Non-laser percutaneous extraction of pacemaker and defibrillation leads: a decade of progress

Abstract

Aims

Non-laser-based methods are safe in lead extraction but in the past have been less effective than laser methods. In the past decade, new equipment has been introduced including the Evolution® Mechanical Dilator Sheath and the Evolution® RL. We sought to determine the impact of new equipment on outcome in mechanical lead extraction.

Methods and results

We considered 288 consecutive patients (age 66 ± 18 years) who underwent transvenous lead extraction (TLE) of 522 leads in the decade to the end of 2014. Three groups were identified: Group 1 (pre-Evolution® period, 76 patients, 133 leads), Group 2 (original Evolution® period, 115 patients, 221 leads), and Group 3 (Evolution® RL period, 97 patients, 168 leads). The age of leads was significantly greater in Groups 2 and 3 (6.2 ± 4.4 and 6.1 ± 5.4 years vs.4.7 ± 4.5, P < 0.05) as was the proportion of implantable cardioverter defibrillator leads (27.2 and 28.9 vs. 14.3%, P < 0.05). The groups were similar in the number of leads extracted per patient. Despite the increasing complexity of the systems extracted, complete extraction was achieved in a progressively greater proportion of leads (88.0% in Group 1, 95.5% in Group 2, and 97.6% in Group 3, P < 0.05), and procedure duration was similar. The proportion of leads for which femoral access was required was greater in Group 3 (11%, 18/164) compared with Group 2 (3%, 7/211), P = 0.006. The only major complications were a post-procedure subacute tamponade in Group 1 and an oesophageal injury related to transoesophageal echocardiography in Group 3.

Conclusion

With current equipment, mechanical extraction provides a good combination of efficacy and safety.

Introduction

Mechanical methods have demonstrated a better safety profile than laser in a meta-analysis of transvenous lead extraction (TLE)¹ but in the past have not matched the high rate of success of laser procedures,² except for isolated high-volume centres.³ New tools and techniques have been introduced to improve the efficacy and maintain the safety of mechanical extraction⁴ in response to an increasing need for TLE procedures of increasingly complexity.^5,6 The Evolution® Mechanical Dilator Sheath (Cook Medical, Bloomington, IN, USA) is a hand-powered device for extracting chronically implanted leads.^7–9 A rotational mechanism of the inner sheath is used to free the lead from the fibrous and calcified adhesions; an outer telescopic sheath provides support and can be used for blunt dissection.

In the 1990s, our unit made a decision to avoid the use of laser techniques in lead extraction,¹⁰ relying instead on mechanical dissection sheaths, the Perfecta® Electrosurgical Dissection Sheath (Cook Medical) and femoral methods. The Perfecta® system was completely superseded by the Evolution® in mid-2010; this in turn was superseded by the Evolution® RL, a newer model characterized by bidirectional rotation and a less aggressive profile at the sheath tip. In this study, we evaluated the clinical and procedural impact of evolving technologies on the outcome of TLE procedures.

Methods

For all procedures performed at our centre in the decade to the end of 2014 that met the Heart Rhythm Society⁵ and European Heart Rhythm Association⁶ definition of a TLE, clinical details were collected prospectively by a cardiology technician dedicated to the task and present throughout each case. Institutional ethical committee approval was obtained.

Procedures were considered in three groups. Procedures performed up to mid-2010 were designated as Group 1 TLEs. In this period, a step-by-step approach was used, starting with simple traction followed by the use of a Liberator® Locking Stylet (Cook® Medical), and then the use of Perfecta® Electrosurgical Dissection Sheaths (Cook® Medical) if required.

The Evolution® Mechanical Dilator Sheath was introduced in mid-2010 and immediately became the instrument of choice in all cases where difficulty was encountered during a TLE. It also led to a change in the approach to lead extraction: rather than progressing to this instrument after failure of traction alone, it was used from the start of the procedure whenever difficulty was anticipated. In early 2013, the Evolution® RL superseded the original version in our unit and the One-Tie® Compression Coil (Cook Medical) and the SteadySheath® Evolution® Tissue Stabilization Sheath (Cook Medical) were introduced (Figure 1). Procedures performed from the introduction of the Evolution® system to switch to the Evolution® RL were classified as Group 2, subsequent procedures as Group 3.

All TLEs were performed in the cardiac catheterization laboratory with surgical backup available in an adjacent operating theatre. Throughout the study period, retrieval of fragmented leads was attempted when required using the Byrd Workstation™ Femoral Intravascular Retrieval Set (Cook® Medical) and/or Needle's Eye Snare® (Cook® Medical) via a femoral and/or jugular approach. Completeness of extraction was verified by radiological examination at the end of the procedure and by inspection including reassembly of the extracted fragments.

Follow-up

All patients were monitored for complications during hospitalization and at 1 month post-procedure. The severity of complications and the completeness of extraction were defined in accordance with the guidelines of the Heart Rhythm Society.⁵

Statistical analysis

Statistical analyses were performed using SPSS software (SPSS, Inc., Chicago, IL, USA). Continuous variables were expressed as mean and standard deviation and compared using the unpaired Student's t-test and the Mann–Whitney test, where appropriate. χ² and Fisher's exact tests were used for evaluating categorical variables. A P-value of <0.05 was considered statistically significant.

Results

Patient demographics

In the 10 years to the end of 2014, 522 leads were extracted from 288 patients, with an increasing workload over the study period (Figure 1). One hundred and thirty-three leads were extracted from 76 patients in Group 1, 221 leads from 115 patients in Group 2, and 168 leads from 97 patients in Group 3.

There was a significantly higher proportion of implantable cardioverter defibrillator (ICD) patients in Groups 2 and 3 vs. Group 1 (41, 37, and 18%, respectively, P = 0.002 Group 2 vs. Group 1 and P = 0.012 Group 3 vs. Group 1), whereas a higher prevalence of pacemaker patients was documented in Group 1 (57 vs. 35% in Group 2 and 45% in Group 3). No significant differences between groups were found in other clinical characteristics (Table 1).

Indications for extraction

In all groups, the most common indication for TLE was infection, although the proportion of extractions performed for this reason declined over time from 64% in Group 1 to 57% in Group 2 and 38% in Group 3 (Figure 1). There was a higher prevalence of local than of systemic infection in all groups with local infection accounting for 80% of infection in Group 1, 67% in Group 2, and 89% in Group 3.

Lead dysfunction was the second commonest indication, including 13 (of which 11 were in Groups 2 and 3) malfunctioning Sprint Fidelis® leads Models 6931 and 6949 (Medtronic, Inc., Minneapolis, MN, USA) and 6 (5 in Groups 2 and 3) malfunctioning Riata™ ST leads Models 7000 and 7002 (St. Jude Medical, St. Paul, MN, USA).

In 9% of TLEs in Group 2 and 5% in Group 3, extraction was performed for Sprint Fidelis® advisory in the absence of any evidence of dysfunction, all at the time of generator substitution. In Group 1, no extraction was performed for an advisory alone (P = 0.037 compared with Groups 2 and 3 together). In Group 3, there was a significantly higher prevalence of TLEs performed to obtain venous access to permit upgrade to cardiac resynchronization therapy (CRT) or ICD compared with Group 1 (3%, P = 0.003) and Group 2 (0.9%, P < 0.001).

Lead characteristics

The groups were similar in the number of extracted leads per patient (1.75 in Group 1 vs. 1.92 in Group 2, 1.73 in group 3, P = NS). The age of leads was significantly greater in Groups 2 and 3 than in Group 1 (6.2 ± 4.8, range 0.3–32.9 years vs. 4.7 ± 4.5, range 0.3–30.8 years, P < 0.001; Table 2). All major manufacturers of pacing equipment were represented among the leads extracted (Table 3). Passive fixation leads were more prevalent in Group 1 (68%, 91/133) vs. Groups 2 and 3 (49% in each group, 108/221 and 82/168), P < 0.001 (Figure 2).

Safety

No death related to the TLE procedure occurred in either group; no patient required emergency surgery. The only complication requiring urgent intervention was a subacute pericardial tamponade in Group 1 that occurred at 6 h after the extraction of 4 pacing leads, 2 of which had been in position for 18.6 years; pericardiocentesis was performed, but no other intervention was required. Two patients required transfusion for blood loss occurring from the access veins during the procedure. One patient in Group 3 suffered a non-fatal oesophageal perforation from a transoesophageal echocardiogram performed at the time of TLE. No other complication related to the extraction procedure occurred during follow-up.

Efficacy

Incomplete extraction was recorded in 30 leads in 22 cases across the 3 groups. Surgical extraction was required after a failed TLE in 2 cases in Group 1; in one further case in Group 1, a redundant lead was abandoned after a failed attempt to extract it. Surgery was required in only 1 case in Group 2, for retrieval of a pacing lead chronically migrated to a pulmonary artery branch. One patient crossed over successfully to percutaneous extraction after a failed attempt at surgical extraction.¹¹ All other cases incomplete extraction related to the retention of fragments of a lead of <2 cm in length, usually the tip electrode only.

In Group 2, the percentage of complete TLEs was significantly higher than that in Group 1 (95.5 vs. 88.0% of extracted leads, P = 0.016). The overall rate of complete success in Group 3 was also significantly higher than that in Group 1 (97.6%, P = 0.002), but not significantly different from Group 2 (P = 0.395). The Evolution® Mechanical Dilator Sheath was used for 115 of the leads extracted in Group 2, the Evolution® RL for 109 of the leads in Group 3.

The percentage of complete extraction was higher for ICD leads than for pacing leads [98.5% (128/130) vs. 92.6% (362/391), P = 0.014]. A trend towards higher percentages of complete extraction for ICD leads compared with pacing leads was confirmed in each of the groups separately.

Efficiency

Procedure duration, including the reimplantation when this occurred as part of the same procedure, was similar in all groups (114 ± 70 min in Group 1, 91 ± 49 min in Group 2, and 117 ± 69 min in Group 3, P = 0.308).

The proportion of leads extracted completely using a secondary access point (femoral and/or jugular) in addition to the original access vein was significantly higher in Group 3 (11%, 18/164) than that in Group 2 (3%, 7/211), P = 0.006. No difference was detected between Group 1 (6%, 6/117) and Group 3, P = 0.130 or between Groups 1 and 2, P = 0.610. The 18 leads extracted by a secondary access site in Group 3 included 5 ICD leads and 9 passive fixation leads; the mean dwell time of these leads was 10.1 years.

Discussion

Our data show that advances in equipment have made it possible for a centre with a moderate volume to achieve a high rate of success in mechanical lead extraction without compromising safety.

Safety

In a recent structured meta-analysis of results, the risk of death or serious complication was more than twice as high when laser sheaths were used rather than mechanical methods in lead extraction.¹ This compliments older but inconclusive data from trials that were not powered to measure mortality as an endpoint.⁴ A substantial majority (83%) of serious complications occurring during laser lead extraction relate to injury to the superior vena cava; these injuries are lethal in 40% of the cases.¹² This complication is seldom seen when mechanical techniques are used.¹³

Efficacy

In the past, mechanical methods have generally given lower success rates than laser.^1,10 Isolated high-volume centres have matched the success rates of laser,³ but this has been difficult to replicate in centres with a lower extraction volume.

Recent evidence suggests that the balance in efficacy may now have shifted in favour of mechanical methods.¹⁴ Several studies^7–9 have been published documenting the safety and the efficacy of the Evolution® system in TLE procedures. Our data are in keeping with these, showing that a high level of safety can be maintained even with the achievement of a high rate of success and in a centre extracting fewer than 100 leads yearly.¹⁵

Implantable cardioverter defibrillator vs. pacing leads

In our population, the rate of complete success was higher for ICD leads compared with pacing leads, suggesting that, in a population such as ours with a preponderance of active fixation single-coil leads, ICD lead extraction may be safer and less difficult than is commonly expected.¹⁶ This supports the case for prophylactic extraction of leads that are subject to an advisory.¹⁷ In our experience, the Evolution® seems to be well suited to removing defibrillator coils.

The improved rate of success observed since adopting the Evolution® system may relate in part to an altered approach to the procedure: instead of resorting to the use of sheaths after failing with traction alone, the sheaths were brought into the procedure from the start in any case in which difficulty was anticipated. This helped to preserve the integrity of the lead so that it could be used as a rail for the extraction sheath. Ancillary tools such as the compression coil (Figure 1) may have contributed to the increasing rate of success.¹⁸

Evolution® vs. Evolution® RL

The success rate in our series continued to increase after switching from the original model to the Evolution® RL, but the improvement stems entirely from improved success in using a femoral and/or jugular approach after failure of the mechanical sheath to advance or breakage of the lead. The success rate using an access vein only approach fell significantly after switching to the newer model. This was an unexpected finding.

Previous studies have shown a high rate of success with the Evolution® RL but did not compare it with the original Evolution®.¹⁹ The apparent change may reflect a greater willingness on our part to switch to a femoral approach or may be a by-product of the less aggressive design of the cutting tip of the new model. Another mechanical extraction sheath has recently been introduced. Like the Evolution® RL, it has a less aggressive tip design than the original Evolution® sheath. Initial results with this have been favourable,²⁰ but neither it nor the Evolution or Evolution RL has been subject to a substantial randomized comparison with any of the other extraction tools.

Limitations

Our comparison of different methods and equipment was non-randomized. Our results may have been influenced by the increasing experience of the institution during the period of the study, though individual operator experience was held relatively constant due to staff changes. The falling ratio of passive fixation to active fixation leads seen over the period in question and the increasing proportion of ICD leads may have influenced the rate of success.

Conclusions

We have shown a progressive improvement in the efficacy of non-laser percutaneous lead extraction over the past decade with a constant high level of safety. The Evolution® Mechanical Dilator Sheath and the Evolution® RL have been shown to be safe, efficient, and effective tools when introduced early in the course of CIED lead extraction procedures, particularly with ICD leads.

Funding

G.D. was supported by a grant from the European Heart Rhythm Association.

Conflict of interest: none declared.

References