Delivery Catheter Research Articles

Testing radiofrequency energy delivery and catheter entrapment in three left ventricular assist device models in mock circulation

Abstract Funding Acknowledgements Type of funding sources: None. Background The use of Left Ventricular Assist Devices (LVAD) as a bridge to heart transplantation (HTx) or as a destination therapy is increasing. Near half of the patients had ventricular arrhythmias (VA) in the first year of LVAD support. Ablation is common method for recurrent ventricular tachycardias in LVAD patients. Even there are many case reports about successful VT ablations in LVAD patients there is no report about consequences of RF energy delivery inside LVAD or ablation catheter contact – entrapment to the rotor of the LVAD. Method Mock circulation models were created for three mostly used LVAD models ( Figure 1) (HeartMate3, HeartMate2, HVAD) Sheep heart was located inside the mock circulation model and 4mm non-irrigated RF ablation catheter and RF generator used for RF energy delivery tissue ( sheep heart) , ostium, mid and rotor of the LVAD)(Figure 1). During RF delivery flow parameters of the LVAD systems were noted also external noncontact flow monitor located out flow canula of the LVAD. All LVADs out flows were tested for 24 hours after RF energy delivery for long term malfunction. Also RF ablation catheters were tested for mechanical and functional disfunctions after contact of the LVAD rotors. Results No malfunctions were observed during and after RF energy delivery inside the LVADs. Only LVAD flow parameters temporary decreased in HeartMate 3 when the catheters had a contact to the rotor of the LVAD. This phenomenon occurred irrespective of RF energy delivery status. There were no changes in HVAD and Heartmate 2. After 24 hours continuous testing of the flow of the LVADs any changes were not observed . Impedance changes were noticed during RF energy delivery. Impedance values were dropped when RF catheter moved from tissue to the ostium of the LVAD in all models. Small increases observed during contact to the rotor of the LVAD in HeartMate 3 ( Figure 2). No mechanical damage were observed on the tip of the catheters after contact to the rotors also RF lesion dimensions were compared before and after the contact and there were no differences. Conclusion RF energy delivery and catheter entrapment of the RF catheters to the rotors of the LVADs caused no changes in LVAD functioning in ex-vivo conditions in a mock circulation.

Shape memory polymer technology in peripheral vascular embolization.

Porous, radiolucent, shape memory polymer is a new technology available in discrete peripheral vascular embolization devices. Shape memory polymers can exist in two stable shapes; crimped for catheter delivery and expanded for vessel embolization. The expanded shape memory polymer in these new devices is hemostatic, and the porous polymeric scaffold has been shown to support tissue ingrowth and eventually bioabsorbs in preclinical animal studies. This report describes clinical experience with this novel material in vascular plug devices. a prospective, single-arm, safety study at a single center in New Zealand with longer term follow-up via retrospective imaging review. The study device was a pushable shape memory polymer vascular plug with a distal nitinol anchor coil and a proximal radiopaque marker. Ten male patients were each implanted with a single shape memory polymer vascular plug. Three inferior mesenteric arteries and an accessory renal artery were embolized during endovascular aneurysm repair. An internal iliac artery was treated prior to the open surgical repair of aorto-iliac aneurysms. An internal iliac artery and a subclavian artery were embolized to treat/prophylactically address potential endoleaks. A profunda branch was embolized prior to tumor resection, and two testicular veins were embolized to treat varicoceles. Acute technical success of target vessel embolization was achieved in all implantation cases. Patients were followed for 30days as part of the study, and no serious adverse events with a relationship to the study device occurred. No recurrent clinical symptoms attributable to treated vessel embolization or recanalization were documented. There was no evidence of recanalization on retrospective review of follow-up imaging through a mean of 22.2months (range, <1-44months) post-procedure. Shape memory polymer vascular embolization devices were safe and effective over the follow-up period of this small safety study. Further experience and longer term follow-up will assess further applicability.

MP-453087-3 REMOVAL OF A CHRONICALLY-IMPLANTED MICRA LEADLESS VENTRICULAR – SINGLE CENTER EXPERIENCE

Leadless cardiac pacemakers (LPs) are an effective and safe alternative to transvenous pacemakers for single-chamber ventricular pacing. However, the feasibility of retrieving and replacing chronically implanted LPs is not well understood. We report an unique single center series of chronically implanted MICRA TPS™ leadless pacemakers. Since 2014 there were 227 MICRA LP devices implanted successfully to the right ventricle (RV) position. In 8 patients with average time of 685 ± 373 days retrieval procedure was indicated. The main indication for LP extraction was: a) pacemaker syndrome; b) battery depletion (in two patients together with WiSE EBR left ventricle (LV) co-implant); c) needs to upgrade VVI pacing for resynchronization therapy with LV systolic dysfunction. In all 8 patients we used MICRA delivery catheter with single loop 7 mm snare inserted into the central lumen of the original delivery catheter. Besides fluoroscopy we guided the retrieval procedure with intracardiac echocardiography (ICE). The retrieval procedure was successful in 7 out of 8 petients (87,5%). Average time of the index retrieval procedure was 118 ± 27 minutes and average fluoroscopy time was 26.6 ± 10.5 minutes. In the case with retrieval procedure failure (348 days after implant) we couldn’t snare the docking bottom of the device. In rest of the cases where we were able to snare it and connect with the delivery catheter cap, we were able to reach the insertion of the LP to the tissue and apply contratraction force with 100% success. When we analysed ICE images, the LP retrieval failure was associated with massive tissue overgrow around the device capsule. In 6 patients new MICRA TPS™ LP was implanted with excellent pacing parameters and optimal sensing and impedance during the same procedure. In one patient we implanted CRT-D transvenous system due to LV dysfunction. This series demonstrates the feasibility of retrieval of even long-term chronically-implanted MICRA LPs. The dedicated retrieval system for LPs with anchors will be of interest when we can consider needs to exchange of LPs specifically in younger patients.

PO-05-014 SUCCESSFUL IMPLANTATION OF A MICRA LEADLESS PACEMAKER THROUGH THE LEFT SUBCLAVIAN VEIN IN A PATIENT WITH SITUS AMBIGUOUS

Primary ciliary dyskinesia patients often have situs ambiguous, a congenital condition with abnormal arrangement of visceral organs in the abdomen and chest. It is associated with an increased risk of congenital heart defects and anomalous venous connections. As a result, placement of the leadless pacemaker through the femoral approach may not be viable in these patients. Herein we describe a successful placement of a leadless pacemaker through the left subclavian approach in a patient with primary ciliary dyskinesia with associated interrupted IVC, right internal jugular (RIJ) thrombus, failed epicardial pacers, and extraction of infected transvenous pacer. N/A A 36-year-old female with primary ciliary dyskinesia, situs ambiguous, RIJ thrombus, and azygous venous connection presents with paroxysmal atrial fibrillation, sinus node dysfunction and syncope (A); History of multiple pacemakers, including failed epicardial pacer, substance abuse and recurrent bacteremia with multiple transvenous pacer infections requiring extractions. Ultrasound access was gained in the left subclavian vein via the modified Seldinger technique. Access was serially dilated until a 23Fr dilator. A manual curve was applied to the tip of the Micra-introducer sheath and the long 27Fr hydrophilic micra-introducer sheath was advanced over a Lunderquist wire, using a stiff rail, into middle of the right atrium (B). The 105 cm Micra delivery catheter was inserted into the sheath, and advanced with fluoroscopic guidance into the right atrium. The introducer sheath was pulled back into the SVC and the delivery catheter was counter-clocked, flexed downward and advanced across the tricuspid valve. The pacemaker was directed to the midseptal position. Contrast was injected to verify positioning against the myocardium (C). The device was deployed with satisfactory parameters noting R waves of 12mV and threshold less than 1V at 0.24 msec pulse with. The pacer was then released with tugging testing confirming adequate deployment. (D). The patient was discharged safely home 2 days later. The left subclavian vein is a viable and safe approach for placing the Micra leadless pacemaker.

PO-01-006 CHRONIC SAFETY AND EFFICACY OF A NOVEL BASKET PFA CATHETER IN A SWINE MODEL

Pulsed Field Ablation (PFA) is an emerging and promising form of catheter ablation for the treatment of arrhythmias. Open questions remain regarding the optimal magnitude & composition of energy delivery, electrode designs, chronic lesion performance and various safety aspects. We report on first animal data from a Novel PFA Catheter in a chronic Swine Model. Six animals were treated with a novel variable diameter, 8 spline basket, PFA, Bi-D catheter & survived for 30 days. Three veins per animal (18 total, 5 LSPV, 6 RSPV, 3 CIPV, 4 SVC) were treated with R-wave gated PFA using only 2 applications per vein with repositioning in each animal. Catheters were visualized using EnSite X & fluoroscopy. Entrance and exit block techniques were used to assess Pulmonary vein isolation at ≥30 minutes & 30 days post therapy (Tx) with a diagnostic loop (Advisor VL) & or ablation (TactiCath SE) catheter. PV stenosis was assessed using venograms with contrast from 2 views at each of the treatment sites prior to Tx & Tx+30 days in 4 animals (12 veins). Phrenic nerve function by threshold pacing (∼≤2mA, 2ms) in high SVC was assessed and fluoroscopic assessment of spontaneous diaphragm motion was conducted after Tx (N=4) & at 30 days (all). Hematoxylin & eosin, Masson’s trichrome, and S100 or Luxol fast blue (nerve) stained sections of treatment sites & collateral tissues were evaluated. PFA catheter bipole EGMs showed voltage elimination during & immediately post PFA Tx consistent with EAM post voltage maps. Functional block was seen in 18 veins (100%: 5 LSPV, 6 RSPV, 3 CIPV, 4 SVC) at Tx+30 Min & 17 veins at Tx+30 Days (94%: 4 LSPV, 6 RSPV, 3 CIPV, 4 SVC). No acute sustained arrhythmias requiring pacing were induced during PFA Tx. No venous stenosis was observed (n=0/12). All animals were recovered with intact phrenic nerve function & symmetric diaphragm motion confirmed at 30 Days. Histopathology of representative sections from all vein Tx sites revealed transmural fibrotic lesions in all but a section from the LSPV without chronic entrance block. Normal histologic architecture was also seen in sections from phrenic nerve & esophagus with no evidence of collateral ablation lesions or tissue alteration. This novel PFA delivery catheter & PFA waveform enabled electrophysiologic & histologic confirmation of chronic PV isolation with a minimum number of PFA applications, favorable usability & an optimal safety profile.

Actual conditions of atrial septal lead implantation and the factors related to successful implantation

BackgroundPacemaker leads were originally implanted into the right atrial appendage (RAA) and right ventricular apex, but septal pacing, which is more physiological, is becoming increasingly popular. The usefulness of atrial lead implantation in the RAA or atrial septum is inconclusive, and whether or not atrial septum implantation is accurate has not yet been verified. MethodsPatients who underwent pacemaker implantation between January 2016 and December 2020 were included. The success rate of atrial septal implantation was validated using thoracic computed tomography performed for any reason postoperatively. We examined factors related to the successful implantation of the atrial lead in the atrial septum. ResultsForty-eight people were included in this study. Lead placement was performed with a delivery catheter system (SelectSecure MRI SureScan; Medtronic Japan Co., Ltd., Tokyo, Japan) in 29 cases and a conventional stylet in 19 cases. The mean age was 74 ± 12 years old, and 28 (58%) were male. Successful atrial septal implantation was performed in 26 patients (54%), with only 4 (21%) successful implantations in the stylet group. There were no significant differences in the age, gender, body mass index (BMI), pacing P wave axis, duration, or amplitude between the atrial septal implantation group and non-septal groups. The only significant difference was for delivery catheter use [22 (85%) vs. 7 (32%), p < 0.001]. In multivariate logistic analysis, the use of a delivery catheter was independently associated with successful septal implantation [odds ratio (OR): 16.9, 95% confidence interval 3.0–90.9] after adjusting for the age, gender, and BMI. ConclusionThe success rate of atrial septal implantation was very low at 54%, and only the use of a delivery catheter was associated with successful septal implantation. However, even with a delivery catheter, the success rate was 76%, so further investigations are warranted.

Transcatheter heart valve commissural alignment: an updated review.

Transcatheter aortic valve replacement (TAVR) indications recently extended to lower surgical risk patients with longer life expectancy. Commissural alignment (CA) is one of the emerging concepts and is becoming one of the cornerstones of the TAVR procedure in a patient with increased longevity. Indeed, CA may improve transcatheter heart valve (THV) hemodynamics, future coronary access, and repeatability. The definition of CA has been recently standardized by the ALIGN-TAVR consortium using a four-tier scale based on CT analysis. Progress has been made during the index TAVR procedure to optimize CA, especially with self-expandable platforms. Indeed, specific delivery catheter orientation, THV rotation, and computed-tomography-derived views have been proposed to achieve a reasonable degree of CA. Recent data demonstrate feasibility, safety, and a significant reduction in coronary overlap using these techniques, especially with self-expandable platforms. This review provides an overview of THV CA including assessment methods, alignment techniques during the index TAVR procedure with different THV platforms, the clinical impact of commissural misalignment, and challenging situations for CA.

Separable and Recombinable Magnetic Robot for Robotic Endovascular Intervention

This study presents a separable and recombinable magnetic robot (SRMR) to deliver and retrieve an untethered magnetic robot (UMR) to a target vascular lesion safely and effectively for robotic endovascular intervention. The SRMR comprises a delivery catheter and UMR connected to the end of the delivery catheter by a connecting section. An external magnetic field (EMF) interacts with the permanent magnet of the UMR; it can effectively generate magnetic torque and steer the delivery catheter to reach a target lesion. Furthermore, the rotating EMF allows the UMR of the SRMR to separate from the delivery catheter and perform the tunneling task. After completing the tunneling task, the UMR can be safely recombined with the delivery catheter in the vasculature via a simultaneous application of the EMF and suction force to the delivery catheter. The SRMR functions of steering, separation, movement, tunneling, drug delivery, and recombination are validated in a mimetic vascular model with a pseudo blood clot. Finally, the SRMR is successfully validated in an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vivo</i> experiment of a mini pig's superficial femoral artery for contrast delivery, separation, movement, and recombination.

Identification of the Position of a Tethered Delivery Catheter to Retrieve an Untethered Magnetic Robot in a Vascular Environment.

In this paper, we propose a method of identifying the position of a tethered delivery catheter in a vascular environment, recombining an untethered magnetic robot (UMR) to the tethered delivery catheter, and safely retrieving them from the vascular environment in an endovascular intervention by utilizing a separable and recombinable magnetic robot (SRMR) and a magnetic navigation system (MNS). From images of a blood vessel and a tethered delivery catheter taken from two different angles, we developed a method of extracting the position of the delivery catheter in the blood vessel by introducing dimensionless cross-sectional coordinates. Then, we propose a retrieval method for the UMR by using the magnetic force considering the delivery catheter's position, suction force, and rotating magnetic field. We used thane MNS and feeding robot to simultaneously apply magnetic force and suction force to the UMR. In this process, we determined a current solution for generating magnetic force by using a linear optimization method. Finally, we conducted in vitro and in vivo experiments to verify the proposed method. In the in vitro experiment, which was in a glass tube environment, by using an RGB camera, we confirmed that the location of the delivery catheter in the glass tube could be recognized within an average error of 0.05 mm in each of the X- and Z-coordinates and that the retrieval success rate was greatly improved in comparison with that in the case without the use of magnetic force. In an in vivo experiment, we successfully retrieved the UMR in the femoral arteries of pigs.

Abstract Number ‐ 172: First‐in‐Human Experience: Route 92 Medical 132 cm FreeClimb 88 Catheter for Anterior Circulation LVOs

Introduction Direct aspiration thrombectomy of proximal anterior circulation large vessel occlusions (LVOs) with super‐bore catheters (SBCs, 0.088” ID) may result in improved first pass success, though their consistent delivery to the target occlusion remains challenging. We report the first‐in‐human experience with a novel full‐length 132 cm 0.088” ID FreeClimb ® 88 catheter (Route 92 Medical, San Mateo, CA, currently approved for neurovascular access), and its customized Tenzing ® 8 delivery catheter, for anterior circulation LVO acute stroke patients. Methods We performed a retrospective review of thrombectomy cases for proximal anterior circulation large vessel occlusions performed at three stroke centers from May 2022 through August 2022. All patients were treated using the Route 92 Medical 8F Base Camp® guide catheter, FreeClimb ® 88 catheter and Tenzing ® 8 delivery catheter in an off‐label fashion. Results Ten consecutive acute stroke patients with anterior circulation LVOs were treated. The median age was 71 (45‐91) and 6 were female (60%). The median presenting NIHSS score and ASPECT score were 17 (8‐24) and 9 (6‐10), respectively. LVO locations were as follows: two right carotid termini, three right M1 middle cerebral arteries, and five left M1 middle cerebral arteries. Three patients also had tandem occlusion/near‐occlusion of the respective cervical internal carotid artery. The FC88 catheter was delivered to the target occlusion with 100% success. The median time from groin puncture to catheter delivery to the target occlusion was 14 minutes (7‐35). First pass complete reperfusion (modified Thrombolysis in Cerebral Infarction score, mTICI, of 3) was achieved in 9/10 (90%) patients (self‐adjudicated). Adjunctive therapy for a residual M2 occlusion was utilized in 1/10 patients. There were no adverse events or post‐procedural symptomatic hemorrhages. Conclusions Our first‐in‐human experience with a novel 132 cm full‐length super‐bore catheter (Route 92 FreeClimb ® 88 catheter) and its customized catheter delivery device (Tenzing ® 8) for aspiration thrombectomy of proximal anterior circulation large vessel occlusions demonstrated 100% successful delivery to the target occlusion, with TICI 3 first pass reperfusion achieved in 90% of patients.

Abstract Number ‐ 37: A Clinical Multicenter Experience of Novel Tenzing Delivery Catheter for Thrombectomy in Acute Stroke

Introduction Mechanical thrombectomy has become the standard of care to treat acute ischemic stroke patients with large vessel occlusions. Device performance and physician technique have developed since early trials proving the efficacy of the procedure1‐3. One of these techniques, direct aspiration first pass technique (ADAPT)4involves navigating a large‐bore catheter to the face of the clot and initiating suction. Navigating large‐bore catheters through intracranial neurovasculature has been accomplished using microcatheters and/or guidewires. Due to the large sizes of these aspiration catheters, the microcatheters used to help deliver the aspiration catheters into the brain form a “ledge” between the disparate lumens and prevent progression of the aspiration catheter into the distal neurovasculature and increase the risk of damaging arteries during advancement. A novel navigation support catheter, the Tenzing Delivery Catheter, has shown promising benchtop performance assisting large‐bore aspiration catheter delivery to the occlusion sitein vitro5. It demonstrated superior performance over traditional microcatheter/guidewire techniques in delivering the aspiration catheter to the occlusion in this model. While limited initial clinical experience from examining a small sample group appears to confirm this observation, a cumulative, large‐scale analysis of experience using the Tenzing catheter in clinical practice to further examine its safety, efficacy, and usability has not yet been performed. With that in mind, this study serves as an initial multicenter first‐experience investigation to assess the aforementioned factors and determine the utilization potential of Tenzing catheters. Methods This study was conducted via retrospective chart review across three institutions. Patients included in the study are 18 years old or older, underwent a thrombectomy procedure between January 1, 2020 and July 31, 2022, and whose procedures involved the use of the Tenzing delivery catheter system. Our primary outcome measures were success in delivering aspiration catheter, post treatment thrombus, and perioperative complications. Results In our sample size of n = 95, inclusive of patients from multiple institutions, it was found that in 96% of cases, the Tenzing catheter was successfully delivered to the occlusion site and successful reperfusion (mTICI less than or equal to 2b) was achieved in 90% of cases.In the majority of cases, the Tenzing delivery catheter was used to deliver an aspiration catheter to a middle cerebral artery occlusion (75%). Tenzing was advanced past the occlusion location (identified as the angiographic limit of contrast) in 59% of cases. Secondary emboli were observed 11% of the time. Other procedural complications were observed in 8% of patients while none was seen in 74%. On average, the median NIHSS decreased from 17 pre‐treatment to 10 post‐treatment. Conclusions Based on these findings, we conclude that the Tenzing Delivery Catheter is a safe and efficacious instrument in thrombectomy procedures. Given its high rate of revascularization and delivery success with few complications as demonstrated in this multicenter study.Future studies with larger patient volume are necessary to evaluate this important delivery catheter as it is used more frequently around the world.

Contemporary Outcomes Following Transcatheter Edge-to-Edge Repair: 1-Year Results From the EXPAND Study

BackgroundThe third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system was introduced to assist in leaflet grasping with the longer clip arms of MitraClip XTR and to improve ease of use with the modified delivery catheter. ObjectivesThe EXPAND study evaluated contemporary real-world outcomes in subjects with mitral regurgitation (MR) treated with the third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system. MethodsEXPAND is a prospective, multicenter, international, single-arm study that enrolled patients with primary MR and secondary MR at 57 centers. Follow-up was conducted through 12 months. Echocardiograms were analyzed by an echocardiographic core laboratories. Study outcomes included: MR severity, functional capacity measured by New York Heart Association functional class, quality of life measured by Kansas City Cardiomyopathy Questionnaire, heart failure hospitalizations, all-cause mortality. Results1,041 patients were enrolled from April 2018 through March 2019, of which 50.5% had primary or mixed etiology. Implant success was 98.9%; 1.5 ± 0.6 clips were implanted per subject. Significant MR reduction from baseline (≥MR 3+: 56.0%) to 30 days (≤MR 1+:88.8%) was maintained through 1 year (MR ≤1+: 89.2%). A total of 84.5% and 93.0% of subjects in primary MR and secondary MR, respectively, had ≤1+ MR at 1 year. Significant improvements were observed in clinical outcomes (New York Heart Association functional class I/II in 80.3%, +21.6 improvement in Kansas City Cardiomyopathy Questionnaire score) at 1 year. All-cause mortality and heart failure hospitalizations at 1 year were 14.9% and 18.9%, respectively, which was significantly lower than previous studies. ConclusionsThe study demonstrates treatment with the third-generation system resulted in substantial reduction of MR in a contemporary real-world practice, compared with the results of earlier EVEREST and COAPT trials.(The MitraClip® EXPAND Study of the Next Generation of MitraClip® Devices [EXPAND]; NCT03502811)

Levofloxacin impregnation and extended release: Concentration model for insulin catheters

Increasing the lifetime of percutaneous insulin delivery catheters to minimize painful needle sticks increases the risk of infection. To combat surface-adherent bacteria and potential biofilm formation, we developed a method to impregnate levofloxacin antibiotic into the outer polymer of the catheter so that it can leach into the external medium. Complementarily, we developed a method to quantify the concentration of antibiotic to ensure the minimum inhibitory concentration (MIC) is maintained throughout the duration of catheter use. Additionally, we have investigated the extent of antibiotic resistance after a zwitterionic nonfouling coating treatment to ensure suitable release after further surface modification. Levofloxacin was incorporated into the catheter through the swelling of the outer polyurethane of the bilayer catheter and subsequent solvent evaporation. The zone of inhibition was measured over time with S. epidermidis on LB agar plates. The release of levofloxacin was measured using optical absorbance spectroscopy in water and quantified against a linear standard curve at 292 nm. We developed a model using Fick's second law of diffusion to calculate the concentration around the catheter. Visible inhibition of bacterial growth and biofilm formation was shown for up to 38 days. A total of 8–45 µg of antibiotic was released over 26 days and a concentration of 820,000 µg/mL in the 0.17 µL control volume was reached at day 26 for the minimally-loaded samples, an amount many orders of magnitude greater than the MIC. After the nonfouling treatment, the lowest concentration reached was 16 µg/mL after 26 days. In conclusion, we have demonstrated a suitable method to induce antibacterial activity for insulin catheters, maintain the MIC, and sustain antibacterial character following further surface coatings.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Removal of a leadless pacemaker using a 2.5cc syringe and silk thread during surgical treatment of infective endocarditis

Removal of a leadless pacemaker using a 2.5cc syringe and silk thread during surgical treatment of infective endocarditis

Cervical catheter placement leads to improved rostral distribution of a radiolabeled 18F-baclofen analog in cynomolgus monkeys

BackgroundIntrathecal (IT) catheter delivery of baclofen via continuous infusion using an implantable pump is an important means of treating patients with severe spasticity. We evaluated the impact of IT catheter tip placement (upper vs. lower) on brain and spine distribution of a radioactive tracer molecule.MethodsCynomolgus monkeys were implanted with an IT catheter, with the distal tip located at either C1 or T10 and attached to an implanted continuous infusion pump. A radioactive tracer molecule, an 18F-baclofen analog, and PET imaging were utilized to observe tracer distribution and quantitate levels of tracer in both the brain and spine according to catheter tip location.ResultsIt was consistently determined that a high cervical (C1) catheter tip placement resulted in both more rapid distribution and higher concentrations of radiotracer in the brain and upper spine compared with lower thoracic (T10) during the first 6 hours of infusion.ConclusionsThese results indicate that delivery of 18F-baclofen by IT catheter results in repeatable proportional distribution within regions of the brain and spine. The data also suggest that the greatest exposure to the brain and cervical spinal cord occurs when the catheter tip is located at the first cervical vertebra.

Left ventricular lead delivery system used to implant right ventricular lead via persistent left superior vena cava.

Left ventricular lead delivery system used to implant right ventricular lead via persistent left superior vena cava.

Effect of Early Balloon Inflation of Balloon Guide Catheter in Mechanical Thrombectomy for Large Vessel Occlusion.

A balloon guide catheter (BGC) is widely used in mechanical thrombectomy (MT). However, the balloon inflation timing of BGC has not been clearly established. We evaluated whether balloon inflation timing of BGC affects the results of MT. Patients who underwent MT with BGC for anterior circulation occlusion were enrolled. Patients were dichotomized into early and late balloon inflation groups, according to the timing of BGC inflation. Angiographic and clinical outcomes were compared between the two groups. Multivariable analyses were performed to evaluate the predictive factors for first-pass reperfusion (FPR) and successful reperfusion (SR). Of 436 patients, the early balloon inflation group showed a shorter procedure time (21 min [11-37] vs. 29 min [14-46], P = 0.014), a higher rate of SR with aspiration only (64.0% vs. 55.4%, P=0.016), a lower aspiration catheter delivery failure rate (11.1% vs. 19.4%, P = 0.005), less frequent technique conversion (36.0% vs. 44.5%, P = 0.009), higher rate of FPR (58.2% vs. 50.2%, P = 0.011), and a lower rate of distal embolization (7.9% vs. 11.7%, P = 0.006), compared to the late balloon inflation group. In multivariate analysis, early balloon inflation was an independent predictor for FPR (odds ratio, OR 1.53, 95% confidence interval, CI 1.37-2.57; P = 0.011) and SR (OR 1.26, 95% CI 1.18-1.64; P = 0.018). Early balloon inflation of BGC enables an effective procedure than late balloon inflation. Early balloon inflation was associated with higher rates of FPR and SR.

A feasible and safe standardized protocol for ultrasound and intracavitary electrocardiogram-based tip navigation and tip location during placement of peripherally inserted central catheters.

Peripherally inserted central catheters (PICCs) are performed for medium and long term intravenous therapy. The most recent guidelines recommend the use of ultrasound-guided venipuncture to reduce surgery-related complications. In recent years, bedside ultrasound has also been used as evidence of accuracy in tip navigation and tip positioning. This paper is aimed to investigate using tip navigation with the ultrasonic technique and intracavitary electrocardiogram during the catheterization, and to suggest a feasible and safe standardized protocol for clinical practice. A total of 1727 tumor clients who suffered from combined the ultrasonic technique with intracavitary electrocardiogram (ECG + US group) to confirm the tip location of PICC were included in Peking Union Medical College Hospital in 2020. And based on electronic medical records according to the types of cancer as 1:1 to select 1727 cases who only underwent electrocardiogram (ECG group) to verify the tip location of catheters with the same team in 2019. Compared two groups of purpose of catheter, insertion site of upper limbs, times of puncture and delivery catheters, tip location and malposition of peripherally inserted central catheter, and analysis of the safety and feasibility. There were no significant differences between the two groups in the purpose of catheter, insertion site of upper limbs, times of puncture, and delivery catheters. The percentage of optimal tip location in ECG + US group was significantly higher than that in ECG group, and the rate of malposition of catheters was obviously lower than that in ECG group (p < 0.001). Tip navigation based with ultrasound and intracavitary electrocardiogram has high accuracy to confirm tip location of PICC, and it is also feasible and safe, which can not only to make up for the deficiency of patients without surface P waves who could not be applied ECG but also to fit for all patients.

457 CORONARY ROTATIONAL ATHERECTOMY AFTER TAVI: A PROCEDURAL CHALLENGE

Abstract Background Selective cannulation must be ensured especially in patient with coronary artery disease (CAD). Commissural alignment in self-expanding transcatheter heart valve (THV) is fundamental to facilitate subsequent coronary reaccess. Clinical Scenario A man of 84 years old, suffering from hypertension, dyslipidemia, diabetes mellitus, third stage of chronic kidney disease and obesity was admitted in our hospital for treatment. He had angina and dyspnea with a third NYHA class. The echocardiogram showed severer aortic stenosis with mean gradient of 48 mmHg and aortic valve area of 0.6cmq with preserved ejection fraction. He was eligible for transfemoral transcatheter aortic valve implantation (TAVI) and he had intermediate risk score. The preprocedural coronary angiogram revealed subocclusive and severe calcified lesion on mid circumflex artery. Methods The Acurate NEO 2 size L THV was chosen and was planned to implant the bioprosthesis with commissural orientation correlated to the native commeasures, selecting at the CT scan the projection of cusp overlap (right and left coronary cusp on the right of the screen). The delivery catheter was inserted into the introducer sheath with its flush port facing the six o’clock position and the after crossing the aortic arch and native annulus, the handle of the delivery catheter was torqued clockwise until 1 of the Acurate NEO 2 commissural posts faced the commissural of the aortic root. The final angiogram showed optimal position and orientation of the THV without paravalvular leak. The patient was discharged the next day with a mean gradient of 9mmHg. One month after TAVI, elective PCI was performed. We’ve prepared the lesion with rotational atherectomy, due to severe calcification. Three forward advancements of rotating abrasive burr was performed and subsequently one DES was implanted. The angiogram check showed excellent result with TIMI 3 flow. Conclusion The Acurate Neo 2 supra-annular valve platform provides a successful coronary cannulation. Coronary rotational atherectomy for severe calcified lesions after TAVI with Acurate Neo 2 is a feasible strategy