Needle Placement Research Articles

Concept for parallel placement of flexible needles for Irreversible Electroporation

Abstract Irreversible Electroporation (IRE) is a non-thermal tumor ablation treatment applicable for prostate cancer. IRE uses ultra-short but strong electrical pulses to destroy cancer cells nonthermally [1]. Clinically available IRE therapy requires two or more needle electrodes placed around the target tissue to apply the electric fields. A pre-requirement to achieve successful and effective ablation is an accurate and parallel needle placement to cover the tumor zone. Differences in tissue density, organ surface curvature as well as organ and patient motion in combination with long and highly flexible needle electrodes causes’ difficulties to achieve the desired target accuracy during needle placement process. We propose a concept of a shooting mechanism in combination with a grid template support to improve the parallel needle placement process for prostate cancer treatment. Instead of conventionally inserting the needle in the body by hand, it can be placed with high speed using a shooting device setup, that works similar like a biopsy gun.

Collaborative robot assisted smart needle placement

Abstract Needles are key tools to realize minimally invasive interventions. Physicians commonly rely on subjectively perceived insertion forces at the distal end of the needle when advancing the needle tip to the desired target. However, detecting tissue transitions at the distal end of the needle is difficult since the sensed forces are dominated by shaft forces. Disentangling insertion forces has the potential to substantially improve needle placement accuracy.We propose a collaborative system for robotic needle insertion, relaying haptic information sensed directly at the needle tip to the physician by haptic feedback through a light weight robot. We integrate optical fibers into medical needles and use optical coherence tomography to image a moving surface at the tip of the needle. Using a convolutional neural network, we estimate forces acting on the needle tip from the optical coherence tomography data. We feed back forces estimated at the needle tip for real time haptic feedback and robot control. When inserting the needle at constant velocity, the force change estimated at the tip when penetrating tissue layers is up to 94% between deep tissue layers compared to the force change at the needle handle of 2.36 %. Collaborative needle insertion results in more sensible force change at tissue transitions with haptic feedback from the tip (49.79 ± 25.51)% compared to the conventional shaft feedback (15.17 ± 15.92) %. Tissue transitions are more prominent when utilizing forces estimated at the needle tip compared to the forces at the needle shaft, indicating that a more informed advancement of the needle is possible with our system.

Needle insertion planning for obstacle avoidance in robotic biopsy

Abstract Understanding the underlying pathology in different tissues and organs is crucial when fighting pandemics like COVID-19. During conventional autopsy, large tissue sample sets of multiple organs can be collected from cadavers. However, direct contact with an infectious corpse is associated with the risk of disease transmission and relatives of the deceased might object to a conventional autopsy. To overcome these drawbacks, we consider minimally invasive autopsies with robotic needle placement as a practical alternative. One challenge in needle based biopsies is avoidance of dense obstacles, including bones or embedded medical devices such as pacemakers. We demonstrate an approach for automated planning and visualising suitable needle insertion points based on computed tomography (CT) scans. Needle paths are modeled by a line between insertion and target point and needle insertion path occlusion from obstacles is determined by using central projections from the biopsy target to the surface of the skin. We project the maximum and minimum CT attenuation, insertion depth, and standard deviation of CT attenuation along the needle path and create two-dimensional intensity-maps projected on the skin. A cost function considering these metrics is introduced and minimized to find an optimal biopsy needle path. Furthermore, we disregard insertion points without sufficient room for needle placement. For visualisation, we display the color-coded cost function so that suitable points for needle insertion become visible. We evaluate our system on 10 post mortem CTs with six biopsy targets in abdomen and thorax annotated by medical experts. For all patients and targets an optimal insertion path is found. The mean distance to the target ranges from (49.9 ± 12.9)mm for the spleen to (90.1 ± 25.8)mm for the pancreas.

THE USE OF 360° VIRTUAL REALITY VISUALIZATION IN VANISHING LUNG SYNDROME

TOPIC: Cardiothoracic Surgery TYPE: Medical Student/Resident Case Reports INTRODUCTION: Vanishing lung syndrome (VLS) is also known as giant bullous emphysema (GBE) and is a subset of emphysema in which bullae occupy more than one-third of the affected hemithorax. Often this causes mass effect on adjacent structures including normal lung parenchyma and the mediastinum. Video-assisted thoracic surgery (VATS) has been shown to safely and effectively treat GBE leading to improved symptoms and lung function1. Traditionally, chest radiography and computerized tomography (CT) scans have been used for surgical planning and patient education prior to lung volume reduction surgery. Virtual reality (VR) has emerged as a potentially useful adjunct for preoperative patient education2 and it was utilized in this case of VLS. CASE PRESENTATION: A 56-year-old African-American male was referred to our thoracic surgery clinic for progressive dyspnea. He was unable to walk one city block without stopping. On examination, he could not complete a sentence without stopping. Breath sounds were absent on the left and diminished on the right. Chest radiography (fig. 1) and CT scan (fig. 2) revealed asymmetrical bullous disease significantly worse on the left with mass effect on the remaining normal lung parenchyma, creating the vanishing lung phenomenon. Pulmonary function tests were significant for FEV1 0.88L (23% predicted), FEF25-75% 0.43 L/sec (12% predicted), and RV 205%. DICOMs from the patient's CT were used to create the 360°VR rendering. The immersive 360°VR experience utilizes the Oculus Rift headset to engage the patient who then becomes an avatar navigating through his or her own chest. At thoracoscopy, we encountered extensive air trapping requiring decompression of the giant bullae prior to resection. On extubation, the patient immediately desaturated to SpO2 of 22% requiring immediate needle decompression and placement of a 28F right-sided chest tube. Post-operatively, the patient reported improvement in his dyspnea. Following treatment for pneumonia, he was discharged to home with supplemental oxygen. In clinic 3 weeks postoperatively, his dyspnea was substantially improved, and he was able to walk and bicycle more regularly. He used supplemental oxygen as needed at night. DISCUSSION: Here we demonstrate the use of 360°VR as an imaging adjunct to assist in patient education and preoperative planning in select cases. CONCLUSIONS: Our prior research has demonstrated that compared to standard consultation, 360°VR consultation provides significantly higher levels of understanding and comfort with the proposed treatment option3. The use of 360°VR consultation in this case of VLS reaffirms both the value and ease of utilizing virtual reality as a novel imaging adjunct in the preoperative setting. REFERENCE #1: Geddes D, Cavies, M, Koyama, H, Hansell D. Effect of lung-volume-reduction surgery in patients with severe emphysema. NEJM. 2000; 343:239-245. doi: 10.1056/NEJM200007273430402. REFERENCE #2: Pandrangi VC, Gaston B, Appelbaum NP, et al. The application of virtual reality in patient education. Annals of Vascular Surgery. 2019; 59:184-189. doi: 10.1016/j.avsg.2019.01.015. REFERENCE #3: Mortman KD, Mortman R, Sadur A. Three hundred and sixty-degree virtual reality consultation for the thoracic surgery patient. J Am Coll Surg 2019;229(4):e211. doi: https://doi.org/10.1016/j.jamcollsurg.2019.08.1439 DISCLOSURES: No relevant relationships by Marie-Genevieve Flood, source=Web Response Consultant relationship with Ethicon Please note: $5001 - $20000 by Keith Mortman, source=Web Response, value=Consulting fee Consultant relationship with Medtronic Please note: $5001 - $20000 by Keith Mortman, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with BD Please note: $5001 - $20000 by Keith Mortman, source=Web Response, value=Honoraria Employee relationship with Surgical Theater Please note: 2019-2021 Added 03/26/2021 by Aneil Srivastava, source=Web Response, value=Salary No relevant relationships by Mira Tanenbaum, source=Web Response

Predictors of discogenic pain in magnetic resonance imaging: a retrospective study of provocative discography performed by posterolateral approach.

BackgroundProvocative discography (PD) is a test that is useful in diagnosing discogenic pain (DP). In this study, to diagnose DP, we used a posterolateral approach of needle placement and followed pressure criteria laid down by the Spine Intervention Society. The aim was to identify the correlation between magnetic resonance imaging (MRI) findings (desiccation, high intensity zone and change in shape and size of the disc) and the results of PD.MethodsRecords of 50 patients who underwent PD for DP were analyzed. A total of 109 PDs were performed, with 54 suspect and 55 control discs. Alternate pain generators were ruled out.ResultsA total of 35 suspect discs were positive on PD. The mean disc pressure in the suspect disc was 31.9 ± 7.9 psi (range, 15-44). Of the 50 patients who underwent PD, 35 had positive MRI findings. A significant positive correlation was found only between disc desiccation and discography result (r = 0.6, P < 0.001). Logistic regression analysis revealed that only desiccation successfully predicted the result of discography (OR = 26.5, P < 0.001); a high intensity zone and a disc protrusion/extrusion had an OR 2.3 and 1.24, respectively. Disc desiccation of Pfirmann grade 3 or more had a sensitivity and specificity of 0.93 and 0.64 respectively in identifying painful discs; the positive likelihood ratio was 2.58 while the negative likelihood ratio was 0.11.ConclusionsIn patients with DP, disc desiccation is the most useful MRI feature that predicts a painful disc on PD.

Piloting a New Curriculum: Guided At-Home Pediatric Regional Anesthesia Education Using a Portable Ultrasound.

Ultrasound-guided regional anesthesia is the standard of care for most regional blocks in pediatric anesthesiology.Training programs must educate physicians to perform regional blocks safely and efficiently. Hands-on learning with simulation and live models is the gold standard. The coronavirus disease 2019 (COVID-19) pandemic has greatly hampered our ability to safely hold in-person workshops. We describe an at-home, guided virtual workshop using portable ultrasound to safely continue experiential trainee education.The primary objective of this pilot virtual workshop was to develop an effective experiential learning program without the need for live child models. The main goal was to give trainees hands-on experience obtaining anatomical ultrasound images necessary for regional anesthesia blocks in a guided-virtual setting and to evaluate the effectiveness of skills acquisition. This workshop included two pediatric anesthesiology fellows and a pediatric anesthesiologist.Trainees were instructed on ultrasound-guided regional block acquisition. For two weeks, trainees acquired images/movies of regional block anatomy at home using their own children. Virtual video assistance was available. Trainees then used acquired images/movies to discuss needle and local anesthetic placement with a pediatric regional anesthesiologist. Trainees completed pre- and post-workshop surveys assessing attitudes, perceived educational efficacy, and procedural skill acquisition. The faculty member also assessed trainees’ skills.The virtual workshop was successful. Trainees expressed successful active learning and increased comfort in performing regional blocks on live patients. They correctly identified relevant anatomy of acquired images/movies, as well as needle and local anesthetic placement at the time of debriefing. Faculty were pleased with trainees’ initial performance of regional blocks.Adapting an in-person workshop to an at-home guided experience is a safe, feasible, and well-received method for anesthesiology trainees to obtain experiential learning of ultrasound-guided regional anesthesia. This facilitated at-home learning experience allows for hands-on skill practice while preventing exposure of child models to the hospital setting during a pandemic.

Novel Automated Three-Dimensional Surgical Planning Tool and Magnetic Resonance Imaging/Ultrasound Fusion Technology to Perform Nanoparticle Ablation and Cryoablation of the Prostate for Focal Therapy

Purpose: Although MRI/ultrasound fusion has been primarily used to assist in the diagnosis of prostate cancer, this technology can also be used to focally treat localized prostate cancer. We present one case of nanoparticle-directed ablation and two cases of cryoablation to focally treat prostate tumors. Patients and Methods: Three patients underwent MRI/ultrasound fusion transperineal prostate biopsies to confirm low- to intermediate-risk prostate cancer. The MRI lesions correlated with the biopsy-proven disease. Pelvic MRI segmentation was performed with DynaCAD 5.0 workstation. The MRI lesion including a 6 to 10 mm margin, prostate, bladder, urethra, urethral sphincter, rectum, and pubic bone were segmented. MRI/ultrasound fusion was performed with the novel Philips UroNav 4.0 system. Lesions were treated with focal nanoparticle ablation or focal cryoablation. Results: A 69-year-old man with a right posterior medial peripheral zone lesion positive for Gleason grade group (GG)3 cancer was treated with focal nanoparticle ablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 94% of the 6 to 10 mm margin at the end of the case. A 68-year-old man with a left anterior fibromuscular stroma lesion positive for Gleason GG2 cancer and a 71-year-old man with a right peripheral zone posterior lateral lesion positive for Gleason GG1 cancer were treated with focal cryoablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 82% of the 6 to 10 mm margin at the end of the case. Conclusion: Observation of the prostate tumor(s), surrounding critical structures, and pelvis in three dimensions (3D), along with the anticipated ablation zone, is one of the challenges of pelvic surgery and percutaneous ablation. The DynaCAD 5.0 Urology system can create an auto-segmented 3D rendering of critical structures and the tumor(s), as well as observation and quantification of the anticipated ablation coverage, to facilitate preoperative planning of needle placement. ClinicalTrials.gov nos.: NCT02680535 and NCT04656678.

Caudal Epidural Injections in Lumbar Spinal Stenosis: Comparison of Nonimage, Ultrasonography-, and Fluoroscopy-Guided Techniques. A Randomized Clinical Trial.

Caudal epidural injections (CEIs) are widely used in the treatment of lumbar spinal stenosis (LSS). Imaging modalities, such as fluoroscopy and ultrasonography, are frequently employed to confirm proper needle placement and to prevent possible complications. This is a prospective, randomized, study aiming to compare the efficacy of nonimage, ultrasonography-, and fluoroscopy-guided CEIs for the management of LSS. A total of 45 patients were included based on their clinical symptoms and their magnetic resonance images indicative of LSS. Patients were randomized and allocated into 3 equal groups, the nonimage, the ultrasonography-guided, and the fluoroscopy-guided group. All patients received 12 mg betamethasone and 4 mg ropivacaine dissolved in 20 mL normal saline. The injections were administered twice, with a 30-day interval. Visual Analogue Scale (VAS) and Oswestry Disability Index were recorded before the injections and 1 month after the second injection. The procedure times for each group were also compared. Visual Analogue Scale scores and Oswestry Disability Index values were improved in all the groups compared to the baseline values (p < 0.001). The intergroup difference in Visual Analogue Scale scores and Oswestry Disability Index values before and after CEIs was not statistically significant (p = 0.836 and p = 0.438, respectively). The mean procedure time was higher for the fluoroscopy-guided group, followed by ultrasonography-guided, but the differences were not statistically significant (p = 0.067). CEIs are an effective analgesic method for patients suffering from LSS. Nonimage, ultrasonography-, and fluoroscopy-guided CEIs are similarly effective in terms of pain relief and functional improvement.

V14-08 NOVEL AUTOMATED 3D SURGICAL PLANNING TOOL AND MRI/ULTRASOUND FUSION TECHNOLOGY TO PERFORM NANOPARTICLE ABLATION AND CRYOABLATION OF THE PROSTATE FOR FOCAL THERAPY

You have accessJournal of UrologyProstate Oncology II & Testis Oncology & Misc. Oncology (V14)1 Sep 2021V14-08 NOVEL AUTOMATED 3D SURGICAL PLANNING TOOL AND MRI/ULTRASOUND FUSION TECHNOLOGY TO PERFORM NANOPARTICLE ABLATION AND CRYOABLATION OF THE PROSTATE FOR FOCAL THERAPY Joshua Jue, Samuel Coons, Gilion Hautvast, Scott Thompson, Jack Geraats, Lee Richstone, Michael Schwartz, and Ardeshir Rastinehad Joshua JueJoshua Jue More articles by this author , Samuel CoonsSamuel Coons More articles by this author , Gilion HautvastGilion Hautvast More articles by this author , Scott ThompsonScott Thompson More articles by this author , Jack GeraatsJack Geraats More articles by this author , Lee RichstoneLee Richstone More articles by this author , Michael SchwartzMichael Schwartz More articles by this author , and Ardeshir RastinehadArdeshir Rastinehad More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002111.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Although MRI/Ultrasound fusion has been primarily used to assist in the diagnosis of prostate cancer, the next logical step forward would be using the technology to focally treat localized prostate cancer. We present one case of nanoparticle directed ablation and two cases of cryoablation to focally treat prostate tumors. METHODS: Three patients underwent MRI/Ultrasound fusion transperineal prostate biopsies to confirm low to intermediate risk prostate cancer prior to treatment. The MRI lesions correlated with the biopsy proven disease, and no prostate cancer was present on systematic biopsies using the modified Barzel template. Pelvic MRI segmentation was performed with DynaCAD 5.0 workstation. The MRI lesion including a 6-10 mm margin, prostate, bladder, urethra, urethral sphincter, rectum, and pubic bone were segmented. MRI/Ultrasound fusion was performed with the novel Philips UroNav 4.0 system. Lesions were treated with focal nanoparticle ablation or focal cryoablation. RESULTS: A 69-year-old male with a 10mm lesion in the right mid gland posterior medial peripheral zone was positive for Gleason GG3 cancer and was treated with focal nanoparticle ablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 94% of the 6-10 mm margin at the end of the case. A 68-year-old male with a 13mm lesion in the left anterior fibromuscular stroma apex positive for Gleason GG2 cancer and a 71-year-old male with a 16mm lesion in the right peripheral zone posterior lateral positive for Gleason GG1 cancer, were treated with focal cryoablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 82% of the 6-10mm margin at the end of the case for the left anterior fibromuscular stroma apex lesion. CONCLUSIONS: Visualization of the prostate tumor(s), surrounding critical structures, and pelvis in 3 dimensions, along with the anticipated ablation zone, is one of the challenges of pelvic surgery and percutaneous ablation. The DynaCAD 5.0 Urology system can create anauto-segmented 3D rendering of critical structures and the tumor(s), as well as visualization and quantification of the anticipated ablation coverage, to facilitate preoperative planning of needle placement. Ultimately, this MRI/Ultrasound fusion technology combined with 3D mapping holds significant potential and will be utilized for new applications in the future. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e1167-e1168 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joshua Jue More articles by this author Samuel Coons More articles by this author Gilion Hautvast More articles by this author Scott Thompson More articles by this author Jack Geraats More articles by this author Lee Richstone More articles by this author Michael Schwartz More articles by this author Ardeshir Rastinehad More articles by this author Expand All Advertisement Loading ...

Computed Tomography-Navigation™ Electromagnetic System Compared to Conventional Computed Tomography Guidance for Percutaneous Lung Biopsy: A Single-Center Experience.

The aim of our study was to assess the efficacy of a computed tomography (CT)-Navigation™ electromagnetic system compared to conventional CT methods for percutaneous lung biopsies (PLB). In this single-center retrospective study, data of a CT-Navigation™ system guided PLB (NAV-group) and conventional CT PLB (CT-group) performed between January 2017 and February 2020 were reviewed. The primary endpoint was the diagnostic success. Secondary endpoints were technical success, total procedure duration, number of CT acquisitions and the dose length product (DLP) during step ∆1 (from planning to initial needle placement), step ∆2 (progression to target), and the entire intervention (from planning to final control) and complications. Additional parameters were recorded, such as the lesion’s size and trajectory angles. Sixty patients were included in each group. The lesions median size and median values of the two trajectory angles were significantly lower (20 vs. 29.5 mm, p = 0.006) and higher in the NAV-group (15.5° and 10° vs. 6° and 1°; p < 0.01), respectively. Technical and diagnostic success rates were similar in both groups, respectively 95% and 93.3% in the NAV-group, and 93.3% and 91.6% in the CT-group. There was no significant difference in total procedure duration (p = 0.487) and total number of CT acquisitions (p = 0.066), but the DLP was significantly lower in the NAV-group (p < 0.01). There was no significant difference in complication rate. For PLB, CT-Navigation™ system is efficient and safe as compared to the conventional CT method.

The Crossed-leg Position Increases the Dimensions Within the Acoustic Target Window for Neuraxial Needle Placement in Term Pregnancy: A Prospective Observational Study

(Int J Obstet Anesth. 2020;44:106–111) Anatomic changes associated with pregnancy may render conduct of neuraxial procedures in parturients more difficult. The standard position for a neuraxial block requires a patient to sit on a bed with the spine flexed and legs supported on a stool, but spinal flexion may be improved by instead sitting cross-legged on the bed. Given the lack of prospective studies on this topic, the aim of this study was ultrasonographic assessment of the paramedian target area’s size when a pregnant woman sits in the cross-legged position (CLP) for neuraxial needle placement compared with standard sitting position (SP). The authors hypothesized that a CLP would increase the measured lengths of the posterior longitudinal ligament (PLL) indicating an improved acoustic window between vertebrae.

Low-Cost and Easily Fabricated Ultrasound-Guided Breast Phantom for Breast Biopsy Training

We aimed to develop an inexpensive and easy-to-fabricate gelatin-based training phantom for improving the breast biopsy skill and confidence level of residents. Young’s modulus and acoustic properties of the gelatin tissue phantom and simulated tumors were investigated. Six residents were requested to evaluate the effectiveness of the breast phantom. The results showed that 83% (n = 5) of the participants agreed that the ultrasound image quality produced by the breast phantom was excellent or good. Only 17% (n = 1) of the participants claimed that there was room for improvement for the haptic feedback they received during the placement of the core needle into the breast phantom. The mean pre-instructional score was 17% (SD 17%) for all participants. The mean post-instructional score was 83% (SD 17%), giving an overall improvement of 67%. In conclusion, the mean needle biopsy skill and confidence levels of the participants substantially increased through simulation training on our breast phantom. The participants’ feedback showed the phantom is sufficiently realistic in terms of ultrasound imaging and haptic feedback during needle insertion; thus, the training outcome can be linked to the performance of residents when they perform a live biopsy.

Robotic Assistance System for Cone-Beam Computed Tomography-Guided Percutaneous Needle Placement

PurposeThe study aimed to evaluate a new robotic assistance system (RAS) for needle placement in combination with a multi-axis C-arm angiography system for cone-beam computed tomography (CBCT) in a phantom setting.Materials and MethodsThe RAS consisted of a tool holder, dedicated planning software, and a mobile platform with a lightweight robotic arm to enable image-guided needle placement in conjunction with CBCT imaging. A CBCT scan of the phantom was performed to calibrate the robotic arm in the scan volume and to plan the different needle trajectories. The trajectory data were sent to the robot, which then positioned the tool holder along the trajectory. A 19G needle was then manually inserted into the phantom. During the control CBCT scan, the exact needle position was evaluated and any possible deviation from the target lesion measured.ResultsIn total, 16 needle insertions targeting eight in- and out-of-plane sites were performed. Mean angular deviation from planned trajectory to actual needle trajectory was 1.12°. Mean deviation from target point and actual needle tip position was 2.74 mm, and mean deviation depth from the target lesion to the actual needle tip position was 2.14 mm. Mean time for needle placement was 361 s. Only differences in time required for needle placement between in- and out-of-plane trajectories (337 s vs. 380 s) were statistically significant (p = 0.0214).ConclusionUsing this RAS for image-guided percutaneous needle placement with CBCT was precise and efficient in the phantom setting.

To Assess the Technical Feasibility of Ultrasound Lumbar Sympathetic Block with Electrical Stimulation Needle in Out-of-Plane Needle Orientation: A Prospective Interventional Study.

We describe the technical feasibility of a new technique of ultrasound lumbar sympathectomy validated by fluoroscopy. Prospective interventional study. Pain block area. Thirty patients with peripheral arterial disease with pain at rest (numerical rating score [NRS] ≥3) were recruited. In the lateral position, a curved probe (FUJIFILM SonoSite Edge, Bothell, WA, USA, 2-5 MHz) was placed transversely at the iliac crest. An electrical stimulation needle was inserted out of plane, below the lower pole of the kidneys, directed anterior to the vertebral body below. When the needle tip was not visualized, a current of 2.0 A was applied. Patients' quadriceps contractions, ultrasound psoas contractions, and bone contact guided needle placement, which was confirmed on fluoroscopy. Other parameters noted were the number of needle insertions, vertebral level, pain NRS at baseline and at 4 hours, 24 hours, 1 week, and 2 weeks after block, temperature rise, and any other complications. In all patients, the needle tip was correctly placed in one to three attempts. In 73% of patients, the needle tip was at L3. Baseline pain NRS was 8 (interquartile range 7-8), which decreased to 2 (interquartile range 2-3) at 1 week after the procedure, and it was maintained in this range until 2 weeks later. A temperature rise of >2ºC was noted in all patients. Ultrasound lumbar sympathectomy can be performed safely in patients with peripheral arterial disease by an out-of-plane approach in the lateral patient position with an electrical stimulation needle. Before injection of the drug, aspiration of blood should be ruled out in view of the possibility of aortocaval injection.

Intraoperative lateral rectus electromyographic recordings optimized by deep intraorbital needle electrodes

ObjectiveWe demonstrate the advantages and safety of long, intraorbitally-placed needle electrodes, compared to standard-length subdermal electrodes, when recording lateral rectus electromyography (EMG) during intracranial surgeries. MethodsInsulated 25 mm and uninsulated 13 mm needle electrodes, aimed at the lateral rectus muscle, were placed in parallel during 10 intracranial surgeries, examining spontaneous and stimulation-induced EMG activities. Postoperative complications in these patients were reviewed, alongside additional patients who underwent long electrode placement in the lateral rectus. ResultsIn 40 stimulation-induced recordings from 10 patients, the 25 mm electrodes recorded 6- to 26-fold greater amplitude EMG waveforms than the 13 mm electrodes. The 13 mm electrodes detected greater unwanted volume conduction upon facial nerve stimulation, typically exceeding the amplitude of abducens nerve stimulation. Except for one case with lateral canthus ecchymosis, no clinical or radiographic complications occurred in 36 patients (41 lateral rectus muscles) following needle placement. ConclusionsIntramuscular recordings from long electrode in the lateral rectus offers more reliable EMG monitoring than 13 mm needles, with excellent discrimination between abducens and facial nerve stimulations, and without significant complications from needle placement. SignificanceLong intramuscular electrode within the orbit for lateral rectus EMG recording is practical and reliable for abducens nerve monitoring.

Image‐guided spinal injection for pain management

Radiculopathy and spinal pain are debilitating conditions affecting millions of people worldwide each year. While most cases can be managed conservatively with physiotherapy and nonsteroidal anti-inflammatory medications, minimally invasive corticosteroid injections are the mainstay intervention for those not responsive to conservative treatment. Historically, spinal injections were performed in the absence of imaging guidance; however, imaging modalities, in particular fluoroscopy and computer tomography (CT), have become the standard of care in performing most of these procedures. Under imaging guidance, operators can accurately confirm needle placement and safely target localised pathologies.

Multiple direction needle-path planning and inverse dose optimization for robotic low-dose rate brachytherapy

PurposeRobotic systems to assist needle placements for low-dose rate brachytherapy enable conformal dose planning only restricted to path planning around risk structures. We report a treatment planning system (TPS) combining multiple direction needle-path planning with inverse dose optimization algorithms. MethodsWe investigated in a path planning algorithm to efficiently locate needle injection points reaching the target volume without puncturing risk structures. A candidate needle domain with all combinations of trajectories is used for the optimization process. We report a modular algorithm for inverse radiation plan optimization. The initial plan with V100>99% is generated by the “greedy optimizer”. The “remove-seed algorithm” reduces the number of seeds in the high dose regions. The “depth-optimizer” varies the insertion depth of the needles. The “coverage-optimizer” locates under-dosed areas in the target volume and supports them with an additional amount of seeds. The dose calculation algorithm is benchmarked on an image set of a phantom with a liver metastasis (prescription dose Dpr=100 Gy) and is re-planned in a commercial CE-marked TPS to compare the calculated dose grids using a global gamma analysis. The inverse optimizer is benchmarked by calculating 10 plans on the same phantom to investigate the stability and statistical variability of the dose parameters. ResultsThe path planning algorithm efficiently removes 72.5% of all considered injection points. The candidate needle domain consists of combinations of 1971 tip points and 827 injection points. The global gamma analysis with gamma 1%=2.9 Gy, 1 mm showed a pass rate of 98.5%. The dose parameters were V100=99.1±0.3%, V150=76.4±2.5%, V200=44.5±5.5% and D90=125.9±3.6 Gy and 10.7±1.3 needles with 34.0±0.8 seeds were used. The median of the TPS total running time was 4.4minutes. ConclusionsThe TPS generates treatment plans with acceptable dose coverage in a reasonable amount of time. The gamma analysis shows good accordance to the commercial TPS. The TPS allows taking full advantage of robotic navigation tools to enable a new precise and safe method of minimally invasive low-dose-rate brachytherapy.

State of the art: percutaneous tracheostomy in the intensive care unit.

Percutaneous tracheostomy is a commonly performed procedure for patients in the intensive care unit (ICU) and offers many benefits, including decreasing ICU length of stay and need for sedation while improving patient comfort, effective communication, and airway clearance. However, there is no consensus on the optimal timing of tracheostomy in ICU patients. Ultrasound (US) and bronchoscopy are useful adjunct tools to optimize procedural performance. US can be used pre-procedurally to identify vascular structures and to select the optimal puncture site, intra-procedurally to assist with accurate placement of the introducer needle, and post-procedurally to evaluate for a pneumothorax. Bronchoscopy provides real-time visual guidance from within the tracheal lumen and can reduce complications, such as paratracheal puncture and injury to the posterior tracheal wall. A step-by-step detailed procedural guide, including preparation and procedural technique, is provided with a team-based approach. Technical aspects, such as recommended equipment and selection of appropriate tracheostomy tube type and size, are discussed. Certain procedural considerations to minimize the risk of complications should be given in circumstances of patient obesity, coagulopathy, or neurologic illness. Herein, we provide a practical state of the art review of percutaneous tracheostomy in ICU patients. Specifically, we will address pre-procedural preparation, procedural technique, and post-tracheostomy management.

Towards a companion system for collision avoidance during robot-assisted needle placement

Abstract Robotic assistance systems for surgery enable fast and precise interventions with reduced complication rates. However, these benefits are accompanied by a more complex operating room (OR) and the risk of collision with robotic assistance systems. Current strategies for collision avoidance and minimizing possible injuries require the adaptation of robotic trajectories and a computational model of the surroundings. In contrast, this work presents a novel companion system for collision avoidance without influencing robotic trajectories. The companion system consists of a preoperative planning application and an augmented reality application for intraoperative support. The companion system visualizes the workflow within the OR and allows robot movements to be seen virtually, before they are executed by the actual robotic assistance system. Preliminary experiments with users imply that the companion system leads to a positive user experience, enables users to follow a predefined workflow in the OR, but requires further refinement to improve accuracy for practical collision avoidance.

Depth of spinal needle insertion and its associated factors among patients who underwent surgery under spinal anesthesia

BackgroundLumbar puncture is a difficult medical skill and used by anesthetists for administering local anesthetics to the subarachnoid space. Prior knowledge of how far the needle needs to be inserted from skin to the subarachnoid space distance (SSD) has a paramount role to guide spinal needle placement and reduce complications related to lumbar puncture. Therefore, we aimed to determine the depth of spinal needle insertion and its associated factors among patients who underwent surgery under spinal anesthesia. MethodsAn institutional based cross-sectional study design was conducted among 274 patients who underwent surgery under spinal anesthesia. Following very successful lumbar puncture procedure, the distance from skin entry point to the tip of the spinal needle was measured. The data were entered into an Epi data version 4.3.1 and exported to SPSS software version 20 for analysis. Descriptive analysis, simple linear and multiple linear regression analysis were used. Then, in order to assess the correlation of depth of spinal needle insertion with other independent variables Pearson's correlation coefficient (r) was applied. ResultsTwo hundred seventy four patients comprising 112 (40.8%) male and 162 (59.1%) female were included in the study with a mean height, weight and body mass index (BMI) of 1.63 m, 62.9 kg, and 23.9 kg/m2 respectively. The mean distance from skin to the subarachnoid space was 5.13 ± 0.69 cm ranging from 3.5 to 7.1 cm. Pregnancy, weight and BMI had statistically significant effect on the mean SSD (p < 0.001, p < 0.001 and p = 0.014) respectively. ConclusionsThe distance from the skin to the subarachnoid space was differed among individuals. The SSD was affected by individuals’ pregnancy status, BMI and weight. Hence, to minimize complications, these factors should be taken into consideration at the time of spinal needle insertion.