Neuraxial pathology and regional anesthesia: an education guide to decision-making.

In current clinical practice, spinal anesthesia and analgesia techniques-including epidural and subarachnoid procedures-are frequently executed without imaging like X-ray or epidurography. Unrecognized spinal pathology has resulted in serious morbidity in the context of performing neuraxial anesthesia. Typically, preoperative consultations incorporate a patient's medical history but lack a detailed spinal examination or consideration of recent MRI or CT scans. In contrast, within the domain of pain clinics, a multidisciplinary approach involving anesthesiologists and neuroradiologists is common. Such collaborative settings rely on exhaustive clinical history and scrutinization of recent imaging studies, which may influence the decision to proceed with invasive spinal interventions. There are no epidemiological data concerning rates of the different baseline pathologies that would potentially pose morbidity risks from neuraxial procedures, but the most common among these is canal stenosis, which significantly affects almost 20% of people over 60 years of age. This paper aims to elucidate these critical findings and advocate for incorporating meticulous preoperative assessments for individuals slated for spinal anesthesia or analgesia procedures, thereby attempting to mitigate potential risks.

Prone Position MRI of the Lumbar Spine in Patients With Low Back Pain and/or Radiculopathy Refractory to Treatment.

BACKGROUND: There are patients with limiting low back pain (LBP) with or without radicular pain in whom conventional supine magnetic resonance imaging (MRI) show no causative pathology. Despite the limitations of dynamic axially loaded MRI examinations, these imaging studies have shown a striking ability to diagnose pathology unrecognized by conventional MRI. The difference in findings between supine and prone MRI with patient symptom correlation has not been studied. METHODS: Nineteen patients suffering from chronic moderate-to-severe LBP and/or radicular pain nonresponsive to conventional therapy or interventional treatment, were included in this study. Both supine and prone MRIs were performed and analyzed by a neuroradiologist. Specific supine and prone measurements were registered, including spinal canal area, lateral recess diameter, foraminal area, and ligamentum flavum thickness. Three-dimensional  MRI reconstructions of varying pathology patterns were created. RESULTS: The mean patient age was 48.7 years (range [R]: 30-69), 63% of patients were women. The mean numeric pain score  was 6.5 (R: 4-8). In 52.6% of cases, disc pathology/increased disc pathology was seen only on prone imaging. We observed significant buckling and increased thickness of the ligamentum flavum in 52.6 % of cases in the prone position that was absent from the supine MRIs. We also documented varying grades of spondylolisthesis and facet joint subluxation resulting in significant foraminal stenosis in 26.3% of prone cases not seen from supine MRIs. CONCLUSIONS: Four patterns of pathological findings have been identified by MRI performed in the prone position. These findings were not observed in the supine position. Prone MRI can be a significant and useful tool in the diagnosis and treatment of patients with back pain refractory to treatment whose conventional supine MRIs appeared unremarkable.

Painful Total Hip Arthroplasty: A Systematic Review and Proposal for an Algorithmic Management Approach.

BACKGROUND: The etiological diagnosis of painful primary total hip arthroplasty and its management is a complex clinical challenge for pain physicians. Extrinsic sources of pain in the hip joint might be efficiently treated by clinical pain units, although the topic remains controversial. OBJECTIVES: To conduct a literature review and suggest an evidence-based algorithmic approach to managing painful hip arthroplasty. STUDY DESIGN: Systematic literature review with qualitative data synthesis. METHODS: We conducted an online search of Medline/Pubmed, Embase, Clinical Trials, and Cochrane database using the Medical Subject Heading (MeSH) and free terms on all biomedical literature published up to August 2019. Articles that described either the etiologies and management of painful primary total hip arthroplasty or the imaging techniques to specifically assess any of its causes were included. We collected the demographic data (gender, age, body mass index), main etiologies, diagnostic tests, and specific treatments applied in each study. Based on the reviewed evidence, we propose an algorithmic approach, with a special emphasis on etiologies that should be referred to pain clinics. RESULTS: Twenty-four studies were included for the synthesis, 16 of which were observational studies and 8 of which were non-systematic literature reviews that described a wide range of etiologies of painful primary total hip arthroplasty. The results showed that 2/3 of the causes of pain were intrinsic and need to be managed by orthopedic surgeons. One third of the etiologies were extrinsic and should be referred to pain clinics once intrinsic causes have been ruled out. Among extrinsic sources of pain, the most frequent was myofascial etiology. LIMITATIONS: A publication bias might have been present due to the inclusion of studies published only in English, Spanish, and German. The included studies also had heterogeneous methodologies. CONCLUSIONS: The current review suggests that painful hip arthroplasty is not a rare condition in clinical practice. We systematically reviewed etiologies and various treatments published in the literature and we suggest an algorithmic approach to management based on the available evidence. This approach incorporates the evidence regarding our knowledge of the etiologies, diagnosis, and management of chronic pain after total hip arthroplasty. Systematic review registration: The protocol was registered in PROSPERO the international prospective register of systematic reviews, ID CRD42020185663.

Case series of fluoroscopic findings and 3D reconstruction of human spinal MRIs of the space of Okada.

OBJECTIVE: To better understand the unexpected spread of contrast medium observed by conventional fluoroscopic X-ray images during standard neuraxial techniques used in the treatment of pain. The support of 3D reconstruction of MRI images of structures within the lumbar spine was used to better understand the space of Okada. METHODS: Lumbar facet joint and epidural corticosteroid injections in five patients under fluoroscopic guidance with loss of resistance to air or saline to identify the facet joints or epidural space. Next, in a retrospective study, the authors examined the retrodural space of Okada and the neighboring tissues with 3D reconstruction of spinal MRIs of seven patients without any demonstrable spinal pathology to better understand the characteristics of the space of Okada. RESULTS: Contrast medium spread to the ipsilateral and contralateral sides was observed in five patients. The contralateral spread was thought to be through the retrodural space of Okada, which is a potential space between the anterior surface of the vertebral lamina and the posterior surface of the ligamentum flavum. It facilitates communication between the contralateral articular facet joints of the spine. CONCLUSIONS: This study provides new evidence for the existence of the space of Okada where an unexpected contralateral spread occurred following facet joint and attempted epidural injection. The 3D reconstructions of MRIs may help us better understand the nature of the retrodural space of Okada and its clinical implications.

A 1-Year Cost Analysis of Spinal Surgical Procedures in Spain: Neurosurgeons Versus Orthopedic Surgeons.

OBJECTIVE: To evaluate the direct costs of various spinal surgical procedures within 1 year of follow-up and to compare the profiles of neurosurgeons and orthopedic surgeons. METHODS: All spinal procedures performed within a 10-month period in patients covered by a private insurance company were included. Costs related to the spinal interventions were systematically registered in the company database. Associated costs during the 1-year follow-up were recorded. RESULTS: In total, 1,862 patients were included, with a total cost of €11,050,970, of whom 34.8% underwent noninstrumented lumbar decompression (€3,473), 27.1% dorsolumbar instrumented fusion (€6,619), 14.6% nucleoplasty (€1,323), 13.5% cervical surgery (€4,463), 3.4% kyphoplasty (€4,200), 2.9% scoliosis (€15,414), 1.2% oncologic surgery (€5,590), 0.5% traumatic compression (€7,844), and 4.7% (€1,343) other minor interventions (mainly rhizotomies). Approximately 42% of patients required reinterventions within the first year, with a global extra cost of €7,280,073; 11% were referred to the pain clinic, with a €114,663 cost; 55.5% were men; and the most common age range of patients who received an intervention was 65-75 years. Neurosurgeons performed 60% of all interventions. Noninstrumented lumbar operations were performed by neurosurgeons twice as often as instrumented operations, and they performed 76% of cervical operations. Orthopedic surgeons performed 2.5 times more instrumented than noninstrumented lumbar operations, and almost all scoliosis and rhizotomy procedures. CONCLUSION: The direct costs of spinal surgery in Spain were generally lower than those reported in other European Union countries and the United States. Neurosurgeons and orthopedic surgeons had different spine surgical profiles and costs.

Comparison of the antinociceptive profiles of morphine and oxycodone in two models of inflammatory and osteoarthritic pain in rat.

Oxycodone and morphine are two opioid drugs commonly used for the treatment of moderate to severe pain. However, their use in the management of noncancer pain remains a controversial issue and, in this respect, the evidence on their effectiveness and safety, particularly in osteoarthritis, is being questioned. In order to analyse their analgesic profile, two different pain models in rats were used: the formalin-induced inflammatory pain and the monosodium iodoacetate (MIA)-induced knee osteoarthritic pain. Drugs were administered systemically (i.p.) and their antinociceptive effect and potency were assessed. In the formalin test, both morphine and oxycodone produced a dose-dependent antinociceptive effect, but oxycodone outdid morphine in terms of effectiveness and potency (nearly two times) in the early (acute nociceptive) as in the late phase (inflammatory). In the osteoarthritis model, both drugs reduced movement-evoked pain (knee-bend test), mechanical allodynia (von Frey test) and heat hyperalgesia (Plantar test). Pretreatment with naloxone and naloxone methiodide reduced morphine and oxycodone effects. Peripheral mu-opioid receptors play a crucial role in the antinociceptive effect of both drugs on movement-evoked pain and heat hyperalgesia, but not on tactile allodynia. The main finding of our study is that oxycodone has a better antinociceptive profile in the inflammatory and osteoarthritic pain, being more effective than morphine at 14 days post-MIA injection (phase with neuropathic pain); it overcame the morphine effect by improving the movement-induced pain, tactile allodynia and heat hyperalgesia. Therefore, oxycodone could be an interesting option to treat patients suffering from knee osteoarthritis when opioids are required.

Transforaminal Epiduroscopy in Patients with Failed Back Surgery Syndrome.

BACKGROUND: Epiduroscopy is a useful diagnostic and therapeutic tool for managing failed back surgery syndrome (FBSS). The conventional approach is via either the sacral hiatus or the interlaminar. Major causes of FBSS include epidural fibrosis, disc herniation, and stenosis. When these problems are located at the intervertebral foramen level, it can be difficult to reach the lateral recess and the foramen with the epiduroscope. Transforaminal epiduroscopy could be a useful alternative approach in patients with FBSS located at the foraminal level. OBJECTIVE: We present a new procedure for lumbar epiduroscopy via a transforaminal approach and its application in patients with FBSS. The technique is described and long-term results are reported. STUDY DESIGN: This study used a single-arm prospective observational design. SETTING: The research took place at the University Hospital in Spain. METHODS: Patients with FBSS suffering severe chronic radicular pain (Numeric Rating Scale [NRS-11] > 7) who had not responded to other treatments were included. Selective root stimulation during a pulsed radiofrequency procedure confirmed the origin of pain by means of an exact reproduction of typical pain. Transforaminal epiduroscopy was performed at the affected level. The severity of fibrosis observed was recorded. The NRS-11 score was reevaluated at 1, 6, and 12 months after the procedure. Any complications related to the treatment were recorded. RESULTS: Twenty-four patients were included. The mean number of back surgeries was 1.66 (range, 1-5). The basal NRS-11 score was 7.83 (0.14); at 1 month, 3.66 (0.38) (P < 0.001); at 6 months, 4.46 (0.48) (P < 0.01); and at 1 year after treatment, 4.17 (0.51) (P < 0.01). Most patients (54%; 95% CI, 34%-74%) obtained > 50% pain reduction on the NRS-11, maintained during a 1-year follow-up period. No major complications were registered. LIMITATIONS: The research was limited by the lack of a control group. CONCLUSIONS: We have described a new procedure for epiduroscopy via the transforaminal approach. It is a useful and safe approach to managing FBSS at the foraminal level and shows better long-term results than other endoscopic procedures. KEY WORDS: Epidural, epiduroscopy, chronic pain, spinal cord, back surgery.

Neuralgia del pudendo: algoritmo de manejo diagnóstico y terapéutico desde una unidad del dolor / Pudendal neuralgia: algorithm for diagnostic and therapeutic management in a pain unit

Objetivo. Presentar un algoritmo de manejo del dolor perineal crónico severo con sospecha de neuralgia del trigémino. Casos. Se presentan 3 casos clínicos con etiología y evolución clínica diversa. Discusión. Análisis de los criterios diagnósticos y tratamientos vigentes. Evaluación de los casos a la luz del algoritmo de diagnóstico y tratamiento propuesto (AU)

Objective. To describe a new algorithm for the management of severe chronic perineal pain/pudendal neuralgia. Cases. We report 3 clinical cases with different etiologies and outcomes. Discussion. We analyze the diagnostic criteria and treatments and evaluate the rational management of these patients according to the algorithm (AU)

One-year results of an algorithmic approach to managing failed back surgery syndrome.

BACKGROUND: Failed back surgery syndrome (FBSS) is a major clinical problem. Different etiologies with different incidence rates have been proposed. There are currently no standards regarding the management of these patients. Epiduroscopy is an endoscopic technique that may play a role in the management of FBSS. OBJECTIVE: To evaluate an algorithm for management of severe FBSS including epiduroscopy as a diagnostic and therapeutic tool. METHODS: A total of 133 patients with severe symptoms of FBSS (visual analogue scale score ≥7) and no response to pharmacological treatment and physical therapy were included. A six-step management algorithm was applied. Data, including patient demographics, pain and surgical procedure, were analyzed. In all cases, one or more objective causes of pain were established. Treatment success was defined as ≥50% long-term pain relief maintained during the first year of follow-up. Final allocation of patients was registered: good outcome with conservative treatment, surgical re-intervention and palliative treatment with implantable devices. RESULTS: Of 122 patients enrolled, 59.84% underwent instrumented surgery and 40.16% a noninstrumented procedure. Most (64.75%) experienced significant pain relief with conventional pain clinic treatments; 15.57% required surgical treatment. Palliative spinal cord stimulation and spinal analgesia were applied in 9.84% and 2.46% of the cases, respectively. The most common diagnosis was epidural fibrosis, followed by disc herniation, global or lateral stenosis, and foraminal stenosis. CONCLUSIONS: A new six-step ladder approach to severe FBSS management that includes epiduroscopy was analyzed. Etiologies are accurately described and a useful role of epiduroscopy was confirmed.

Effect of nitroglycerine in popliteal preparations from patients with peripheral occlusive arteriopathy precontracted with KCl or 5-hydroxytryptamine.

1. At the present time, there are no studies in isolated arteries from patients suffering from peripheral occlusive arteriopathy (POA). In the present study, we attempt to characterize the effect of nitroglycerine (GTN) in isolated popliteal preparations obtained after leg amputation in 60-90-year-old men and women suffering from POA. 2. After surgical operation, arterial samples were stored in a refrigerator at 4 degrees C and, after 12-36 h, they were cut into rings and mounted in organ baths containing Krebs'-Henseleit solution at 37 degrees C and gassed constantly with 95% CO2 and 5% O2. Because noradrenaline elicited very poor contractile responses in these preparations, in the present study we evaluated the concentration-dependent contractions induced by KCl (15-90 mmol/L) and 5-hydroxytryptamine (5-HT; 10-7 to 10-4 mol/L) in arteriopathic popliteal rings and, when the corresponding maximum contractile effect had been obtained, we also evaluated the concentration-dependent relaxing effect produced by GTN (10-10 to 10-5 mol/L) in all precontracted preparations. As a reference, similar experiments were performed in popliteal preparations obtained following surgery on non-arteriopathic vascular tissue where it was necessary to resect a certain percentage of healthy vessel. 3. The responses to KCl and 5-HT were greater in healthy vessel than in arteriopathic rings. The relaxing effect of GTN was greater in preparations precontracted with 5-HT than in those preparations precontracted with KCl. In addition, preparations precontracted with KCl relaxed even less when they were obtained from patients with POA. 4. The present data indicate that GTN is a vasodilator with little effect on depolarized arteries. The results also indicate that the effect of this drug is even less in depolarized arteries from patients with POA.

Importance of creatine kinase activity for functional recovery of myocardium after ischemia-reperfusion challenge.

To define the relation between the phosphoryl transfer via creatine kinase and the ability to recover from an ischemia-reperfusion challenge, the authors chemically inhibited creatine kinase activity with iodoacetamide (IAm) and then measured myocardial recovery after 2, 10, or 30 min of global ischemia followed by 30 min of reperfusion in the isolated, arterially perfused interventricular septa of the rabbit heart. During normoxia, IAm (0.5 M perfused for 15 min) did not by itself modify developed tension, maximal rate of tension development, or resting tension. In ischemia, IAm pretreatment increased the rate of developed tension loss and highly diminished developed tension recovery after reperfusion for all the ischemia periods tested. Moreover, IAm significantly enhanced the maximal increase in the resting tension induced by 10 or 30 min of ischemia plus reperfusion. Lactate dehydrogenase activity in reperfusion was also significantly increased over untreated septa. On the basis of the present results, the authors suggest that the aggravating effects exhibited by IAm on the ischemic myocardium are compatible with its creatine kinase inhibition properties and that creatine kinase activity is essential for full recovery from an ischemia-reperfusion challenge.