Towards rapid intraoperative axial localization of spinal cord ischemia with epidural diffuse correlation monitoring.

Spinal cord ischemia leads to iatrogenic injury in multiple surgical fields, and the ability to immediately identify onset and anatomic origin of ischemia is critical to its management. Current clinical monitoring, however, does not directly measure spinal cord blood flow, resulting in poor sensitivity/specificity, delayed alerts, and delayed intervention. We have developed an epidural device employing diffuse correlation spectroscopy (DCS) to monitor spinal cord ischemia continuously at multiple positions. We investigate the ability of this device to localize spinal cord ischemia in a porcine model and validate DCS versus Laser Doppler Flowmetry (LDF). Specifically, we demonstrate continuous (>0.1Hz) spatially resolved (3 locations) monitoring of spinal cord blood flow in a purely ischemic model with an epidural DCS probe. Changes in blood flow measured by DCS and LDF were highly correlated (r = 0.83). Spinal cord blood flow measured by DCS caudal to aortic occlusion decreased 62%. This monitor demonstrated a sensitivity of 0.87 and specificity of 0.91 for detection of a 25% decrease in flow. This technology may enable early identification and critically important localization of spinal cord ischemia.

Spinal Epidural Fistulas-A Separate Entity to Dural Fistulas with Different Angioarchitecture and Treatment Approach.

OBJECTIVE: Spinal epidural arteriovenous fistulas (SEAVFs) are the rarest variety of spinal vascular malformation and are often misdiagnosed as type 1 spinal dural fistula. This retrospective study highlights the salient anatomic differentiating points of these entities and also highlights the importance of a planned endovascular treatment approach using different routes of access. Efficacy of the endovascular treatment at 3 months follow-up was also studied. METHODS: We retrospectively reviewed 11 treated patients with SEAVF. Existence of epidural arteriovenous fistula in all these patients was confirmed by spinal angiography. The Aminoff-Logue Scale score was assigned both before and after the procedure. The statistical results were expressed as percentages, and the preprocedure scale was compared with the postprocedure scale at 3 months by using a nonparametric Wilcoxon signed-rank test. RESULTS: The patients ranged in age from 7 to 53 years, with male predominance. Paraparesis was the commonest symptom, and 1 patient had congestive cardiac failure caused by a large fistula. Location was mostly dorsolumbar with intradural venous reflux into the perimedullary venous system (Castilla type A) noted in 3/11(27%) patients, and the remaining 73% patients had Castilla type B1 with an enlarged epidural venous sac. Therapeutic embolization was performed from arterial, venous, or combined routes. The 3-month postprocedure clinical assessment showed statistically significant (P < 0.004) improvement in the Aminoff-Logue Scale score. CONCLUSIONS: The differentiating points between SEAVF compared with type 1 spinal dural fistula are emphasized. The study also highlights the importance of a good angiographic assessment to best access the fistula by arterial, venous, percutaneous, or combined routes. Endovascular treatment resulted in statistically significant clinical improvement at 3 months follow-up.

Clinical and Imaging Characteristics of Spinal Dural Arteriovenous Fistulas and Spinal Epidural Arteriovenous Fistulas.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEDAVFs) are an increasingly recognized form of spinal vascular malformation and are distinct from spinal dural arteriovenous fistulas (SDAVFs). Differentiating between these 2 entities is important as operative strategies often differ based on angioarchitecture. OBJECTIVE: To compare demographic, clinical, anatomic, and imaging findings of SDAVFs and SEDAVFs. METHODS: Consecutive patients diagnosed and/or treated for SDAVF or SEDAVF at our institution between January 2000 and November 2018 were included. Data were collected on demographics, clinical presentation, and imaging findings. All cross-sectional and angiographic imaging were reviewed. To compare continuous variables, t-test was used Chi-squared was used for categorical variables. RESULTS: A total of 169 patients were included. In total 47 patients had SEDAVFs and 122 patients had SDVAFs. Clinical presentation and magnetic resonance imaging (MRI) imaging findings were similar between the 2 groups. SEDAVF patients were significantly more likely to have an epidural venous pouch on gadolinium bolus MR angiography (MRA) (0.0% vs 92.1%, P < .0001). SEDAVFs were more commonly located in the lumbar and sacral spine than SDAVFs (85.1% vs 34.4%, P < .0001). When in the lumbar spine, SEDAVFs unlike SDAVFs were more likely to involve the most caudal segments (L4 and L5, P = .02). CONCLUSION: SEDAVF share clinical and radiological findings similar to SDAVFS, including high T2 cord signal, cord enhancement, and perimedullary flow voids on conventional MRI. However, they have a characteristic appearance on spinal MRA and DSA with a pouch of epidural contrast. SEDAVFs are more commonly located in the lumbosacral spine.

Cauda Equina Syndrome Caused by Epidural Venous Plexus Engorgement in a Patient with May-Thurner Syndrome.

The purpose of this article is to present a case of cauda equina syndrome in a patient with incomplete motor and sensory deficits due to epidural venous plexus engorgement, owing to May-Thurner syndrome successfully treated with venous iliac stenting. A 40-year-old woman, with previous history of deep vein thrombosis and miscarriages, gradually developed right leg and back pain, with functional limitation, perineal hypoesthesia, and sphincter incontinence. Magnetic resonance imaging revealed epidural venous plexus engorgement and cauda equina roots involvement. Phlebography showed perimedullary venous enlargement and left common iliac vein stenosis, leading to the diagnosis of May-Thurner syndrome. Stenting of the left common iliac vein was performed resulting in pain improvement and disappearance of neurological symptoms. Thrombophilia study was positive to heterozygous factor V Leiden. Cauda equina syndrome as the first presentation of a May-Thurner syndrome is very rare. In this case, venous iliac stent placement was an effective and safe treatment.

Presentation and outcomes of patients with thoracic and lumbosacral spinal epidural arteriovenous fistulas: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Thoracolumbar and sacral spinal epidural arteriovenous fistulas (SEDAVFs) are an increasingly recognized form of spinal vascular malformation. The purpose of this study was to perform a systematic review of the demographics, clinical presentation and treatment results of thoracolumbar SEDAVFs. MATERIALS AND METHODS: Pubmed, Scopus and Web of Science databases were searched from January 2000 to January 2018 for articles on treatment of SEDAVFs. Pooled data of individual patients were analyzed for demographic and clinical features of SEDAVFs as well as treatment outcomes. RESULTS: There were 125 patients from 11 studies included. Mean age was 63.5 years. There was a male sex predilection (69.6%). Sensory symptoms including pain or numbness were the most frequently presenting symptoms. Fistula location was the lumbosacral spine in 79.2% and the thoracic spine in 20.8%. Involvement of intradural venous drainage was more common than extradural venous drainage only (89.6% vs 10.4%). Of the 123 treated patients, endovascular therapy was performed in 67.5% of patients, microsurgery in 23.6%, and combined treatment in 8.9%. The overall complete obliteration rate was 83.5% and did not differ between groups. Clinical symptoms improved in 70.7% of patients, were stable in 25%, and worsened in 1.7% with no difference between treatment modalities. CONCLUSIONS: Thoracic and lumbosacral SEDAVFs often present with symptoms secondary to congestive myelopathy or compressive symptoms. Both endovascular and microsurgical treatments were associated with high obliteration rates and good clinical outcomes.

Osseous versus Nonosseous Spinal Epidural Arteriovenous Fistulas: Experiences of 13 Patients.

BACKGROUND AND PURPOSE: Spinal epidural arteriovenous fistulas are rare vascular malformations. We present 13 patients with spinal epidural arteriovenous fistulas, noting the various presenting symptom patterns, imaging findings related to bone involvement, and outcomes. MATERIALS AND METHODS: Among 111 patients with spinal vascular malformations in the institutional data base from 1993 to 2017, thirteen patients (11.7%) had spinal epidural arteriovenous fistulas. We evaluated presenting symptoms and imaging findings, including bone involvement and mode of treatment. To assess the treatment outcome, we compared initial and follow-up clinical status using the modified Aminoff and Logue Scale of Disability and the modified Rankin Scale. RESULTS: The presenting symptoms were lower back pain (n = 2), radiculopathy (n = 5), and myelopathy (n = 7). There is overlap of symptoms in 1 patient (No. 11). Distribution of spinal epidural arteriovenous fistulas was cervical (n = 3), thoracic (n = 2), lumbar (n = 6), and sacral (n = 2). Intradural venous reflux was identified in 7 patients with congestive venous myelopathy. The fistulas were successfully treated in all patients who underwent treatment (endovascular embolization, n = 10; operation, n = 1) except 2 patients who refused treatment due to tolerable symptoms. Transarterial glue (n = 7) was used in nonosseous types; and transvenous coils (n = 3), in osseous type. After 19 months of median follow-up, the patients showed symptom improvement after treatment. CONCLUSIONS: Although presenting symptoms were diverse, myelopathy caused by intradural venous reflux was the main target of treatment. Endovascular treatment was considered via an arterial approach in nonosseous types and via a venous approach in osseous types.

An Unusual Cause of Cauda Equina Syndrome: Lumbar Epidural Venous Engorgement.

BACKGROUND Epidural venous plexus (EVP) engorgement occurs due to many conditions, so it can be easily misdiagnosed. This becomes problematic when the diagnosis requires prompt treatment for a good outcome, especially when it results in cauda equina syndrome (CES). We report a case of extensive iliocaval thrombosis leading to epidural venous plexus and ascending lumbar vein engorgement as an outcome of deep venous thrombosis (DVT) due to probable adverse effects of oral combined contraceptive pills (OCCP). CASE REPORT A 42-year-old woman presented to a rural medical facility with bilateral lower-limb swelling and skin darkening for 2 days. She was transferred to a tertiary medical facility where her condition deteriorated to severe CES. A lower-limbs ultrasonography confirmed the presence of extensive DVT extending to the lower segment of the inferior vena cava. Spine magnetic resonance imaging showed abnormal enhancement of the conus medullaris with thick enhanced cauda equina nerve roots, consistent with a possible case of Guillain-Barré syndrome. However, there was engorgement of the EVP extending to the ascending lumbar, azygos, and hemiazygos veins, which was misdiagnosed. The patient was managed immediately with low-molecular-weight heparin and steroids. She died 4 weeks after admission due to hospital-acquired pneumonia and acute respiratory distress syndrome, probably due to the high dose of steroids. CONCLUSIONS Acute CES has a wide differential diagnosis. This report describes an unusual cause of CES and emphasizes the importance of early recognition to avoid misdiagnosis and management delay. Early identification of this clinical entity markedly decreases morbidity and mortality and thus improves the prognosis. Likewise, underlying causing factors such as venous congestion due to OCCP-related DVT should be considered in the diagnosis.

Lumbar Epidural Varix Causing Radicular Pain: A Case Report and Differential Diagnosis of Lumbar Cystic Lesions.

Lumbar epidural varices are a rare cause of radicular pain mimicking lumbar disc herniation or other cyst-like masses including sequestrated disc herniation, facet joint synovial cyst, or perineural cyst. We report a case of a 36-year-old woman presenting with lumbar radicular pain caused by a lumbar epidural varix. Lumbar magnetic resonance imaging (MRI) revealed a cystic lesion in the ventral epidural space posterior to the right L4 body. Surgery was conducted and histopathology confirmed the diagnosis of an epidural varix. Lumbar epidural varices and other lumbar cystic lesions can commonly cause radicular pain. Physicians will benefit from increased awareness of epidural varices as a cause of lumbosacral radicular pain and the associated radiologic findings supporting differential diagnosis. In particular, careful interpretation of MRI scans may help ensure proper diagnosis of an epidural varix versus other cystic lesions. LEVEL OF EVIDENCE: V.

Cauda Equina Syndrome Due To Dural Sac Shift with Engorgement of the Epidural Venous Plexus: Rare Complication After Lumbar Microdiscectomy.

BACKGROUND: Several postoperative complications related to lumbar microdiscectomy have been reported, including cauda equina syndrome. However, to the best of our knowledge, postoperative cauda equina syndrome resulting from dural sac shift with engorgement of the epidural venous plexus is yet to be reported. CASE DESCRIPTION: A 71-year-old male patient was referred to our hospital with a chief complaint of pain and sensory disturbance due to the lumbar disc herniation of L5-S1. Microdiscectomy was performed to treat the lumbar disc herniation, and his sensory disturbance improved. However, from postoperative day 2, he started to complain of motor weakness, sensory disturbance of S2, and difficulty in urination. Magnetic resonance imaging showed the dural sac shifted to the bone window of L5-S1 with engorgement of the ventral epidural venous plexus. The dural sac shift was thought to be the cause of postoperative cauda equina syndrome, and laminoplasty was chosen to return the dural sac shift into the spinal canal. Cauda equina syndrome completely resolved after laminoplasty. Postoperative magnetic resonance imaging showed the reduction of the dural sac into the spinal canal. The patient was discharged from the hospital without any residual clinical symptoms. CONCLUSION: We report a rare case of postoperative cauda equina syndrome due to dural sac shift and discuss the nascent mechanism of the dural sac shift focusing on anatomic features of the dural sac. We also propose laminoplasty as an option to treat dural sac shift with engorgement of the epidural venous plexus.

A New Type of Spinal Epidural Arteriovenous Fistulas Causes Spinal Epidural Hemorrhage: An Analysis of Five Cases and Natural History Consideration.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEDAVFs) are peculiar and poorly understood lesions with a poorly understood natural history. They usually are subclassified into 2 types according to their drainage components. This study aimed to describe a new type of SEDAVFs that is featured with a unique drainage pattern and present our natural history hypothesis of SEDAVFs. METHODS: Five SEDAVF cases of the new type were reviewed retrospectively from a high case-volume spinal vascular malformation database. The clinical manifestations, neuroradiologic findings, angioarchitecture, treatment strategies, and clinical outcomes were assessed. RESULTS: All patients presented with spontaneous spinal epidural hematoma, and 2 of them exhibited rebleeding. The median age at the initial episode was 20 years. Spinal digital subtraction angiography revealed slow-flow epidural fistulas drained by spinal epidural venous plexus without intradural drainage or engorged venous pouches in all 5 patients. Three patients underwent microsurgical treatment. The outcomes of all of the patients were favorable. CONCLUSIONS: Our study reported a special type of hemorrhagic SEDAVF without an intradural drainage component or epidural mass effect. The key diagnostic clue was early opacification of spinal epidural venous plexus on spinal angiogram. We believe SEDAVFs may form at an early age and gradually develop with time. Different types of SEDAVFs may represent different developing stages of one disease, and our type may represent the early stage of SEDAVFs.

Immediate Spinal Cord Collateral Blood Flow During Thoracic Aortic Procedures: The Role of Epidural Arcades.

The objective of this study was to investigate the functional differences between paraspinal and intraspinal compartments of the spinal collateral network and the importance of circular epidural arcades in thoracic aortic surgery. N = 33 pigs (mean body weight: 34 ± 3kg) were included. A single-inlet-model of spinal collateral flow was created: paraspinal inflow into the collateral network was isolated by cephalad and caudal interruption of inflow into epidural arcades using laminectomies. Animals were assigned to treatment groups (Treatment "open" [patent epidural arcades, n = 10] and Treatment "closed" [closed epidural arcades, n = 10]) and Sham groups (Sham "open" n = 8 and Sham "closed" n = 5). Treatment was a simulated Frozen Elephant Trunk procedure with occlusion of left subclavian and thoracic segmental arteries under mild permissive hypothermia. Observation time was 3 hours. Endpoints were motor and somatosensory evoked potentials (motor evoked potentials and sensory evoked potentials), spinal cord perfusion pressure, cerebrospinal fluid pressure, regional spinal cord blood flow, and neurologic outcome. Animals with interrupted inflow into epidural arcades (Group Treatment "closed") had higher cerebrospinal fluid pressure levels (P < 0.05), were not able to maintain sufficient spinal cord perfusion pressure during Frozen Elephant Trunk procedure (P < 0.001) and did not generate reactive hyperemia as did group Treatment "open." spinal cord blood flow was strongly decreased in group Treatment "closed" (P < 0.001) at 0 hour, did not recover out to 3 hours of observation and 90% of the animals suffered flaccid paraplegia (P < 0.05). Immediate spinal cord backup blood flow is almost exclusively delivered using the system of epidural arcades in the immediate setting, serving as an immediate backup system. Intraspinal arcades are responsible for generating sufficient intraspinal perfusion pressures, reactive hyperemia, and spinal cord integrity. Paraspinal collaterals might need to undergo arteriogenesis, and thus serve as a long-term backup system.

Lower vertebral-epidural spinal arteriovenous fistulas: a unique subtype of vertebrovertebral arteriovenous fistula, treatable with coil and Penumbra Occlusion Device embolization.

A vertebral-epidural spinal arteriovenous fistula (AVF) is an abnormal arteriovenous shunt connecting the vertebral artery to the spinal epidural venous plexus, and may occur spontaneously or secondary to a variety of causes. These unique lesions are uncommon in adults and rarer still in children. Previous reports have grouped together a heterogeneous collection of such arteriovenous lesions, including arterial contributions from the upper and lower vertebral artery, with venous drainage into a variety of spinal and paraspinal collectors. Here, through two cases, we delineate a distinct entity, the lower vertebral-to-epidural AVF. The salient clinical and anatomic features are summarized and contextualized within the broader constellation of vertebrovertebral AVF, the utility of a transarterial intravenous/retrograde intra-arterial endovascular approach is highlighted, and a new use of the Penumbra Occlusion Device (Penumbra Inc) for this purpose is reported.

Lumbar Epidural Varicose Vein: Early Neurological Improvement and Late Radiological Full Recovery with Surgery; The Importance of Magnetic Resonance Imaging in Follow-Up.

A lumbar epidural varicose vein is a rare clinical condition that can lead to neurological deficits. 3 types of lumbar epidural varicose veins were described according to the magnetic resonance imaging (MRI) findings: Type 1 is a thrombosed dilated epidural vein, type 2 is a non-thrombosed dilated epidural vein and type 3 is a sub-membraneous epidural hematoma. Enlarged epidural venous plexuses must be decompressed if they have lead to a neurological deficit. Surgical treatment is by excision or disrupting the cyst's integrity. We present a case of lumbar epidural varicose vein that was surgically treated twice and showed no radiological change despite the disruption of integrity with a partial excision. The lesion spontaneously and completely disappeared in the late period. We emphasize the importance of MRI in follow-up.

Changes of epidural blood flow after epidural administration of epinephrine in young rats.

PURPOSE: For caudal epidural analgesia, the needle is inserted at a site where vessels are abundant. To avoid complications related to intravascular administration of the local anesthetic, epinephrine is usually added, but there is no evidence about the safety of epidural administration of epinephrine in pediatric patients. The objective of this study was to assess the changes in epidural blood flow after epidural injection of epinephrine in young rats. METHODS: With approval of the local ethics committee, four young Sprague-Dawley rats weighing 110-120 g were investigated. The rats were anesthetized with isoflurane via a mask. After there was no escape reaction to pain, an arterial catheter, epidural blood flow monitor (Laser Doppler blood flow ALF 21; ADVANCE Corp.), and caudal epidural catheter were inserted while the rats remained under general anesthesia. Exactly, 10 µl of 1 : 1000 epinephrine was then infused, followed by measurement of the blood pressure and epidural blood flow. After the recovery of the blood pressure and epidural blood flow to baseline, 10 µl of saline was infused through the epidural catheter. The blood pressure and epidural blood flow were then measured again. RESULTS: One rat was excluded because epinephrine was inadvertently injected into the epidural vessels. Therefore, three rats were investigated in this experiment. Blood flow in the epidural space showed no change after the injection of saline. When epinephrine was administered into the epidural space, epidural blood flow decreased immediately and low flow persisted for 6-15 min. The reduction of blood flow was not very great, being only 8-14%, so there was no risk of spinal ischemia which would require 60-80% reduction. CONCLUSION: Administration of epinephrine into the epidural space was safe in young rats. While reduction of epidural blood flow was observed, there was no spinal ischemia.

Study on salvianolic acid B in the reduction of epidural fibrosis in laminectomy rats.

BACKGROUND: Epidural fibrosis (EF) is a common complication after laminectomy. Salvianolic acid B (Sal B) is a major bioactive component of a traditional Chinese medical agent, Salvia miltiorrhiza, which has shown anti-inflammatory, anti-fibrotic and anti-proliferative properties. The object of this study was to investigate the effect of Sal B on the prevention of epidural fibrosis in laminectomy rats. METHODS: A controlled double-blinded study was conducted in sixty healthy adult Wistar rats that underwent laminectomy at the L1-L2 levels. The rats were randomly divided into 3 groups of 20: (1) Sal B treatment group; (2) Vehicle group; (3) Sham group (laminectomy without treatment). All rats were sacrificed 4 weeks post-operatively. The extent of epidural fibrosis, fibroblast proliferation and the expression of vascular endothelial growth factor (VEGF) and inflammatory factors were analyzed. RESULTS: The recovery of all rats was uneventful. In the laminectomy sites treated with Sal B, the dura mater showed no adhesion. Collagen deposition was significantly lower in the Sal B group than the other two groups. In addition, both fibroblast and inflammatory cell counting in the laminectomy sites treated with Sal B showed better grades than the other two groups. The expression of VEGF and inflammatory factors in operative sites also suggested better results in the Sal B group than the other two groups. CONCLUSIONS: Sal B inhibits fibroblast proliferation, blood vessel regeneration, and inflammatory factor expression. Thus, Sal B is able to prevent epidural scar adhesion in post-laminectomy rats.

Angiographic suppression of the artery of Adamkiewicz by venous hypertension resolving after embolization in a case of spinal epidural arteriovenous fistula.

A case of complete angiographic suppression of the artery of Adamkiewicz and anterior spinal artery in a patient with a spinal epidural arteriovenous fistula (AVF) is reported. Slow flow AVFs typically present with progressive myelopathy secondary to spinal venous hypertension (SVH). The lack of a normal venous phase during angiography and its restoration after treatment is commonly observed with these lesions, yet a similar phenomenon seems exceptional at the arterial level. Right T11 intercostal artery angiograms obtained before and after treatment of a left L4 epidural AVF documented the initial suppression of the artery of Adamkiewicz and anterior spinal artery, and their normal appearance immediately after correction of the SVH by embolization. This report confirms that SVH can angiographically suppress prominent and functionally important spinal arteries, re-emphasizing the potential role played by secondary arterial changes in SVH induced myelopathy. This hemodynamic phenomenon also represents a potential pitfall during diagnostic and therapeutic endovascular procedures.

[Morpho-functional characteristic of the lateral vaults of the epidural space of the spinal cord and their clinical significance].

The study of the epidural space was performed on 362 samples of the vertebral column obtained from the fetuses aged from 16 weeks, newborns, children and adult persons aged up to 90 years, using anatomical and histological methods. Within the lateral parts of the epidural space, the lateral vaults were distinguished. A new anatomical interpretation of these structures is proposed, considering them as a complex of anatomical structures including the periosteum of the intervertebral foramen, the sleeve of dura mater, intervertebral veins, spinal arteries, adipose tissue, the system of the connective-tissue trabeculae, recurrent nerves controlling the blood flow in the vascular system of the vertebral channel and promoting the communication of the epidural space with the paravertebral areas.

Lumbosacral epiduroscopy findings predict treatment outcome.

OBJECTIVE: The aim of this study was to evaluate the significance of diagnostic markers obtained through epiduroscopy by evaluating the accuracy of outcome prediction after treatment of epidural pathology using epiduroscopy. DESIGN: A prospective observational study of 139 patients was performed. Patients with chronic low back and leg pain were included. Of the 150 patients who underwent epiduroscopy in the year 2008 at a US hospital, 139 were available for evaluation at 1 month. STUDY: Outcome of treatment was predicted based on direct visual information (hyperemia, vascularity, and fibrosis) and mechanical information (pain to touch, contrast spread, and patency) obtained through epiduroscopy. MAIN OUTCOME MEASURES: Outcome of treatment was measured at 1 month. Accuracy of prediction of outcome was calculated using contingency tables and odds ratios. RESULTS: A prediction of outcome was made in 114 of 139 patients (82%). This prediction was correct in 89 of these 114 patients (accuracy of 78%). The sensitivity and specificity of epiduroscopy with respect to the prediction of outcome were 75% and 82%, respectively. These results were statistically significant (P < 0.01). In 25 of the 139 patients (18%), discrete epidural pathology was not observed. Nine of these 25 patients reported good relief after epiduroscopy. The sensitivity and specificity of epiduroscopy in the diagnosis of epidural pathology were 91% and 39%, respectively. These results were not statistically different (P > 0.1). CONCLUSION: Our results show that lumbosacral epiduroscopy predicts outcome of treatment accurately in the majority of patients. This suggests that information obtained through epiduroscopy may carry significant diagnostic and prognostic value.