The Efficacy of Radiofrequency Ablation for Pain Management in Patients with Pre-Existing Hardware at the Site of Ablation

Catheter-to-tissue contact angle's effect on lesion formation and characterisation using multichannel bioimpedance method

Objective.Radiofrequency (RF) catheter ablation is a standard treatment for patients with cardiac arrhythmias, providing an efficient, minimally invasive solution. However, the ablation efficiency remains suboptimal due to numerous contributed factors that are overlooked in the literature and not monitored during the procedure. This paper explores the effect of catheter-to-tissue contact angles on lesion formations and the feasibility of the multichannel bioimpedance method in characterising the angles to inform cardiologists.Approach.Two silico simulations based on a realistic human model were built to: (1) simulate lesion formations with different catheter-to-tissue angles under varying conditions of powers and convection cooling, and (2) simulate multichannel bioimpedances measured at each catheter's location and angle. 13 locations were picked in all four chambers with 3 contact conditions (catheter lies along the muscle (0° and 180°), in perpendicular to the muscle (90°) and in middle angles (45° and 135°)). 64 electrodes divided into 4 bands were placed on the thorax for multichannel bioimpedances (3-terminal) measured between the catheter's second electrode E2 (I+,V+), and each pair of adjacent surface electrodes (I-,V-). ANOVA and Tukey's Honestly Significant Difference (HSD) tests were used to evaluate the contact angle's effect on the lesion formations and the bioimpedance's capability in distinguishing between angles.Main results.The results showed that 0° and 180° configurations generated significantly different lesions from other angles. The multichannel bioimpedances could recognise 0°/180° from other angles and correlated moderately to lesion sizes at low ablation power.Significance.This paper concludes that catheter-to-tissue angles can influence the lesion outcomes significantly and the multichannel bioimpedance is able to detect the angles that matter.

The efficacy of pulsed radiofrequency ablation of the dorsal root ganglion in the setting of failed spinal neuromodulation: A case report

Radiofrequency ablation (RFA) is an interventional procedure that has been used to treat chronic back pain for over 50 years; this unique case report demonstrates the effectiveness of pulsed radiofrequency ablation (PRFA) on the dorsal root ganglion (DRG) in the treatment of chronic radicular pain (Russo et al., 2021, J Pain Res, 14, 3897). The RFA provides pain relief by using thermal energy to disrupt peripheral nerves carrying nociceptive signals back to the central nervous system (Abd-Elsayed et al. 2020, Pain Ther, 9, 709). However, there is a lack of literature about the safety and efficacy of PRFA of the DRG.

Failed back surgery syndrome-terminology, etiology, prevention, evaluation, and management: a narrative review

Amid the worldwide increase in spinal surgery rates, a significant proportion of patients continue to experience refractory chronic pain, resulting in reduced quality of life and escalated healthcare demands. Failed back surgery syndrome (FBSS) is a clinical condition characterized by persistent or recurrent pain after one or more spinal surgeries. The diverse characteristics and stigmatizing descriptions of FBSS necessitate a reevaluation of its nomenclature to reflect its complexity more accurately. Accurate identification of the cause of FBSS is hampered by the complex nature of the syndrome and limitations of current diagnostic labels. Management requires a multidisciplinary approach that may include pharmacological treatment, physical therapy, psychological support, and interventional procedures, emphasizing realistic goal-setting and patient education. Further research is needed to increase our understanding, improve diagnostic accuracy, and develop more effective management strategies.

Mitigating Factors in L4 and L5 Medial Branch Motor Stimulation During Radiofrequency Ablation

PURPOSE OF REVIEW

Radiofrequency ablation (RFA) is a minimally invasive procedure for facet joint pain. The targets for the procedure are the medial branches of the dorsal spinal nerves which innervate the facet joints. Before RFA, patients undergo diagnostic meal branch blocks to ensure appropriate pain relief and confirm the utility of proceeding to RFA. The success of RFA relies heavily on procedural technique and accurate placement near the medial branch.

RECENT FINDINGS

Motor testing is utilized in the lumbar region to assess the response of the multifidus and ensure proper placement of the RFA probe to prevent inadvertent damage to surrounding spinal anatomy. However, relying on motor responses in this area presents challenges given the frequency of lack of muscle twitching. Factors contributing to limited muscle twitch responses include muscle atrophy, excessive lordosis, facet arthropathy, local anesthetic use before ablation, and previous surgical neurotomy. These complexities highlight the challenges in ensuring precise motor stimulation during RFA. Despite these obstacles, accurate anatomical placement remains crucial. For RFA cases that prove challenging, relying on anatomical placement can be adequate to proceed with the procedure. Bridging knowledge gaps is vital for standardized practices and safer procedures. Further research is necessary to refine techniques, understand patient-specific factors, and enhance the efficacy of RFA in managing chronic lumbar facet joint pain.

FactFinders for patient safety: Motor stimulation testing in lumbar radiofrequency neurotomy and radiofrequency neurotomy in patients with posterior hardware

This series of FactFinders presents a brief summary of the evidence and outlines recommendations regarding the use of motor stimulation testing in lumbar radiofrequency neurotomy and performance of radiofrequency neurotomy in patients with posterior spinal hardware. The evidence in support of the following facts is presented: (1) Motor stimulation does not inherently protect against unwanted damage to the spinal nerve, exiting spinal nerve root or its ventral ramus due to a lack of sensitivity of this test for identification of electrode contact or close proximity to sensorimotor nerves. Even when motor stimulation is performed, verification of correct electrode placement with multiplanar imaging including a minimum of true anterior-posterior and lateral fluoroscopic views is a recommended safeguard. (2) The existence of posterior spinal hardware is not an absolute contraindication to radiofrequency neurotomy, but direct contact with hardware should be avoided.