Search Results (36)

Peripheral nerve injuries are a significant concern in surgical procedures, often leading to chronic pain and functional impairment. Despite advancements in imaging, preoperative and intraoperative visualization of peripheral nerves remains a challenge. This study introduces and evaluates a novel tri-iodinated lidocaine-based contrast agent for computed tomography neurography, aiming to enhance the intraoperative visibility of peripheral nerves in vivo. A tri-iodinated lidocaine analogue was synthesized and characterized for its radiodensity, sodium channel binding and nerve affinity. Sodium channel affinity was performed using molecular docking. In vitro contrast enhancement was assessed by comparing the agent’s Hounsfield unit (HU) values with those of Omnipaque, a clinically approved contrast medium. In vivo imaging was conducted on rat sciatic nerves using micro-CT, followed by ex vivo validation. Nerve conduction blockade was assessed via electrical stimulation and histological analysis was performed to evaluate neurotoxicity. Experimental results revealed the tri-iodinated lidocaine analogue to have similar or higher affinity toward voltage-gated sodium channels than the parent lidocaine and a radiodensity comparable to the commercial CT contrast agent Omnipaque in vitro. In vivo, the contrast agent provided CT visualization of the sciatic nerve, with a significant increase in HU values compared to untreated nerves. Electrical stimulation confirmed transient nerve conduction blockade without observable histological damage, supporting its dual role as an imaging and nerve-blocking agent. This study presents a novel tri-iodinated lidocaine-based contrast agent that enables clear CT visualization of peripheral nerves while maintaining reversible nerve inhibition. These findings support its potential application in preoperative planning and intraoperative nerve protection to reduce surgical nerve injuries. Further studies are warranted to optimize imaging conditions and evaluate its clinical feasibility. Full article

Chemotherapy-induced peripheral neuropathy and the accompanying affective disorders are serious side effects, and their resolution is not guaranteed. Oxidative stress and elevated levels of Nod-like receptor protein 3 (NLRP3) have been detected in the peripheral and central nervous systems of animals with neuropathic pain provoked by several antineoplastic drugs, such as paclitaxel (PTX). Several studies have further indicated that NLRP3 inflammasome inhibition could be an approach for treating chronic pain, but its impact on the anxiodepressive-like behaviors and memory deficits related to PTX-provoked neuropathy has not yet been investigated. MCC950 is a potent and specific inhibitor of the NLRP3 pathway that acts through inhibiting NLRP3 activation and inflammasome formation. We hypothesized that the administration of MCC950 could alleviate the affective and cognitive disorders accompanying PTX-provoked neuropathy. Using male C57BL/6 mice, we assessed the effects of MCC950 on the mechanical and thermal allodynia, anxiodepressive-like behavior, and memory deficits incited by this taxane. The results indicated that the intraperitoneal administration of 10 mg/kg of MCC950 twice daily for three consecutive days fully reversed the PTX-induced mechanical and thermal allodynia. This treatment also completely attenuated the anxiolytic (p < 0.004) and depressive-like behaviors (p < 0.022) and memory deficits (novel object recognition test; p < 0.0018) incited by PTX. These actions were mainly achieved through blocking NLRP3 inflammasome activation in the sciatic nerve, amygdala, and hippocampus, and oxidative stress in the amygdala and hippocampus. MCC950 also normalized the p-ERK 1/2 overexpression in the sciatic nerve and apoptotic responses in the sciatic nerve and the amygdala. This study suggests that MCC950 might be a promising treatment for PTX-induced mental illnesses and neuropathy. Full article

The anatomy of the sciatic nerve allows it to be blocked at different levels using various anesthetic approaches. However, for several reasons, performing these approaches may be challenging or disadvantageous in specific categories of patients, particularly in obese patients. The objective of this brief technical report is to describe a new technical approach to sciatic nerve block, designed to simplify the procedure for certain categories of patients and less experienced practitioners. Since 2010, more than 5000 procedures have been performed by both experienced anesthesiologists and novice trainees in several hospitals. The ultrasound lateral mid-shaft technique appears to be a safe and effective method for performing a sciatic nerve block, even in obese patients with significant subcutaneous fat and unclear ultrasound images. This approach is particularly beneficial given the various anatomical variations that can occur. By targeting the mid-thigh area, the ultrasound beam accesses anatomical structures that are more superficial, improving the technique’s efficacy. Various hospital groups have been performing this technique as a routine procedure, achieving a success rate of nearly 100%. This impressive success rate exceeds that of other conventional techniques documented in the literature. Additionally, there have been significant improvements in comfort and ease for anesthetists. This method allows the anesthetic to spread around the paraneural sheath, covering the posterior femoral cutaneous nerve. Finally, it is performed in the supine position without the need to mobilize the lower limbs, ensuring patient comfort, especially in cases of fractures or lower limb injuries. Further studies are needed to confirm these results. Full article

Controlling pain after major orthopedic surgery may be challenging, and it is related to delayed recovery, the development of chronic pain, and analgesic dependence. It is well known that effective postoperative pain control can reduce hospital stays by ensuring a more rapid rehabilitation,
thereby decreasing the overall costs. Despite the development of analgesics, the use of opioids and their derivates remains the cornerstone of treatment for patients with acute moderate-to-severe pain in association with general or regional anesthesia. To reduce the risk of side effects and opioid addiction, considering the alarming epidemiological reports in relation to opioid abuse, combined analgesic methods are used, in addition to lower dosages or different forms of administration, such as transdermal administration. Fentanyl transdermal patches appear to be effective in controlling postoperative pain as part of multimodal analgesic regimens in knee and hip surgery, shoulder arthroplasty, traumatic fractures, and one-day surgery; this treatment has fewer associated side effects and can be safely used even in patients with renal impairment. It is also recommended for postoperative pain management in combination with a femoral–sciatic nerve block during foot and ankle surgery. Full article

Objectives: This study aimed to compare the effectiveness of spinal anesthesia (SA) alone versus combined spinal anesthesia with adductor canal block (ACB) and sciatic nerve block (SNB) (SA + ACB + SNB) in patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction. We hypothesized that SA + ACB + SNB would provide better analgesia, greater patient satisfaction, and shorter postanesthesia recovery times than SA alone. Methods: A prospective randomized controlled trial was conducted with 60 patients aged 15–49 years scheduled for elective arthroscopic ACL reconstruction. Participants were randomly assigned to receive either SA or SA + ACB + SNB. Postoperative pain was assessed using the Visual Analog Scale (VAS) at 4, 12, and 24 h post-operation. General health was evaluated using the 12-item Short Form Survey (SF-12) at 1 month postoperatively. Range of motion and analgesic consumption were also recorded. Results: The median VAS score at 4 h post-operation was significantly lower in the SA + ACB + SNB group compared to the SA group (0 [IQR: 0–1] vs. 2 [IQR: 1–3], p = 0.0137). No significant differences in VAS scores were found at 12 h (p = 0.9282) and 24 h (p = 0.5809). PCS-12 and MCS-12 scores did not differ significantly between groups. The SA group had a lower postoperative range of motion (ROM) compared to the SA + ACB + SNB group, with a mean active ROM of 40.67 degrees (±23.52) versus 72.17 degrees (±24.69), respectively (p < 0.0001). Analgesic consumption was similar, with 53.33% of participants in each group using postoperative analgesics (p = 1.0). The mean surgery duration was 74.6 min. The gender distribution was 83% male and 17% female, with an average age of 27.7 years. Conclusions: Adding ACB and SNB to spinal anesthesia improved immediate postoperative pain relief and preserved range of motion in patients undergoing ACL reconstruction, suggesting potential clinical benefits in pain management and functional recovery. Full article

Background: Several local regional anesthesia regimes have been described in the literature to reduce post-surgical pain following total knee arthroplasty (TKA), but it is unclear which regime has the best analgetic effect combined with the best motor function. The aim of this study was to determine if patients with infiltration between the popliteal artery and capsule of the posterior knee (IPACK) combined with an adductor canal block (SACB) had less pain, better motor function, and less opioid consumption after TKA than patients with a femoral nerve block (FNB) combined with a popliteal sciatic nerve block (PSB). Methods: In a retrospective cohort analysis, 342 patients following primary TKA were examined; 175 patients were treated with an IPACK combined with a SACB, and 167 patients with a femoral FNB combined with a PSB. The outcome parameters postoperative pain (visual analogue scale (VAS) for mobilization and at rest, functional recovery, opioid consumption, hospital discharge, and complications were analyzed and compared between both groups. Results: The IPACK/SACB group had a higher postoperative need for opioids despite higher doses of ropivacaine compared to the FNB/PSB group, accompanied by higher VAS scores. Patients’ satisfaction was equal between the groups. Both groups showed comparable mobilization rates and walking distances following TKA. Conclusions: IPACK/SACB showed equal results compared to FNB/PSB for mobilization rates and patients’ satisfaction following TKA without a reduction in opioid consumption. Full article

Background: Pediatric regional anesthesia has been driven by the gradual rise in the adoption of opioid-sparing strategies and the growing concern over the possible adverse effects of general anesthetics on neurodevelopment. Nonetheless, performing regional anesthesia studies in a pediatric population is challenging and accounts for the scarce evidence. This study aimed to review the scientific foundation of studies in cadavers to assess regional anesthesia techniques in children. Methods: We searched the following databases MEDLINE, EMBASE, and Web of Science. We included anatomical cadaver studies assessing peripheral nerve blocks in children. The core data collected from studies were included in tables and comprised block type, block evaluation, results, and conclusion. Results: The search identified 2409 studies, of which, 16 were anatomical studies on the pediatric population. The techniques evaluated were the erector spinae plane block, ilioinguinal/iliohypogastric nerve block, sciatic nerve block, maxillary nerve block, paravertebral block, femoral nerve block, radial nerve block, greater occipital nerve block, infraclavicular brachial plexus block, and infraorbital nerve block. Conclusion: Regional anesthesia techniques are commonly performed in children, but the lack of anatomical studies may result in reservations regarding the dispersion and absorption of local anesthetics. Further anatomical research on pediatric regional anesthesia may guide the practice. Full article

Introduction: In the context of the current opioid crisis, non-pharmacologic approaches to pain management have been considered important alternatives to the use of opioids or analgesics. Advancements in nano and quantum technology have led to the development of several nanotransporters, including nanoparticles, micelles, quantum dots, liposomes, nanofibers, and nano-scaffolds. These modes of nanotransporters have led to the development of new drug formulations. In pain medicine, new liposome formulations led to the development of DepoFoam™ introduced by Pacira Pharmaceutical, Inc. (Parsippany, NJ, USA). This formulation is the base of DepoDur™, which comprises a combination of liposomes and extended-release morphine, and Exparel™, which comprises a combination of liposomes and extended-release bupivacaine. In 2021, Heron Therapeutics (San Diego, CA, USA) created Zynrelef™, a mixture of bupivacaine and meloxicam. Advancements in nanotechnology have led to the development of devices/patches containing millions of nanocapacitors. Data suggest that these nanotechnology-based devices/patches reduce acute and chronic pain. Methods: Google and PubMed searches were conducted to identify studies, case reports, and reviews of medical nanotechnology applications with a special focus on acute and chronic pain. This search was based on the use of keywords like nanotechnology, nano and quantum technology, nanoparticles, micelles, quantum dots, liposomes, nanofibers, nano-scaffolds, acute and chronic pain, and analgesics. This review focuses on the role of nanotechnology in acute and chronic pain. Results: (1) Nanotechnology-based transporters. DepoDur™, administered epidurally in 15, 20, or 25 mg single doses, has been demonstrated to produce significant analgesia lasting up to 48 h. Exparel™ is infiltrated at the surgical site at the recommended dose of 106 mg for bunionectomy, 266 mg for hemorrhoidectomy, 133 mg for shoulder surgery, and 266 mg for total knee arthroplasty (TKA). Exparel™ is also approved for peripheral nerve blocks, including interscalene, sciatic at the popliteal fossa, and adductor canal blocks. The injection of Exparel™ is usually preceded by an injection of plain bupivacaine to initiate analgesia before bupivacaine is released in enough quantity from the depofoarm to be pharmacodynamically effective. Finally, Zynrelef™ is applied at the surgical site during closure. It was initially approved for open inguinal hernia, abdominal surgery requiring a small-to-medium incision, foot surgery, and TKA. (2) Nanotechnology-based devices/patches. Two studies support the use of nanocapacitor-based devices/patches for the management of acute and chronic pain. A randomized study conducted on patients undergoing unilateral primary total knee (TKA) and total hip arthroplasty (THA) provided insight into the potential value of nanocapacitor-based technology for the control of postoperative acute pain. The results were based on 2 studies, one observational and one randomized. The observational study was conducted in 128 patients experiencing chronic pain for at least one year. This study suggested that compared to baseline, the application of a nanocapacitor-based Kailo™ pain relief patch on the pain site for 30 days led to a time-dependent decrease in pain and analgesic use and an increase in well-being. The randomized study compared the effects of standard of care treatment to those of the same standard of care approach plus the use of two nanocapacitor-based device/patches (NeuroCuple™ device) placed in the recovery room and kept in place for three days. The study demonstrated that the use of the two NeuroCuple™ devices was associated with a 41% reduction in pain at rest and a 52% decrease in the number of opioid refills requested by patients over the first 30 days after discharge from the hospital. Discussion: For the management of pain, the use of nano-based technology has led to the development of nano transporters, especially focus on the use of liposome and nanocapacitors. The use of liposome led to the development of DepoDur™, bupivacaine Exparel™ and a mixture of bupivacaine and meloxicam (Zynrelef™) and more recently lidocaine liposome formulation. In these cases, the technology is used to prolong the duration of action of drugs included in the preparation. Another indication of nanotechnology is the development of nanocapacitor device or patches. Although, data obtained with the use of nanocapacitors are still limited, evidence suggests that the use of nanocapacitors devices/patches may be interesting for the treatment of both acute and chronic pain, since the studies conducted with the NeuroCuple™ device and the based Kailo™ pain relief patch were not placebo-controlled, it is clear that additional placebo studies are required to confirm these preliminary results. Therefore, the development of a placebo devices/patches is necessary. Conclusions: Increasing evidence supports the concept that nanotechnology may represent a valuable tool as a drug transporter including liposomes and as a nanocapacitor-based device/patch to reduce or even eliminate the use of opioids in surgical patients. However, more studies are required to confirm this concept, especially with the use of nanotechnology incorporated in devices/patches. Full article

The current case report describes a successful ultrasound-guided mid-femur sciatic nerve block in an emu. A 2-month-old emu suffering from acute-onset lameness was referred to the University Clinic of Liège, where he was diagnosed with a lateral luxation of the Achilles tendon on both hind limbs. Two surgical procedures were performed for treatment. Both surgical procedures were performed under general anaesthesia with butorphanol, ketamine, midazolam and isoflurane in oxygen. The anaesthesia was continuously monitored. An ultrasound-guided sciatic nerve block was performed to prevent and treat surgically induced nociception. The technique was adapted from what is already described in other species. Levobupivacaine was injected perineurally under ultrasound-guidance. Intraoperative nociception was assessed based on the heart rate and mean arterial pressure changes. The recovery was uneventful and with no clinical signs of postoperative pain. Full article

Ultrasound-guided regional anaesthesia with real-time visualization of anatomical structures and needle trajectory has become the standard method for accurately achieving nerve block procedures. Nevertheless, ultrasound is particularly limited in accurately detecting the needle tip in tissues with complex echogenicity. Fat-filled circumneural fascial tissue provides a barrier to local anaesthetic diffusion. Injection during gentle needle nerve contact is more likely to spread under the circumneurium (halo sign). On the other hand, excessive force may cause hematoma or activate the piezo ion channels and intraneural calcium release. Therefore, it is vital to understand the mechanics of needle–tissue interaction for optimizing the procedural outcomes and patients’ safety. We hypothesised that continuous fluid infusion would reduce the needle force applied on the nerve compared to that of bolus injection. Thus, the primary objective of this study was to compare the forces associated with the bolus injection and continuous infusion techniques on the sciatic nerves of fresh lamb legs ex vivo. A needle combining pressure and force was inserted into six legs of lambs ex vivo using a motor stage at a constant velocity and imaged with a linear transducer. Saline injections were block randomised to bolus injection or infusion in the muscle upon gently touching and indenting of the epineurium at nine sites on six sciatic nerves at three angles (30°, 45° and 60°) in each location. The bolus was delivered over 6 s and infused for over 60 s. The result showed less force was generated during the infusion technique when gently touching the epineurium than that of the bolus technique, with p = 0.004, with significant differences observed at a 60° angle (0.49 N, p = 0.001). The injection pressure was also lower when light epineurium touches were applied (9.6 kPa, p = 0.02) and at 60° (8.9 kPa). The time to peak pressure varied across the insertion angles (p < 0.001), with the shortest time at 60° (6.53 s). This study explores future applications by emphasizing the significance of understanding needle–tissue interaction mechanics. This understanding is crucial for optimizing the procedural outcomes and enhancing patients’ safety in ultrasound-guided regional anaesthesia administration. Specifically, continuous infusion demonstrated a notable reduction in needle force compared to that of the bolus injection, especially during gentle epineurium contact. Full article

Arthroscopic anterior cruciate ligament (ACL) reconstruction with hamstring grafting is a common orthopedic procedure that is associated with moderate-to-severe pain. Peripheral nerve blockade as an anesthetic technique is an appealing option in the era of modern anesthesia. The aim of this narrative review is to document the efficacy and safety of the combination of femoral, obturator, and sciatic (FOS) nerve blocks as an exclusive method for anesthesia in patients undergoing ACL reconstruction. An electronic search of the literature published up to October 2023 was conducted in the Medline, Embase, Cochrane, Web of Science, and Google Scholar databases to find studies on ACL reconstruction and peripheral obturator nerve block. Overall, 8 prospective studies—with a total of 315 patients—published between 2007 and 2022 were included in this review. Ultrasound-guided peripheral FOS nerve blockade is an effective anesthetic technique for ACL reconstruction, offering good perioperative pain management, minimal opioid consumption, and an excellent safety profile. Further well-designed prospective studies are needed to determine the best approach for obturator nerve blockade and the appropriate type and dosage of local anesthetic. Full article

The objective of our study was to compare the efficacy of sciatic and saphenous ultrasound nerve blocks with and without US-guided obturator nerve block in dogs undergoing tibial-plateau-levelling-osteotomy (TPLO) surgery. This study was developed in two phases: identification of an ultrasound window in the inguinal region for obturator nerve block and utilization of it in dogs undergoing TPLO. Dogs were assigned randomly to one of two groups: one received the three blocks with 0.5% ropivacaine (ON group) and the second one (NoON group) with NaCl instead of ropivacaine for the obturator block. In phase 1, the obturator nerve was visible between the pectineus and the abductor muscles and was approached using an in-plane technique. It was possible to use the ultrasound window for phase two. The number of dogs that received at least one bolus of intraoperative rescue analgesia in the NoON group (12/15 dogs) was significantly higher (p = 0.003) in comparison with the ON group (4/15). An ultrasound window to block the obturator nerve in the inguinal compartment with an in-plane technique was found. The use of this approach could produce adequate analgesia with less motor function impairment in dogs for TPLO surgery. Full article

Krabbe disease is a rare neurodegenerative disease with an autosomal recessive character caused by a mutation in the GALC gene. The mutation leads to an accumulation of psychosine and a subsequent degeneration of oligodendrocytes and Schwann cells. Psychosine is the main biomarker of the disease. The Twitcher mouse is the most commonly used animal model to study Krabbe disease. Although there are many references to this model in the literature, the lipidomic study of nervous system tissues in the Twitcher model has received little attention. This study focuses on the comparison of the lipid profiles of four nervous system tissues (brain, cerebellum, spinal cord, and sciatic nerve) in the Twitcher mouse compared to the wild-type mouse. Altogether, approximately 230 molecular species belonging to 19 lipid classes were annotated and quantified. A comparison at the levels of class, molecular species, and lipid building blocks showed significant differences between the two groups, particularly in the sciatic nerve. The in-depth study of the lipid phenotype made it possible to hypothesize the genes and enzymes involved in the changes. The integration of metabolic data with genetic data may be useful from a systems biology perspective to gain a better understanding of the molecular basis of the disease. Full article

The hyperexcitability of the anterior cingulate cortex (ACC) has been implicated in the development of chronic pain. As one of the key causes of ACC hyperexcitation, disinhibition of the ACC may be closely related to the dysfunction of inhibitory parvalbumin (PV)-expressing interneurons (PV-INs). However, the molecular mechanism underlying the ACC PV-INs injury remains unclear. The present study demonstrates that spared sciatic nerve injury (SNI) induces an imbalance in the excitation and inhibition (E/I) of the ACC. To test whether tumor necrosis factor-α (TNF-α) upregulation in the ACC after SNI activates necroptosis and participates in PV-INs damage, we performed a differential analysis of transcriptome sequencing using data from neuropathic pain models and found that the expression of genes key to the TNF-α-necroptosis pathway were upregulated. TNF-α immunoreactivity (IR) signals in the ACCs of SNI rats were co-located with p-RIP3- and PV-IR, or p-MLKL- and PV-IR signals. We then systematically detected the expression and cell localization of necroptosis-related proteins, including kinase RIP1, RIP3, MLKL, and their phosphorylated states, in the ACC of SNI rats. Except for RIP1 and MLKL, the levels of these proteins were significantly elevated in the contralateral ACC and mainly expressed in PV-INs. Blocking the ACC TNF-α-necroptosis pathway by microinjecting TNF-α neutralizing antibody or using an siRNA knockdown to block expression of MLKL in the ACC alleviated SNI-induced pain hypersensitivity and inhibited the upregulation of TNF-α and p-MLKL. Targeting TNF-α-triggered necroptosis within ACC PV-INs may help to correct PV-INs injury and E/I imbalance in the ACC in neuropathic pain. Full article

Peripheral nerve injury (PNI) remains a medical challenge with no easy resolution. Over the last few decades, significant advances have been achieved in promoting peripheral nerve regeneration, and new assessment tools have been developed, both functional and imaging, to quantify the proportion and quality of nerve recovery. The exploration of new animal models, larger, more complex, and with more similarities to humans, has made it possible to reduce the gap between the results obtained in classic animal models, such as rodents, and the application of new therapies in humans and animals of clinical interest. Ultrasonography is an imaging technique recurrently used in clinical practice to assess the peripheral nerves, allowing for its anatomical and topographic characterization, aiding in the administration of anesthesia, and in the performance of nerve blocks. The use of this technique in animal models is scarce, but it could be a useful tool in monitoring the progression of nerve regeneration after the induction of controlled experimental lesions. In this work, sheep, a promising animal model in the area of peripheral nerve regeneration, were subjected to an ultrasonographic study of three peripheral nerves of the hind limb, the common peroneal, and tibial and sciatic nerves. The main aim was to establish values of dimensions and ultrasound appearance in healthy nerves and landmarks for their identification, as well as to perform an ultrasound evaluation of the cranial tibial muscle, an effector muscle of the common peroneal nerve, and to establish normal values for its ultrasound appearance and dimensions. The results obtained will allow the use of these data as control values in future work exploring new therapeutic options for nerve regeneration after induction of common peroneal nerve injuries in sheep. Full article