Regional and Conducted Vascular Effects of Endovascular Ultrasound Catheters.
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ABSTRACT:
SUBMITTER: Muller MA
PROVIDER: S-EPMC7720779 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Endovascular catheter-based technologies have revolutionized the treatment of complex vascular pathology. Catheters and endovascular devices that can be maneuvered through tortuous arterial anatomy have enabled minimally invasive treatment in the peripheral arterial system. Although mechanical factors drive an interventionalist's choice of catheters and sheaths, these decisions are mostly made qualitative and based on personal experience and procedural pattern recognition. However, a definitive quantitative characterization of endovascular tools that are best suited for specific peripheral arterial beds is currently lacking. To establish a foundation for quantitative tool selection in the neurovascular and lower extremity peripheral arterial beds, we developed a nonlinear beam theory method to quantify catheter and sheath flexural rigidity. We applied this assessment to a sampling of commonly utilized commercially available peripheral arterial catheters and sheaths. Our results demonstrated that catheters and sheaths adopted for existing practice patterns to treat peripheral arterial disease in the lower extremities and neurovascular system have different but overlapping ranges of flexural rigidities that were not sensitive to luminal diameters within each procedure type. Our approach provides an accurate and effective method for characterization of flexural rigidity properties of catheters and sheaths, and a foundation for developing future technologies tailored for specific peripheral arterial systems.
| S-EPMC8802324 | biostudies-literature
Project description:Catheter-based intra-arterial drug therapies have proven effective for a range of oncologic, neurologic, and cardiovascular applications. However, these procedures are limited by their invasiveness and relatively broad drug spatial distribution. The ideal technique for local pharmacotherapy would be noninvasive and would flexibly deliver a given drug to any region of the body with high spatial and temporal precision. Combining polymeric perfluorocarbon nanoemulsions with existent clinical focused ultrasound systems could in principle meet these needs, but it has not been clear whether these nanoparticles could provide the necessary drug loading, stability, and generalizability across a range of drugs, beyond a few niche applications. Here, we develop polymeric perfluorocarbon nanoemulsions into a generalized platform for ultrasound-targeted delivery of hydrophobic drugs with high potential for clinical translation. We demonstrate that a wide variety of drugs may be effectively uncaged with ultrasound using these nanoparticles, with drug loading increasing with hydrophobicity. We also set the stage for clinical translation by delineating production protocols that are scalable and yield sterile, stable, and optimized ultrasound-activated drug-loaded nanoemulsions. Finally, we exhibit a new potential application of these nanoemulsions for local control of vascular tone. This work establishes the power of polymeric perfluorocarbon nanoemulsions as a clinically-translatable platform for efficacious, noninvasive, and localized ultrasonic drug uncaging for myriad targets in the brain and body.
| S-EPMC6486876 | biostudies-literature
Project description:IntroductionRadiographic fluoroscopy is the current standard for placement of tunneled central venous catheters (CVCs) for hemodialysis. Radiographic fluoroscopy requires structural and personnel infrastructure and exposes the patient to ionizing radiation. Here, we investigate the feasibility of solely ultrasound-guided placement of tunneled central venous dialysis catheters (USCVCs).MethodsWe evaluated prospectively collected single-center data regarding safety and catheter function of 134 consecutive patients who underwent USCVC implantation between 2020 and 2021. We used the inset guidewire to visualize the position of the catheter tip. In the case of inadequate visibility by ultrasound, we used intracardiac electrocardiography (ECG) recording or agitated saline. A total of 1844 catheter days were assessed. The optimal CVC position was defined as being within the upper right atrium (URA) and middle to deep right atrium.ResultsOf the 134 USCVCs, 87% were placed on the right side. The primary success rate for optimal tip position and catheter function was 98%. Of the USCVCs, 97% were placed solely by ultrasound. Regarding positioning, 6% were in the vena cava superior zone, 70% in the URA and 24% in the middle to deep right atrium, resulting in a rate of 94% with optimal positioning. Effective blood flow averaged 292 ± 39 ml/min. There were no immediate procedure-associated complications.ConclusionPlacement of CVC for hemodialysis solely by ultrasound is an effective alternative to fluoroscopy-assisted placement.
| S-EPMC10577359 | biostudies-literature
Project description:Conduction processes in the vasculature have traditionally been described using cable theory, i.e., locally induced signals decaying passively along the arteriolar wall. The decay is typically quantified using the steady-state length-constant, λ, derived from cable theory. However, the applicability of cable theory to blood vessels depends on assumptions that are not necessarily fulfilled in small arteries and arterioles. We have employed a morphologically and electrophysiologically detailed mathematical model of a rat mesenteric arteriole to investigate if the assumptions hold and whether λ adequately describes simulated conduction profiles. We find that several important cable theory assumptions are violated when applied to small blood vessels. However, the phenomenological use of a length-constant from a single exponential function is a good measure of conduction length. Hence, λ should be interpreted as a descriptive measure and not in light of cable theory. Determination of λ using cable theory assumes steady-state conditions. In contrast, using the model it is possible to probe how conduction behaves before steady state is achieved. As ion channels have time-dependent activation and inactivation, the conduction profile changes considerably during this dynamic period with an initially longer spread of current. This may have implications in relation to explaining why different agonists have different conduction properties. Also, it illustrates the necessity of using and developing models that handle the nonlinearity of ion channels.
| S-EPMC3309280 | biostudies-literature
Project description:Background and purposeThe relative contribution of each Alberta Stroke Program Early CT Score (ASPECTS) region to poststroke disability likely varies across regions. Determining the relative weights of each ASPECTS region may improve patient selection for endovascular stroke therapy (EST).MethodsIn the combined Solitaire Flow Restoration with the Intention for Thrombectomy (SWIFT), Solitaire Flow Restoration Thrombectomy for Acute Revascularization (STAR), and Solitaire Flow Restoration with the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME) databases, we identified patients treated with the Solitaire stent retriever. Using 24-h CT scan, a multivariate ordinal regression was used to determine the relative contribution of each ASPECTS region to clinical outcome separately in each hemisphere. The coefficients from the regression were used to create a weighted ASPECTS (wASPECTS), which was compared with the original ASPECTS to predict 90-day modified Rankin Scale disability outcomes in an independent validation cohort.ResultsAmong 342 patients treated with EST, the average age was 67 years, 57% were female, and the median National Institutes of Health Stroke Scale (NIHSS) score was 17 (IQR 13-20). The median ASPECTS at presentation was 8 (IQR 7-10). The most commonly involved ASPECTS regions on 24-h CT were the lentiform nuclei (70%), insula (55%), and caudate (52%). In multivariate analysis, preservation of M6 (β = 9.7) and M4 (β = 4.4) regions in the right hemisphere was most strongly predictive of good outcome. For the left hemisphere, M6 (β = 5.5), M5 (β = 4.1), and M3 (β = 3.1) generated the greatest parameter estimates, though they did not reach statistical significance. A wASPECTS incorporating all 20 parameter estimates resulted in improved discrimination against the original ASPECTS in the independent cohort (C-statistic 0.78 vs. 0.67, right hemisphere).ConclusionsFor both right and left hemisphere, preservation of the high cortical regions was more strongly associated with improved outcomes compared to the deep regions. Our findings support taking into consideration the location and relative weightings of the involved ASPECTS regions when evaluating a patient for EST.
| S-EPMC6216699 | biostudies-literature
Project description:The endovascular technique has led to a revolution in the care of patients with vascular disease; however, acquiring and maintaining proficiency over a broad spectrum of procedures is challenging. Three-dimensional (3D) printing technology allows the production of models that can be used for endovascular training. This article aims to explain the process and technologies available to produce vascular models for endovascular training, using 3D printing technology. The data are based on the group experience and a review of the literature. Different 3D printing methods are compared, describing their advantages, disadvantages and potential roles in surgical training. The process of 3D printing a vascular model based on an imaging examination consists of the following steps: image acquisition, image post-processing, 3D printing and printed model post-processing. The entire process can take a week. Prospective studies have shown that 3D printing can improve surgical planning, especially in complex endovascular procedures, and allows the production of efficient simulators for endovascular training, improving residents' surgical performance and self-confidence.
| S-EPMC6604582 | biostudies-literature
Project description:BackgroundPlacing a peripheral vein catheter can be challenging due to several factors, but using ultrasound as guidance increases the success rate. The purpose of this review is to investigate the knowledge already existing within the field of education in ultrasound-guided peripheral vein catheter placement and explore the efficacy and clinical impact of different types of education.MethodsIn accordance with PRISMA-guidelines, a systematic search was performed using three databases (PubMed, EMBASE, CINAHL). Two reviewers screened titles and abstracts, subsequently full-text of the relevant articles. The risk of bias was assessed using the Cochrane Collaboration risk of bias assessment tool and the New Ottawa scale.ResultsOf 3409 identified publications, 64 were included. The studies were different in target learners, study design, assessment tools, and outcome measures, which made direct comparison difficult. The studies addressed a possible effect of mastery learning and found e-learning and didactic classroom teaching to be equally effective.ConclusionCurrent studies suggest a potential benefit of ultrasound guided USG-PVC training on success rate, procedure time, cannulation attempts, and reducing the need for subsequent CVC or PICC in adult patients. An assessment tool with proven validity of evidence to ensure competence exists and education strategies like mastery learning, e-learning, and the usage of color Doppler show promising results, but an evidence-based USG-PVC-placement training program using these strategies combined is still warranted.
| S-EPMC8237454 | biostudies-literature
Project description:ObjectivesDuring mechanical recanalization of large vessel occlusions (LVO), the use of proximal flow arrest with balloon guide catheters (BGC) was shown to be associated with better angiographic and even clinical outcome. The aim of the study was to analyze the impact of BGC use on microstructural alterations in the salvaged penumbra.MethodsAll patients who underwent mechanical recanalization of LVO of the anterior circulation were reviewed within a prospective stroke registry of a single comprehensive stroke center. Fifty-two patients received an admission CT perfusion together with post-interventional diffusion tensor imaging. Technical details such as BGC usage were correlated with microstructural integrity changes of the salvaged gray matter through the mean diffusivity (MD) index. Moderation analysis was performed to test the interaction of BGC on the correlation between angiographic and clinical outcomes.ResultsFor all patients with complete reperfusion, microstructural integrity changes with lowered MD index were found within the salvaged penumbra for cases of non-BGC usage (mean - 0.02) compared to cases with BGC usage (0.01, p = 0.04). The importance of complete reperfusion for good clinical outcome is predominantly based on patients treated with BGC (effect 2.78, p = 0.01 vs. for non-BGC: 0.3, p = 0.71).ConclusionsThe lowered MD index early after mechanical recanalization without BGC usage can be interpreted as microstructural ischemic damage of the salvaged penumbra. It was shown that achieving complete reperfusion in a setting of BGC usage with proximal flow arrest minimizes penumbral damage and improves long-term outcomes.Key points• Microstructural ischemic damage can be reduced by using proximal flow arrest during endovascular treatment with balloon guide catheter. • Complete reperfusion in a setting of balloon guide catheter minimizes penumbral damage and improves long-term outcome.
| S-EPMC7979594 | biostudies-literature
Project description:BACKGROUND:Continuous interscalene blocks provide excellent analgesia after shoulder surgery. Although the safety of the ultrasound-guided in-plane approach has been touted, technical and patient factors can limit this approach. We developed a caudad-to-cephalad out-of-plane approach and hypothesized that it would decrease pain ratings due to better catheter alignment with the brachial plexus compared to the in-plane technique in a randomized, controlled study. OBJECTIVES:To compare an out-of-plane interscalene catheter technique to the in-plane technique in a randomized clinical trial. PATIENTS AND METHODS:Eighty-four patients undergoing open shoulder surgery were randomized to either the in-plane or out-of-plane ultrasound-guided continuous interscalene technique. The primary outcome was VAS pain rating at 24 hours. Secondary outcomes included pain ratings in the recovery room and at 48 hours, morphine consumption, the incidence of catheter dislodgments, procedure time, and block difficulty. Procedural data and all pain ratings were collected by blinded observers. RESULTS:There were no differences in the primary outcome of median VAS pain rating at 24 hours between the out-of-plane and in-plane groups (1.50; IQR, [0 - 4.38] vs. 1.25; IQR, [0 - 3.75]; P = 0.57). There were also no differences, respectively, between out-of-plane and in-plane median PACU pain ratings (1.0; IQR, [0 - 3.5] vs. 0.25; IQR, [0 - 2.5]; P = 0.08) and median 48-hour pain ratings (1.25; IQR, [1.25 - 2.63] vs. 0.50; IQR, [0 - 1.88]; P = 0.30). There were no differences in any other secondary endpoint. CONCLUSIONS:Our out-of-plane technique did not provide superior analgesia to the in-plane technique. It did not increase the number of complications. Our technique is an acceptable alternative in situations where the in-plane technique is difficult to perform.
| S-EPMC4688811 | biostudies-literature
Project description:Introduction:The peripheral internal jugular (IJ), also called the "easy IJ," is an alternative to peripheral venous access reserved for patients with difficult intravenous (IV) access. The procedure involves placing a single-lumen catheter in the IJ vein under ultrasound (US) guidance. As this technique is relatively new, the details regarding the ease of the procedure, how exactly it should be performed, and the safety of the procedure are uncertain. Our primary objective was to determine the success rate for peripheral IJ placement. Secondarily, we evaluated the time needed to complete the procedure and assessed for complications. Methods:This was a prospective, single-center study of US-guided peripheral IJ placement using a 2.5-inch, 18-gauge catheter on a convenience sample of patients with at least two unsuccessful attempts at peripheral IV placement by nursing staff. Peripheral IJ lines were placed by emergency medicine (EM) attending physicians and EM residents who had completed at least five IJ central lines. All physicians who placed lines for the study watched a 15-minute lecture about peripheral IJ technique. A research assistant monitored each line to assess for complications until the patient was discharged. Results:We successfully placed a peripheral IJ in 34 of 35 enrolled patients (97.1%). The median number of attempts required for successful cannulation was one (interquartile range (IQR): 1 to 2). The median time to successful line placement was 3 minutes and 6 seconds (IQR: 59 seconds to 4 minutes and 14 seconds). Two lines failed after placement, and one of the 34 successfully placed peripheral IJ lines (2.9%) had a complication - a local hematoma. There were, however, no arterial punctures or pneumothoraces. Although only eight of 34 lines were placed using sterile attire, there were no line infections. Conclusion:Our research adds to the growing body of evidence supporting US-guided peripheral internal jugular access as a safe and convenient procedure alternative for patients who have difficult IV access.
| S-EPMC6123094 | biostudies-literature