Regional Anesthesia and Pain Medicine最新文献

Background: Cancer pain has a significant impact on patient's quality of life. Astrocytes play an important role in cancer pain signaling. The direct targeting of astrocytes can effectively suppress cancer pain, however, they can cause many side effects. Therefore, there is an urgent need to identify the specific signaling pathways or proteins involved within astrocytes in cancer pain as targets for treating pain.

Methods: A neuropathic cancer pain (NCP) model was established by inoculating mouse S-180 sarcoma cells around the right sciatic nerve in C57BL/6 mice. Spontaneous persistent pain and paw withdrawal thresholds were measured using von Frey filaments. The NCP spinal cord dorsal horn (L4-L6) and mouse astrocyte cell line MA-C were used to study protein palmitoylation using acyl-biotin exchange, real-time polymerase chain reaction, ELISA, western blotting, and immunofluorescent staining.

Results: In a cancer pain model, along with tumor growth, peripheral nerve tissue invasion, and cancer pain onset, astrocytes in the dorsal horn of the spinal cord were activated and palmitoyltransferase ZDHHC23 expression was upregulated, leading to increased palmitoylation levels of GFAP and increased secretion of inflammatory factors, such as (C-X-C motif) ligand (CXCL)10 (CXCL-10), interleukin 6, and granulocyte-macrophage colony-stimulating factor. These factors in turn activate astrocytes by activating the signal transducer and activator of transcription 3 (STAT3) signaling pathway. A competitive peptide targeting GFAP palmitoylations was designed to effectively alleviate morphine tolerance in cancer pain treatment as well as cancer pain signaling and inflammatory factor secretion.

Conclusions: In a rodent model, targeting GFAP palmitoylation appears to be an effective strategy in relieving cancer pain and morphine tolerance. Human translational research is warranted.

Background: Different approaches to the obturator nerve have been described. However, few have focused on the injection point inferior the iliopubic ramus, specifically at the exit of the obturator canal. This study aims to anatomically evaluate the ultrasound-guided obturator nerve block at the exit of the obturator canal, detailing anatomical landmarks and solution distribution.

Methods: This anatomical study was conducted using 10 cadavers to generate 20 hemipelvis samples. Ultrasound references were utilized to identify the obturator canal, iliopubic ramus, pectineus and external obturator muscles, and the obturator membrane. An ultrasound-guided obturator nerve block was performed using a low-frequency convex probe for initial identification and a high-frequency linear transducer for the injection of a methylene blue solution. Subsequent dissections were performed to evaluate the distribution of the dye within the obturator nerve.

Results: The injection of methylene blue consistently stained the common trunk and anterior branch of the obturator nerve in 100% of the cases and the posterior branch in 80% of the samples. Intrapelvic staining was observed in 65% of the specimens, indicating effective diffusion of the dye. Key anatomical landmarks, such as the iliopubic ramus and the obturator membrane, were crucial for accurate identification and injection.

Conclusion: In conclusion, sagittal approaches using the iliopubic ramus as an anatomical reference achieve the most complete obturator nerve block. Our anatomical study details the structures of the obturator canal and access to the obturator nerve at its exit. Future studies are needed to confirm its safety and efficacy.

Background: Lumbar facet joint syndrome (FJS) is a common cause of chronic low back pain (LBP). Radiofrequency treatments are commonly used to treat chronic LBP-related FJS that is refractory to conservative treatment, although evidence supporting this treatment is controversial.

Objective: We explored the therapeutic effects of radiofrequency on FJS using a network meta-analysis (NMA).

Evidence review: A comprehensive systematic search of multiple databases was conducted to identify randomized controlled trials (RCTs) that compared radiofrequency with other treatments (sham procedures, facet joint corticosteroid injection, and conservative treatment) for FJS. We searched PubMed, Embase, Web of Science, the Cochrane Database, and handsearching. The primary outcomes were pain score and Oswestry Disability Index (ODI). Statistical analysis included conventional pairwise meta-analysis and NMA using the frequentist method.

Findings: The treatments were ranked using surface under the cumulative ranking curve (SUCRA) values. The search yielded 25 RCTs (1969 patients) and a mixed quality regarding the risk of bias, with most studies exhibiting a low risk of bias for most domains. Endoscopic neurotomy consistently ranked highest in terms of pain reduction and ODI score improvement at 1, 3, 6, and 12 months. At 1 and 6 months, endoscopic neurotomy had the highest SUCRA value for pain reduction (0.833 and 0.860, respectively), followed by medial branch thermal radiofrequency.

Conclusions: This NMA demonstrates that endoscopic neurotomy is the most effective treatment for lumbar FJS, providing superior and sustained pain relief and functional improvement compared with other treatments. Further, high-quality RCTs are needed to confirm these findings and address the existing limitations.

Prospero registration number: CRD42024524657.

Background: There is scarce literature regarding the use of continuous peripheral nerve blocks in acute burn patients, who may be at higher risk for catheter-related complications, including infection. We sought to describe our center's experience and infection rate with continuous perineural catheters in the setting of pain management for patients suffering from burns.

Methods: A retrospective observational study was performed including all patients admitted to an American Burn Association-verified regional burn center between January 2018 and July 2023 who received a continuous peripheral nerve block for an acute burn injury.

Results: There were 281 patients in the study cohort who received 484 perineural catheters. The cohort was 52% men with a median age of 39 years (IQR 30-55). A catheter-associated infection, defined as a clinical diagnosis by the treating physicians requiring the need for treatment with antibiotics or surgical debridement, was identified in six perineural catheters (1.2%, 95% CI 0% to 2.2%) involving six different patients (2.1%, 95% CI 0% to 3.8%). The median total body surface area burned was 5% (IQR 2-9%) and 20% of patients had full-thickness burns. The most commonly used catheters were infraclavicular (49%), popliteal sciatic (29%), femoral (19%), and adductor canal (17%). One-third (33%) of patients did not require operating room debridement as the block provided sufficient analgesia for bedside debridement. The median duration of catheter use was 6 days (IQR 4-8). There were no documented cases of nerve injury or toxicity, vascular injury, or local anesthetic systemic toxicity.

Conclusions: In our practice, continuous perineural catheters in the setting of acute burns are associated with an infection rate comparable to other surgical populations.

Innervation of the shoulder joint is complex and remains poorly understood among regional anesthesiologists and chronic pain specialists. Current literature supports the important contribution of the axillary nerve to the total innervation of the shoulder, as well as its blockade for perioperative pain and denervation for chronic shoulder pain. However, a description of the entire course of the axillary nerve, the corresponding optimal targets, and the sonoanatomy pertinent to pain intervention is lacking. This educational article discusses in detail the functional anatomy and sonographic identification of possible windows for axillary nerve intervention. We discuss the contribution, extent, and type of innervation the axillary nerve provides to the shoulder joint, which is often misunderstood. Ultimately, this article serves to stimulate thoughts and ideas for future research in an area where literature is scarce.

Background and objectives: Chronic knee pain, including postarthroplasty knee pain, is a major cause of morbidity. Radiofrequency ablation of genicular nerve branches is a treatment option. The literature to date has demonstrated and recommended consistent rhizotomy targets in the coronal and axial position of the three primary genicular nerve branches (superomedial genicular nerve, superolateral genicular nerve, inferomedial genicular nerve). The debate on genicular nerve positions focuses on the anterior-posterior courses of the nerve branches.

Methods: The sagittal positions of the three primary genicular neurovascular bundles were measured in 28 consecutive knee MRI and described relative to the total anterior-posterior depth of the bony cortex. Standard radiofrequency capture radius at the classic rhizotomy targets sites was compared with identified nerve position to report proportion of observed nerves within the capture radius.

Results: The genicular neurovascular bundles were found further posterior than classic landmark targets. Proportion of visualized nerve branches captured by classic rhizotomy target radius varied by genicular nerve branch.

Conclusions: This study supports updated guidance on genicular rhizotomy targets. Nerve localization studies using MRI data may be a promising avenue in future nerve localization research pertinent to rhizotomy.