The study sample:
120 (one hundred and twenty) patients diagnosed with chronic lumbosacral radicular pain were elected by their pain specialists to undergo pulsed radiofrequency treatment adjacent to lumbosacral dorsal root ganglion(s). A patient with radicular pain affecting more than one segment on one side will be treated for all the involved segments with the same technique and this will be considered a single intervention for the study.
60 (sixty) patients (the experimental Celestone group) undergoing pulsed radiofrequency treatment will receive transforaminal epidural injection of the solution of 1 cc of Lidocaine 1% with 1 cc of Celestone Chronodose around each dorsal root ganglion immediately after the radiofrequency treatment has been performed. 60 (sixty) patients (the control group) undergoing pulsed radiofrequency treatment will receive transforaminal epidural injection of the solution of 1 cc of Lidocaine 1% with 1 cc of normal saline around each dorsal root ganglion immediately after the radiofrequency treatment will be performed.
Randomization and blinding:
Patients will be randomly assigned to the Celestone group (N = 60) or the control group (N = 60). The allocation of patients into either group will be performed using a computer-generated randomization program. Each patient's randomization number will be concealed until the end of the study from both the patients and the outcome assessor, who will be an independent research coordinator at the investigators pain clinic. The patients will be explained that they will not know which medicine they will receive until the study completion.
Procedure:
The study will take place in the Chaim Sheba TelHashomer Medical Center, Ramat Gan, Israel. Participants will be recruited from the hospital's Pain Management outpatient clinic from the patients eligible for the procedure involving pulsed radiofrequency of the lumbosacral dorsal root ganglion. After receiving the hospital's Helsinki approval, the P.I. and/or other designated staff in the department will approach relevant patients (in line with the mentioned inclusion and exclusion criteria), describe the procedure, inform of the possible adverse events and collect informed consent if the patients are interested in participating. Consent will be obtained from the patient during the patient's visit when the option of RF is agreed upon and scheduled for the future.
Eligible patients will not receive any financial reimbursement. It will be stressed to prospective subjects that participation in the research will have no implications on their treatment in the hospital, or the relationship with their current healthcare providers. The patients will be advised that they may unconditionally revoke their consent at any given time during participation without repercussion on future care. For the first month after the procedure, patients will be instructed not to change their previously prescribed analgesic medications. All patients will be made aware of this guideline prior to study participation. After the first month follow-up visit, the prescribed doses of any analgesics will be increased or decreased in regard to the pain intensity of the patient. Patients who will have increments in analgesic medication or who will be elected for alternative treatments will be considered treatment failure. Data collected during the experiment will be kept in a secure location and will be shredded after the project's completion. All information regarding patients treatment both inside and outside of the project will be kept in the utmost of confidentiality, respecting both legal and ethical constraints.
Patients agreeing to participate in the study will come to the pre-operative room of the Pain Department at the designated time. There they will be monitored, initial intensity of the pain (0 to 10) on the numerical rating scale (NRS) will be recorded and pre-operative vital signs assessed (e.g.- blood pressure, heart rate, oxygen saturation). Each patient will complete the Roland Disability Questionnaire and the Oswestry Disability Index score. All syringes with the solutions to be injected by the transforaminal approach will be prepared prior to entering the operating room. After that the patient will enter the operating room to undergo pulsed radiofrequency treatment. The patient will sign consent for the procedure. The patient will be placed in the prone position with a pillow under the lower abdomen to provide an easy transforaminal approach. It will be forbidden to call name or the dose of any medication which will be injected during the procedure except the 1.5cc of Midazolam IV that will be given for light sedation. Fluoroscopy will be used to identify the specific site of the injections and radiofrequency in all cases. After sterile preparation of the needle insertion area, the skin will be infiltrated with 1% Lidocaine, and a 22-gauge, 4-in radiofrequency needle with a 10 mm curved active tip will be advanced under fluoroscopic guidance. Anatomic landmarks will be identified, and the needle will be positioned closely to the dorsal root ganglion under fluoroscopy guidance. The tip of the needle will be placed in the dorsal-cranial quadrant of the intervertebral foramen on the oblique image, and the tip will be positioned between one-third and halfway to the pedicle column on the antero-posterior image. If intravenous uptake will be occurred, the needle will be repositioned until intravenous uptake was absent and an epidural flow pattern was achieved. If intra-arterial, intrathecal, or intradiscal flow will be identified, the procedure was aborted. After confirmation of epidural spread (using a contrast dye) and the radiofrequency needle positioning adjacent to the appropriate dorsal root ganglion, 1 cc of normal saline will be injected to decrease electrical impedance around the radiofrequency needle. Then the stylet will be replaced by the radiofrequency probe and the probe will be connected to the radiofrequency generator. Defining the final position of the radiofrequency probe will require a sensory stimulation (50 Hz) threshold ≤0.5 V, which will create paresthesia corresponding to the existing distribution of the patient's radicular pain. Then in the two groups of patients two cycles of pulsed radiofrequency will be performed at 42°C for 120 seconds. Immediately after the radiofrequency treatment in the Celestone group the solution of 1 cc of Lidocaine 1% with 1 cc of Celestone Chronodose will be injected around each dorsal root ganglion through the radiofrequency needle. In the control group the solution of 1 cc of Lidocaine 1% with 1 cc of normal saline will be injected.
All patients will be treated according to the protocol. If an emergency situation occurs or in case of unblinding, the treatment will be altered and the patients will be considered withdrawn. Such patients will proceed with conservative or interventional management without unblinding. They will also continue their structured exercise program, as other patients do.
After the procedure the patient will be taken to the recovery room in the pain clinic and will be monitored for at least for 30 minutes. Vital signs will be assessed immediately post-op in the recovery room and again after 30 minutes, just prior to discharge.
Requests for additional analgesia (Optalgin, etc) will be assessed. During the 30 minutes following the entry to recovery room the patients will be asked if they are experiencing any of a number of the symptoms used by the list of adverse events and their responses will noted in their records. All the patients will be warned of potentially serious complications requiring immediate evaluation (e.g. progressive weakness). To examine delayed adverse events the patients will be asked to select any of a number of the symptoms used by the list of adverse events for up to 72 hours after the procedure (the patients will be asked to bring the completed lists of the symptoms to their follow up visit in 1 month after a procedure). All patients will be seen at a follow-up appointment with their pain treating physician in the Pain Department of Tel HaShomer in 1, 2 and 3 months following the procedure.
Results:
The baseline characteristics of all participating patients will be collected. Numerical data will include age, height, weight, body mass index, total duration of pain. Categorical data will include sex, diagnosis, coexisting medical conditions such as diabetes and hypertension, target location, and level of the compromised nerve root(s).
A comprehensive review and statistical analysis of data will be conducted at the completion of the study. Changes in pain scores, as reported by the patients via the NRS scores, will be analyzed before the procedure and at 1, 2 and 3 months postprocedure. Changes in ADL and QoL will be measured using the Roland Disability Questionnaire and the Oswestry low back pain disability scales. Both the Roland Disability Questionnaire and the Oswestry scores will be completed by the patients both before the procedure and at 1, 2 and 3 months postprocedure.
Successful pain relief (responders) will be defined as either ≥50% or ≥4-point pain reduction in the NRS; functional success will be defined as either ≥40% reduction in Roland Disability Questionnaire or Oswestry Disability Index scores.
Data analyses will be carried out with the help of a package of statistical programs Win Pepi (the fourth version). Categorical and continuous data comparison, Chi-squared test (Fisher's exact test where necessary) and t test will be performed.
The outcome data of the patients will be measured at 4 periods of time therefore a repeated measures analysis of variance will be performed. A P value of less than 0.05 will be considered as statistically significant.
