Relationship between epidural catheter migration beneath the skin and subcutaneous fat thickness assessed using postoperative CT imaging: a retrospective cross-sectional study.

PURPOSE: The causes of epidural catheter migration beneath the skin have not been previously investigated. We hypothesized that greater subcutaneous fat thickness might be associated with increased catheter migration beneath the skin. METHODS: We conducted a retrospective cross-sectional study of patients who had undergone combined general and epidural anesthesia, selecting individuals who received thoracic and abdominal CT scans within the first 5 postoperative days. Needle depth was defined as the distance from the needle tip to the skin surface when the anesthesiologist determined that the needle tip had reached the epidural space. We measured the length of the epidural catheter from the skin surface to the epidural space (catheter length), and subcutaneous fat thickness (fat thickness) using CT imaging. Migration distance was calculated by subtracting needle depth from catheter length. RESULTS: We analyzed 127 patients (72 males), all undergoing epidural catheter insertion in the left lateral decubitus position via a paramedian approach. The median age of the patients was 71 years. Epidural catheters were postoperatively found to substantially curve beneath the skin. Regression analysis revealed no significant influence of fat thickness on catheter length (regression coefficient 0.10, 95% confidence interval [CI]: - 0.17, 0.38). However, it indicated a positive correlation between fat thickness and needle depth (regression coefficient 0.50, 95% CI: 0.30, 0.70), and a negative correlation between fat thickness and migration distance (regression coefficient - 0.40, 95% CI: - 0.65, - 0.14). CONCLUSION: We found a negative correlation between epidural catheter migration beneath the skin and subcutaneous fat thickness. Anesthesiologists should be aware of the possibility of substantial subcutaneous curving of the catheter, especially in patients with scant subcutaneous fat.

Short-term changes in chest CT images among individuals at low altitude after entering high-altitude environments.

Objective: To investigate the short-term changes in chest CT images of low-altitude populations after entering a high-altitude environment. Methods: Chest CT images of 3,587 people from low-altitude areas were obtained within one month of entering a high-altitude environment. Abnormal CT features and clinical symptoms were analyzed. Results: Besides acute high-altitude pulmonary edema, the incidence of soft tissue space pneumatosis was significantly higher than that in low-altitude areas. Pneumatosis was observed in the mediastinum, cervical muscle space, abdominal cavity, and spinal cord epidural space, especially the mediastinum. Conclusion: In addition to acute high-altitude pulmonary edema, spontaneous mediastinal emphysema often occurs when individuals in low-altitude areas adapt to the high-altitude environment of cold, low-pressure, and hypoxia. When the gas escapes to the abdominal cavity, it is easy to be misdiagnosed as gastrointestinal perforation. It is also not uncommon for gas accumulation to escape into the epidural space of the spinal cord. The phenomenon of gas diffusion into distant tissue space and the mechanism of gas escape needs to be further studied.

Unintentional Injection Into the Retrodural Space of Okada During Transforaminal Epidural Steroid Injection.

BACKGROUND: Transforaminal epidural steroid injection (TFESI) is commonly used for radicular pain, but can lead to an unintentional injection into the retrodural Space of Okada (RSO), an extradural space located dorsal to the ligamentum flavum, instead of the epidural space. OBJECTIVES: To determine the prevalence and describe the fluoroscopic imaging features of an unintentional injection into the RSO during a TFESI and to review the history of injections into the RSO. STUDY DESIGN: Observational study and original research. SETTING: This work was conducted at Jeju National University School of Medicine, Jeju, Republic of Korea. METHODS: A total of 5,429 lumbar TFESIs performed from the September 1, 2018 through October 31, 2021 were analyzed for unintentional RSO injections using fluoroscopic-guided contrast medium patterns. RESULTS: The rate of unintentional injection into the RSO was 0.20% (11 incidents). Contrast medium patterns in the RSO had a sigmoid or ovoid shape confined to the affected facet joint, or a butterfly-shaped pattern extending into the contralateral facet joint, but rarely extending beyond the upper or lower level. LIMITATION: The rarity of unintentional injection into the RSO prevented a randomized controlled study design. CONCLUSIONS: Careful fluoroscopic examination of contrast medium patterns during lumbar TFESI is crucial to identify needle placement in the RSO. If detected, the procedure can be corrected by slightly advancing the needle into the foramen.

Ultrasound-assisted Thoracic Intervertebral Foramen Block. A Cadaveric Study.

BACKGROUND: A thoracic paravertebral block can be a useful opioid-sparing technique for controlling postoperative pain after thoracic and visceral abdominal surgery. OBJECTIVES: Our aim was to assess dye spread into the ventral branch, connecting branch, sympathetic trunk, thoracic paravertebral space, and epidural space after performing a modified ultrasound-assisted thoracic paravertebral block via the intervertebral foramen. STUDY DESIGN: This was a nonrandomized cadaveric study. SETTING: The cadavers were kept at the Department of Anatomopathology of the San Salvatore Academic Hospital of L'Aquila (L'Aquila, Italy). METHODS: We performed a bilateral thoracic paravertebral block via the intervertebral foramen at the second, fifth, ninth, and twelfth thoracic vertebrae. A linear array ultrasound transducer was used. Then, cadaveric dissection was performed. A Tuohy needle was gently inserted in-plane with the ultrasound beam in a lateromedial direction to contact the spinous process. Subsequently, the needle tip was advanced 2 mm along the transverse process of the vertebra, and 5 mL of methylene blue 1% dye was injected at each level. Then, 2 continuous catheter sets were inserted. RESULTS: Forty intervertebral foramen blocks were performed in 5 cadavers. For 38 injection sites, we found dye on both sides of the thoracic paravertebral space and epidural space at each level of puncture. The retropleural organs were also stained. In 2 cases, methylene blue accumulated intramuscularly at the level of the twelfth thoracic vertebra. RESULTS: The spread of dye into the ventral rami, communicating rami, and sympathetic trunk in the thoracic paravertebral space and the epidural space was assessed. We also evaluated the position and the distance (mm) between the catheter tip and the thoracic intervertebral foramen content. Finally, puncturing of intervertebral blood vessels, nerve rootlet and root damage, lung and pleural injuries, and the extent of intramuscular dye accumulation were evaluated and recorded as iatrogenic complications related to the anesthetic procedure. Forty thoracic paravertebral blocks in 5 cadavers were performed. For 38 injection sites, we found dye on both sides of the thoracic paravertebral space and the epidural space at each level of puncture. The ventral rami, the communicating rami, and the sympathetic trunk were also stained. In 2 cases, methylene blue accumulated intramuscularly at the level of the twelfth thoracic vertebra. LIMITATIONS: The first limitation of this study is its small sample size. In addition, the study design did not consider or measure the width of the transverse processes. Another limitation is that the ultrasound beam could not identify the thoracic intervertebral foramen content or the needle tip behind the acoustic shadow of the transverse and vertebral articular processes. CONCLUSION: Paravertebral block via the thoracic intervertebral foramen achieved consistent dye spread into the thoracic paravertebral space and epidural space, capturing retropleural organs.

On the spinal venous sinus of Alligator mississippiensis.

The epidural space of the American alligator (Alligator mississippiensis) is largely filled by a continuous venous sinus. This venous sinus extends throughout the trunk and tail of the alligator, and is continuous with the dural sinuses surrounding the brain. Segmental spinal veins (sl) link the spinal venous sinus (vs) to the somatic and visceral venous drainage. Some of these sl, like the caudal head vein along the occipital plate of the skull, are enlarged, suggesting more functional linkage. No evidence of venous valves or external venous sphincters was found associated with the vs; the relative scarcity of smooth muscle in the venous wall of the sinus suggests limited physiological regulation. The proatlas (pr), which develops between the occipital plate and C1 in crocodylians, is shaped like a neural arch and is fused to the dorsal surface of the vs. The present study suggests that the pr may function to propel venous blood around the brain and spinal cord. The vs effectively encloses the spinal dura, creating a tube-within-a-tube system with the (smaller volume) spinal cerebrospinal fluid (CSF). Changes in venous blood pressure, as are likely during locomotion, would impact dural compliance and CSF pressure waves propagating along the spinal cord.

Monitored epidural catheter placement-ultrasound-guided neurostimulation-aided thoracic catheter placement via caudal route for perioperative analgesia in neonatal thoracotomies: A technical feasibility study.

In this case series, we investigated the feasibility of combining ultrasound and neurostimulation for inserting a stimulating epidural catheter in the thoracic epidural space through the caudal route in neonates. Twelve neonates undergoing tracheo-oesophageal fistula repair under general anaesthesia were studied. The catheter was visible on ultrasound as a hyperechoic dot in the epidural space. Inadvertent high placement was identified in two neonates with neurostimulation, in whom the catheter was withdrawn to the thoracic epidural space, and the position was confirmed on ultrasound. A 0.5 ml/kg bolus dose of 0.125% bupivacaine injected through the epidural catheter was imaged in real-time in the epidural space. Block was effective in 10 neonates; two needed an additional local anaesthetic (LA) bolus. To conclude, ultrasound with neurostimulation facilitates accurate positioning of the caudally placed epidural catheter to the mid-thoracic level in neonates.

A Morphometric Study Analyzing the Anterior Epidural Space Volume Throughout Childhood.

BACKGROUND: Following disc herniations, fragments migrate into the anterior epidural space within the lumbar spine. Although the volume of this area has been previously described in the adult population, the volume is relatively unknown within children. OBJECTIVES: Investigate the relative volume in the lumbar anterior epidural space within the growing spine by using imaging studies. STUDY DESIGN: Retrospective chart review. SETTING: University Medical Center in Lubbock Texas. A teaching hospital affiliated with Texas Tech University Health Sciences Center. METHODS: We conducted a retrospective review of the charts of pediatric patients seen at our institution from 2018 through 2020. Charts chosen for our investigation contained computed tomography imaging of the lumber spine, showing no deformities. Thirty patients were stratified equally among 3 age groups, 2-5 years old, 10-12 years old, and 16-18 years old. The anterior epidural space was measured in each patient 3 times using the previously reported method used by Teske et al (1). Results were compared with a combination of analysis of variance (ANOVA) and single tail paired t test. RESULTS: There was a statistically significant difference in the anterior epidural space size among age groups at all levels of the lumbar spine. When comparing only 2 groups together, the younger age group had anterior epidural space sizes significantly smaller than the other age group for all levels of the lumbar spine. The 10-12 age group had a significantly smaller space in the anterior epidural space than the 16-18-year olds only at the level of L2, L4, and L5 (P = 0.048,0.039, and 0.031, respectively). Within the 16-18-year age group, the anterior epidural space was significantly different between L4 and L3 and L2 and L3 (P < 0.001 and P = 0.019, respectively). LIMITATIONS: Our study is limited by its retrospective nature and the sample size of the patient groups. Furthermore, the use of computed tomography imaging and not making physical measurements limits our accuracy. CONCLUSION: The volume of the anterior epidural space is smaller in the pediatric population than the adult population. The inability of herniated discs to fit within the epidural space in children and adolescents could potentially be the cause of the increased failure of conservative treatment for pediatric lumbar disc herniations.

Acute Paraparesis Caused by Spinal Epidural Fluid After Balloon Kyphoplasty for Traumatic Avascular Necrosis: A Case Report.

Minimally invasive procedures, such as percutaneous vertebroplasty or balloon kyphoplasty (BK), eliminate motion at the fracture site and relieve pain associated with traumatic avascular necrosis when conservative treatment fails. However, these are associated with complications, most of which are directly related to cement leakage. Herein, we report a rare case of acute paraparesis caused by spinal cord compression by epidural fluid following BK for the treatment of Kummell's disease in the absence of cement leakage. To the best of our knowledge, this is the first report describing this complication.

Confirming identification of the epidural space: a systematic review of electric stimulation, pressure waveform analysis, and ultrasound and a meta-analysis of diagnostic accuracy in acute pain.

To review the use of epidural electric stimulation test, pressure waveform analysis, and ultrasound assessment of injection as bedside methods for confirming identification of the epidural space in adults with acute pain, the PubMed database was searched for relevant reports between May and August 2022. Studies reporting diagnostic accuracy with conventional Touhy needles and epidural catheters were further selected for meta-analysis. Sensitivity and specificity were estimated using univariate logistic regression for electric stimulation and pressure analysis, and pooling of similar studies for ultrasound. Risk of bias and applicability was assessed using QUADAS-2. For electric stimulation, pressure waveform analysis, and ultrasound, respectively 35, 22, and 28 reports were included in the review and 9, 9, and 7 studies in the meta-analysis. Electric stimulation requires wire-reinforced catheters and an adequate nerve stimulator, does not reliably identify intravascular placement, and is affected by local anaesthetics. Sensitivity was 95% (95% CI 93-96%, N = 550) and specificity unknown (95% CI 33-94%, N = 44). Pressure waveform analysis is unaffected by local anaesthetics, but does not identify intravascular nor intrathecal catheters. Sensitivity was 90% (95% CI 72-97%, N = 694) and specificity 88% (95% CI 78-94%, N = 67). B-mode, M-mode and doppler ultrasound may be challenging, and data is still limited. Risk of bias was significant and accuracy estimates must be interpreted with caution. Electric stimulation and pressure waveform analysis seem clinically useful, although they must be interpreted cautiously. In the future, clinical trials in patients with difficult anatomy will likely be most useful. Ultrasound requires further investigation.

Recent Advances in Smart Epidural Spinal Needles.

Lumbar puncture is a minimally invasive procedure that utilizes a spinal needle to puncture the lumbar epidural space to take a sample from the cerebrospinal fluid or inject drugs for diagnostic and therapeutic purposes. Physicians rely on their expertise to localize epidural space. Due to its critical procedure, the failure rate can reach up to 28%. Hence, a high level of experience and caution is required to correctly insert the needle without puncturing the dura mater, which is a fibrous layer protecting the spinal cord. Failure of spinal anesthesia is, in some cases, related to faulty needle placement techniques since it is blindly inserted. Therefore, advanced techniques for localization of the epidural space are essential to avoid any possible side effects. As for epidural space localization, various ideas were carried out over recent years to provide accurate identification of the epidural space. Subsequently, several methodologies based on mechanical and optical schemes have been proposed. Several research groups worked from different aspects of the problem, namely, the clinical and engineering sides. Hence, the main goal of this paper is to review this research with the aim of remedying the gap between the clinical side of the problem and the engineering side by examining the main techniques in building sensors for such purposes. This manuscript provides an understanding of the clinical needs of spinal needles from an anatomical point of view. Most importantly, it discusses the mechanical and optical approaches in designing and building sensors to guide spinal needles. Finally, the standards that must be followed in building smart spinal needles for approval procedures are also presented, along with some insight into future directions.

Comparison of accuracy between augmented reality/mixed reality techniques and conventional techniques for epidural anesthesia using a practice phantom model kit.

BACKGROUND: This study used an epidural anesthesia practice kit (model) to evaluate the accuracy of epidural anesthesia using standard techniques (blind) and augmented/mixed reality technology and whether visualization using augmented/mixed reality technology would facilitate epidural anesthesia. METHODS: This study was conducted at the Yamagata University Hospital (Yamagata, Japan) between February and June 2022. Thirty medical students with no experience in epidural anesthesia were randomly divided into augmented reality (-), augmented reality (+), and semi-augmented reality groups, with 10 students in each group. Epidural anesthesia was performed using the paramedian approach with an epidural anesthesia practice kit. The augmented reality (-) group performed epidural anesthesia without HoloLens2Ⓡ and the augmented reality (+) group with HoloLens2Ⓡ. The semi-augmented reality group performed epidural anesthesia without HoloLens2Ⓡ after 30 s of image construction of the spine using HoloLens2Ⓡ. The epidural space puncture point distance between the ideal insertion needle and participant's insertion needle was compared. RESULTS: Four medical students in the augmented reality (-), zero in the augmented reality (+), and one in the semi-augmented reality groups failed to insert the needle into the epidural space. The epidural space puncture point distance for the augmented reality (-), augmented reality (+), and semi-augmented reality groups were 8.7 (5.7-14.3) mm, 3.5 (1.8-8.0) mm (P = 0.017), and 4.9 (3.2-5.9) mm (P = 0.027), respectively; a significant difference was observed between the two groups. CONCLUSIONS: Augmented/mixed reality technology has the potential to contribute significantly to the improvement of epidural anesthesia techniques.

Preprocedural ultrasonography as an adjunct to landmark technique for identification of epidural space in parturients for labor analgesia.

Background: Pregnancy-induced softening of tissues and ligaments may increase the false-positive rates when identifying the epidural space in parturients by the landmark technique. To mitigate these problems, Ultrasonography (USG), which has now become the eye of anesthesiologists, can be used as a reliable tool to facilitate more accurate epidural needle placement in parturients. This study was conducted to know the efficacy of USG when compared to the traditional landmark method. Methods: After the approval from the institutional ethics committee and CTRI registration, 62 parturients of ASA-2 requesting labor analgesia were randomized into 2 groups of 31 each: Group-L (conventional landmark technique) and Group-U (preprocedural USG done before epidural). In group-U, Tuohy's needle was introduced through the USG predetermined insertion point and epidural space was located using the LOR technique. Results: USG increased the success rate of epidural at first attempt from 51.6% in group "L" to 87% in group "U." Fewer needle attempts (P-value - 0.001) were required in group "U" as compared to group "L." No accidental dural puncture in group-U, compared to 2 in group-L. Mean Depth of epidural space (cm) ultrasound depth (UD) = 3.89 ± 0.45 cm and needle depth (ND) = 4.05 ± 0.37 cm. Side effects profile in the ultrasound group was better. Conclusion: Preprocedural ultrasonography is a simple safe, accurate tool with less number of attempts to determine the needle insertion site, decrease the incidence of accidental dural punctures, and assess epidural space depth in parturients.

Influence of maternal position during combined spinal-epidural anesthesia for labor analgesia on technical difficulties and complications.

PURPOSE: Generally, combined spinal-epidural anesthesia (CSEA) for labor analgesia is performed in the lateral or sitting position; however, only few studies have investigated the effect of maternal position on labor analgesia induction. We aimed to retrospectively assess the influence of maternal position on induction time and complications. METHODS: We retrospectively analyzed anesthetic and medical records regarding labor analgesia in 201 parturients treated between January 2019 and November 2019. Patients were classified into 2 groups based on their position (sitting or lateral) during induction. The primary outcome was the time required for CSEA induction. We compared 2 groups on the primary outcome and the occurrences of other complications during CSEA induction using hyperbaric bupivacaine. Moreover, we performed multiple linear regression analysis to identify independent factors associated with induction time. RESULTS: There was no significant between-group difference in the time required for induction. Multiple linear regression analysis revealed an independent association of the distance from the skin to the epidural space with the time required for induction. The lateral group had a significantly higher incidence of paresthesia than the sitting group (P = 0.028). The lateral group had a significantly higher ephedrine requirement (P < 0.001) than the sitting group. CONCLUSION: Maternal position was not associated with the time required for CSEA induction. However, the sitting group had a lower paresthesia occurrence and ephedrine requirement than the lateral group. Other technical complications were not associated with maternal position during CSEA induction.

Fidel Pagés, el auténtico descubridor de la anestesia epidural, en el centenario de su publicación Anestesia metamérica (1921-2021) / Fidel Pagés, the true discoverer of epidural anesthesia, on the centenary of his publication Anestesia metamérica (1921-2021)

Resumen: Pocas han sido las Figuras españolas que han aportado alguna interesante novedad al mundo de la anestesia, pero ninguna tan injustamente tratada y olvidada como la de Pagés, verdadero pionero de la anestesia epidural, que él denominaría «anestesia metamérica¼ en su artículo publicado en el mes de marzo de 1921 en la Revista Española de Cirugía, fundada por él mismo. Años después, en 1931, Dogliotti, profesor de Cirugía de Módena publicó sus experiencias sobre la anestesia epidural, a la que llamó «anestesia peridural segmentaria¼, ignorando el trabajo de Pagés publicado 10 años antes. El trabajo de Dogliotti fue rápidamente reconocido, asumiendo todos los méritos de la paternidad de la técnica epidural, quedando Pagés relegado a un olvido injusto que con este trabajo tratamos de reparar. La idea central de este texto versará sobre el reconocimiento de Pagés como verdadero promotor del abordaje epidural con fines quirúrgicos. Destacar sus ideas innovadoras sobre el bienestar del paciente y la minimización de los efectos adversos de las técnicas anestésicas y quirúrgicas, así como valorar una obra que, aunque corta, bien podría incluirse entre los mejores cirujanos españoles de principio del siglo XX, un cirujano con alma de anestesiólogo.

Abstract: Few Spanish Figures have contributed any interesting novelty to the world of anesthesia. But none so unjustly treated and forgotten such as Pagés, a true pioneer of epidural anesthesia, which he would call «metameric anesthesia¼ in his article published in March 1921 in the Spanish Journal of Surgery, founded by himself. Later, in 1931, Dogliotti, Modena Professor of Surgery published his experiences on epidural anesthesia, which he called «segmental peridural anesthesia¼, ignoring Pagés work published 10 years earlier. Dogliotti's work was quickly recognized, assuming all the merits of the paternity of the epidural technique, leaving Pagés relegated to an unjust oblivion that with this work we try to repair. The central idea of this text will focus on the recognition of Pagés as a true promoter of the epidural approach for surgical purposes. Highlight his innovative ideas about patient well-being and minimizing the adverse effects of anesthetic and surgical techniques. As well as assessing a work that, although short, could well be included among the best Spanish surgeons of the early twentieth century, a surgeon with the soul of an anesthesiologist.

Cervical radiculopathy as first presentation of CD3-positive diffuse large B-cell lymphoma of the cervico-thoracic junction.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) in rare cases can presents an unusual expression of CD3 T-cell specific antigen. We report the first case of a CD3-positive DLBCL of the cervico-thoracic junction presenting with persistent cervical radiculopathy. CASE PRESENTATION: A 74-years-old male patient presented a severe and persistent right C8 radiculopathy associated with right-sided neck pain, progressive numbness and weakness of the right arm. The symptoms prominent during the night interfering with sleep and were resistant to anti-inflammatory drugs and cervical orthosis. Spine MRI showed a solid hypointense lesion on T2-weighted images and hyperintense on STIR sequences involving the epidural space at C7, T1 and T2. The patient underwent a C7-T1 decompressive laminectomy and left T2 hemilaminectomy with resection of the epidural tissue resulting in subtotal removal. Histology showed a DLBCL germinal center B-cell lymphoma with expression of CD3 T-cell specific antigen. Then the patient underwent adjuvant radiotherapy and chemotherapy consisting of R-CHOP protocol. At last follow-up (2 years) the patient is still in good clinical status (KPS = 80) with almost complete recovery of the cervical radiculopathy. CONCLUSIONS: To our knowledge this is the first case of DLBLC GCB-like CD3 positive to present with radiculopathy.

Measurement of S1 foramen depth for ultrasound-guided S1 transforaminal epidural injection.

Background: Ultrasound-guided first sacral transforaminal epidural steroid injection (S1 TFESI) is a useful and easily applicable alternative to fluoroscopy or computed tomography (CT) in lumbosacral radiculopathy. When a needle approach is used, poor visualization of the needle tip reduces the accuracy of the procedure, increasing its difficulty. This study aimed to improve ultrasound-guided S1 TFESI by evaluating radiological S1 posterior foramen data obtained using three-dimensional CT (3D-CT). Methods: Axial 3D-CT images of the pelvis were retrospectively analyzed. The radiological measurements obtained from the images included 1st posterior sacral foramen depth (S1D, mm), 1st posterior sacral foramen width (S1W, mm), the angle of the 1st posterior sacral foramen (S1A, °), and 1st posterior sacral foramen distance (S1ds, mm). The relationship between the demographic factors and measured values were then analyzed. Results: A total of 632 patients (287 male and 345 female) were examined. The mean S1D values for males and females were 11.9 ± 1.9 mm and 10.6 ± 1.8 mm, respectively (P < 0.001); the mean S1A 28.2 ± 4.8° and 30.1 ± 4.9°, respectively (P < 0.001); and the mean S1ds, 24.1 ± 2.9 mm and 22.9 ± 2.6 mm, respectively (P < 0.001); however, the mean S1W values were not significantly different. Height was the only significant predictor of S1D (ß = 0.318, P = 0.004). Conclusions: Ultrasound-guided S1 TFESI performance and safety may be improved with adjustment of needle insertion depth congruent with the patient's height.

Correlation Between the Extent of Injectate Spread and Clinical Outcomes in Cervical Interlaminar Epidural Injection.

BACKGROUND: Cervical interlaminar epidural injection (CILEI) is commonly used to treat acute or chronic pain that affects the head, neck, and upper extremities. Thus far, studies on CILEI have focused on determining the optimal volume of contrast medium or analyzing the spread of contrast medium during a CILEI. To our knowledge, few studies have attempted to assess the correlation between epidurogram patterns and clinical outcomes of CILEI. OBJECTIVES: This study aimed to investigate the relationship between contrast medium spread and pain relief after a CILEI in patients who complained of neck and/or unilateral upper extremity pain. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary university hospital. METHODS: Patient demographics, pain duration, and radiographic findings, including cervical simple radiograph and magnetic resonance imaging, were reviewed from medical records. The spread pattern of contrast medium during a CILEI was analyzed based on anteroposterior (AP) and lateral fluoroscopic views. The spread pattern in the AP view was classified into 4 categories using predetermined anatomical references, including the medial border, bisector, and lateral border of the articular pillar at the targeted vertebral level. The spread pattern in the lateral view was divided into 2 groups based on whether the contrast medium was present at the ventral epidural space. Every CILEI procedure was performed under fluoroscopic guidance by skilled experts. A responsive outcome was defined as a reduction in the numeric rating scale for pain by more than 50% at one month postoperatively compared to preoperatively. RESULTS: Among 656 patients, 526 were excluded from the analysis according to predetermined criteria. The remaining 130 patients were analyzed, and 78 (60%) patients showed responsive results one month after a CILEI. According to a multivariable logistic regression analysis, the negative predictors of a CILEI were long symptom duration (P = 0.045), high grade of central stenosis (P = 0.022), and limited spread of contrast medium solely within the central canal in the AP view (P = 0.008). LIMITATIONS: The limitations of this study include its retrospective design, absence of clinical parameters other than pain intensity, and short follow-up period. CONCLUSIONS: If the duration of symptoms is lengthy, central stenosis is severe, or contrast medium spread is limitedly solely within the central canal and does not reach the dorsal root ganglion any further, the outcome after a CILEI is likely to be poor. Therefore, efforts should be made to spread injectate around the dorsal root ganglion at the target level.

Meningovertebral ligaments could be a barrier for migration of a herniated intervertebral disc: An anatomical study.

Purpose: Intervertebral disc degeneration can manifest as sequestration. In most cases, the material could be found ipsilateral to the annular tear; however, a contralateral migration is also possible. We present an anatomical description of anterior meningovertebral ligaments (MVLs) as a possible barrier for disc migration. Methods: Anatomical dissection of 20 fresh human cadavers was carried out. Complete lumbar laminectomies with facetectomies were performed. All lumbar segments were exposed. Morphologic and morphometric descriptions of anterior MVLs were presented, with special attention to possible routes of herniated disc migration. Results: Anterior MVLs were present in all cases. They were divided in three separate groups: medial, lateral, and attached to the nerve roots. The medial group was the thickest, its mean length was 26.2 ± 1.2 mm, and it had no attachment to the disc in 51% of cases. The lateral group was less firm than the medial group, its mean length was 26.9 ± 1.0 mm, and it had no relation with the disc in 47% of cases. Ligaments related to the nerve root were the most delicate and always attached to the intervertebral disc. Their mean length was 14.9 ± 1.8 mm. Conclusions: The medial group of anterior MVLs are strong connective tissue bands dividing the anterior epidural space. The lateral group is more delicate, and in most cases, lateral MVLs lack annular attachment. MVLs could be an anatomical barrier for disc migration in particular cases.

Spontaneous Intracranial Hypotension and Multi-Level Cervical and Lumbar Epidural Blood Patches: A Case Report.

Spontaneous intracranial hypotension (SIH) is a neurologic condition where the intracranial pressure is reduced due to a loss of cerebrospinal fluid from its reservoir, the intrathecal space, to surrounding tissues. It is commonly characterized by an incapacitating headache, phono-photophobia, nausea, and vomiting, commonly refractory to medical treatment and requires further investigation. We describe the case of a healthy young man who presented to the emergency room with a postural headache, accompanied by nausea, vomiting, and phono-photophobia. Brain computed tomography (CT) imaging study was unremarkable and he was initially treated symptomatically. Because of persisting pain even on medical treatment, additional imaging studies, including a myelo-CT scan, were performed and a diagnosis of multi-level cerebrospinal fluid fistulas was made. To treat the underlying cause, a first epidural blood patch (EBP) was initially performed at C7-T1 with 20 mL of autologous blood, but failed to provide complete symptomatic relief. Months later, a second EBP was conducted at C6-C7 with higher volume (30 mL) but as in the first EBP this procedure too did not result in total resolution of the headache and accompanying symptoms. Since there was no surgical indication from Orthopedics and Neurosurgery and the symptoms persisted, a third EBP was carried out, this time at a lumbar level (L2-L3) with infusion of 60 mL of blood so the upper dorsal and cervical epidural space was reached. This resulted in a better symptom relief, allowing the patient to now carry out his normal activities with only residual pain. The need for repeat procedures is one of the pitfalls of the blood patching technique. If possible, it should be performed at the level of the documented fistula, but always with safety in mind and by experienced hands, especially when cervical levels are concerned. A consensus has not been reached regarding the blood volume to be administered; however, any discomfort or pain reported by the patient should be seen as warning sign and the procedure should be interrupted. Although not being a perfect solution, EBP can completely or partially resolve SIH symptoms, without the need for surgical intervention.

Daily persistent headache with nutcracker physiology and spinal epidural venous congestion: Treatment with lumbar vein embolization.

Nutcracker phenomenon (NCP) can cause various congestion syndromes secondary to the superior mesenteric artery (SMA) compressing the left renal vein (LRV) resulting in venous reflux. It has recently been suggested that reflux into the lumbar vein (LV) and epidural venous plexus (EVP) may cause headaches in some patients with NCP. This report illustrates an example of a patient with refractory headaches and imaging findings suggestive of NCP that underwent treatment with percutaneous LV embolization. The patient is a 60-year-old female with daily persistent headaches for 5 years that failed numerous headache preventative medications. Time-resolved magnetic resonance angiography demonstrated NCP with reflux and congestion of the LV and EVP. Catheter-based venography confirmed these findings and the patient was treated with percutaneous embolization of the LV. This case report demonstrates the use of LV embolization to prevent EVP reflux and treat daily headaches due to NCP. The patient's headache resolved the next day. She has been headache-free for 5 months post-treatment. These findings support prior data suggesting that NCP can cause retrograde LV flow, EVP congestion, and elevated cerebrospinal fluid pressures leading to daily persistent headaches. Percutaneous embolization of the LV may be a minimally invasive treatment option for refractory headaches in patients with NCP, retrograde LV flow, and EVP congestion.