Safety and feasibility of trans‐venous cardiac device extraction using conscious sedation alone—Implications for the post‐COVID‐19 era

Abstract Background Transvenous lead extraction (TLE) for implantable cardiac‐devices is traditionally performed under general anesthesia (GA). This can lead to greater risk of exposure to COVID‐19, longer recovery‐times and increased procedural‐costs. We report the feasibility/safety of TLE using conscious‐sedation alone with immediate GA/cardiac‐surgery back‐up if needed. Methods Retrospective case‐series of consecutive TLEs performed using conscious‐sedation alone between March 2016 and December 2019. All were performed in the electrophysiology‐laboratory using intravenous Fentanyl, Midazolam/Diazepam with a stepwise approach using locking‐stylets/cutting‐sheaths, including mechanical‐sheaths. Baseline patient‐characteristics, procedural‐details and TLE outcomes (including procedure‐related complications/death) were recorded. Results A total of 130 leads were targeted in 54 patients, mean age ± SD 74.6 ± 11.8years, 47(87%) males; dual‐chamber pacemakers (n = 26; 48%), cardiac resynchronization therapy‐defibrillators (n = 17; 31%) and defibrillators (n = 8; 15%) were commonest extracted devices. Mean ± SD/median (range) lead‐dwell times were 11.0 ± 8.8/8.3 (0.3‐37) years, respectively. Extraction indications included systemic infection (n = 23; 43%) and lead/pulse‐generator erosion (n = 27; 50%); mean 2.1 ± 2.0 leads were removed per procedure/mean procedure‐time was 100 ± 54 min. Local anesthetic (LA) was used for all (mean‐dose: 33 ± 8 ml 1% lidocaine), IV drug‐doses used (mean ± SD) were: midazolam: 3.95 ± 2.44 mg, diazepam: 4.69 ± 0.89 mg and fentanyl: 57 ± 40 µg. Complete lead‐extraction was achieved in 110 (85%) leads, partial lead‐extraction (<4 cm‐fragment remaining) in 5 (4%) leads. Sedation‐related hypotension requiring IV fluids occurred in 2 (managed without adverse‐consequences) and hypoxia requiring additional airway‐management in none. No procedural deaths occurred, one patient required emergency cardiac surgery for localized ventricular perforation, nine had minor complications (transient hypotension/bradycardia/pericardial effusion not requiring intervention). Conclusion TLE undertaken using LA/conscious‐sedation was safe/feasible in our series and associated with good clinical outcome/low procedural complications. Reduced risk of aerosolization of COVID‐19 and quicker patient recovery/reduced anesthetic risk are potential benefits that warrant further study.


| INTRODUC TI ON
Use of cardiac implantable electronic devices (CIEDs) has been steadily expanding worldwide given these devices improve morbidity and mortality. 1 procedural risks related to cardiac tamponade, vascular bleeding 4,5 and peri-operative mortality correlated with device infection. [6][7][8] The 2017 Heart Rhythm Society (HRS) TLE consensus guidelines strongly advocate the importance of a collaborative and multidisciplinary approach to address lead extraction management optimizing both safety and efficacy. 9 The logistic approach to TLE differs across different hospitals. Cases are often performed under general anesthesia (GA), but this carries its own risks to patients, who are typically at high risk. In addition, in the current pandemic there is increased risk of COVID-19 infection transmission from aerosolization associated with GA. 10 There are very limited data on the use of conscious sedation alone for such procedures. We have developed a protocol for performing TLE using conscious-sedation by default and evaluated the feasibility and safety of this approach in our study.

| Patient population
We started our policy of performing TLE using conscious-sedation alone at University Hospitals Coventry and Warwickshire NHS Trust, a large tertiary hospital in the UK, from March 2016. We attempted TLE using conscious-sedation alone in all consecutive patients as the primary approach irrespective of lead type, lead dwell-time or co-morbidities unless a patient was known to need concomitant cardiac surgery (e.g., heart valve surgery/bypass grafting) from the outset. Rapid response back up from Anaesthesiology and Cardiothoracic Surgery was always available with facilities to convert the case to GA if needed, as well as facilities to open the chest in the electrophysiology (EP) cath-lab if required.
We performed a retrospective study of all TLE cases that were planned to be performed using conscious sedation alone from the outset between March 2016 and December 2019. Patients with recently implanted leads (less than 6 months), requiring lead explant by traction alone with no extraction tools, were excluded. Lead extraction procedures were defined in accordance with the HRS TLE guideline 9 and European Heart Rhythm Association (EHRA) consensus statement. 11 Complete procedural success was defined as removal of all lead material from the vascular space with no permanent/disabling complications. Clinical procedural success was defined as removal of all targeted leads with retention of ≤4 cm of lead material that did not cause undesired outcomes. Procedural failure was defined as inability to reach complete procedure or clinical procedural success irrespective of clinical outcome alone. Major/minor complications were defined as per guidelines. 9,11 Demographic, clinical, and procedural data were collected on all and written informed consent obtained from all. The study was approved by our institution's research committee and was in accordance with the Declaration of Helsinki. Patients were involved by being aware they were undergoing a high risk procedure and being invited to participate in research which is on-going on optimal management strategies at our center. There was no direct patient involvement in outcome measures or study design but all patients provided informed consented pre-procedure.

| Pre-procedural assessment
Prior to the extraction procedure all patients were evaluated in the device clinic if an elective extraction or if an in-patient, by a consultant Electrophysiologist. Evaluation included a comprehensive none. No procedural deaths occurred, one patient required emergency cardiac surgery for localized ventricular perforation, nine had minor complications (transient hypotension/bradycardia/pericardial effusion not requiring intervention).
Conclusion: TLE undertaken using LA/conscious-sedation was safe/feasible in our series and associated with good clinical outcome/low procedural complications.
Reduced risk of aerosolization of COVID-19 and quicker patient recovery/reduced anesthetic risk are potential benefits that warrant further study.

K E Y W O R D S
cardiac implantable electronic devices, conscious-sedation, Fentanyl, lead extraction, Midazolam clinical and device history, pre-procedural risk stratification, determination of need for concomitant cardiothoracic surgery, and assessment of device re-implantation. Patients were discussed in a multi-disciplinary meeting before extraction with both cardiologist and cardiac surgeon present. We classified patient risk pre-procedure into low, medium or high risk according to baseline features ( Figure 1); these were determined from previous studies and guidelines. 9,11 The factors that were used in our classification included lead dwell time, number and type of leads, gender, age of patient at time of extraction, comorbidity (such as severe left ventricular systolic dysfunction, chronic kidney disease/on hemodialysis), on-going active sepsis, low body mass index (defined <22 kg/m 2 ), and anemia (defined as hemoglobin concentration were able to perform other non-operating duties during this time (such as administration tasks) ensuring their time was utilized productively if they were not needed during the case.

| Patient monitoring and sedation
All procedures were performed in our EP laboratory by two expe-  used for analgesia and not to aid lead extraction by veno-dilation.
Doses were adjusted as indicated by patients' comfort level and hemodynamic status. If necessary, patients received IV saline infusion to achieve and maintain systolic blood pressure above 90 mm Hg. Oxygen was applied via an oxygen mask and flow adjusted to achieve oxygen saturation levels >90%. If peripheral oxygen saturation decreased <90% and patient was unresponsive to increased oxygen flow and repositioning of the head/neck, patients were ventilated by face-mask/laryngeal-mask; if endotracheal intubation was needed, an anesthetist was always immediately available. All underwent pre-procedure TTE and where indicated pre-op TOE and/or cardiac CT/MRI. As cases were performed using conscious sedation alone and intraoperative TOE was not utilized. All patients were asked whether they experienced an unacceptable level of pain peri-procedure.

| Lead extraction
Local anesthesia (1% lidocaine) was administered at the device and femoral sites in all patients. Pacemaker dependent patients received temporary right ventricular pacing via the femoral venous route. After opening the pocket, the leads were exposed, untied and if manual traction unsuccessful, a systematic approach ap-

| Cost analysis
The cost for an Anaesthetist, Operating Department Practitioner (ODP) and post-operative GA recovery bed space was obtained from our finance department. We calculated the cost savings to our hospital that occurred during the period of study for those patients who were performed using conscious-sedation only and not requiring these additional costs. Those needing a GA and /or cardiac surgery, for whatever reason, were excluded from our costsaving analysis.

| Lead extraction success and complications
Of 130 leads targeted for extraction, complete lead extraction was achieved in 110 (85%) leads, partial lead extraction in 5 (4%).
Complete procedural success was achieved in 40 patients and complete clinical success in 45 patients (i.e. ≤4 cm fragment remained for 5 leads in five patients). Extraction failed (defined as either >4 cm fragment remaining/aborted procedure) for 15 leads (12%) in nine patients and none of these needed cardiac surgery. The indication for lead extraction in these nine patients was lead failure or superficialpocket infection only. Figure 2 shows the relationship between lead dwell times and procedural success. As expected the lead extraction failure rate was highest in those with lead dwell times >10 years. Table 3 highlights the relationship between pre-extraction risk and baseline patient demographic data. As expected those in the high risk group had much longer lead dwell times compared with those in the intermediate or low risk groups. Table 4 shows the procedural success and complications according to risk group. Once again, as expected, all minor and the one major complication seen were all within the high risk cohort and success rate was lower in the high risk cohort.
There were no air embolic events noted in our study.
There was no association between sedation related events and procedural clinical success. One patient developed

| D ISCUSS I ON
Lead extraction is a complex and high-risk intervention. 9,11 In the current study we have shown that TLE in our case series was feasible and safe; this is the first report to our knowledge using conscious sedation alone. Titrated doses of Benzodiazepines/Fentanyl were safely administered by a competent cardiology team member without needing in-lab anesthetic support. Sedation related side-effects were rare and managed adequately. Currently, GA is recommended for TLE with intra procedural TOE and resuscitation if needed. 9 We found fluoroscopy, hemodynamic monitoring and bedside TTE effectively diagnosed pericardial tamponade during the procedure.
Complication rates and mortality associated with TLE have been shown to be low, irrespective of whether the procedure was done in cardiac-theatre under GA or in the EP lab with deep sedation 13,14 ; this is in keeping with our study. One patient in our study suffered cardiac tamponade with immediate pericardiocentesis leading to hemodynamic stabilization, but required surgical repair to control bleeding. The most serious complication, vascular tears, is associated with 50% mortality even with immediate surgical treatment; deployment of an endovascular Bridge Balloon (Philips (Spectranetics)) can help reduce this mortality. 15 We adapted our TLE policy before availability of the Bridge Balloon; however, we have not had to use it in any cases to date.
Although performing these cases in the setting of an OR can offer immediate surgical intervention, its use adds to the scheduling complexity, cost, and resource utilization. In most centers, the EPlab typically has superior fluoroscopy and more ready access to percutaneous tools and support staff trained in their use. A hybrid lab with surgical capability and superior fluoroscopy, with staff trained in both lead extraction and cardiac surgical intervention, can provide the optimal balance but this type of facility is not widely available.
but is associated with risk of hypotension and possible exposure to aerosolized pathogens such as COVID-19. 10 In a cohort of patients with more comorbidities (85% ASA Classes III/IV) undergoing CIED surgery, the reported incidence of compromising hypoxia/hypotension under sedation by anesthetists were higher (16%/15% respectively) 19 ; in our small cohort all adverse events were managed successfully.
We always limited Fentanyl to a maximum 200 µg IV as these patients can be at higher risk of sedation related complications.
Well trained cath-lab staff can manage sedation to prevent critical persistent hypotension/hypoxia, avoiding transition to GA, and be able to resolve critical situations if they appear. 13 In the UK, use of Propofol is limited to anesthetists and therefore we were unable to use this agent. Propofol is short acting with broad use for induction of anesthesia/deep sedation; however, it's potential to cause rapid changes in neuropsychological function, from conscious sedation to deep sedation, or even narcosis with cardiorespiratory depression/apnea should be borne in mind. However, its use in TLE has been shown to be safe and effective in high-volume experienced centers. 13 Risk stratification pre-extraction is absolutely vital in helping to guide the type of anesthetic and surgical cover needed. 20 Partial lead extractions 0 (0) 1 (3) 5 (6) .612 Failed lead extractions 0 (0) 0 (0) 12 (14) .030

Major complications
Pericardiocentesis requiring sternotomy 0 (0) 0 (0) .758 is as safe as for cases done using GA, but there is no signal of a major increase or decrease in safety. The LExlCon study 24 indicated procedural major adverse events were higher in low volume centers than in experienced centers. Selection of conscious-sedation or GA should be evaluated in each case and in each center with cardiac surgeon and anesthetist.
Our cost-analysis revealed that TLE cases performed with conscious-sedation alone can be associated with significant cost savings for healthcare providers. Our institute made a significant cost savings over the period of study and this is important in both developed and developing healthcare systems where costs are rising, especially given the current financial climate worldwide. Not all units recover post-GA cath-lab cases differently to those performed using conscious-sedation. This may not avoid the cost of a recovery bed but where sedation is can be performed by specialist cath-lab nurses; this may save on the cost of an anesthetist and ODP. In future, a policy of conscious sedation by default could offer large scale benefits in terms of quality, productivity and cost efficacy.

| Study limitations
There are several limitations of the current study. It is a single center small retrospective study. We did not compare different anesthesia approaches and our results may not be generalizable. Our limited sample size means our results should be interpreted with caution and be considered 'hypothesis generating.' Although we questioned patients post procedure about their pain experience, this was limited and future studies should investigate patient pain perception and overall patient satisfaction in greater detail.

ACK N OWLED G M ENT
We would like to thank our Anaesthetic and Research & Development departments for their support with the study.

CO N FLI C T O F I NTE R E S T
Authors declare no Conflict of Interests for this article.