Implantation of electronic cardiac devices has risen as the evidence-based morbidity and mortality benefits have translated into clinical guidelines. The 2010 Clinical Audit of Heart Rhythm Device Implementation, demonstrated a 10-year growth in de novo pacemaker and intracardiac defibrillator implants (4.1% and 14.9% respectively), with a significant increase in cardiac resynchronisation therapy (CRT).¹ However, a wide variation among regional clinical networks persists.

 

The aging population continue to increase the proportion of procedures performed for bradyarrhythmia and CRT indications but advances in risk stratification of inherited cardiac disease and the expanding adult congenital heart disease population, are fertile areas for growth. Future device extraction is of paramount importance among individuals surviving congenital heart disease, due to the potential multiple complex procedures required during their lifetime and the vascular crowding from redundant leads.

 

Precise definitions for the removal of intracardiac leads depend on the duration of lead residence and removal technique used. Explantation is defined as the removal of a lead within 1 year of implantation, through the implant vein and requiring only simple traction.² Beyond 1 year, or elimination of a lead via a vascular route not utilised at implant or employing specialist equipment, is termed extraction. ² Infection is the most prevalent indication for extraction, with infection rates at <1% with new implants, rising to beyond 3% when re-instrumentation has ocurred.³ Impoverished vascular perfusion of the generator pocket and haematoma development, provide the perfect culture media and environment for microbial colonisation. Aside from infection, lead or system removal may be mandated through patient request, oncological management, device upgrading, lead redundancy or manufacture advisories (Sprint Fidelis, Riata).

 

A small but significant risk of complication exists when performing explants and extractions. Individualized risk-benefit analysis is therefore required pre-procedure, particularly when device advisories are concerned. Extraction is mandatory for endocarditis and systemic infection but conservative management with extensive debridement and pocket irrigation, may be more appropriate for high-risk individuals where skin erosion or low-grade infection is present. Success can be achieved in a third of conservatively managed patients with a mild infection.

 

Fibroblasts encase the leads as dwell duration increases, with adherence to local vasculature and endocardium. Subsequent extraction therefore requires fragmentation of such attachments, with successful lead extraction requiring entire lead removal and retention of >4cm, being considered an unsuccessful extraction.

 

The methods developed to liberate leads have evolved from simple traction using pulley systems and mechanical dilators, to locking stylets, radio-frequency sheaths and laser dissection.^4,5,6 Laser sheaths provide a circle of photo-abalation to a shallow tissue depth, using short duration and high energy pulses. The Pacing Lead Extraction with Excimer Sheath trial (PLEXES) identified laser assisted extraction to be significantly more efficacious for successful removal than non-laser techniques (94 vs. 64%; P 0.001), with no statistical significance in life-threatening complications. Extractions are usually performed through superior access routes, with recourse to femoral workstations during failing procedures. A prospective single center French study, confirmed overall procedure time and fluoroscopy time were significantly shorter with superior laser sheath use than femoral snare extractions.⁷

 

Major and minor complications have been categorised by the Heart Rhythm Society ² but comparison of complication rates by different extraction methods is challenging, due to the variation in reporting of results (per patients recruited, per leads attempted). Potential risk factors for complications are the duration of implant, female gender, patient age, calcification around the lead, multiple leads in situ and extraction of an ICD lead. Conversely, a short dwell interval, the presence of infection and active lead extraction are more favourable.^8,9,10

 

Studies addressing the extraction of coronary sinus leads have a tendency to recruit small patient numbers. An Italian study of 145 patients, achieved successful removal in 99% of the leads attempted to be extracted (70% with traction alone, 30% with dilatation).¹¹ Laser extraction has been demonstrated to be feasible,¹² however if re-implantation in the coronary sinus is planned this is likely to be challenging, due to a high rate of venous occlusion.¹³

 

The only modifiable factors at the time of extraction are the method and route of extraction, both highly dependent on the operating physicians experience. A survey of Heart Rhythm Society members, identified only 18% of physicians performing >50 extractions a year and 25% of procedures being undertaken without surgical standby.¹³ A retrospective cohort from North Carolina demonstrated the importance of surgical support during transvenous extractions. Among 112 patients, 103 successful laser extractions were performed over a 6 year duration, with sternotomy required in 4 procedures (caval perforation, subclavian injury, right atrial laceration), three whom died.¹⁴ The innominate vein, subclavian vein entrance into the superior vena cava, the high right atrium, tricuspid valve and right ventricle, are the sites of greatest risk for fatal extraction injuries.¹⁵

 

Complication rates steeply decline during a physicians first 30 explant/extraction procedures, continuing up to 400 patients. ^{16, 17} Even among experienced physicians, laser extraction success declines when <15 procedures per year are performed.

 

With the future focus on near patient care, complex device services may progressively ebb to secondary care cardiology centres, with potential increased demand on extraction services to resolve the complications arising during the natural learning curve of physicians.

 

References

 

1. CCAD 2010

2. 2009 Heart Rhythm Society Expert Consensus

3. Bracke F. Complications and lead extraction in cardiac pacing and defibrillation Neth Heart J. 2008 October; 16(Suppl 1): S2831

4. Bracke FA. The Lead Extractors Toolbox: A Review of Current Endovascular Pacemaker and ICD Lead Extraction Techniques. Indian Pacing and Electrophysiology Journal 2003;3(3):101-8

5. Bongiorni MG, Soldati E, Zucchelli G, Cori AD, Segreti L, Lucia RD, Solarino G, Balbarini A, Marzilli M, Mariani M. Transvenous removal of pacing and implantable cardiac defibrillating leads using single sheath mechanical dilatation and multiple venous approaches: high success rate and safety in more than 2000 leads. EHJ 2008;29:2886-2893

6. Malecka B, Kutarski A, Grabowski M. Is the transvenous extraction of cardioverter-defibrillator leads more hazardous than that of pacemaker leads? Kardiol Pol 2010;68(8):884-90

7. Bordachar P, Defaye P, Peyrouse E, Boveda S, Mokrani B, Marqui C, Barandon L, Fossaert EM, Garrigue S, Reuter S, Laborderie J, Marijon E, Deharo J-C, P, Kacet S, Ploux S, Deplagne A, Haissaguerre M, Clementy J, Ritter P, Klug D Extraction of Old Pacemaker or Cardioverter-Defibrillator Leads by Laser Sheath Versus Femoral Approach Circulation: Arrhythmia and Electrophysiology. 2010; 3: 319-323

8. Kay GN, Brinker JA, Kawanishi DT. Risks of spontaneous injury and extraction of an active fixation pacemaker lead: report of the Accufix Multicenter Clinical Study and Worldwide Registry. Circulation 1999;100:2344

9. Byrd CL, Wilkoff BL, Love CJ et al Clinical study of the laser sheath for lead extraction: the total experience in the United States. Pacing Clin Electrophysiol 2002;25:804

10. Cooper JM, Stephenson EA, Berul CL et al. Implantable cardioverter defobrillator lead complications and laser extraction in children and yound adults with congenital heart disease: implications for implantation and management. J Cardiovasc Electrophysiolo 2003;14:344

11. DI Cori A, Bongiorni MG, Zucchelli G, Segreti L, Viani S, DE Lucia R, Paperini L, Soldati E. Large, Single-Center Experience in Transvenous Coronary Sinus Lead Extraction: Procedural Outcomes and Predictors for Mechanical Dilatation. Pacing Clin Electrophysiol. 2012;35:215

12. Hamid S, Arujna A, Khan S, Ladwiniec A, McPhail M, Bostock J, Mobb M, Patel N, Bucknall C, Rinaldi CA. Extraction of chronic pacemaker and defibrillator leads from the coronary sinus: laser infrequently used but required. Europace 2009;11:213215

13. Burke MC, Morton J, Lin AC, Tierney S, Desai A, Hong T, Kim S, Salem Y, Alberts M, Knight BP. Implications and outcome of permanent coronary sinus lead extraction and reimplantation. J Cardiovasc Electrophysiol. 2005 Aug;16(8):830-7

14. Gaca JG, Lima B, Milano CA, Lin SS, Davis RD, Lowe JE, Smith PK. Laser-assisted extraction of pacemaker and defibrillator leads: the role of the cardiac surgeon. Ann Thorac Surg. 2009 May;87(5):1446-50; discussion 1450-1

15. Neuzil P, Taborsky M, Rezek Z, Vopalka R, Sediva L, Niederie P, Reddy V. Pacemaker and ICD lead extraction with electrosurgical dissection sheaths and standard transvenous extraction systems: results of a randomised trial. Europace 2007;9:98-104

16. Ghosh N, Yee R, Klein GJ. Laser lead extraction: is there a learning curve? Pacing Clin Electrophysiol 2005;28:180

17. Wilkoff BL, Byrd CL, Love CJ. Trends in Intravascular Lead Extraction: Analysis of Data from 539 Procedures in 10 Years. Xith World Symposium on Cardiac Pacing and Electrophysiology: Berlin. Pacing Clin Electrophysiol 1999;22:6