Pan African Clinical Trials Registry
South African Medical Research Council, South African Cochrane Centre
PO Box 19070, Tygerberg, 7505, South Africa
Telephone: +27 21 938 0506 / +27 21 938 0834 Fax: +27 21 938 0836
Email: pactradmin@mrc.ac.za Website: pactr.samrc.ac.za
Trial no.: PACTR202106879183788 Date of Approval: 21/06/2021
Trial Status: Registered in accordance with WHO and ICMJE standards
TRIAL DESCRIPTION
Public title Bipolar pulsed radiofrequency of intercostal nerves versus paravertebral steroid injection for post-herpetic neuralgia
Official scientific title Bipolar pulsed radiofrequency of intercostal nerves versus paravertebral steroid injection for post-herpetic neuralgia
Brief summary describing the background and objectives of the trial Postherpetic neuralgia (PHN) is the most common chronic nerve pain caused by chickenpox (herpes zoster) viral infection. PHN leads to burning pain that lasts long after the skin rash disappear in some patients. The concomitant inflammation of the ganglion, peripheral nerve, and nerve endings (skin damage) is supposedly responsible for this pain [1]. There are limited pain management options because the underlying mechanisms remains unclear [2, 3]. PHN occurs in a subset of the population suffering from an episode of acute HZ. A meta-analysis of the risk factors for the development of PHN published in 2016 noted that approximately 13% of patients older than or equal to 50 years of age with HZ would go on to develop PHN [4]. Recent studies showed that traditional oral drugs, nerve block therapy (NBT) and pulsed radiofrequency (PRF) can shorten pain duration in some patients. PHN can be severe and debilitating in some cases. However, no single treatment modality reduces pain for all patients with consistent success [5, 6]. Therefore, combinational treatments are needed in many PHN cases [7, 8]. Pulsed radiofrequency (PRF) is increasingly being applied to alleviate several types of pain including neuralgia, joint pain, and muscle pain [9-11]. This technique works by delivering an electrical field and heat bursts to targeted nerves or tissues via a catheter needle tip without damaging these structures [12-14]. Conventional radiofrequency (CRF) thermocoagulation exposes target nerves or tissues to continuous electrical stimulation and ablates the structures by increasing the temperature around the tip of the RF needle. In contrast to CRF, PRF applies a brief electrical stimulation, followed by a long resting phase; thus, PRF does not produce sufficient heat to cause structural damage [15]. Although the mechanisms of PRF remain unclear, various researchers have been working toward revealing the underlying processes including structural changes in the principal sensory nociceptors, activation of noradrenergic and serotonergic descending pain inhibitory pathways, inhibition of excitatory nociceptive C-fibers, decreased microglial activity, and decreased formation of inflammatory cytokines [16, 17]. Regional anesthetic procedures, including subcutaneous anesthetic and steroid injections, sympathetic and intrathecal nerve blocks, and ESI, are often used for management of PHN, even though these treatments are not strongly evidence based. Epidural steroid injection (ESI) with the transforaminal and interlaminar administration of steroids and local anesthetics is among the more common treatments for patients with refractory PHN. However, its effectiveness is controversial [18]. A case report by Mehta et al. described a 64-year-old man with refractory thoracic dermatome PHN, 1.5 years after HZ onset; 12 weeks after transforaminal ESI, he had complete resolution of symptoms [19]. Interventional procedures have been frequently conducted by fluoroscopy‐guided or blind methods. However, fluoroscopy‐guided methods have the limitations of radiation risks, hypersensitivity reactions to contrast media, and high cost. Recently, ultrasound (US) has been widely used to treat pain from variable causes; it can be used for cost‐effective, portable, real‐time imaging or visualization of underlying pleura and without radiation risks [20-22]. To the best of our knowledge, there is paucity of studies comparing the efficacy of PRF to ESI in such cases. Therefore, we will conduct the current study.   AIM OF THE WORK AND HPOTESIS This study aims to compare between the efficacy of ultrasound guided bipolar pulsed radiofrequency of intercostal nerves and steroid injection for post-herpetic neuralgia. We hypothesize that bipolar pulsed radiofrequency of intercostal nerves will provide more prolonged analgesia than paravertebral steroid injection for post-herpetic neuralgia.
Type of trial RCT
Acronym (If the trial has an acronym then please provide)
Disease(s) or condition(s) being studied Anaesthesia,Nervous System Diseases
Sub-Disease(s) or condition(s) being studied
Purpose of the trial Treatment: Drugs
Anticipated trial start date 14/07/2021
Actual trial start date 15/07/2021
Anticipated date of last follow up 20/07/2022
Actual Last follow-up date
Anticipated target sample size (number of participants) 32
Actual target sample size (number of participants)
Recruitment status Recruiting
Publication URL
Secondary Ids Issuing authority/Trial register
STUDY DESIGN
Intervention assignment Allocation to intervention If randomised, describe how the allocation sequence was generated Describe how the allocation sequence/code was concealed from the person allocating the participants to the intervention arms Masking If masking / blinding was used
Parallel: different groups receive different interventions at same time during study Randomised Simple randomization using a randomization table from a statistics book Sealed opaque envelopes Open-label(Masking Not Used)
INTERVENTIONS
Intervention type Intervention name Dose Duration Intervention description Group size Nature of control
Control Group paravertebral steroid injection The paravertebral steroid injection will be performed by a transforaminal approach with 0.5 to 1 mL of contrast dye, which will be injected through tubing with the use of live fluoroscopy. If an epidural flow pattern on dye uptake appears, a volume of 20 mg of dexamethasone plus 0.5% lidocaine will be subsequently injected into the posterior epidural space [19]. An interlaminar epidural nerve block approach will be permitted only for the patients who were difficult to approach by the transforaminal area [26]. 12 months The paravertebral steroid injection will be performed by a transforaminal approach with 0.5 to 1 mL of contrast dye, which will be injected through tubing with the use of live fluoroscopy. If an epidural flow pattern on dye uptake appears, a volume of 20 mg of dexamethasone plus 0.5% lidocaine will be subsequently injected into the posterior epidural space [19]. An interlaminar epidural nerve block approach will be permitted only for the patients who were difficult to approach by the transforaminal area [26]. 26 Active-Treatment of Control Group
Experimental Group Ultrasound pulsed radiofrequency technique The targeted ribs will be marked at 8 cm lateral to the spinous processes. A SonoSite® M-turbo ultrasound machine (Bothell, WA, USA) with a linear transducer probe (HFL 38X/13-6 MHz) will be used to perform the intercostal nerve PRF. The US probe will be placed on the marked area in the longitudinal plane, and using an appropriate tilt, the ribs and the pleura became visible. The PRF needle (100 cm insulated with a 10-mm straight tip) will be viewed with the in-plane technique and will be then directed toward the caudal edge of the ribs [25]. When the edge of the needle will be observed to be in the intercostal groove, the location of the concerned intercostal nerve will be verified both by motor nerve stimulation (2 Hz, 1 ms, 2 V) and by confirming that the impedance value is 300–350 Ω. While maintaining visualization of the needle at the caudal edge of rib, PRF will be applied at 42 °C for 120 s with an PRF generator (NT1100, NeuroTherm®). After two PRF cycles, 3 ml 0.25 % bupivacaine will be injected by real-time observation of the local anesthetic spread under US guidance, and the RF needle was removed [25]. 12 month The targeted ribs will be marked at 8 cm lateral to the spinous processes. A SonoSite® M-turbo ultrasound machine (Bothell, WA, USA) with a linear transducer probe (HFL 38X/13-6 MHz) will be used to perform the intercostal nerve PRF. The US probe will be placed on the marked area in the longitudinal plane, and using an appropriate tilt, the ribs and the pleura became visible. The PRF needle (100 cm insulated with a 10-mm straight tip) will be viewed with the in-plane technique and will be then directed toward the caudal edge of the ribs [25]. When the edge of the needle will be observed to be in the intercostal groove, the location of the concerned intercostal nerve will be verified both by motor nerve stimulation (2 Hz, 1 ms, 2 V) and by confirming that the impedance value is 300–350 Ω. While maintaining visualization of the needle at the caudal edge of rib, PRF will be applied at 42 °C for 120 s with an PRF generator (NT1100, NeuroTherm®). After two PRF cycles, 3 ml 0.25 % bupivacaine will be injected by real-time observation of the local anesthetic spread under US guidance, and the RF needle was removed [25]. 26
ELIGIBILITY CRITERIA
List inclusion criteria List exclusion criteria Age Category Minimum age Maximum age Gender
• Age > 18 years. • PHN at T 2 – 11 levels. • Refractory to formal treatment according to the International Association for the Study of Pain guidelines (such as antiepileptic medicine, antidepressants, opioids and physical treatments). • Visual analogue scale (VAS) > 3. • VAS < 3. • The presence of skin infection at injection site. • Bleeding diathesis. • Uncontrolled systemic comorbidities. • Drug abuse. • Current steroid therapy. 80 and over: 80+ Year,Adult: 19 Year-44 Year,Aged: 65+ Year(s),Middle Aged: 45 Year(s)-64 Year(s) 19 Year(s) 80 Year(s) Both
ETHICS APPROVAL
Has the study received appropriate ethics committee approval Date the study will be submitted for approval Date of approval Name of the ethics committee
Yes 24/04/2021 Mansoura Faculty of Medicine Institutional Review Board
Ethics Committee Address
Street address City Postal code Country
2 El-Gomhouria Street Mansoura 35516 Egypt
OUTCOMES
Type of outcome Outcome Timepoint(s) at which outcome measured
Primary Outcome Duration of pain control. 1, 3, 6, and 12 months
Secondary Outcome • Pain measures by VAS • Quality of life measured by SF-36 questionnaires. • Procedure related side effects. 1, 3, 6, and 12 months
RECRUITMENT CENTRES
Name of recruitment centre Street address City Postal code Country
Mansoura university hospital 2 El-Gomhouria Street Mansoura 35516 Egypt
FUNDING SOURCES
Name of source Street address City Postal code Country
Ibrahim Abdelbaser 2 El-Gomhouria Street Mansoura 35516 Egypt
SPONSORS
Sponsor level Name Street address City Postal code Country Nature of sponsor
Primary Sponsor Mansoura university hospital 2 El-Gomhouria Street Mansoura 35516 Egypt Hospital
COLLABORATORS
Name Street address City Postal code Country
Ibrahim Ibrahim Abd Elbaser 2 El-Gomhouria Street Mansoura 35516 Egypt
Elsayed Elemam 2 El-Gomhouria Street Mansoura 35516 Egypt
CONTACT PEOPLE
Role Name Email Phone Street address
Principal Investigator Ibrahim Abdelbaser ibrahimbaser2010@yahoo.com +201004976825 2 El-Gomhouria Street
City Postal code Country Position/Affiliation
Mansoura Mansoura Egypt Assistant Professor of Anesthesia at Faculty of Medicine Mansoura University
Role Name Email Phone Street address
Public Enquiries Nabil Mageed nabil_abdelraouf@yahoo.com +201001538948 2 El-Gomhouria Street
City Postal code Country Position/Affiliation
Mansoura 35516 Egypt Professor of Anesthesia at Faculty of Medicine Mansoura University
Role Name Email Phone Street address
Scientific Enquiries Elsayed Elemam sayedemam0606@gmail.com +201008765995 2 El-Gomhouria Street
City Postal code Country Position/Affiliation
Mansoura 35516 Egypt Assisstan Professor of Anesthesia at Faculty of Medicine Mansoura University
REPORTING
Share IPD Description Additional Document Types Sharing Time Frame Key Access Criteria
Yes We will individual participate data and share it through the PubMed indexed journal Informed Consent Form,Study Protocol Beginning 6 months and ending 12 months following article publication We will individual participate data and share it through the PubMed indexed journal
URL Results Available Results Summary Result Posting Date First Journal Publication Date
No
Result Upload 1: Result Upload 2: Result Upload 3: Result Upload 4: Result Upload 5:
Result URL Hyperlinks Link To Protocol
Result URL Hyperlinks
Changes to trial information