Author + information
- Received July 12, 2017
- Revision received November 30, 2017
- Accepted December 7, 2017
- Published online February 19, 2018.
- Saumya Sharma, MD∗ (, )
- Ijeoma A. Ekeruo, MD,
- Nikita P. Nand, MD,
- Ajay Sundara Raman, MD,
- Xu Zhang, PhD,
- Sunil K. Reddy, MD and
- Ramesh Hariharan, MD
- Department of Cardiac Electrophysiology, The University of Texas Health Science Center at Houston, Houston, Texas
- ↵∗Address for correspondence:
Dr. Saumya Sharma, Department of Cardiac Electrophysiology, The University of Texas Health Science Center at Houston, Texas, 6400 Fannin Street, Suite 2550, Houston, Texas 77030.
Objectives The goal of this study is to assess the safety and efficacy of mechanical lead extraction utilizing the Evolution system.
Background Compared with other techniques commonly used for lead extraction, data regarding the safety and efficacy of mechanical lead extraction using the Evolution system is limited and needs further evaluation.
Methods Between June 1, 2009 and September 30, 2016, we retrospectively analyzed 400 consecutive patients who exclusively underwent mechanical lead extraction utilizing the Evolution system.
Results A total of 400 patients underwent mechanical lead extraction of 683 leads. Mean age of extracted leads was 6.77 ± 4.42 years (range 1 to 31 years). The extracted device system was an implantable cardioverter-defibrillator in 274 patients (68.5%) and a pacemaker system in 126 patients (31.5%). Complete lead removal rate was 97% with a clinical success rate of 99.75%. Incomplete lead removal with <4-cm remnant was associated with older leads (lead age >8 years). Failure to achieve clinical success was noted in 1 patient (0.25%). Cardiac papillary avulsion, system-related infection, and cardiac tamponade were the major complications noted in 6 patients (1.5%). Minor complications were encountered in 24 patients (6%), of which hematoma requiring evacuation was the most common minor complication. There were no patient deaths.
Conclusions In our single-center study, lead extractions utilizing the Evolution mechanical lead extraction system were safe and effective and resulted in high clinical and procedural success, with low complication rates and no fatalities.
Over the past 20 years, the population of patients with cardiac implantable electronic devices (CIED) has increased (1,2). Consequently, there are more patients requiring CIED interventions, including device upgrades and lead revisions that may mandate lead extraction (LE). Implanted leads develop fibrotic adhesions over time that bind the leads to adjacent structures, and these adhesions determine the complexity of LE if required, as well as risks of the procedure (3). The Evolution mechanical dilator sheath (Cook Medical, Bloomington, Indiana) was developed as a useful extraction tool, designed with a rotational tip at the end of a flexible sheath that efficiently deals with binding adhesions, with an external telescoping sheath that protects surrounding structures from damage from the sharp rotational tip.
Previous studies have described their experience with this tool (4,5) and report successful outcomes (6–11). However, these studies were limited in their number of patients and complexity of procedures, requiring further clinical evaluation with a larger study population. Our study aims at evaluating the safety and efficacy of the Evolution system for mechanical lead extraction (MLE) in a larger population.
We retrospectively analyzed 400 consecutive patients who exclusively underwent MLE of pacemaker and implantable cardioverter-defibrillator (ICD) leads using the Cook Medical Evolution MLE sheath between June 1, 2009 and September 30, 2016. The study was reviewed and approved by the Institutional Review Board. Data was collected at a single center, with indications for extraction, outcomes, and complications defined in accordance with the 2009 Heart Rhythm Society expert consensus document on LE (12). Conclusions from that document were used to evaluate the safety and efficacy of extraction using the MLE device.
Data collection procedure
A study database was created using the secure, web-based Research Electronic Data Capture (REDCap) application (REDCap Consortium, Vanderbilt University, Nashville, Tennessee). Patients who exclusively underwent LE utilizing the Evolution system were included in our analysis. Leads that were explanted by simple traction without using the Evolution system were excluded from our analysis. Each patient was given a unique record identifier, and patient records were reviewed from admission to discharge. Demographic, historical, and procedural data were abstracted from the electronic medical records by a trained data collector to populate the LE database.
In our study, indications for LE were classified as: 1) infection; 2) dislodgement; 3) upgrade; 4) venous access; 5) lead failure; and 6) other. Infection included all patients with CIED pocket infection as evidenced by pocket abscess, device erosion, skin adherence, or chronic draining sinus; as well as patients with device-related endocarditis defined as CIED system infection evidenced by valvular endocarditis, lead endocarditis, and/or sepsis. Dislodgement was an indication for lead displacement that provoked a malfunction in the CIED system. Leads extracted when upgrading a system to another such as pacemaker to ICD, or pacemaker/ICD to a cardiac resynchronization device, were categorized as upgrade. Venous access was the indication in patients with ipsilateral venous occlusion preventing access to the venous circulation for placement of an additional lead. Lead failure was defined as leads with abnormal parameters on device interrogation (e.g., elevated threshold) posing a threat to the patient. Leads with mechanical complications and the ICD leads (Sprint Fidelis, Medtronic, Minneapolis, Minnesota; Riata, St. Jude Medical, St. Paul, Minnesota) recalled by the Food and Drug Administration were also included in this category. Superior vena cava syndrome, pocket pain, and lead thrombus were other reasons for the extraction of functional leads. Also included in the other category were leads extracted in patients being treated for malignancy, receiving radiotherapy, or undergoing medically necessary cardiac magnetic resonance imaging in which the presence of the CIED system would cause serious harm.
Lead extraction procedure
MLE was performed in a hybrid cardiovascular operating room under general anesthesia with cardiothoracic surgery backup immediately available. A thorough interrogation of the device was performed prior to the procedure in all patients. If warranted, temporary pacing was achieved via a pacing wire inserted either from the internal jugular vein or femoral vein based on operator preference. After sterile skin preparation and draping, the device pocket was reopened along the old incision line, and leads were separated from the pocket adhesions by blunt dissection, and were disconnected from the CIED generator. Removal by simple traction was first attempted, and if unsuccessful, a locking stylet (Liberator Universal Locking stylet, Cook Vascular Inc., Vandergrift, Pennsylvania) was introduced into the pace/sense component of the lead and deployed. The Evolution mechanical dilator sheath (Cook Medical) was then used to cut through the fibrous adhesions surrounding the lead to enable extraction. The original Evolution or the Evolution R/L sheath was used depending on physician preference. The outer polymer sheath covered the distal tip while advancing over the lead in tracts free from adhesions to protect the venous wall from damage (Figure 1). The Evolution Shortie, another tool with a shorter sheath, was used to gain venous access when extensive scarring or calcification prevented the same. In some patients, 0-silk suture and Bulldog Lead Extender were used to grasp lead insulation and superior vena cava and right ventricular coil components for greater lead stability. In later years, a One-tie compression coil was used. If required, remnant lead fragments were removed via the femoral approach using the Needle’s Eye Snare (Cook Vascular).
Complete procedural and clinical success definitions were in accordance with previously published guidelines (12,13). Complete procedural success was defined as removal of all targeted leads and lead material from the vascular space in absence of any permanently disabling complication or procedure-related death. Note was also made of procedures in which removal of all but a small portion of the lead (4 cm or less) was seen. Clinical success was defined as the ability to remove all the targeted leads and lead material from the vascular space, or retention of a small portion of the lead that did not negatively impact the outcome goals of the procedure.
Failure was considered the inability to achieve complete procedural or clinical success, the development of any permanently disabling complication, or procedure-related death.
All adverse outcomes were documented both acutely during the extraction as well as during follow-up. Major complications were classified as any outcomes that were life-threatening, resulting in significant disability or death, or requiring surgical intervention. A minor complication was any undesired event related to the procedure that required medical intervention or minor procedural intervention.
Distribution of continuous variables was examined by plotting histograms and boxplots. Descriptive statistics for normally distributed continuous variables were expressed as mean ± SD. Continuous variable with skewed distribution was summarized as median and range. Categorical variables were presented as frequencies and percentages. Fisher exact test, 2-sample Student's t-test and large-sample Wald test for 2 proportions were used for association evaluation or comparing outcomes between 2 subgroups. The Cochran-Armitage trend test with ordinal score 1 to 5 was used to test the decreasing trend in the incidence of hematoma from 2012 to 2016. All p values were 2-sided and p < 0.05 was considered significant. All statistical analyses were performed with SAS (version 9.4, SAS Institute Inc., Cary, North Carolina).
Between June 1, 2009 and September 30, 2016, 400 consecutive patients underwent MLE at the Memorial Hermann-Texas Medical Center. Patient characteristics are presented in Table 1. The extracted device system was an ICD in 274 patients (68.5%) and a pacemaker system in 126 patients (31.5%).
A total of 683 leads were extracted utilizing the Cook Medical Evolution system. Table 2 shows the characteristics of extracted leads. Leads were extracted from the right atrium, right ventricle, and coronary sinus. The mean implant duration was 6.77 years (range 1 to 31 years). The right ventricular leads included pacemaker and ICD leads, of which 218 (31.9%) were dual-coil ICD leads and 32 (4.7%) were single-coil ICD leads. Most leads were active fixation leads.
The indications for LE are reported in Figure 2. The most common indication was lead failure.
Overall, 663 leads (97%) were completely extracted. Of these, 17 leads (2.4%) required use of an additional snare for extraction. Complete procedural success without the use of an additional snare was achieved with 646 leads (94.5%). In 19 instances (2.7%), some lead remnants (fragments <4 cm) were unable to be extracted. These cases were associated with more chronic leads (p = 0.02) with a median implant duration of 8 years (1 to 24 years) and involved leads in the lead fracture or infection categories (Table 3).
Of the total leads extracted, 145 (21.2%) were recalled ICD leads (117 Medtronic Sprint Fidelis and 28 St. Jude Riata ICD leads). Considering the Riata, most leads had externalized cables prior to the procedure. Of these, 23 leads were completely extracted without additional femoral snare and contributed to the complete procedural success. Five Riata leads were only partially extracted.
Clinical success was achieved in 399 patients (99.75%). One patient was considered both a clinical and procedural failure. This patient was an 18-year-old man with history of long QT syndrome, who received an ICD 7 years ago but desired extraction of his device. The ICD lead was separated up to the cavo-atrial junction without difficulty, but severe adhesions of the lead to the tricuspid valve and right ventricular outflow tract made it difficult to engage the distal ICD coil. Femoral approach with the Needle’s Eye Snare was attempted for extraction of the lead. However, due to the potential risk of cardiac avulsion and perforation, the procedure was terminated.
Procedural adverse events
A total of 30 adverse events (7.5%) occurred in 400 patients. Of these, 6 (1.5%) were major adverse events in 6 patients and 24 (6%) were minor adverse events in as many patients. Hematoma requiring evacuation was the most common minor complication. Cardiac papillary avulsion, system-related infection of a previously noninfected site, and cardiac tamponade were the major complications seen. There were no patient deaths. Table 4 lists all major and minor adverse events in the study. Risk factors evaluated include age, sex, body mass index, history of diabetes, hypertension, and lead age. These were analyzed and were not shown to be associated with overall procedural adverse events (Table 5).
Both, the original Evolution (first generation) and the Evolution R/L (second generation) sheaths were used for LE. We assessed the difference in the outcomes between these 2 groups.
A total of 515 leads were extracted with the original Evolution and 168 leads with the Evolution R/L sheath. Leads extracted with Evolution R/L sheath were older (p < 0.001). No statistically significant differences were observed in the success rates between the 2 groups (Table 6).
This study demonstrates that the Evolution extraction system provides a safe and efficacious alternative to laser LE in a high-volume center.
Increase in CIED implantation over the last quarter century has necessitated a concomitant increase in LE for various reasons, infection being chief among them (1,2). Whereas previously, tools used for extraction made this a tenuous option at best, evolution of devices and techniques for extraction have made the procedure safer, leading to the procedure being carried out on a more routine basis. The development of the Evolution system is 1 such advancement in the field.
From a review of the published reports, LE were historically performed as a procedure of last resort due to the presence of leads causing or complicating systemic endocarditis (14). At that time, the only option for extraction was manual traction or open heart surgery, and it would be safe to say that the procedure, when indicated, was very high risk and had a high failure and mortality rate. The development of the “locking stylet” opened new strategies for extraction and was followed by the use of cutting sheaths; the most common of which was the laser cutting sheath. This system was introduced in the mid-1990s, has been studied in a fair number of retrospective studies, and has been shown to be a very successful tool. The LExICon study (15) in particular was a landmark trial that established laser LE as a safe and efficacious method for LE.
While laser-assisted extraction has been proven to be relatively safe (15–18), it has its limitations. Due to its cost and steep operator learning curve, use of this system is limited to high-volume centers (4,8,19,20). Moreover, its use is limited in patients with difficult venous access due to calcifications or tough fibrous adhesions (10,11,21), and so MLE systems were developed as an adjunct to the laser system. In 2010, a study by Hussein and Wilkoff et al. (4) introduced the Evolution mechanical system as a new LE tool mainly to help overcome the extensive fibrosis and calcification seen with more chronic leads. The system includes a tool with a long malleable sheath, but it also has a short version (Evolution Shortie RL) that is solely used in patients with difficult, calcified vascular access. That study helped provide a viable alternative to laser LE.
As described, the Evolution system utilizes a hand-triggered mechanical dilator sheath with a rotational tip that helps overcome calcific and fibrous adhesions while advancing the dilator sheath down the lead simultaneously. This distinctive feature of the Evolution system offers additional clinical benefits, including: 1) tactile feedback: adhesions and calcifications are well appreciated in the trigger mechanism; 2) power control: hand-held trigger permits the operator to titrate power to need and safety; 3) sheath flexibility: braided flexible sheath allows negotiation of the superior vena cava/right atrial junction relatively safely; and 4) presence of a protective outer sheath, which prevents damage to the vascular wall while advancing down the lead body.
Considering these benefits, rather than as an adjunct, we decided to use the Evolution system as a primary technique for LE at our center. To the best of our knowledge, this is the largest patient population studied so far with the Evolution system.
In prior small studies, MLE utilizing the Evolution system has been associated with a high success rates, low major complication rate, and no mortality (9,11,19,22). This proved to be the same in our study. Complete extraction of most leads (94.5%) without the use of rescue tools was noted. Leads with extensive adhesions were also successfully extracted. Figure 3 shows an example of a similar lead with fibrotic tissue adherent at multiple sites, extracted using the Evolution mechanical dilator sheath. Complete procedural success rose to 97% with additional use of the femoral snare. Clinical success was achieved in 99.75% of patients with 1 clinical failure seen in a patient with extensive adhesions, where the procedure was abandoned due to a potential risk of cardiac avulsion.
Results of our study are comparable to other studies performed in populations where laser LE was the primary extraction method used (15,17). Our study demonstrated similar complete procedural and clinical success rates as those studies. Our population differed from other studies in that the most common reason for LE in our population was mechanical lead failure, as opposed to infection in other studies performed (9,11,15,16).
Regarding safety, most published studies have reported a high level of safety with the Evolution system (9,11), and we experienced the same. Our study demonstrated low complication rates and no mortality with this technique. We had a major complication rate of 1.5% and minor complication rate of 6%. Major complications were not directly related to the demographic characteristics or risk factors such as diabetes, hypertension, and lead age. Pocket hematoma requiring evacuation was the most common minor complication in our study. Interestingly, on review of our data, the incidence of hematoma was high in the initial years (2010 to 2012) of our study, but dropped markedly in the recent years when a conscious effort was made to minimize the presence of antiplatelet agents and anticoagulants perioperatively. Figure 4 demonstrates a decreasing trend in the incidence of hematoma requiring evacuation since 2012 (p = 0.014 based on Cochran-Armitage trend test).
We also compared the success rates of LE with the original Evolution and Evolution R/L sheath. Earlier data suggest that the Evolution R/L sheath resulted in a higher complete success rates (23). However, no statistically significant differences were observed in the success rates and outcomes between the 2 groups in our study (Table 6).
As previously noted, the majority of leads extracted in our study were due to mechanical lead failure. This was because of the high number of recalled leads (21.2%), most of which were fractured or malfunctioning leads. A recent study by Witte et al. (23) reported an increasing number of malfunctioning leads, indicating a potential change in the trend with the indications for LE. Extraction of recalled leads has been controversial based on longer implant duration and lack of structural integrity with these leads, making it a more complex procedure (24,25). Riata leads in general are traditionally difficult leads to extract because of the externalization of cables and excessive scarring from the presence of nonbackfilled high voltage coils. This is particularly true with rotational mechanical tools due to the potential risk for further insulation damage. To avoid this and attain complete procedural success, we utilized the 13-F Evolution sheath for all Riata LE. We also used the One-tie compression coil to tie the superior vena cava/right ventricular coils together and the Bulldog Lead Extender, when applicable. Though we do not have documentation of externalization of lead wires at the time of extraction, removal of such leads contributed significantly to our partial extractions. Our experience with Riata leads is limited by the number of leads and mechanical extraction being the only technique used for LE. Other studies have reported better outcomes with laser LE (26). This needs further evaluation. Regardless, we found that extraction of these leads, both with externalized and nonexternalized cables was safe and effective with the Evolution system.
Our findings therefore suggest that the Evolution system is a very safe and effective tool and can be used as a first-line method for LE. As always, assessment of risks and benefits of the procedure to the patient are important to review, with operator experience an important predictor of success, and cardiothoracic surgical team backup necessary to act quickly in case of complications.
This was a retrospective, observational study performed at a single center. We only studied patients undergoing mechanical LE utilizing the Evolution system. No comparison was made between MLE and other techniques currently used for extraction.
In our experience, transvenous LE was safe and effective utilizing the Cook Medical Evolution mechanical dilator sheath with high clinical and procedural success rate, very limited complication rate, and no mortality.
COMPETENCY IN MEDICAL KNOWLEDGE: The Evolution system has been used as an adjunct to other techniques for LE. Data evaluating this system for LE in a large-study population has been much awaited. Results from this study are the largest to date, demonstrating the safety and efficacy of MLE utilizing the Evolution system. Our results will favorably contribute to the current experience with this system and enable electrophysiologists to use this system as a first-line technique for LE.
TRANSLATIONAL OUTLOOK: Larger prospective multicenter trials should be conducted to validate our findings and assess the risk factors and outcomes of the Evolution system in comparison to other techniques for LE.
Dr. Sharma has received speaking fees from Cook Medical. Dr. Reddy has received consulting/teaching fees from Biosense Webster, St. Jude, Abbott, and Biotronik. Dr. Hariharan has received speaking fees from Cook Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the author’s institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Abbreviations and Acronyms
- cardiovascular implantable electronic device
- implantable cardioverter-defibrillator
- lead extraction
- mechanical lead extraction
- Received July 12, 2017.
- Revision received November 30, 2017.
- Accepted December 7, 2017.
- 2018 American College of Cardiology Foundation
- ↵Hussein AA, Tarakji KG, Martin DO, et al. Cardiac implantable electronic device infections: added complexity and suboptimal outcomes with previously abandoned leads. J Am Coll Cardiol EP 2017;3:1–9.
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