Ventricular Fibrillation Cardiopulmonary Arrest Following Micra™ Leadless Pacemaker Implantation.

Leadless cardiac pacemakers such as the Micra™ transcatheter leadless pacing system (Medtronic, Minneapolis, MN, USA) are an alternative to traditional transvenous pacemakers. Implantation of leadless pacemakers, albeit safe, may be associated with complications, including cardiac tamponade; high capture thresholds; and, rarely, ventricular arrhythmias. We report a case of ventricular fibrillation arrest following the implantation of a Micra™ leadless pacemaker.

Body Piercing with a Metallic Tongue Stud Resulting in Ineffective Implantable Cardioverter-defibrillator Shocks: "Heart to Mouth".

Left ventricular assist devices (LVADs) provide circulatory support to patients with severe left ventricular systolic dysfunction. Many such patients have a pre-existing implantable cardioverter-defibrillator (ICD) at the time of their LVAD surgery. LVAD implantation can alter the ICD lead parameters, including R-wave sensing, right ventricular capture threshold, and impedance. These changes can in turn affect the ability of the ICD to successfully treat malignant ventricular arrhythmias. In most patients who present with ineffective ICD shocks, the failed shock is assumed to be secondary to the patient's severe cardiomyopathy. Especially, the role of physical examination in such patients is often minimized. In our patient, a thorough history-taking and history-guided physical examination led us to the root cause of the failed ICD shocks. Our patient was noted to have a metal tongue piercing, which was the likely cause of his ineffective ICD shocks. Our case highlights the importance of a comprehensive history-taking and physical examination.

Cryoballoon Ablation for Persistent Atrial Fibrillation in a Patient with a Left Pneumonectomy.

Pulmonary vein (PV) isolation (PVI) is the most important component of catheter ablation of atrial fibrillation (AF) and can be achieved by radiofrequency or cryoballoon ablation (CBA). The CBA system has shown excellent efficacy and safety in a number of clinical trials and is independent of the PV anatomy. However, pneumonectomy can significantly alter the anatomy posing a challenge to CBA. Few cases of PVI accomplished by CBA have been described in patients with lobectomy, but none in the pneumonectomy population. We describe a case of successful CBA for paroxysmal AF in a patient with a left total pneumonectomy.

Azygous Vein Coil Implantation in Left Ventricular Assist Device Patients: A Hands-on Approach.

Recently, there have been reports of left ventricular assist device (LVAD) patients presenting with multiple ineffective implantable cardioverter-defibrillator (ICD) shocks. In such patients, the placement of an azygous vein coil by providing an alternative anteroposterior trajectory of the electrical shock vector can enable successful defibrillation. This review discusses a hands-on approach to azygous vein coil implantation. Additionally, we compare our tools and technique to those that have been previously described by other operators. From 2018 to 2021, eight patients were identified who underwent azygous vein coil implantation at MedStar Washington Hospital Center using a specific technique and tools. Demographic and procedural data were obtained by a retrospective review of patient charts, procedure logs, fluoroscopy, and venography performed during coil implantation. The indication for azygous vein coil implantation was ineffective ICD shocks in seven patients. The presenting rhythm was ventricular fibrillation in six (75%) cases and sustained ventricular tachycardia in two (25%) cases. Using the approach described, we were able to successfully implant an azygous vein coil in all eight (100%) patients. There were no procedure-related complications. Postimplantation, defibrillation threshold (DFT) testing was successfully performed in six of eight (75%) patients. One patient failed DFT testing despite placement of an azygous vein coil. In another patient, DFT testing was not performed because the patient was in atrial fibrillation and was not systemically anticoagulated. In conclusion, the placement of an azygous vein coil in LVAD patients with failed ICD shocks using the tools and technique described in this report is safe and highly efficacious (successful in 100% of cases).

"Retained wire femoral lead removal and fibroplasty" for obtaining venous access in patients with refractory venous obstruction.

BACKGROUND: Patients with wire and catheter refractory venous occlusion are traditionally referred for pectoral transvenous lead extraction (TLE) to obtain venous access. TLE causes 1-2 mm circumferential mechanical or laser destruction of tissue surrounding the lead(s). This not only exposes the patient to the risk of major complications but also can damage nontargeted leads. We present a series of patients where retained wire femoral lead removal and fibroplasty was used to obtain venous access in patients with refractory obstruction. METHODS: Between 2008 and 2021, we identified 17 patients where retained wire lead removal followed by fibroplasty was used to retain venous access. Demographic and procedural data were obtained by retrospective review of patient charts. RESULTS: We were able to successfully obtain venous access in all 17 patients in whom this technique was attempted. In two patients the target lead was less than or equal to 1 year old. In the remaining 15 patients, the average dwell time of the target lead(s) was 6 years. There were no procedure-related complications, and no changes in the parameters of other leads were noted. CONCLUSION: Retained wire femoral lead removal and fibroplasty is safe and highly efficacious at obtaining venous access in patients with refractory venous occlusion. If the target lead(s) is less than or equal to 1 year old, this technique can help obtain venous access at the time of the initial surgery, hence avoiding the need for TLE. Furthermore, in patients referred for TLE to obtain venous access, this technique by avoiding the use of TLE tools spares the patient of the associated risks.

Successful implantation of a left ventricular lead in an anomalous coronary sinus.

We describe the case of a 56-year-old man who was referred for CRT implantation and found to have anomalous CS. Catheterization of the CS initially failed due to this anomaly. However, a single large posterior-lateral branch with diminutive CS in the atrioventricular groove allowed for successful implantation of the LV lead.

The combination of coronary sinus ostial atresia/abnormalities and a small persistent left superior vena cava-Opportunity for left ventricular lead implantation and unrecognized source of thromboembolic stroke.

BACKGROUND: Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ventricular (LV) lead implantation. Some patients with CS ostial abnormalities also have a small persistent left superior vena cava (sPLSVC). OBJECTIVE: The purpose of this study was to describe CS ostial abnormalities and sPLSVC as an opportunity for LV lead implantation and unrecognized source of stroke. METHODS: Twenty patients with CS ostial abnormalities and sPLSVC were identified. Clinical information, imaging methods, LV lead implantation techniques, and complications were summarized. RESULTS: Forty percent had at least 1 previously unsuccessful LV lead placement. In 70%, sPLSVC was identified by catheter manipulation and contrast injection in the left brachiocephalic vein, and in 30% by levophase CS venography. In 30%, sPLSVC was associated with drainage from the CS into the left atrium (LA). When associated with CS ostial abnormalities, the sPLSVC diameter averaged 5.6 ± 3 mm. sPLSVC was used for successful LV lead implantation in 90% of cases. In 80%, the LV lead was implanted down sPLSVC, and in 20%, sPLSVC was used to access the CS from the RA. Presumably because of unrecognized drainage from the CS to the LA, 1 patient had a stroke during implantation via sPLSVC. CONCLUSION: When CS ostial abnormalities prevent access to the CS from the RA, sPLSVC can be used to successfully implant LV leads. In some, the CS partially drains into the LA and stroke can occur spontaneously or during lead intervention. It is important to distinguish sPLSVC associated with CS ostial abnormalities from isolated PLSVC.

Interventional device implantation, Part I: Basic techniques to avoid complications: A hands-on approach.

INTRODUCTION: The essence of cardiac resynchronization therapy (CRT) is biventricular (BiV) pacing, which involves implanting pacing leads in both the right ventricle (RV) and left ventricle (LV). Unlike traditional RV pacing, many hurdles lie ahead of successful LV lead implantation. METHODS AND RESULTS: In this review, we first highlight the importance of optimizing the patient and the tools. Next, we describe the CRT tools developed over several decades, to facilitate successful implantation. Thereafter, we provide a streamlined step-by-step summary of the basic BiV implantation procedure. Lastly, we discuss some commonly encountered challenges during implantation and the techniques to tackle them. CONCLUSION: A systematic approach to every step of the implantation process can reduce procedure time, decrease patient exposure to radiation and contrast, and minimize complications. The use of right tools and techniques can enable all implanters to become more successful with BiV implantation.

Challenging Implants Require Tools and Techniques Not Tips and Tricks.

The EP Clinics article "How to implant CRT devices in a busy clinical practice" describes the basics of the "interventional telescoping technique". This article focuses on specific circumstances where the tools and techniques are invaluable: (1) inability to locate the coronary sinus (CS), (2) inability to advance a catheter into the CS, (3) patients with CS atresia, (4) unstable CS access, (4) angulated target veins, (5) small and/or tortuous target veins, (6) target veins into which a wire cannot be advanced, (7) target veins with a drain pipe takeoff, (8) target veins close to the CS ostium.

Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillators: The RAID Trial.

BACKGROUND: Ventricular tachycardia (VT) and ventricular fibrillation (VF) remain a challenging problem in patients with implantable cardioverter-defibrillators (ICDs). OBJECTIVES: This study aimed to determine whether ranolazine administration decreases the likelihood of VT, VF, or death in patients with an ICD. METHODS: This was double-blind, placebo-controlled clinical trial in which high-risk ICD patients with ischemic or nonischemic cardiomyopathy were randomized to 1,000 mg ranolazine twice a day or placebo. The primary endpoint was VT or VF requiring appropriate ICD therapy or death, whichever occurred first. Pre-specified secondary endpoints included ICD shock for VT, VF, or death and recurrent VT or VF requiring ICD therapy. RESULTS: Among 1,012 ICD patients (510 randomized to ranolazine and 502 to placebo) the mean age was 64 ± 10 years and 18% were women. During 28 ± 16 months of follow-up there were 372 (37%) patients with primary endpoint, 270 (27%) patients with VT or VF, and 148 (15%) deaths. The blinded study drug was discontinued in 199 (39.6%) patients receiving placebo and in 253 (49.6%) patients receiving ranolazine (p = 0.001). The hazard ratio for ranolazine versus placebo was 0.84 (95% confidence interval: 0.67 to 1.05; p = 0.117) for VT, VF, or death. In a pre-specified secondary analysis, patients randomized to ranolazine had a marginally significant lower risk of ICD therapies for recurrent VT or VF (hazard ratio: 0.70; 95% confidence interval: 0.51 to 0.96; p = 0.028). There were no other significant treatment effects in other pre-specified secondary analyses, which included individual components of the primary endpoint, inappropriate shocks, cardiac hospitalizations, and quality of life. CONCLUSIONS: In high-risk ICD patients, treatment with ranolazine did not significantly reduce the incidence of the first VT or VF, or death. However, the study was underpowered to detect a difference in the primary endpoint. In prespecified secondary endpoint analyses, ranolazine administration was associated with a significant reduction in recurrent VT or VF requiring ICD therapy without evidence for increased mortality. (Ranolazine Implantable Cardioverter-Defibrillator Trial [RAID]; NCT01215253).

Venous System Interventions for Device Implantation.

Subclavian obstruction is common after lead implantation and the need to add or replace a lead is increasing. Subclavian venoplasty (SV) is a safe and effective option for venous occlusion. Peripheral venography overestimates the severity of the obstruction. A wire can usually be advanced into the central circulation for SV. Compared with dilators, SV improves the quality of venous access, providing unrestricted catheter manipulation for His bundle pacing and left ventricular lead implantation. SV preserves venous access and reduces lead burden. SV can easily be added to the implanting physicians lead management options.

Rationale and design of a randomized trial to assess the safety and efficacy of MultiPoint Pacing (MPP) in cardiac resynchronization therapy: The MPP Trial.

BACKGROUND: Although the majority of Class III congestive heart failure (HF) patients treated with cardiac resynchronization therapy (CRT) show a clinical benefit, up to 40% of patients do not respond to CRT. This paper reports the design of the MultiPoint Pacing (MPP) trial, a prospective, randomized, double-blind, controlled study to evaluate the safety and efficacy of CRT using MPP compared to standard biventricular (Bi-V) pacing. METHODS: A maximum of 506 patients with a standard CRT-D indication will be enrolled at up to 50 US centers. All patients will be implanted with a CRT-D system (Quartet LV lead Model 1458Q with a Quadra CRT-D, Abbott) that can deliver both MPP and Bi-V pacing. Standard Bi-V pacing will be activated at implant. At 3 months postimplant, patients in whom the echocardiographic parameters during MPP are equal or better than during Bi-V pacing are randomized (1:1) to either an MPP or Bi-V arm. RESULTS: The primary safety endpoint is freedom from system-related complications at 9 months. Each patient's response to CRT will be evaluated using a heart-failure clinical composite score, consisting of a change in NYHA functional class, patient global assessment score, HF events, and cardiovascular death. The primary efficacy endpoint is the proportion of responders in the MPP arm compared with the Bi-V arm between 3 and 9 months. CONCLUSION: This trial seeks to evaluate whether MPP via a single quadripolar LV lead improves hemodynamic and clinical responses to CRT, both in clinical responders and nonresponders.

Safety and Efficacy of Multipoint Pacing in Cardiac Resynchronization Therapy: The MultiPoint Pacing Trial.

OBJECTIVES: The MultiPoint Pacing (MPP) trial assessed the safety and efficacy of pacing 2 left ventricular sites with a quadripolar lead in patients with heart failure indicated for a CRT-D device. BACKGROUND: Cardiac resynchronization therapy nonresponse is a complex problem where stimulation of multiple left ventricular sites may be a solution. METHODS: Enrolled patients were indicated for a CRT-D system. Bi-ventricular (Bi-V) pacing was activated at implant. Three months later, clinical response was assessed and the patient was randomized (1:1) to receive Bi-V pacing or MPP. Patients were followed for 6 months post-randomization and clinical response was again assessed. RESULTS: The CRT-D system was successfully implanted in 455 of 469 attempted implants (97%). A total of 381 patients were randomized to Bi-V or MPP at 3 months. The primary safety endpoint was met with freedom from system-related complications of 93.2%. The primary efficacy endpoint of the noninferiority comparison of nonresponder rates between the 2 arms was met. Patients randomized to MPP arm and programmed to pace from anatomically distant poles (MPP-AS) responded to therapy at significantly higher rates than MultiPoint pacing-other programmed settings (MPP-Other). Within this group, 87% were responders at 9 months, 100% designated as nonresponders at 3 months converted to responders at 9 months, and 54% experienced an incremental response compared to MPP-Other. Also within MPP-AS, 92% of patients with de novo CRT-D implant were classified as responders compared with patients with MPP-Other. CONCLUSIONS: MPP is safe and effective for treating heart failure. The study met the pre-specified hypothesis that response to MPP is noninferior to Bi-V pacing with a quadripolar left ventricular lead. (MultiPoint Pacing IDE Study [MPP IDE]; NCT01786993).

Improvement in Clinical Outcomes With Biventricular Versus Right Ventricular Pacing: The BLOCK HF Study.

BACKGROUND: Sustained right ventricular (RV) apical pacing may lead to deterioration in ventricular function and an increased risk of heart failure, especially in patients with pre-existing systolic dysfunction. The BLOCK HF (Biventricular Versus Right Ventricular Pacing in Heart Failure Patients With Atrioventricular Block) trial demonstrated that biventricular-paced patients had a reduced incidence of a composite endpoint of death, heart failure-related urgent care, and adverse left ventricular remodeling. OBJECTIVES: In a pre-specified analysis, this study examined clinical outcomes, including clinical composite score, quality of life (QOL), and change in New York Heart Association (NYHA) functional classification. METHODS: The BLOCK HF trial randomized patients with atrioventricular block, NYHA symptom class I to III heart failure, and left ventricular ejection fraction ≤50% to biventricular or RV pacing. NYHA functional classification, QOL, and clinical composite score were assessed at 6, 12, 18, and 24 months. Bayesian statistical methods were used, with the pre-specified metric of benefit being a posterior probability ≥0.95. RESULTS: Patients with biventricular pacing showed greater improvement in NYHA functional class at 12 months, with 19% improved, 61% unchanged, and 17% worsened, compared with 12%/62%/23% in the RV arm. QOL was improved through 12 months. At 6 months, clinical composite score was improved/unchanged/worsened in 53%/24%/24% in the biventricular arm compared with 39%/33%/28% in the RV arm. This improvement in clinical composite score was sustained through 24 months. CONCLUSIONS: For patients with atrioventricular block and systolic dysfunction, biventricular pacing not only reduces the risk of mortality/morbidity, but also leads to better clinical outcomes, including improved QOL and heart failure status, compared with RV pacing. (Biventricular Versus Right Ventricular Pacing in Heart Failure Patients With Atrioventricular Block [BLOCK HF]; NCT00267098).

Biventricular pacing for atrioventricular block and systolic dysfunction.

BACKGROUND: Right ventricular pacing restores an adequate heart rate in patients with atrioventricular block, but high percentages of right ventricular apical pacing may promote left ventricular systolic dysfunction. We evaluated whether biventricular pacing might reduce mortality, morbidity, and adverse left ventricular remodeling in such patients. METHODS: We enrolled patients who had indications for pacing with atrioventricular block; New York Heart Association (NYHA) class I, II, or III heart failure; and a left ventricular ejection fraction of 50% or less. Patients received a cardiac-resynchronization pacemaker or implantable cardioverter-defibrillator (ICD) (the latter if the patient had an indication for defibrillation therapy) and were randomly assigned to standard right ventricular pacing or biventricular pacing. The primary outcome was the time to death from any cause, an urgent care visit for heart failure that required intravenous therapy, or a 15% or more increase in the left ventricular end-systolic volume index. RESULTS: Of 918 patients enrolled, 691 underwent randomization and were followed for an average of 37 months. The primary outcome occurred in 190 of 342 patients (55.6%) in the right-ventricular-pacing group, as compared with 160 of 349 (45.8%) in the biventricular-pacing group. Patients randomly assigned to biventricular pacing had a significantly lower incidence of the primary outcome over time than did those assigned to right ventricular pacing (hazard ratio, 0.74; 95% credible interval, 0.60 to 0.90); results were similar in the pacemaker and ICD groups. Left ventricular lead-related complications occurred in 6.4% of patients. CONCLUSIONS: Biventricular pacing was superior to conventional right ventricular pacing in patients with atrioventricular block and left ventricular systolic dysfunction with NYHA class I, II, or III heart failure. (Funded by Medtronic; BLOCK HF ClinicalTrials.gov number, NCT00267098.).

Impact of using a telescoping-support catheter system for left ventricular lead placement on implant success and procedure time of cardiac resynchronization therapy.

BACKGROUND: Proper positioning of the left ventricular (LV) lead improves clinical outcomes and survival in patients receiving cardiac resynchronization therapy (CRT). Techniques of LV lead insertion using contrast injection and a telescoping system of delivery catheters to support advancement of the lead into the target branch may allow more efficient, targeted lead placement. We sought to evaluate the impact of an LV lead implant approach using telescoping-support catheters (group TS) on success rate, lead location, and procedural time compared to standard over-the-wire implant techniques (group OTW). METHODS: Four hundred thirty-seven consecutive patients undergoing CRT implantation were divided into group TS (n = 105) or group OTW (n = 332) based upon a review of the operative technique used for LV lead implantation. The primary outcome was success of LV lead implantation at the index procedure. Secondary endpoints included optimal positioning of the LV lead and reduction in procedural fluoroscopy time. RESULTS: Failed LV lead placement was lower (1.9% vs 8.1%, P = 0.02) and optimal lead positioning was achieved more often for group TS than group OTW (87% vs 75%, P = 0.01). In addition, there were significantly shorter fluoroscopy times for group TS versus group OTW (29.6 minutes vs 41.9 minutes, P < 0.01). CONCLUSION: A CRT-implant approach using contrast injection and a telescoping-support catheter system results in fewer failed LV lead implants, improved LV lead location, and shorter procedure times.

Snare coupling of the pre-pectoral pacing lead delivery catheter to the femoral transseptal apparatus for endocardial cardiac resynchronization therapy : mid-term results.

AIMS: Limitations imposed by the coronary sinus venous anatomy triggered the transseptal approach for endocardial LV lead placement. The alignment of the interatrial septum (IAS) and its neighborhood anatomy does not favor transseptal puncture from the pre-pectoral area. Locating and advancing a pre-pectoral LV lead delivery catheter (PDC) through an opening created in the IAS via femoral transseptal puncture (FTP) is time consuming and technically difficult. We describe a method where the PDC is snare coupled to the femoral transseptal apparatus (FTA). When the FTA is advanced into the left atrium (LA) the coupled PDC follows. METHODS: The catheter of a 25-mm loop snare kit is replaced with the PDC (SelectSite®). The snare loop is positioned in the right common iliac vein from the pre-pectoral access. The PDC is coupled to the FTA by advancing the transseptal apparatus through the open snare loop. After conventional FTP, the FTA is withdrawn back into the right atrium (RA) over an extra support wire positioned in the LA. The PDC with open snare loop is pulled over the FTA up to the RA. The PDC is advanced to close the snare loop on the extra support wire immediately distal to the tip of the dilator close to the puncture site. The PDC is deflected to align with the FTA. The snare coupled catheters are gently advanced across the IAS into the LA. The PDC is released from the FTA by advancing the snare and opening the loop; the snare is then removed from the PDC. The PDC is deflected and advanced into the left ventricle (LV). After positioning the 4.1 Fr lumen less LV lead, the PDC is sliced and removed. RESULTS: The PDC snare coupled to the FTA was advanced into the LA in all five patients, however, access was lost during catheter manipulation in the one right-sided case. Endocardial LV lead was successfully positioned in all five patients. CONCLUSION: Snare coupling the pre-pectoral SelectSite® catheter to the FTA is technically simple, reliable and a safe method for transseptal endocardial LV lead placement for left pre-pectoral implantation.

Prolapsed double-canted bipolar left ventricular lead for pacing the left atrium via the coronary sinus: experience in 11 patients.

AIMS: High thresholds and frequent lead dislodgement limit pacing the left atrium (LA) from the mid to distal coronary sinus (CS). The aim of this report is to describe a method for and the results of prolapsing a double-canted bipolar lead into the mid-to-distal CS to eliminate lead dislodgement and improve pacing thresholds. METHODS AND RESULTS: After CS access the 9 Fr. anatomic sheath is withdrawn to the right atrium (RA) over an extra support wire. A double-canted bipolar lead is advanced into the RA until the proximal bend is outside the tip of the sheath. With the stylet withdrawn to the proximal bend, the sheath and lead are advanced over the wire back into the CS. The lead distal to the proximal bend is prolapsed beside the sheath as the tip of the sheath enters the CS. The lead was successfully prolapsed in 11 consecutive patients. In one patient, capture was >5 V in all locations. Of the 10 successful implants, the acute thresholds were: mean 1.53 V, median 1.35 V, range 0.4-4.0 V. Chronic thresholds were: mean 2 V, median 2 V range 0.4-4.0 V. There were no displaced leads or lead fractures through 6-10 months of follow-up. CONCLUSIONS: Prolapse of a commercially available double-canted bipolar passive fixation lead eliminates lead dislodgment and improves thresholds providing a means for permanent pacing of the LA from the mid to distal CS and provides the design principles for a dedicated lead.

Excimer laser to open refractory subclavian occlusion in 12 consecutive patients.

BACKGROUND: Ideally, new leads are placed via the axillary/cephalic vein on the same side as the initial implant; however, 3.6% to 9% of patients have chronic total subclavian/innominate occlusion. In most cases, a wire can be manipulated across the occlusion and venoplasty safely performed. Occasionally, a wire will not cross, and additional tools are required. OBJECTIVE: The purpose of this study was to evaluate our experience with an excimer laser catheter used to cross wire-refractory chronic total subclavian/innominate occlusion in 12 patients. METHODS: We first used the laser to successfully cross a lead-related chronic total occlusion that did not yield to either a wire or microdissection. We subsequently used the laser for 11 additional wire-refractory occlusions. We reviewed the implant reports, hospital records, and videos of each case. RESULTS: The occlusions were successfully crossed and a wire placed for venoplasty in 11 of 12 cases by one of three implanting physicians. No complications occurred, and the existing leads sustained no damage. CONCLUSION: Although the safety of the procedure remains uncertain, if directions are followed and are precautions heeded, physicians with training and experience in venoplasty and laser lead extraction can learn this technique, which provides an important option for adding a lead to an existing device when the ipsilateral access vein is occluded.

Goose neck snare for LV lead placement in difficult venous anatomy.

Venous anatomy frequently impairs placement of the left ventricular (LV) lead. In some cases, the wire will not advance into the vein and in others wire position is lost as the lead is advanced. This article describes how a commonly available goose neck snare is used to gain access to the distal end of the wire as it re-enters the coronary sinus retrograde via collaterals through an adjacent vein. The snare is advanced into the coronary sinus through the same catheter as the wire. The snare opens perpendicular to the long axis of the coronary sinus due to which the wire must pass through the open loop, provided the diameter of the snare is approximately the same as the coronary sinus. Thus no time-consuming manipulation of the snare is required. With access to both ends of the wire the vein is approached either retrograde (over the distal end) or antegrade (over the proximal end) while the other end of the wire is secured by the operator. Gaining control of both ends of the wire with a snare is another example of adapting interventional techniques for the device implantation. Unlike venoplasty, the snare does not evoke credentialing concerns and can be easily implemented by most implanting physicians.