Steerable Catheter Research Articles

Experiência inicial com a extensão de cateter-guia ExpressmanTM em um centro terciário de cardiologia de alto volume

Background: Guide catheter extensions provide increased support in complex percutaneous coronary interventions. The ExpressmanTM is a novel guide catheter extension and the objective was to assess the impact of its use on procedural success and complications in a high-volume reference center. Methods: We analyzed data from all consecutive procedures in which the ExpressmanTM guide catheter extension was used. The decision to use a guide catheter extension was at operator’s discretion. Device success was defined as the successful positioning of the guide catheter extension in the coronary vessel and procedural success was defined as <20% residual stenosis and TIMI 3 flow, with no loss of significant side branches. Major adverse cardiac and cerebrovascular events were defined as the composite of all-cause death, myocardial infarction, target vessel revascularization and stroke. Results: From April 2022 to January 2023, 34 procedures were included. The majority of the patients were male (59%) and the mean age was 66.5 years. Guide catheter extension use was not planned pre-procedure in 17 procedures (50%). The most common reasons for guide catheter extension use were target vessel angulation or tortuosity and unfavorable coronary ostium position. Device success was obtained in 88% and revascularization success in 91%. There were three side branch occlusions. During in-hospital clinical follow-up, no major adverse cardiac and cerebrovascular events or major bleeding occurred. Conclusion: The device success and procedural success were high and the rate of complications was low. Guide catheter extension use as bailout technique in complex anatomies allowed procedural success in the vast majority of otherwise untreatable patients.

In Reply: Transradial Carotid Artery Stenting Using Walrus Balloon Guide Catheter: Technical Aspects and Clinical Outcome.

In Reply: Transradial Carotid Artery Stenting Using Walrus Balloon Guide Catheter: Technical Aspects and Clinical Outcome.

Right Ventricular Outflow Tract Melanoma Diagnosed Using a Transfemoral Biopsy Through a Shortened Jr-4 Guiding Catheter

Right Ventricular Outflow Tract Melanoma Diagnosed Using a Transfemoral Biopsy Through a Shortened Jr-4 Guiding Catheter

Integrated Magnetic Location Sensing and Actuation of Steerable Robotic Catheters for Peripheral Arterial Disease Treatment

Integrated Magnetic Location Sensing and Actuation of Steerable Robotic Catheters for Peripheral Arterial Disease Treatment

A Novel Quasilinear Viscoelastic Model of the Bending of a Steerable Catheter

Abstract The present study proposes a novel model that establishes the relationship between the bending moment and the curvature of a steerable catheter. The catheters exhibit a nonlinear viscoelastic tendency, so the moment-curvature relationship is modeled as a bending of a quasi-linear viscoelastic (QLV) cantilever beam. Stress relaxation tests with multiple magnitudes are performed on a catheter, and the parameter tuning is carried out with the test results to find out the coefficients of the model. The form of the instantaneous moment response, which is an important term within the QLV equation, is selected as a logarithmic form by analyzing the test results. This differentiates the accuracy of the model from using the commonly used exponential form. The performance of the logarithmic QLV model is compared to the conventional models by checking the curvature range each model can cover with a certain accuracy. The covering range for elastic, linear viscoelastic, and exponential QLV models are 22.1%, 64.4%, and 55.5%, respectively, whereas the covering range of the logarithmic QLV model is 100%.

The balloon occlusion sheath for stroke (BOSS) balloon guide catheter for stroke intervention: Safety and technical success.

We describe the first-in-human experience using the Balloon Occlusion Stroke Sheath (BOSSTM) balloon-guide catheter to perform stroke thrombectomy in 50 consecutive patients enrolled in the Flow Arrest Safety and Technical success with balloon-guide catheters trial. This aspiration system includes a novel 9.4F balloon-guide catheter conduit for the insertion and guidance of catheters with a balloon providing temporary flow arrest. The Flow Arrest Safety and Technical success with balloon-guide catheter trial is a single-arm, prospective, multi-center, non-randomized, observational registry evaluating the use of the market-released BOSSTM balloon-guide catheter in adult patients diagnosed with an acute ischemic stroke attributable to large vessel occlusion. The purpose of the current trial was to assess the safety and technical success associated with the use of the BOSSTM balloon-guide catheter. Fifty patients met inclusion criteria with a mean baseline National Institutes of Health Stroke Scale (NIHSS) of 16. Treatment devices, including aspiration and stent retriever devices, were used in a total of 88 passes. The BOSSTM balloon-guide catheter was compatible with all stroke thrombectomy treatment devices used in 98% (49/50) of procedures. Balloon inflation and flow arrest were achieved in 100% (50/50) and 98% (49/50) of cases, respectively. Balloon deflation and retraction were observed in 100% (50/50) of cases. Successful reperfusion (modified thrombolysis in cerebral infarction score > 2b) was achieved in 100% of cases with single-pass reperfusion achieved in 62% (31/50) of cases. The BOSSTM balloon-guide catheter is a safe and technically effective adjunctive device for mechanical thrombectomy of acute ischemic stroke due to large vessel occlusion.

Practical and systematic approach using the steerable catheter and stylet-driven lead to deliver safe and effective left bundle branch area pacing.

Current delivery tools were not designed for left bundle branch area pacing (LBBAP). Challenges using these tools include lack of reach into the right ventricle and poor support for the lead to penetrate the interventricular septum. Concerns using stylet-driven leads (SDL) for LBBAP have been previously highlighted. Knowledge and the technical know-how of using SDL for LBBAP need to be evaluated in a fair and consistent manner. A stepwise approach is devised for use of Agilis HisProTM steerable catheter with Tendril STS Model 2088TC lead for LBBAP and evaluated for safety and reproducibility. Consecutive patients undergoing LBBAP using the stepwise approach with Agilis HisProTM steerable catheter were analyzed. The safety, efficacy and reproducibility of the technique were evaluated. The lead parameters were analyzed in the immediate (1 day) and short-term period (3-6 months) post implantation. LBBAP was attempted in 41 patients using the stepwise approach of which 37 (90.7%) were successful. The lead parameters were stable in the immediate and short-term post implantation in all our patients. There was no significant difference between the group of patients with multiple repositioning of the lead compared to those successful at the 1st attempt. There were no acute or short-term lead and procedural complications. A stepwise and systematic approach using the Agilis HisProTM steerable catheter and proper handling of the Tendril STS Model 2088TC stylet-driven lead is an important part of the armamentarium to deliver LBBAP in a practical, effective and reproducible manner.

Initial clinical experience with the Bendit steerable articulating tip microcatheter for intracranial access and intervention.

The increasing complexity and sophistication of neurovascular implants and other therapeutic devices depend on access and delivery systems. Advancements in access technologies are required to improve minimally invasive endovascular procedures. Steerable catheters have been available in other disciplines, however, their implementation in neurovascular interventions has been a barrier previously due to issues with miniaturization and vascular caliber/complexity. A retrospective review of the neurovascular stroke database was conducted in accordance with local IRB to identify patients that received neurointerventional endovascular procedures using a novel first iteration 0.021'' microcatheter with controlled articulating tip flexion. Indications, management, demographics, comorbidities, and clinical and technical outcomes were recorded and analyzed. Primary operator feedback on the novel catheter was collected and reviewed. Ten consecutive patients receiving treatment that involved a novel steerable 0.021'' microcatheter were identified and analyzed. No complications were reported. Novel useful features of the catheter were reported on a case-by-case basis. Initial clinical experience with the controlled articulation that permits flexion at the tip of the microcatheter demonstrated it to be safe. Access to difficult proximal origin curves, and distal clinoidal/ophthalmic segment anatomy may be improved due to the high torque transmission, and acute angulation of this microcatheter. Further experience with the delivery of therapeutic devices will be necessary to better understand the potential role that the present catheter may play in modern neurointerventional procedures.

Contrast Injection from an Intermediate Catheter Placed in an Intradural Artery is Associated with Contrast-Induced Encephalopathy following Neurointervention.

Contrast-induced encephalopathy can result from neurotoxicity of contrast medium in the affected area. The development of intermediate catheters has allowed guidance of catheters to more distal arteries. This study focused on the association between contrast-induced encephalopathy and contrast injection from an intermediate catheter guided into a distal intradural artery during neurointervention for cerebral aneurysms. We retrospectively reviewed 420 consecutive aneurysms in 396 patients who underwent neurointervention for extracranial aneurysms and unruptured intracranial aneurysms at our institution from February 2012 to January 2023. Patients were divided into a group with contrast-induced encephalopathy and a group without. To identify risk factors for contrast-induced encephalopathy, we compared clinical, anatomic, and procedural factors between groups by multivariate logistic regression analysis and stepwise selection. Among the 396 patients who underwent neurointervention for cerebral aneurysms, 14 (3.5%) developed contrast-induced encephalopathy. Compared with the group without contrast-induced encephalopathy, the group with contrast-induced encephalopathy showed significantly higher rates of patients on hemodialysis, previously treated aneurysms, intradural placement of a catheter for angiography, nonionic contrast medium, and flow-diversion procedures in univariate analyses. Stepwise multivariate logistic regression analysis revealed intradural placement of a catheter for angiography (OR = 40.4; 95% CI, 8.63-189) and previously treated aneurysms (OR = 8.20; 95% CI, 2.26-29.6) as independent predictors of contrast-induced encephalopathy. Contrast injection from an intradural artery and retreatment of recurrent aneurysms were major risk factors for contrast-induced encephalopathy. Attention should be paid to the location of the intermediate catheter for angiography to avoid developing contrast-induced encephalopathy.

Feasibility and Efficacy of a Novel Sheathless Guiding Catheter Equipped With Peel-Off External Dilator for Percutaneous Coronary Intervention With Distal Radial Approach – A Japanese Multicenter Study

Feasibility and Efficacy of a Novel Sheathless Guiding Catheter Equipped With Peel-Off External Dilator for Percutaneous Coronary Intervention With Distal Radial Approach – A Japanese Multicenter Study

Zero fluoroscopy ablation for atrioventricular nodal reentrant tachycardia and typical atrial flutter is equally safe and effective with EnSite NavX, Carto3, and Rhythmia mapping systems.

Our purpose was to compare the procedural characteristics, success rate, and complication rate of the conventional fluoroscopic (CF) and the zero-fluoroscopic (ZF) approach in patients undergoing catheter ablation of AVNRT or typical atrial flutter (Aflu). 186 consecutive patients with an indication for AVNRT or Aflu ablation were enrolled. Based on the operator's preference, the patients were assigned to either CF or ZF group. In the ZF group EnSite NavX, Carto3, or Rhythmia EAMS were used for catheter guidance. The median age was 56 (IQR = 42-68) years, 144 patients had AVNRT, and 42 had Aflu ablation. CF approach was chosen in 123 cases, while ZF in 63 cases. ZF approach was used more often in case of AVNRT patients [56 (39%) vs. 7 (17%), p = 0.006] and in the case of female patients [43 (68%) vs. 20 (32%), p = 0.008]. Acute procedural success was obtained in all cases. There was no difference in the complication rate (1 vs. 1, p > 0.99) between the two groups. No difference was found regarding the procedure time between the CF and ZF groups [CF: 55 (46-60) min, ZF 60 (47-65) min; p = 0.487] or in the procedure time for the different EAMS [EnSite NavX: 58 (50-63) min, Carto3: 60 (44.5-66.3) min, Rhythmia: 55 (35-69) min; p = 0.887]. A similar success rate was seen at the 3-month follow-up in the two groups [41 (100%) vs. 96 (97%); p = 0.55]. The ZF approach demonstrated non-inferiority in safety and efficacy compared with CF for the AVNRT and Aflu ablations.

Toward a novel soft robotic system for minimally invasive interventions.

During minimally invasive surgery, surgeons maneuver tools through complex anatomies, which is difficult without the ability to control the position of the tools inside the body. A potential solution for a substantial portion of these procedures is the efficient design and control of a pneumatically actuated soft robot system. We designed and evaluated a system to control a steerable catheter tip. A macroscale 3D printed catheter tip was designed to have two separately pressurized channels to induce bending in two directions. A motorized hand controller was developed to allow users to control the bending angle while manually inserting the steerable tip. Preliminary characterization of two catheter tip prototypes was performed and used to map desired angle inputs into pressure commands. The integrated robotic system allowed both a novice and a skilled surgeon to position the steerable catheter tip at the location of cylindrical targets with sub-millimeter accuracy. The novice was able to reach each target within ten seconds and the skilled surgeon within five seconds on average. This soft robotic system enables its user to simultaneously insert and bend the pneumatically actuated catheter tip with high accuracy and in a short amount of time. These results show promise concerning the development of a soft robotic system that can improve outcomes in minimally invasive interventions.

Towards a Procedure-Optimised Steerable Catheter for Deep-Seated Neurosurgery.

In recent years, steerable needles have attracted significant interest in relation to minimally invasive surgery (MIS). Specifically, the flexible, programmable bevel-tip needle (PBN) concept was successfully demonstrated in vivo in an evaluation of the feasibility of convection-enhanced delivery (CED) for chemotherapeutics within the ovine model with a 2.5 mm PBN prototype. However, further size reductions are necessary for other diagnostic and therapeutic procedures and drug delivery operations involving deep-seated tissue structures. Since PBNs have a complex cross-section geometry, standard production methods, such as extrusion, fail, as the outer diameter is reduced further. This paper presents our first attempt to demonstrate a new manufacturing method for PBNs that employs thermal drawing technology. Experimental characterisation tests were performed for the 2.5 mm PBN and the new 1.3 mm thermally drawn (TD) PBN prototype described here. The results show that thermal drawing presents a significant advantage in miniaturising complex needle structures. However, the steering behaviour was affected due to the choice of material in this first attempt, a limitation which will be addressed in future work.

Soft Multi-Material Magnetic Fibers and Textiles.

Magnetically responsive soft materials are promising building blocks for the next generation of soft robotics, prosthesis, surgical tools, and smart textiles. To date, however, the fabrication of highly integrated magnetic fibers with extreme aspect ratios, that can be used as steerable catheters, endoscopes, or within functional textiles remains challenging. Here, we propose multi-material thermal drawing as a material and processing platform to realize 10s of meters long soft, ultra-stretchable, yet highly resilient magnetic fibers. We demonstrate fibers with a diameter as low as 300μm and an aspect ratio of 105 , integrating nano-composite domains with ferromagnetic micro-particles embedded in a soft elastomeric matrix. With the proper choice of filler content that must strike the proper balance between magnetization density and mechanical stiffness, we show fibers withstanding strains of more than 1000%, that can be magnetically actuated and lift up to 370 times their own weight. The magnetic fibers can also integrate other functionalities like micro-fluidic channels, and be weaved into conventional textiles. We show that the novel magnetic textiles can be washed and sustain extreme mechanical constraints, as well as be folded into arbitrary shapes when magnetically actuated, paving the way towards novel intriguing opportunities in medical textiles and soft magnetic systems. This article is protected by copyright. All rights reserved.

Successful management of the leaflet perforation after the transcatheter edge-to-edge repair procedure using transcatheter occlusion.

A 57-year-old female was diagnosed with chronic heart failure and severe functional mitral regurgitation (FMR) despite guideline-directed medical therapy. An echocardiogram revealed severe mitral regurgitation (MR) (4+) vena contracta width 8 mm with ejection fraction (21%), and no calcification on the annulus and leaflets was noted. Mitral transcatheter edge-to-edge repair (TEER) was attempted for this patient. Transcatheter edge-to-edge repair was done under general anaesthesia with transoesophageal echocardiography (TEE) guidance using a novel designed SQ-Krin TEER system (Shenqi Medical). After transseptal puncture was achieved, a 24F guiding sheath was placed in the left atrium (LA). Then, one LW-size clip (6 mm width with 12 mm arm length) was placed in the A2/P2 region (Panel A). Mitral regurgitation severity was reduced to none (Panel A). However, 20 min after release, TEE revealed a large regurgitant gap (7–8 mm) between the anterior mitral leaflet (AML) and the clip arm with torrential MR (Panels B–D), and clip-induced leaflet perforation was confirmed. Considering the high risk of open-heart surgery, transcatheter occlusion was attempted. A 14F steerable catheter was placed in the LA through the previous puncture site, and the guide wire was placed into the left ventricle (LV) through the tear hole, and then a 14 mm Amplatzer Vascular Plug II (St Jude Medical, Abbott) was implanted through the delivery system to occlude the hole (Panels E and F). Mitral regurgitation was reduced to a mild degree after the procedure (Panels G and H). Post-operative recovery was uneventful and no sign of haemolysis. In the 1-year follow-up, the patient presented good condition with mild MR, and both the clip and the plug were in a stable position (Panel I). Leaflet perforation after the TEER procedure is a rare complication with a poor prognosis, especially for an FMR patient. Other than open-heart surgery, transcatheter occlusion may provide a reliable salvage management option.

Acute success, stability and safety of left bundle branch area pacing with steerable catheter and stylet-driven leads: A single center experience

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Right ventricular apical pacing is associated with adverse outcomes and there is an increasing preference to perform conduction system pacing as it allows for more physiological left ventricular activation. His-bundle pacing is known to be technically challenging and results in higher pacing thresholds and increased rates of lead dislodgement. Left bundle branch area pacing (LBBAP) is an emerging alternative form of conduction system pacing. Purpose We aim to study the acute success rates, short-term stability and safety using steerable catheter and stylet-driven (SD) leads for the purpose of LBBAP. Methods 40 consecutive patients who underwent LBBAP with steerable catheter and SD leads in our center from August 2021 to November 2022 were included in this series. Patients’ demographics, pacing indications, baseline QRS morphologies and duration and left ventricular ejection fraction (LVEF) were analysed. Acute success was defined as achieving stimulation to LV activation time (Stim-LVAT) ≤75ms or incomplete right bundle branch paced morphology in V1 [1, 2]. We also reported any left bundle branch (LBB) potential (if present) and the V6-V1 interpeak interval. All lead parameters and complications in the immediate (1 day) and short-term (1 week and 3-6 months) timeframe were evaluated. Results 40 patients' age (mean 72.75), gender (male 52.5%), body mass index (mean 24.15) and LVEF (mean 52.75%) were analysed. Pacing indications included sinus nodal dysfunction (25%), atrioventricular block (70%), heart failure with failed cardiac resynchronisation therapy (CRT) (2.5%) and atrial fibrillation (AF) requiring atrioventricular node ablation (2.5%). We achieved an acute success rate of 87.5% (5% with left ventricular septal pacing, 5% converted to conventional right ventricular septal pacing, and 2.5% converted to CRT). Reasons for failure to achieve successful LBBAP include persistent left superior vena cava, high pacing thresholds or inability to burrow lead into the septum for acceptable V1 morphology and Stim-LVAT due to resistance encountered during turning of the lead. 51.43% patients of the successful LBBAP patients had LBB potential present and/or interpeak interval >33ms [3]. Immediate and short-term lead parameters were stable and acceptable in all cases. There were no complications (such as lead dislodgement, rise in lead impedance or threshold) reported during the acute and short-term follow-up. Conclusion LBBAP is successful in 87.5% of our cases with use of steerable catheter deploying stylet-driven leads and is proven to be a safe and feasible method for conduction system pacing. Incremental experience with the delivery tools will further improve successful implantation. Longer term follow-up of these patients is needed to determine the long-term safety and stability of LBBAP using steerable catheter and stylet-driven leads.

Zero or near-zero x-ray pacemaker implantation in paediatric patients. dream or reality?

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Transvenous implantation of pacemaker is performed with fluoroscopy for leads’ insertion and implantation in the heart. This implies radiation exposure for patients and operators. Fluoroscopy allows a two-dimensional view of lead movements, and sometimes it is difficult to implant lead in the complex heart anatomy, or in alternative right ventricular (RV) pacing sites, that often requires higher radiation doses. These alternative pacing sites may prevent pacing-induced ventricular dysfunction. They are his bundle pacing area (HBP), ventricular septum close to the conduction system area (VS), RV outflow tract (RVOT). The use of three-dimensional-electroanatomic mapping system (3D-EAM) may reduce fluoroscopy and guide lead implantation. Published median fluoroscopy data for similar procedure are: 6 mGy (1), 13 mGy and 231 microGy/m2 (2). Purpose of this study is to seek out if a 3D-EAM-guided transvenous implantation into RV alternative sites pacing in paediatric patients can be accomplished with zero or near-zero X-rays. Methods Retrospective analysis of children and adolescents with congenital or acquired (idiopathic) complete atrioventricular block (CAVB) without other congenital heart defects who underwent 3D-EAM-guided pacing in alternative RV sites. The implant procedure was divided in 4 steps: 1-contrast venography; 2- 3D mapping: with a steerable catheter (femoral vein), the 3D-EAM acquired geometric reconstruction of the right heart and a pacing map identified RV sites with narrower paced QRS; 3-axillary vein puncture; 4-lead and pacemaker implantation: 3D-EAM guided stylet-directed screw-in lead implantation toward desired RV sites. Data are reported as median (25th-75th centiles). Results 54 CAVB patients (42 females), underwent 3D EAM-guided pacing (27 VVIR, 27 DDD) at age 11.5 (7.7-14) years, weight 42 (26-54) kg. Pacing sites were: 10 HBP, 4 RVOT, 40 VS (Figure 1). Procedure time was 170 (143-193) min, total fluoroscopy exposure and that of the 4 steps are reported in Table 1. The lowest exposures were: 0.2 mGy, 8 microGy/m2 (VVIR) and 0.6 mGy, 15 microGy/m2 (DDD). Paced QRS was 115 (100-120) ms. Conclusions 3D-EAM-guided alternative RV pacing sites was accomplished with very low fluoroscopic exposure, close to zero in some cases. Therefore, with 3D-EAM we can significantly reduce radiological doses also in difficult pacing procedures in paediatric patients, thus reducing radiological risks and preserving ventricular function. The dream is becoming reality.

Coronary sinus cannulation as real time anatomical landmark to facilitate left bundle branch area pacing

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Left bundle branch area pacing (LBBAP) is an established form of conduction system pacing. Innovative fluoroscopic imaging technique with use of radio-opaque contrast in the right ventricle or using pre-mapped His potential has been advocated as an acquired road map to assist in implantation of LBBAP(1) lead. Purpose We aim to explore a different technique by cannulating the coronary sinus (CS) with a sheath and wire to provide real-time anatomical guidance of location of the base of the heart to facilitate more effective LBBAP in a consistent fashion. Methods Prior to LBBAP, the body of the CS is cannulated using an AL2 diagnostic angiographic catheter and a 0.035-inch glidewire. The wire is fixated externally, and fluoroscopic image is acquired before proceeding with deployment of the pacing lead onto an optimal ventricular septal position via standard right (RAO 30) and left anterior oblique (LAO 30) views. From August 2021 to October 2022, we enrolled 12 consecutive patients requiring pacemaker for standard indications and explored the CS cannulation method in delivering LBBAP with either steerable catheters or fixed shape sheaths. Thereafter, we analysed and described the success rates, immediate electrical and device parameters, procedural durations, and clinical events. Results 12 patients were studied. The mean age was 75 ± 13.07 years and 6 (50%) patients were male. 1 (8.3%) was for sinus nodal dysfunction, 10 (83.3%) for atrioventricular block and 1 (8.3%) for atrial fibrillation (AF) control with atrioventricular node ablation. Mean left ventricular ejection fraction was 54.17 ± 8.21 % and baseline QRS was 108.08 ± 23.20ms. LBBAP was successful in all 12 patients based on published criteria with a mean paced QRS duration of 115.25 ± 9.28 ms. The mean total procedure duration was 130.75 +/- 29.84 minutes and mean fluoroscopic duration was 23.17 ± 9.11 minutes. After 1st week post implant, the pacing threshold, sensing, and impedances were stable and acceptable in all the patients. There were no acute complications (e.g. pneumothorax, lead complications, lead dislodgements / perforations) during the periprocedural period. Conclusion(s) The CS cannulation method is a feasible, safe, and effective method to to provide real-time anatomical visualisation of the base of the heart. This facilitates the achievement for optimal LBBAP and can be adopted especially in difficult cardiac anatomies or rotated cardiac silhouettes identified on fluoroscopy.

Augmented Reality Improves Learning Curve of Endovascular Navigation

Intra-Operative Positioning System (IOPS) (Centerline Biomedical, Cleveland, OH) is a 3D electromagnetic (EM) endovascular navigation system approved by the US Food and Drug Administration and developed as an adjunct to fluoroscopy. It provides real-time 3D display of sensorized material on an anatomical map on a flat screen. An investigational prototype based on IOPS incorporates the ability to map implanted stent grafts and visualize the stents and anatomy using augmented reality headset. The aim of this study was to compare the completion of bifurcated stent graft gate cannulation performed by participants of varying experience using fluoroscopy or different variations of IOPS. The task was cannulation of the gate of a bifurcated aortic endograft deployed into a 3D printed abdominal aortic aneurysm model connected to flow pump reproducing physiological conditions, performed in a hybrid operating room (GE Allia IGS 7). Each participant performed the tasks with fluoroscopy, EM guidance with flat screen display (EM-FS), and EM guidance with augmented reality headset (EM-AR) (Fig 1), in randomized order. All participants used the same sensorized guidewire and steerable sensorized 6F catheter for the three runs. Participants were classified in three groups of experience. Primary end points included cannulation time and technical success, defined as the advancement of the catheter over the guidewire within the graft main body. Fifteen minutes was the cutoff time for each trial. There were 26 participants including 13 endovascular naïve trainees (group 1), 12 in training surgeons (group 2) and one advanced level vascular surgeon. In group 1, mean cannulation time was lower using EM-AR versus fluoroscopy (4.3 ± 4.4 vs 7.1 ± 4.9 minutes; P = .04), with no difference between EM-FS and fluoroscopy (6.3 ± 4.5 vs 7.1 ± 4.9 minutes; P = .63). In group 1, technical success was 77% with fluoroscopy and 92% with both EM modalities (P = .59). In group 2, there was a trend toward shorter times with EM-FS or EM-AR as compared to fluoroscopy (mean of 2.5 ± 0.9, 4.4 ± 4.0 and 5.2 ± 4.5 minutes, respectively). In group 2, technical success was 92% with fluoroscopy and 100% with IOPS (P > .99). The advanced level vascular surgeon repeated the cannulation task four times for each endovascular approach, with 100% technical success and no difference in mean time (P = .89) (Fig 2). Augmented reality allows for reducing the gate cannulation time as compared to fluoroscopy in participants with no previous experience in endovascular navigation. This auspicious finding suggests that augmented reality can be beneficial for individuals early in their career and can mitigate the learning curve.Fig 2Mean cannulation times of bifurcated stent graft gate cannulation using electromagnetic (EM) guidance with flat screen display or augmented reality compared to fluoroscopy, performed by operators of varying experience.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

PO-01-081 EPICARDIAL PHRENIC NERVE DEFLECTION DURING SINUS NODE MODIFICATION

Endocardial catheter ablation for sinus node modification may be difficult due to right phrenic nerve location and risk of injury. Various strategies to displace the phrenic nerve from target ablation sites have been described previously, including saline infusion and balloon catheter insufflation, all within the epicardial space. To describe a strategy to avoid phrenic nerve injury during endocardial catheter ablation for sinus node modification using a steerable catheter. N/A A 33-year-old female with a history of Behcet’s disease and AF ablations but otherwise without structural heart disease developed symptomatic inappropriate sinus tachycardia (IST) recorded on her loop recorder. Her IST was refractory to multiple drugs including flecainide, sotalol, dofetilide, and ivabradine. She had previously undergone catheter ablation for sinus node modification, which was limited due to proximity of the phrenic nerve near the intended ablation target. She presented for a repeat catheter ablation with planned epicardial access for sinus node modification. The patient presented to the EP lab in sinus rhythm with rates in the 60s. Endocardial and epicardial access were obtained under general anesthesia. The ablation catheter was advanced into the superior vena cava and right atrium, and the IST activation map during isoproterenol infusion and sites of phrenic capture were annotated (Figure A). Using a steerable sheath and a non-irrigated 4mm catheter via the epicardial access, the phrenic nerve was deflected away from the sinus node. The proximity between the endocardial and epicardial catheters was confirmed on fluoroscopy (Figure B). The phrenic nerve was checked before and after each ablation lesion. A total of 11 lesions at 30W with target contact >10 grams and target impedance drop >10 ohms was delivered for a total of 333 seconds (Figure C). Following endocardial catheter ablation, her resting sinus rates decreased to 50s. Isoproterenol infusion challenge before and after the ablation revealed blunted response in her heart rate. Her phrenic nerve remained intact with appropriate diaphragm stimulation. The patient was resumed on sotalol and discharged. Endocardial catheter ablation for IST sinus node modification may be challenging due to the phrenic nerve. Epicardial access for phrenic nerve deflection may be required.