Procedural outcome of lead explant and countertraction‐assisted femoral lead extraction in Thai patients with cardiac implantable electronic device infection

Abstract Background Cardiac implantable electronic device (CIED) implantation rate has been increasing worldwide. Despite proper surgical technique and preincisional intravenous antibiotics, the incidence of infected CIED remains high and leads to serious complications. When encountered with CIED infection, complete CIED system removal is indicated. Several lead extraction approaches have shown a high success rate. However, the facilities are limited in Thailand. In our current practice, we perform lead extraction using the Dotter basket snare femoral approach as our primary method. There are no prior data on this countertraction‐assisted transfemoral technique. Therefore, we aim to study the procedural outcome of countertraction‐assisted transfemoral lead removal technique of CIED infection in Thai patients. Methods Patients diagnosed with CIED infection and with a history of device infection were retrospectively included. Simple manual removal was performed. In case of failure, we proceeded with the modified countertraction‐assisted transfemoral technique. Results There were 35 patients in the study. The success rate was 94.3%. Most of the leads, 62.8%, were removed by simple manual traction. In the 37.1% who required further femoral approach lead extractions, procedural failure was observed in 5.7% and procedure‐related adverse events in 5.6%. CIED infection‐related death accounted for 5.7% and nosocomial infection‐related death, 2.8%. Conclusion The success rate of CIED infection lead explant and countertraction‐assisted transfemoral lead extraction technique was high with small complications and can be performed without advanced facilities. However, the procedure required a main center with a cardiovascular thoracic surgery support team.


| INTRODUC TI ON
Cardiac implantable electronic device (CIED) implantation rate has been continuously increasing worldwide. 1,2 Despite proper skin antiseptic, surgical technique, and preincisional intravenous antibiotics, the incidence of infected CIED remains high at 1%-2%. 3,4 CIED infection is one of the most serious cardiac device complications because of the worsening quality of life, life-threatening condition, prolonged hospitalization, risk of device removal, and high mortality rate. [5][6][7][8] On CIED infection, complete CIED system removal is indicated. 9 Transvenous lead extraction can be performed by the superior, inferior (femoral), or combined approach. Numerous tools and techniques are available, for example, simple manual traction, locking stylets, telescoping sheaths, snares, mechanical cutters, and laser sheaths. 10 However, the locking stylets, telescoping sheaths, powered tools, and Needle's Eye Snare have limited availability in many regions of Thailand because of reimbursement and cost issues, including our center. Therefore, we have been mainly using the Dotter basket snare for that has adequate tensile strength for lead extraction. Through a long deflectable sheath, we placed an ablation catheter in the right ventricle to provide countertraction and prevent right ventricle (RV) inversion. Given the paucity of data on this modified RV support countertraction-assisted transfemoral lead extraction, we studied the safety and efficacy of this approach in patients with CIED infection.

| ME THODS
In this retrospective descriptive single-center study, we included all patients diagnosed with CIED infection who had undergone device removal after obtaining informed consent. The patients who underwent CIED removal at the university hospital (Maharaj Nakorn Chiang Mai Hospital, Thailand) between January 2007 and March 2020 were included. Patient information was collected from the electronic medical record system (Digicard software ® ). Baseline characteristics including age, gender, comorbidities, indication of CIED implantation, targeted leads including their type, the type of device, targeted lead dwell time, and procedure time were collected.

| Definition of cardiac implantable electronic device infection
In accordance with previous studies, 10

| Procedural details
The device was removed under local anesthesia and controlled sedation. Following opening of the device pocket and discharge of the debris, we performed simple manual traction (explant) in all patients through the superior approach at the lead insertion site. If the targeted lead(s) could not be freely removed by simple manual traction with or without using a standard stylet (also mentioned as "explant"), we proceeded to a femoral approach (extraction) by placing one 8-French short sheath and two steerable long sheaths (8.8 F Agilis NxT Steerable Introducer 71 cm, Abbott Cardiovascular System Inc.; formerly St. Jude Medical) into the right femoral vein. We inserted a nonirrigated 4 mm tip ablation catheter through the first steerable sheath, and looped it into the right ventricular (RV) apex to prevent RV inversion, as primary curve, and bent steerable sheath creating a secondary curve (Figure 1). A second nonirrigated 4 mm tip ablation catheter was inserted through a 8-French short sheath and the Dotter basket snare through the remaining steerable sheath. We F I G U R E 1 RAO view showing a 4-mm tip ablation catheter through steerable sheath looped into the right ventricular (RV) apex forming primary (open arrow) and secondary curves (close arrow) of the telescopic countertraction system used this second ablation catheter as a threader passing from one side of the target lead, which is then grasped with the Dotter basket snare that is passed from the other side ( Figure 2). The lead is then pulled down until the distal lead tip is freed from the RV myocardium ( Figure 3). The freed lead is then recaptured with the same snare without threader and pulled further into the countertraction sheath, before lead cutting is made, which allowed complete lead removal be made with transfemoral through deflectable sheath and via the pectoral pocket. Movie files are include in this article as Video S1 and S2.
A similar procedure was used for the right femoral vein.

| Definition of complete procedural success
Complete procedural success is defined as removal of all targeted leads and material, with the absence of any permanently disabling complication or procedure-related death. 10

| Definition of procedural failure
Procedural failure is defined as lead extraction procedures in which complete procedural or clinical success cannot be achieved, or the development of any permanently disabling complication, or procedure-related death. 10 Clinical success is defined as lead extraction procedures with removal of all targeted leads and lead material from the vascular space or retention of a small portion of the lead (4 mm) that does not negatively impact the outcome goals of the procedure.

| Definition of adverse events
Adverse events involve procedural complications and nonprocedural complications described previously. 10,11 Procedural complications are events that span the time the patient enters the operating room and following the procedure.
Major complications are those that pose an immediate threat to life or that result in death, unexpected events that cause persistent or significant disability or any event that requires significant surgical intervention.
Minor complications are undesired adverse events that require medical intervention, including minor procedural interventions, but do not significantly affect the patient's function, nor does it threaten life or cause death.

| Statistical analysis
Continuous variables are presented as mean ± SD or median ± interquartile range when appropriate. Categorical variables are displayed as percentages. Frequency distribution is shown as numerical values and graph ( Figure 4).

| RE SULTS
There were 35 patients who had CIED infection and device removal at our university hospital between January 2007 and March 2020.
The mean age of the patients was 64.4 ± 13.5 years with male predominance (65%). The two most common CIED infections were F I G U R E 2 RAO view showing a second 4-mm tip ablation catheter, from short vascular sheath, advanced over the target defibrillator lead (white arrow). The Dotter basket snare, via the remaining steerable sheath, was then used to grasp the ablation catheter shaft from another side, which ensured capturing the target lead  (Table 3). There was no any atrial avulsion, tricuspid valve or coronary sinus injury during RA or CS leads removal.

| Nonprocedure-related complications
There were two (5.7%) CIED infection-related deaths. One patient died from Staphylococcus aureus sepsis with multiorgan failure. Another patient had CIED infection complicated with infected CAPD and candida sepsis. There was one (2.8%) nosocomial   showed small numbers, two cases (5.5%) of procedure-related adverse events. There were one major (2.8%) and one minor procedure-related adverse event (2.8%). The major adverse event was one RV inversion as the countertraction RF ablator was in a suboptimal position at the RV apex with unstable hemodynamic. The procedure was terminated earlier with abandoned lead in the IVC; however, overall clinical conditions were stable after the RV reversion. Also, another adverse event was a minor complication with right femoral vein injury after complete procedure requiring surgical repair; however, local femoral vein repair was performed at the end of the procedure and no extensive surgery was required. We had no procedure-related death, procedure-related cardiac valve damage, venous lacerations, lead tip fracture that required surgical intervention, cardiac perforation or cardiac tamponade, venous thromboembolism event, or pneumothorax.

| Limitations
The limitations of this study are retrospective design and singlecenter experience. Further limitations include the uncontrolled nature of the data, small sample size, and some missing data.
Although our complication rate was small (5.6%), rate of complications may be differ in different lead dwell time, lead position, propreity of RV countertraction, in which lead to higher rate of RV inversion, atrial avulsion, tricuspid valve or CS injury.
Because of the small sample size, our study showed a different mean lead dwell time between the explant and extraction groups.
The mean lead dwell time in the extraction group was 88 months compared with 20 months in the explant group. Furthermore, our study showed that the shortest lead dwell time in the explant group was 52 months, whereas lead dwell time in the explant group ranged between 1 and 70 months. Unfortunately, there was no further analysis specifically within group with dwell time beyond 50 months.
Another issue is the re-use of steerable and deflectable ablation catheters. We are also aware of recall and warning issues of resterilized Agilis ® sheath.
We used the Dotter basket snare because of its availability, robustness, and adequate tensile strength. Other snares with adequate tensile strength may be also used and taken into consideration.
We performed the extraction procedure with a standby cardiothoracic team, which may or may not be widely applicable. A final limitation is that we included only patients with CIED infection without available standard extraction procedure or not affordable, thereby strongly precluding its broad application.

| CON CLUS ION
RV countertraction-assisted transfemoral lead extraction can be useful RV lead removal procedure in low volume extraction program without available lead locking stylet-based procedures. Advantages include the user-friendly nature, simple tools, and cost-effectiveness.
The operator has to be cognizant of the critical position of the countertraction assembly system technique and also of proper snaring tools for specific transfemoral lead extraction.

CO N FLI C T O F I NTE R E S T
Authors declare no conflict of interests for this article. Abbreviation: CIED, cardiovascular implantable electronic device.