Needle Aligned Ultrasound Image-Guided Access Through Dual-Segment Array

Ultrasound (US) guided access for percutaneous nephrolithotomy (PCNL) is gaining popularity in the urology community as it reduces radiation risk. The most popular technique involves manual image-needle alignment. A misaligned needle however needs to be retracted and reinserted, resulting in a lengthened operation time and complications such as bleeding. These limitations can be mitigated through the co-registration between the US array and needle. The through-hole array concept provides the primary solution, including a hole at the center of the array. Because of the central opening, the image-needle alignment is achieved inherently. Previous literature has described applications that are limited to superficial and intravascular procedures, suggesting that developing a through-hole array for deeper target applications would be a new breakthrough.

OBJECTIVE

Here, we present a dual-segment array with a central opening. As the prototype development, two segments of 32-element arrays are combined with an open space of 10 mm in length in between them.

METHOD

We conducted phantom and ex-vivo studies considering the target depth of the 80-100 mm range. The image quality and needle visibility are evaluated by comparing the signal-to-noise ratio (SNR), full width at half maximum (FWHM), and contrast-to-noise ratio (CNR) results measured with a no-hole linear array under equivalent conditions. An ex-vivo study is performed using porcine kidneys with ceramic balls embedded to evaluate the needle access accuracy.

RESULTS AND CONCLUSION

The mean needle access error of 20 trials is found to be 2.94 ±1.09 mm, suggesting its potential impact on realizing a simple and intuitive deep US image-guided access.

Impact of Predefined Angles and a Revised APPLES Mnemonic on Accuracy and Performance Time for Simulated Ultrasound-Guided Injections

OBJECTIVES

Our objective was to determine whether predefined angles would improve performance time and accuracy of ultrasound-guided procedures by novice operators and whether a revised APPLES (approach, position, perpendicular, lift, entry, sweep) mnemonic was a helpful guide for performing the procedure.

METHODS

Participants attempted to hit targets in-plane and out-of-plane at different depths with a needle under ultrasound guidance with and without predefined angles. Participants were then asked if they thought that the mnemonic would be helpful when learning both methods for ultrasound-guided procedures.

RESULTS

There were 120 participants all of whom had performed fewer than six ultrasound guided procedures. Accuracy increased in all groups when angles were provided; however, only the 3-cm in-plane approach achieved statistical significance. Performance time also achieved statistical significance in two of the four groups. Ninety-five percent of participants thought that the revised APPLES mnemonic would be helpful for learning and performing ultrasound-guided procedures in the future.

CONCLUSIONS

Predefined angles seem to positively impact procedure time and accuracy for some target depths, and the APPLES mnemonic could be a helpful mental checklist for many novice operators. These may be useful tools to facilitate safe and efficient ultrasound-guided procedures in the clinical space.

A prospective, randomized comparison of ultrasonographic visualization of proximal intercostal block vs paravertebral block

BACKGROUND

Thoracic paravertebral blockade is an accepted anesthetic and analgesic technique for breast surgery. However, real-time ultrasound visualization of landmarks in the paravertebral space remains challenging. We aimed to compare ultrasound-image quality, performance times, and clinical outcomes between the traditional parasagittal ultrasound-guided paravertebral block and a modified approach, the ultrasound-guided proximal intercostal block.

METHODS

Women with breast cancer undergoing mastectomy (n = 20) were randomized to receive either paravertebral (n = 26) or proximal intercostal blocks (n = 32) under ultrasound-guidance with 2.5 mg/kg ropivacaine prior to surgery. Block ultrasound images before and after needle placement, and anesthetic injection videoclips were saved, and these images and vidoes independently rated by separate novice and expert reviewers for quality of visualization of bony elements, pleura, relevant ligament/membrane, needle, and injectate spread. Block performance times, postoperative pain scores, and opioid consumption were also recorded.

RESULTS

Composite visualization scores were superior for proximal intercostal compared to paravertebral nerve block, as rated by both expert (p = 0.008) and novice (p = 0.01) reviewers. Notably, both expert and novice rated pleural visualization superior for proximal intercostal nerve block, and expert additionally rated bony landmark and injectate spread visualization as superior for proximal intercostal block. Block performance times, needle depth, opioid consumption and postoperative pain scores were similar between groups.

CONCLUSIONS

Proximal intercostal block yielded superior visualization of key anatomical landmarks, possibly offering technical advantages over traditional paravertebral nerve block.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02911168. Registred on the 22nd of September 2016.

Ultrasound-Guided Regional Anaesthesia: Visualising the Nerve and Needle

Regional anaesthesia involves targeting specific peripheral nerves with local anaesthetic. It facilitates the delivery of anaesthesia and analgesia to an increasingly complex, elderly and co-morbid patient population. Regional anaesthesia practice has been transformed by the use of ultrasound, which confers advantages such as accuracy of needle placement, visualisation of local anaesthetic spread, avoidance of intraneural injection and the ability to accommodate for anatomical variation.An US beam is generated by the application of electrical current to an array of piezoelectric crystals, causing vibration and consequential production of high-frequency sound waves. The sound energy is reflected at tissue interfaces, detected by the piezoelectric crystals in the ultrasound probe, and most frequently displayed as a 2D image.Optimising image acquisition involves selection of the appropriate US frequency: this represents a trade-off between image resolution (better with high frequency) and tissue penetration/beam attenuation (better with low frequency). Altering alignment, rotation and tilt of the probe is often required to optimise the view as nerves are best visualised when the ultrasound beam is directly perpendicular to their fibres. Adjusting the focus, depth, and gain (brightness) of the image display can also help in this matter.Three key challenges exist in regional anaesthesia; image optimisation, image interpretation (nerve visualisation) and needle visualisation. There are characteristic sonographic appearances of the nerve structures for peripheral nerve blocks, as discussed in this chapter, and the above techniques can be used to enhance their appearance. Much research has been done, and is ongoing, with the aim of improving needle visualisation; this is also reviewed. Image interpretation requires the application of anatomical knowledge and understanding of the typical sonographic appearance of different tissues (as well as the needle). Years of practice are required to attain expertise, although it is hoped that continuing advances in nerve and needle visualisation, as described in this chapter, will expedite that process.

A laser mount probe holder facilitates fixation of the optimized ultrasound image and needle alignment in-plane to the ultrasound beam during ultrasound-guided peripheral nerve block

Laser guidance facilitates needle alignment in-plane to the ultrasound beam. Once the ultrasound image is optimized, there is no further need to maneuver the probe. Therefore, we designed a laser mount probe holder prototype, and examined the ease of visualization of the needle tip using the laser mount probe holder. The needle brightness was quantitatively measured using an image analysis software. We found that the laser mount probe holder is useful, not only to visualize the needle tip in the ultrasound plane, but also to fix the best ultrasound image.

Improving the Performance Time and Accuracy of Ultrasound-Guided Interventions: A Randomized Controlled Double-Blind Trial of the Line-of-Sight Approach and the "APPLES" Mnemonic

OBJECTIVES

To determine whether the line-of-sight approach improved the performance time and accuracy of ultrasound (US)-guided needle placement targeting the subdeltoid bursa in a cadaver among novice operators compared to the side approach. A secondary objective was to determine whether participants thought the APPLES (angle, position, perpendicular, line up, entry, sweep) mnemonic was a helpful guide for performing the procedure.

METHODS

Medical students and residents were randomized into either a line-of-sight or side approach group and then crossed over to the other group. The procedure time was determined by 2 blinded reviewers. A survey was administered to determine which method participants preferred and whether they thought the APPLES mnemonic was helpful. A paired t test was used to compare the performance time, and the McNemar test was used to compare the accuracy of the methods.

RESULTS

Among the 110 participants, the performance time with the line-of-sight approach (mean, 14.4 seconds; SD, 9.95 seconds) was significantly decreased compared to the side approach (mean, 18.6 seconds; SD, 10.1 seconds; P = .00029). Additionally, participants who only hit the target using one method were more likely to hit the target in 30 seconds using the line-of-sight approach (P = .035). In total, 72.7% of participants preferred the line-of-sight approach over the side approach, and 88.2% of participants thought that APPLES mnemonic was useful.

CONCLUSIONS

This study highlights the finding that positioning of the operator is important in performing US-guided interventions, and the line-of-sight approach may improve the performance time and accuracy among novice operators. Furthermore, the APPLES mnemonic serves as a useful educational tool for teaching US-guided interventional procedures.

Design and Production of an Articulating Needle Guide for Ultrasound-Guided Needle Block Manufactured With a Three-Dimensional Printer: Technical Communication

Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.

Enhancing needle visualization during parasagittal approach in paravertebral block for patients undergoing simple mastectomy using in-plane, multiangle ultrasound needle guidance system

Background:

Ultrasound-guided paravertebral blocks during breast surgeries with in-plane needle approaches can be challenging due to difficult needle visualization. The purpose of this study was to assess the usefulness of using a needle guide while performing in-plane parasagittal approach paravertebral block for breast surgery.

Patients and Methods:

Eighty patients, American Society of Anesthesiologists physical status I-III, aged 20-40 years with breast mass scheduled for simple mastectomy surgery, were involved in prospective, controlled, randomized study, and were randomly divided by closed envelope method into two groups: Group I (n = 40): Scheduled for ultrasound-guided paravertebral block or group II (n = 40): Scheduled for ultrasound-guided paravertebral block using the needle guide. Both techniques compared as regards: (i) Needle visibility and block performance time; (ii) number of needle passes; (iii) duration of the block; (iv) doctor and patient satisfaction; and (v) incidence of complications.

Results:

Needle visibility score was better in group II (2.92 ± 0.26 vs. 1.9 ± 0.44, P < 0.0001). Block performance time was shorter in group II (90.92 ± 15 vs. 128.25 ± 16s, P < 0.0001). A number of needle passes were less in group II (1.27 ± 0.45 vs. 2.2 ± 0.68, P < 0.0001). Doctor and patient satisfaction were better in group II (P = 0.015). No differences were found regarding the duration of the block and incidence of complications between groups.

Conclusion:

A needle guide can help reduce the time needed to perform a parasagittal in-plane thoracic paravertebral block, with a significant reduction in the block performance time, the number of needle passes, better needle visibility and better doctor and patient's satisfaction. However, there was no significant difference regarding the duration of the block or incidence of complications.

Ultrasound-guided catheterisation of the subclavian vein: freehand vs needle-guided technique

The objective of this prospective, randomised study was to examine the impact of a multi-angle needle guide for ultrasound-guided, in-plane, central venous catheter placement in the subclavian vein. One hundred and sixty patients were randomly allocated to two groups, freehand or needle-guided, and then 159 catheterisations were analysed. Cannulation of the first examined access site was successful in 96.9% of cases with no significant difference between groups. There were three arterial punctures and no other severe injuries. Catheter misplacements did not differ between the groups. Higher success rates within the first and second attempts in the needle-guided group were observed (p = 0.041 and p = 0.019, respectively). Use of the needle guide reduced the access time from a median (IQR [range]) of 30 (18-76 [6-1409]) s to 16 (10-30 [4-295]) s; p = 0.0001, and increased needle visibility from 31.8% (9.7%-52.2% [0-96.67]) to 86.2% (62.5%-100% [0-100]); p < 0.0001. A multi-angle needle guide significantly improved aligning the needle and ultrasound plane compared with the freehand technique when cannulating the subclavian vein. Use of the guide resulted in faster access times and increased success at the first and second attempts.

Simulation in teaching regional anesthesia: current perspectives

The emerging subspecialty of regional anesthesiology and acute pain medicine represents an opportunity to evaluate critically the current methods of teaching regional anesthesia techniques and the practice of acute pain medicine. To date, there have been a wide variety of simulation applications in this field, and efficacy has largely been assumed. However, a thorough review of the literature reveals that effective teaching strategies, including simulation, in regional anesthesiology and acute pain medicine are not established completely yet. Future research should be directed toward comparative-effectiveness of simulation versus other accepted teaching methods, exploring the combination of procedural training with realistic clinical scenarios, and the application of simulation-based teaching curricula to a wider range of learner, from the student to the practicing physician.

Evaluation of the eZono 4000 with eZGuide for ultrasound-guided procedures

Ultrasound-guided procedures are increasingly common in a variety of acute care settings, such as the operating room, critical care unit and emergency room. However, accurate judgment of needle tip position using traditional ultrasound technology is frequently difficult, and serious injury can result from inadvertently advancing beyond or through the target. Needle navigation is a recent innovation that allows the clinician to visualize the needle position and trajectory in real time as it approaches the target. A novel ultrasound machine has recently been introduced that is portable and designed for procedural guidance. The eZono 4000™ features an innovative needle navigation technology that is simple to use and permits the use of a wide range of commercially available needles, avoiding the inconvenience and cost of proprietary equipment. This article discusses this new ultrasound machine in the context of other currently available ultrasound machines featuring needle navigation.

[Seeing more : Technical innovations in regional anesthesia]

Visualization and verification are key factors since the implementation of ultrasound-guided regional anesthesia. This article reviews and discusses newer technical innovations in regional anesthesia with regard to optimization of needle guidance, improvements in needle visibility, technical improvements in ultrasound techniques and innovative technologies in regional anesthesia. Clinically available applications are presented as well as experimental tools and techniques with a potential for clinical implementation in the future. Mechanical needle guides are used to improve alignment of needle axis and ultrasound beam axis. Compound imaging technology improves needle visibility in steep needle insertion angles and is already implemented in daily clinical practice. Sonoelastography improves tissue discrimination and detection of small amounts of fluids. Benefits of 3D and 4D ultrasound in regional anesthesia are discussed as well as experimental tools for tissue discrimination, such as optical reflection spectrophotometry.