Skin Puncture Research Articles

Fluoroscopy-Guided Percutaneous Transthoracic Needle Lung Biopsy with the Aid of Planning Cone-Beam CT: Diagnostic Accuracy and Complications

Background: Fluoroscopy-guided PTNB for fluoroscopy-identifiable lung lesions has been suggested as a useful method for the pathological diagnosis of lung lesions; however, it is lacking in accuracy and safety compared to CT-guided PTNB. Thus, we aimed to investigate the diagnostic accuracy and complications of fluoroscopy-guided percutaneous transthoracic needle biopsy (PTNB) with the aid of pre-procedural planning cone-beam computed tomography (CBCT) in order to take advantage of their respective strengths. Methods: A total of 255 fluoroscopy-guided PTNBs with the aid of planning CBCT were performed. Pre-procedural planning CBCT was conducted to calculate the shortest length from the skin puncture site to the margin of the target lesion for the needle trajectory. No intra-procedural CBCT was performed. The diagnostic performance of fluoroscopy-guided PTNB with the aid of planning CBCT was calculated. The prognostic factors for diagnostic failures and complications were evaluated using logistic regression analysis. Results: The accuracy, sensitivity, specificity, PPV, and NPV were 97.3%, 88.0%, 90.9%, 100%, and 62.5%, respectively. There were 29 diagnostic failures (11.8%), and the multivariable analysis showed that a longer lesion depth on CBCT and a shorter specimen length were each associated with diagnostic failure (p = 0.010 and 0.012, respectively). Complications occurred in 34 PTNBs (13.3%). The multivariable analysis showed that an increased total number of biopsies per lesion, a longer length of lung aeration via needle insertion, a smaller lesion size on CT imaging (≤20 mm), and the presence of an air bronchogram were associated with the occurrence of complications (p = 0.027, <0.001, 0.003, and 0.020, respectively). Conclusions: Excellent diagnostic accuracy was obtained by fluoroscopy-guided PTNB with the aid of planning CBCT. Compared to that of CT- or CBCT-guided PTNB, the procedure-related complication rate was acceptably low, but the radiation dose to patients could be potentially reduced.

Evidence-based recommendations regarding risk reduction practices for people at risk of or with breast cancer-related lymphedema: consensus from an expert panel.

Several recent studies have investigated the validity of precautionary practices for lymphedema risk reduction after breast cancer treatment, such as avoidance of blood pressure measurements, skin puncture, blood draws, and use of prophylactic compression during air travel. Other studies have elucidated risk factors for breast cancer-related lymphedema, such as axillary lymph node dissection and skin infection (cellulitis). Combining the current evidence base with the consensus opinion of lymphatic experts assembled at the American Cancer Society/Lymphology Association of North America Summit in October 2023, updated evidence-based risk reduction recommendations are presented for those with or at risk of breast cancer-related lymphedema. Recommendation topics include prospective surveillance, patient education, individual risk factors, exercise, blood pressure, skin care and hygiene, skin puncture and blood draws, surgical procedures, prophylactic compression, air travel, and hot climate and sauna. These recommendations will help inform education and medical choices for individuals treated for breast cancer who are at risk of or diagnosed with breast cancer-related lymphedema. More high-quality evidence is required to allow the development of risk reduction recommendations for other cancer types such as gynecological, melanoma, and head and neck. It is recommended that clinicians and organizations serving people at risk of or with lymphedema align risk reduction guidelines with the evidence-based recommendations provided within this consensus document and companion manuscripts from the American Cancer Society/Lymphology Association of North America Lymphedema Summit: Forward Momentum: Future Steps in Lymphedema Management.

Vibration-based mitigation of noxious-evoked responses to skin puncture in neonates and infants: a randomised controlled trial

ObjectiveTo assess the effect of a non-noxious vibratory stimulus on noxious-evoked cortical responses to skin puncture and to determine whether the presence of certain behavioural components may be used to...

Echogenic needles versus non-echogenic needles for in-plane ultrasound-guided infraclavicular axillary vein cannulation, a randomized controlled trial.

Echogenic needles improve the reflection of the ultrasound beam. The aim of the study was to compare needle performance during ultrasound-guided cannulation of the infraclavicular axillary vein with an in-plane needle approach, using echogenic needles or non-echogenic standard needles. One hundred adult patients undergoing surgical procedures that required a central venous catheter were randomized for either echogenic or non-echogenic needles. The primary outcome was access time. Secondary outcomes encompassed total procedure time, success in first attempt, number of attempts, number of skin punctures, change of site for vascular access, catheter placement, subjective experience with needle visualization and needle procedure, and adverse events. Median (IQR) [range] venous access time was 21 (15-56) [6-440] in echogenic needle group and 26 (14-91) [6-925] in the non-echogenic needle group (p = 0.40). No statistically significant differences were found in the secondary outcome measures. One patient (non-echogenic needle group) experienced pneumothorax. In three patients in each group (6%) arterial puncture occurred. Echogenic needles did not significantly improve needle control or safety when used for infraclavicular axillary vein cannulation with an in-plane needle approach. The results indicate that standard needles are appropriate for ultrasound guided subclavian vascular access in a perioperative situation.

Comparative Analysis of Taper Point and Reverse Cutting Needles on Skin Puncture Force.

Reverse cutting needles are commonly used in cutaneous surgery due to their perceived ease of use. Despite this, there is limited research evaluating the force required to puncture skin using contemporary needles. This study aims to compare the puncture forces required for two different needle geometries across various gauge sizes. The authors assessed the force necessary to penetrate samples of human abdominal skin samples using taper needles of three different United States Pharmacopeia gauge sizes with their respective reverse cutting needle counterparts. Taper point needles tested were RB-1 (3-0), TF (4-0), and C-1 (5-0), while reverse cutting needles included PS-2 (3-0) and P-3 (4-0, 5-0). An electronic force meter was used to record the puncture force required by each needle type. The mean puncture force in newtons (N) for taper point needles was 1.00, 0.74, and 0.48 for RB-1, TF, and C-1, respectively. The mean puncture force for reverse cutting needles was 0.95 N, 0.60 N, and 0.51 N for PS-2, P-3 (4-0), and P-3 (5-0), respectively. There was a direct relationship between needle body diameter and puncture force for both needle geometries. There was no clinically significant difference in skin puncture force between needle geometries.

Finite Element Analysis of Skin Deformation and Puncture for Microneedle Array Design.

The mechanics of microneedle insertion have thus far been studied in a limited manner. Previous work has focused on buckling and failure of microneedle devices, while providing little insight into skin deformation, puncture, and the final positioning of needle tips under full microneedle arrays. The current study aims to develop a numerical approach capable of evaluating deformation and puncture conditions for full microneedle array designs. The analysis included a series of finite element submodels used to calibrate the microneedle-epidermal interface for failure properties using traction-separation laws. The single needle model is validated using experimental data and imaging, including results from a customized nanoindentation procedure to measure loads and displacements during microneedle insertion. Upon validation, full microneedle arrays are implemented in a 3 D finite element model and a design framework is developed, allowing evaluation of different design variables (i.e. needle shape, material, spacing) with respect to outputs relevant to successful microneedle performance. Results from the model include skin deformation, force to puncture, penetration depth, and the punctured state at each microneedle tip. In addition to microneedle parameters, patient parameters such as subcutaneous tissue thickness are included to evaluate the sensitivity of different microneedle designs to expected patient and anatomical region variability.

The Self-Powered Thermoelectric System Driving an Electric Field for Raman-Spectrum Glucose Quantitative Analysis

For a long time, blood glucose monitoring has been a challenging issue in the field of medicine. Although it is possible to visit a hospital for regular blood tests to track blood sugar concentration, the physiological reactions triggered by blood collection might lead to feeling weak, dizzy, or even vomiting. Therefore, especially for diabetic patients, they need to frequently monitor their blood sugar concentration in their daily lives to ensure their health. Currently, the primary methods for blood glucose testing still rely on invasive techniques, such as using fingertip glucose meters and other methods which require skin puncture to obtain blood samples. Although these methods provide a quick assessment of current blood glucose concentration, they come with the pain and discomfort of blood collection process and the potential risk of infection. As a result, in recent years, many researchers have been dedicated to developing non-invasive blood glucose monitoring methods. However, accurately measuring glucose concentration inside the human body remains a challenging task. One of the primary issues is the presence of strong noise and background noise. To avoid this challenge, we have developed an innovative detection platform that is combines surface-enhanced Raman spectroscopy (SERS) and external electric field sensing technology. With the electromagnetic effect, we add external electric field in our platform to excite more the surface plasmon resonance. By using this method, we can achieve signal amplification to detect lower concentrations of glucose. Now, we can detect down to 0.001mM of glucose. We also exhibit self-powered electric field system, using the flexible themoelctric device to combine our platform. By the property of self-powered, we success to create a self-powered electric field system. We focus on driving themoelectric through the temperature different between body temperature and environment. The approach is aimed at generating power from the human body, providing a self-powered thermoelectric system for Raman-spectrum glucose sensors. This innovative approach holds promise for advancing non-invasive blood glucose monitoring and benefiting a larger population of diabetes patients in the future.

A systematic review of the complications of skin puncturing procedures in the upper limbs of patients that have undergone procedures on the axilla or breast.

The increasing incidence and prevalence of breast malignancies have led to increasing numbers of surgical interventions performed on the axilla and breast, including axillary lymph node dissection (ALND), sentinel lymph node biopsy (SLNB), and mastectomy. The risk of postoperative complications, like breast cancer-related lymphoedema (BCRL), can have significant deleterious cosmetic and quality of life effects. National guidelines and cancer councils publish recommendations to avoid skin puncturing procedures, such as venepuncture and intravenous (IV) cannulation, on arms ipsilateral to the surgical site to prevent BCRL occurrence. The initial trials that established a link between BCRL and skin puncture were conducted in the 1950s and 1960s; the evolution of surgical management of breast cancer has likely led to large decreases in complication rates. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, four databases were systematically searched for relevant articles. Eleven relevant articles were identified for inclusion in the final analysis. Updated Australian and New Zealand College of Anaesthetists & Faculty of Pain Medicine (ANZCA) guidelines were included in the analysis following their publication after the initial search had been completed. The overall quality and quantity of evidence in this field is sufficient to conclude that skin puncturing procedures on ipsilateral arms should not be avoided in patients with previous breast or axillary surgery. The highest-quality and most recent available evidence does not support an association between BCRL and skin puncturing procedures. Policies and practices that advocate avoiding skin puncture procedures to prevent BCRL may lead to delays in clinical care. The 2023 ANZCA guidelines recommend against avoiding affected arms for peripheral access and suggest the removal of institutional policies preventing this practice. In patients that have undergone breast surgery or axillary procedures, venous access procedures can be safely performed on the ipsilateral arm. The evidence does not support overarching restrictions on using the ipsilateral arm without pre-existing lymphoedema.

Comparing the Complications in Central Venous Catheterization by Ultrasound Guidance vs Anatomical Landmark Technique in Critical Ill ICU Patients

Objective: To compare the complication rates during central venous catheterization using ultrasound guidance versus the anatomical landmark technique in critical ill ICU patients. Methodology: A prospective comparative study was conducted in intensive care unit (ICU) of Farooq Teaching Hospital, Rawalpindi from December 2023 to June 2024. Total 127 critically ill ICU patients with acute surgical or medical conditions requiring central venous catheterization (CVC), such as hypotension, dehydration, or required blood resuscitation, where periphery approach was not feasible, underwent CVC insertion. Patients were randomly divided into two groups: one group underwent ultrasound-guided CVC insertion, while the other group used anatomical landmark technique. The rate of complications was measured between the groups. Results: Mean age of the patients was 46.5±11.2 years. The mean time from skin puncture to blood flashback was 104±172 sec in ultrasound group compared to 401±587 sec in landmark group. Among 127 patients, 61 underwent catheterization using ultrasound guidance, while 66 underwent catheterization using the anatomical landmark technique. The complication rates between the two groups were compared. The complications experienced by patients included multiple attempts (>1 puncture), pneumothorax, improper cannulation, hematoma, arterial punctures, incisional bleeding, and ecchymosis. In ultrasound group, 11.5% of patients experienced complications, compared to 28.8% in anatomical landmark group (p = 0.016). Conclusion: Ultrasound-guided central venous catheterization was associated with fewer complications and a higher success rate (correct placement of the CVC), making it easier to perform. This procedure simplicity is linked to enhanced safety and patient comfort.

Fabrication and Characterization of Microneedle Patches for Loading and Delivery of Exosomes.

Exosomes, as emerging "next-generation" biotherapeutics and drug delivery vectors, hold immense potential in diverse biomedical fields, ranging from drug delivery and regenerative medicine to disease diagnosis and tumor immunotherapy. However, the rapid clearance by traditional bolus injection and poor stability of exosomes restrict their clinical application. Microneedles serve as a solution that prolongs the residence time of exosomes at the administration site, thereby maintaining the drug concentration and facilitating sustained therapeutic effects. In addition, microneedles also possess the ability to maintain the stability of bioactive substances. Therefore, we introduce a microneedle patch for loading and delivering exosomes and share the methods, including isolation of exosomes, fabrication, and characterization of exosome-loaded microneedle patches. The microneedle patches were fabricated using trehalose and hyaluronic acid as the tip materials and polyvinylpyrrolidone as the backing material through a two-step casting method. The microneedles demonstrated robust mechanical strength, with tips able to withstand 2 N. Pig skin was used to simulate human skin, and the tips of microneedles completely melted within 60 s after skin puncture. The exosomes released from the microneedles exhibited morphology, particle size, marker proteins, and biological functions comparable to those of fresh exosomes, enabling dendritic cells uptake and promoting their maturation.

Neurological outcomes for patients meeting radiographic criteria for DEFUSE 3 and SELECT2

BackgroundThe DEFUSE 3 and SELECT2 thrombectomy trials included some patients with similar radiographic profiles, although the rates of good functional outcomes differed widely between the studies.ObjectiveTo report neurological outcomes for...

In vitro skin puncture methodology for material characterization

Quantifying the mechanical behavior of skin has been foundational in applications of cosmetics, surgical techniques, forensic science, and protective clothing development. However, previous puncture studies have lacked consistent and physiological boundary conditions of skin. To determine natural skin tension, excision of in situ porcine skin resulted in significantly different diameter reduction (shrinkage) in leg (19.5 %) and abdominal skin (38.4 %) compared to flank skin (28.5 %) (p = 0.047). To examine effects of initial tension and pre-conditioning, five conditions of initial tension (as percentage of diameter increase) and pre-conditioning were tested in quasistatic puncture with a 5 mm spherical impactor using an electrohydraulic load frame and custom clamping apparatus. Samples with less than 5 % initial tension resulted in significantly greater (p = 0.011) force at failure (279.2 N) compared to samples with greater than 25 % initial tension (195.1 N). Eight pre-conditioning cycles of 15 mm displacement reduced hysteresis by 45 %. The coefficient of variance was substantially reduced for force, force normalized by cutis thickness, displacement, stiffness, and strain energy up to 46 %. Pre-conditioned samples at physiological initial tension (14–25 %) resulted in significantly greater (p = 0.03) normalized forces at failure (278.3 N/mm) compared to non-conditioned samples of the same initial tension (234.4 N/mm). Pre-conditioned samples with 14–25 % initial tension, representing physiological boundary conditions, resulted in the most appropriate failure thresholds with the least variation. For in vitro puncture studies, the magnitude of applied initial tension should be defined based on anatomical location, through a shrinkage experimentation, to match natural tension of skin. Characterizing the biological behavior and tolerances of skin may be utilized in finite element models to aid in protective clothing development and forensic science analyses.

A Randomized Study Comparing Ultrasound-Guided Internal Jugular Vein Cannulation Using Two Techniques: Short-Axis Out-of-Plane With Dynamic Needle Tip Positioning Versus Long-Axis In-Plane.

Introduction Internal jugular vein (IJV) cannulation is a routine procedure in operating rooms, critical care units, and perioperative settings. Ultrasound guidance has notably increased the success rates of IJV cannulation. A modified ultrasound technique known as the short-axis out-of-plane method with dynamic needle tip positioning (DNTP) allows for continuous visualization of the needle tip throughout the procedure. This study aims to compare the first-pass success rate of IJV cannulation using the DNTP and long-axis in-plane (LAIP) approaches. Methods One hundred patients between 18 and 70 years undergoing elective surgery requiring IJV cannulation were recruited.Patients were assigned randomly to the DNTP group (n = 50) or the LAIP group (n = 50). We recorded the first-pass success rate, time to achieve successful cannulation, number of skin punctures, overall success rate within five minutes, and potential complications such as pneumothorax and hematoma. Results The first pass success rate was higher in the DNTP group (48/50, 96%) as compared to the LAIP group (38/50, 76%, relative risk, 1.67; 95% confidence interval, 0.039-0.707; p = 0.008). The cannulation time was shorter in DNTP (116.98 ± 22.90 seconds) versus the LAIP group (213.04 ± 52.08 seconds; p < 0.001). No complications like pneumothorax or hematoma were noted in both groups. Conclusion We conclude that the ultrasound-guided DNTP technique for IJV cannulation, as compared with the LAIP technique, may significantly improve the first attempt cannulation, number of attempts, and cannulation time.

Smart goggles augmented reality CT-US fusion compared to conventional fusion navigation for percutaneous needle insertion.

Targeting accuracy determines outcomes for percutaneous needle interventions. Augmented reality (AR) in IR may improve procedural guidance and facilitate access to complex locations. This study aimed to evaluate percutaneous needle placement accuracy using a goggle-based AR system compared to an ultrasound (US)-based fusion navigation system. Six interventional radiologists performed 24 independent needle placements in an anthropomorphic phantom (CIRS 057A) in four needle guidance cohorts (n = 6 each): (1) US-based fusion, (2) goggle-based AR with stereoscopically projected anatomy (AR-overlay), (3) goggle AR without the projection (AR-plain), and (4) CT-guided freehand. US-based fusion included US/CT registration with electromagnetic (EM) needle, transducer, and patient tracking. For AR-overlay, US, EM-tracked needle, stereoscopic anatomical structures and targets were superimposed over the phantom. Needle placement accuracy (distance from needle tip to target center), placement time (from skin puncture to final position), and procedure time (time to completion) were measured. Mean needle placement accuracy using US-based fusion, AR-overlay, AR-plain, and freehand was 4.5 ± 1.7mm, 7.0 ± 4.7mm, 4.7 ± 1.7mm, and 9.2 ± 5.8mm, respectively. AR-plain demonstrated comparable accuracy to US-based fusion (p = 0.7) and AR-overlay (p = 0.06). Excluding two outliers, AR-overlay accuracy became 5.9 ± 2.6mm. US-based fusion had the highest mean placement time (44.3 ± 27.7s) compared to all navigation cohorts (p < 0.001). Longest procedure times were recorded with AR-overlay (34 ± 10.2min) compared to AR-plain (22.7 ± 8.6min, p = 0.09), US-based fusion (19.5 ± 5.6min, p = 0.02), and freehand (14.8 ± 1.6min, p = 0.002). Goggle-based AR showed no difference in needle placement accuracy compared to the commercially available US-based fusion navigation platform. Differences in accuracy and procedure times were apparent with different display modes (with/without stereoscopic projections). The AR-based projection of the US and needle trajectory over the body may be a helpful tool to enhance visuospatial orientation. Thus, this study refines the potential role of AR for needle placements, which may serve as a catalyst for informed implementation of AR techniques in IR.

INJEX50 could improve the success rate of local anesthesia for arterial cannulation in the pediatric intensive care unit: Arandomized, double-blind, single-center study.

Quick arterial cannulation is required in pediatric emergency situation, which require effective local anesthesia to avoid withdrawal movement. However, pediatric local anesthesia could be difficult because of withdrawal movement. Jet injectors, which are needleless and provide local anesthesia quickly, could be helpful for pediatric local anesthesia during arterial cannulation. This study aimed to examine whether new jet injector "INJEX50" could improve the success rate of local anesthesia for arterial cannulation in pediatric intensive care unit compared with the current standard of care, infiltration using a 26-gauge needle. This study was a randomized, double-blind, single-center study. Participants were infants and young children in the pediatric intensive care unit, who required an arterial line. Local anesthesia was performed with either a 26-gauge needle (group C) or INJEX50 (group I) before arterial cannulation. The primary outcome (success of local anesthesia) was the presence of withdrawal movement at the time of skin puncture for arterial cannulation. The secondary outcomes included rescue sedation during arterial cannulation. Data were analyzed using Fisher's exact test and the Mann-Whitney U-test, with values of p < .05 considered statistically significant. Seventy patients were randomly assigned to groups C and I. The local anesthesia success rate in group I (30/35 [86%]) was significantly higher than that in group C (15/35 [43%], odds ratio, 8.00; 95% confidence interval, 2.51-25.5; p = .0005). In conclusion, INJEX50 could improve success rate of local anesthesia for arterial cannulation in pediatric intensive care unit compared with 26-gauge needle.

Caregivers of patients with long-term implantable ventricular assist device: a republication of the article published in the Japanese Journal of Artificial Organs.

Implantable ventricular assist device (VAD) has enabled patients with severe heart failure to be discharged from the hospital and to continue their care at home. The presence of caregivers is essential to maintain home care of patients with VAD. The caregivers are mainly the family members who live with the patient with VAD. The caregivers need to be trained (1) VAD device management, (2) disinfection of driveline skin punctures, (3) medication management, and (4) responding to sudden changes. The caregivers' lifestyle is also forced to change. In this article, we discuss the role of caregivers in the VAD era, where long-term support beyond 5years is now possible. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 81-84), with some modifications.

Wearable Vertical Graphene-Based Microneedle Biosensor for Real-Time Ketogenic Diet Management.

Ketogenic diets have attracted substantial interest in the treatment of chronic diseases, but there are health risks with long-term regimes. Despite the advancements in diagnostic and therapeutic methods in modern medicine, there is a huge gap in personalized health management of this dietary strategy. Hence, we present a wearable microneedle biosensor for real-time ketone and glucose monitoring. The microneedle array possesses excellent mechanical properties, allowing for consistent sampling of interstitial biomarkers while reducing the pain associated with skin puncture. Vertical graphene with outstanding electrical conductivity provides the resulting sensor with a high sensitivity of 234.18 μA mM-1 cm-2 and a low limit detection of 1.21 μM. When this fully integrated biosensor was used in human volunteers, it displayed an attractive analytical capability for tracking the dynamic metabolite levels. Moreover, the results of the on-body evaluation established a significant correlation with commercial blood measurements. Overall, this cost-effective and efficient sensing platform can accelerate the application of a ketogenic diet in personal nutrition and wellness management.

Perioperative arterial catheterization: A prospective evaluation of ultrasound, infection, and patient-focused outcomes.

There is little information regarding complications of arterial catheterization in modern clinical care. We aimed to determine the incidence of abnormal duplex vascular ultrasound and catheter related infections following perioperative arterial catheterization. Patients requiring arterial catheterization for elective surgery were included and insertion details collected prospectively. Duplex ultrasound evaluation was performed 24 h after catheter removal. Symptomatic patients were identified by self-reported questionnaire. On Day 7, patients answered questions by telephone, related to the insertion site, pain, and function. Results of catheter tip and blood culture analyses were sought. Univariate associations of patient and surgical characteristics with abnormal ultrasound were assessed with p < 0.05 considered significant. Of 339 catheterizations, 105 (40%) had ultrasound evaluation. Catheters were indwelling for median (IQR, range) duration of 6.0 h (4.4-8.2, 1.8-28) with no catheter-related infections. There were 16 (15.2%, 95% CI 9.0%-23.6%) abnormal results, including 14 radial artery thromboses, one radial artery dissection, and one radial vein thrombosis. Those with abnormal ultrasound results were more likely to have had Arrow catheters inserted (68.8% vs 27%, p = 0.023) and more than one skin puncture (37.5% vs 26.8%, p = 0.031). Two of the 16 (12.5%) patients with abnormal ultrasound results reported new symptoms related to the hand compared with nine of the 88 (10.2%) with normal results (p = 0.1). No patients required urgent referral for management. Thrombosis was the most common abnormality and was usually asymptomatic. There were no infections, few post-operative symptoms, and minimal functional impairment following arterial catheterization.

Intervertebral disc injury triggers neurogenic inflammation of adjacent healthy discs

BACKGROUND CONTEXTIntervertebral disc degeneration is common and may play an important role in low back pain, but it is not well-understood. Previous studies have shown that the outer layer of the annulus fibrosus of a healthy disc is innervated by nociceptive nerve fibers. In the process of disc degeneration, it can grow into the inner annulus fibrosus or nucleus pulposus and release neuropeptides. Disc degeneration is associated with inflammation that produces inflammatory factors and potentiates nociceptor sensitization. Subsequently neurogenic inflammation is induced by neuropeptide release from activated primary afferent terminals. Because the innervation of a lumbar disc comes from multisegmental dorsal root ganglion neurons, does neurogenic inflammation in a degenerative disc initiate neurogenic inflammation in neighboring healthy discs by antidromic activity? PURPOSEThis study was based on animal experiments in Sprague-Dawley rats to investigate the role of neurogenic inflammation in adjacent healthy disc degeneration induced by disc injury. STUDY DESIGNThis was an experimental study. METHODSSeventy-five 12-week-old, male Sprague-Dawley rats were allocated to 3 groups (sham group, disc injury group and disc injury+TrkA antagonist group). The disc injury group was punctured in the tail disc between the eighth and ninth coccygeal vertebrae (Co8–9) to establish an animal model of tail intervertebral disc degeneration. The sham group underwent only skin puncture and the disc injury+TrkA antagonist group was intraperitoneally injected with GW441756 two days before disc puncture. The outcome measure included quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTSDisc injury induced an increase in aggrecan, NGF, TrkA, CGRP, SP, IL-1β, and IL-6 mRNA levels in the injured (Co8–9) and adjacent discs (Co7–8), which reached a peak on day 1, then gradually decreased, and returned to normal on day 14. After intraperitoneal injection of GW441756 prior to puncture, the mRNA levels of the above indicators were down-regulated in Co7–8 and Co8–9 intervertebral discs on the 1st and 7th days. The protein content of the above indicators in Co7–8 and Co8–9 intervertebral discs showed roughly the same trend as mRNA levels. CONCLUSIONSDegeneration of one disc can induce neurogenic inflammation of adjacent healthy discs in a rat model. CLINICAL SIGNIFICANCEThis model supports a key role of neurogenic inflammation in disc degeneration, and may play a role in the experience of low back pain.

Predicting clinical entry point for thoracic epidural catheter insertion during paramedian approach: A prospective observational study.

Thoracic epidural insertion has high failure rates in the mid-thoracic region due to steep angulation of oblique bending of spinous processes. The preferred skin puncture point for epidural needle insertion in the paramedian sagittal plane with respect to the superior/inferior tip of spinous process or inter-spinous cleft in the mid-thoracic region (T5-8) is not standard. The primary objective of this prospective observational study was to find the skin puncture point which had the best success rate for a successful epidural catheterization. Secondary objectives were to study the number of attempts and passes required to locate epidural space, incidence of failed epidural, and its relationship with patient characteristics and demographics. After informed consent, 155 patients planned for general anesthesia with epidural analgesia in the mid-thoracic region were included in the trial. Patient demographics, the details of epidural attempts with respect to anatomical landmarks, distance from the midline, and number of passes in each attempt were noted. Epidural catheterization was considered successful after demonstrating dermatomal band of sensory blockade. The success rate at different skin puncture sites was not statistically significant (P = 0.58). We found a failure rate of 12.9%. Failed epidural catheterization was significantly high in the age group >56 years (n = 62 and P = 0.007). In our study, none of the skin puncture points had a significant association with successful epidural insertion in mid-thoracic segments using a para-median approach.