Caudal Neuroplasty Using Epidural Catheter Combined with Pulsed Radiofrequency (versus Pulsed Radiofrequency Alone

Lumbosacral radicular pain (LRP) is a frequently encountered symptom, as the annual prevalence in the general population is reported to be from 9.9% to 25% .Acute lumbosacral radiculopathy is a diffuse disease process that affects more than one underlying nerve root, causing pain, loss of sensation, and motor function depending on the severity of nerve compression. Lumbosacral radiculopathy is very common. Most cases of lumbosacral radiculopathy are self-limited. The most common symptom in radiculopathy is paresthesia.Another common presentation is back pain radiating into the foot, with a positive straight leg raising test. Muscle strength is often preserved in the case of radiculopathy because muscles often receive innervation from multiple roots. Thus, muscle strength is often only affected by severe cases of radiculopathy.\[2\] The most common causes of lumbar radiculopathy are either a herniated disc with resultant nerve root compression or spondylosis. This process can be acute or can develop chronically over time. Imaging is not always a helpful diagnostic modality as almost 27% of patients without back pain have been found to have disc herniation on magnetic resonance imaging (MRI). Furthermore, this incidental finding does not appear to be predictive of future development of back pain. To diagnose a herniated disc as a source of a patient's pain, it is important to review the complete history and physical and making sure that the symptoms match the imaging results. Patients with lumbar radicular pain often respond to conservative management.

Patients who do not respond to conservative therapies will likely need an MRI for further evaluation and characterization of nerve root involvement, epidural steroid injections and other interventional treatments should be considered \[3-5\] . When all other treatments have failed, surgery should be considered. Epidural fibrosis may cause chronic radicular lower back pain, negatively affecting patients' quality of life. Adhesions in the epidural space may occur due to surgical or non-surgical causes. Non-surgical causes include annular tear, infection, hematoma, and administration of intrathecal contrast material . Scar tissue may develop in the ventral, dorsal, and lateral regions of the epidural space. Dorsal epidural fibrosis may develop due to surgical hematoma absorption, ventral epidural fibrosis may develop due to disc defects, and lateral epidural fibrosis may develop due to disc defects, facet hypertrophy, and lateral foraminal stenosis . In the neural foramen, epidural veins accompany the nerve roots. Epidural scar tissue causes compression of the veins, which gives rise to edema in the epidural area Stand-alone epidural fibrosis is not a cause of pain. Epidural fibrosis-induced scar tissue fixes the nerve root in one position, causing inflammation of the nerve root. Inflammation causes stretching and compression of the nerve root and increased pain during movement \[4\](13).

Diagnosis of epidural fibrosis is made by physical examination and radiographic methods, including magnetic resonance imaging (MRI), computed tomography (CT), epidurography, and epidural endoscopy. The gold standard diagnostic method is epidural endoscopy .

Epidural neuroplasty, also known as epidural lysis, can be used to treat epidural fibrosis.

Epidural lysis is commonly performed in patients with radiculopathy and nerve root compression caused by epidural scar tissue. The objective of lysis of adhesion areas in neuroplasty is to deliver the drug to the target areas by opening up the scar tissue in order to suppress inflammation Radiofrequency (RF) procedures have been used to provide long term relief for radicular pain . There are two types of RF procedures: ablative and pulsed. Ablative RF (aRF) requires temperatures of 70-80°C and results in neuronal destruction, Pulsed RF (pRF) is usually deployed at temperatures of 40-45°C, thereby avoiding loss of neuronal function but resulting in presumed neuromodulatory effects that contribute to analgesia, The most commonly used sequence for pRF is a pulse frequency of 2 Hz and a pulse width of 20 milliseconds with the treatment delivered over 2-10 min PRF is believed to have a neuromodulator effect rather than a neurorestorative effect which is particularly advantageous during treatment. PRF is a non-neurolytic lesioning technique for pain palliation, and no proof of neural damage has been reported after PRF administration.

Erdine et al. reported that PRF treatment caused microscopic detriment to the internal ultrastructural components of axons, which leads to the deterioration and disorganization of membrane and mitochondrial morphology and microfilaments and microtubules In this study, a trial seeks to find out the safety efficacy and cost-effectiveness of two different nonoperative approaches in patients with lumbosacral radicular pain short- and long-term outcomes as regards its implications on pain reduction ,analgesic consumption, and the patient's quality of life.

• duration of analgesic effect [Срок оценки: baseline]