulant and antiplatelet therapies in progress. In 99% of cases they took opioids for analgesic purposes, associated with NSAID . 33 out of 51 patients underwent repeated low complexity procedures (IP, IF SJ, IF FA, trigger points), with minimal temporary benefit. This confirms the fact that radiofrequencies constitute a method to be applied, according to a pyramid procedural model, in the treatment of more complex patients. For each of these five methods, a specific protocol was used, which represents the standard PDTA of the Pain Therapy Center of Varese, the result of experience gained over the years.
The aim of the study is to carry out a review of the clinical cases of patients in follow-up, in many cases already for 4-6 years, to verify the impact that the radiofrequency procedures they have undergone have within the PDTA in order to understand if:
1) Radiofrequencies may or may not be considered a valid therapeutic tool, capable of representing effective and targeted procedures on the individual patient, and at the same time having a limited economic impact (day surgery interventions with reduced hospitalization and complications, reduced biological risk, scarce invasiveness, short execution times), in a resource management framework that has as its current objective their adequate efficiency.
2)  Radiofrequencies may or may not be considered a valid advanced diagnostic tool in a II level Pain Therapy Centre, which allows us to screen the PG more precisely and initiate the patient towards a possible subsequent more reasoned clinical-therapeutic step and properly modulated. This also implies the possibility of applying more selected patients to procedures of even greater complexity or making an indication for NCH surgery if necessary.
The outcome of medium complexity methods was measured with the NRS pain scale and the ODI. These data were collected both in the preoperative visit before the medium/high complexity procedure and in the visit 3 weeks after surgery.
The NRS method is less discriminating than the VAS, but overcomes the obstacle of visual and motor coordination required to perform the latter and therefore offers greater possibilities of understanding on the part of the patient. For these reasons, we chose the NRS scale in our study over the VAS which, although it is a valid tool, is not always immediately understandable for the patient.
The ODI is an index that derives from the Owestry questionnaire and which measures functional impotence.
It is considered by many authors the gold standard for investigating the level of disability and the quality of life of a patient with LBP. On the basis of the percentage expressed, a qualitative-quantitative assessment of the disability can be made:
  • 0% to 20% is minimum disable
  • 21% to 40% is moderate disable
  • 41% to 60% is severe disable
  • 61% to 80% is severe disability
  • 81% to 100% is complete disability
The study variables were described using the main descriptive statistics: mean, median and standard deviation for the quantitative variables, percentage frequencies for the qualitative variables.
The analysis of the association between quantitative variables (NRS-PRE/NRS-POST and ODI-PRE/ODI-POST) was conducted by means of the Wilcoxon test. The significance level considered was below p?0.05.
We divided the patients enrolled in our study into 3 categories based on the cross-analysis of comprehensive data on age, sex, duration of clinical follow-up at the Pain Therapy Center, previous procedures performed, diagnosis, pre- and post-procedure opioid use and any changes in the dosage of administration, type of medium/high intensity procedure performed and pre- and post-procedural pain assessment with ODI and NRS indices, and finally absence/presence of post-procedural benefit. (Figure 4)
  1. Low responders: pz non responders (NRS <50%) o responders <1 mese
  2. Medium responders: pz responders con NRS >50% tra 1 e 2 mesi
  3. High responders: pz responders >2 mesi

70% of patients undergoing a radiofrequency procedure fall into categories 2) and 3), having in fact had a post-procedural benefit in terms of both pain reduction for at least 2 months and reduction of the dosage or discontinuation of the opioid drugs they were taking in therapy, in some cases returning to NSAIDs alone, in others by suspending the pain-relieving therapy altogether. Furthermore, there was a consequent improvement, albeit variably temporary and to be related to age and etiopathogenesis as well as comorbidities underlying the symptoms, in the quality of life and autonomy in carrying out ADLs.
Analyzing the patients who instead make up the 30% included in category 1), we focus on some considerations (Figure 5). It is in fact a heterogeneous category in terms of reference age (from 53 to 73 years), pathological cause of pain and PG, comorbidities, compliance with follow-up and current medical therapy. Not negligible is the importance to be attributed to the presence of pre-existing psychosocial problems (anxious depressive disorder, patients with frailty due to addiction problems often followed by the SERT, patients in charge of social services), not always easy to identify as sometimes these disorders they manifest themselves for the first time or in a more evident way only after the procedure has been performed. Furthermore, objective difficulties in carrying out the radiofrequency arise due to a rachis anatomy made difficult by possible inveterate structural alterations, often deforming (long-term arthrosis especially in subjects over 65), or by the presence of spine synthesis/fixation devices (FBSS) . The presence of multiple contributing causes and/or triggers of the pain may also be at the origin of a scarce benefit deriving from this procedure, for example patients who have intermediate pictures of mixed pain, partly arthritic, neuropathic from radiculopathy, muscular, vascular. This generates an effective diagnostic difficulty in identifying the PG, compromising in some cases the very appropriateness of the method.

Conclusions

The statistical results of the retrospective study we conducted demonstrate the significant role that radiofrequencies play within a complex PDTA as procedures of medium complexity. In fact, they allow patients to be subjected to further subsequent therapeutic steps to be selected more efficiently, especially if of high complexity, reducing their failures and optimizing the available resources. When the indication to carry out radiofrequency is given for a young patient of working age, this is often correlated to a more severe clinical symptomatological picture which implies a more serious pathology or a more disabling joint comorbidity. Consequently, the use of radiofrequencies is to be included in a path which, very reasonably, will involve the execution of multiple procedures from the simplest to the most complex, of the same type or of different types as well as more frequent over time. In the elderly patient, considering medium-long course pathologies and comorbidities, greater sedentary lifestyle, cessation of work, greater frailty and sensitivity to pharmacological therapies, radio frequencies are a valuable resource when effective, even if the benefit reported by the patient should be short term (1-2 months).
This is part of the perspective that they make possible a temporary state of well-being and pain relief for the patient, reducing or suspending the intake of drugs (often opioids) and give him back a better quality of life and greater autonomy in ADLs. Elderly and very elderly patients are unlikely to be considered candidates for highly complex procedures, such as, for example, the implantation of an ESM; this correlates both with an objective difficulty in the clinical and therapeutic management of these devices, and with the need for adequate resource efficiency.
In conclusion, it has been demonstrated with sufficient statistical significance that to date radio frequencies constitute an essential intermediate step to be taken in the context of a reasoned PDTA, representing both a valid alternative therapeutics is a valid diagnostic tool in LBP, in view of the ever-increasing demand for adequate management capacity of the available resources. However, this objective must always be achieved by having it clear that the central focus of our choices is always the achievement of a balance in the state of psycho-physical well-being of the patients.

Conflict of interest

The authors declare that the article is not sponsored and has been written in the absence of conflict of interest.

Open Access-license (CC BY-NC 4.0)

Published

30th March 23

Reference

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