Percutaneous Retrieval of Implanted Leadless Pacemakers: Feasibility at 2.5 Years Post-Implantation in an In Vivo Ovine Model

Jacob S Koruth; Marian K Rippy; Alexander Khairkhahan; David A Ligon; Christopher A Hubbard; Marc A Miller; Srinivas Dukkipati; Petr Neuzil; Vivek Y Reddy

doi:10.1016/j.jacep.2015.07.013

Percutaneous Retrieval of Implanted Leadless Pacemakers: Feasibility at 2.5 Years Post-Implantation in an In Vivo Ovine Model

JACC Clin Electrophysiol. 2015 Dec;1(6):563-570. doi: 10.1016/j.jacep.2015.07.013. Epub 2015 Oct 22.

Authors

Jacob S Koruth¹, Marian K Rippy², Alexander Khairkhahan³, David A Ligon³, Christopher A Hubbard³, Marc A Miller¹, Srinivas Dukkipati¹, Petr Neuzil⁴, Vivek Y Reddy⁵

Affiliations

¹ Helmsley Electrophysiology Center, Mount Sinai Medical Center, New York, New York.
² Rippy Pathology Solutions, Inc., Woodbury, Minnesota.
³ St. Jude Medical, Inc., Sunnyvale, California.
⁴ Na Homolce Hospital, Prague, Czech Republic.
⁵ Helmsley Electrophysiology Center, Mount Sinai Medical Center, New York, New York. Electronic address: vivek.reddy@mountsinai.org.

PMID: 29759410
DOI: 10.1016/j.jacep.2015.07.013

Abstract

Objectives: This in vivo ovine study describes the feasibility and safety of retrieving implanted leadless pacemakers (LPs).

Background: Although LPs have been shown to be removable soon after implantation, there are no data on the feasibility of removing chronically implanted LPs.

Methods: This study was performed in 2 phases. In the mid-term cohort, 10 chronically (5.3 months) implanted animals underwent retrieval, followed by: 1) immediate necropsy in 5; and 2) in the remaining 5, reimplantation of a new LP followed by necropsy at 6 weeks. In the long-term cohort, 8 additional sheep underwent retrieval at 2.3 ± 0.1 years followed by necropsy. Retrieval was performed using either a single or triple loop snare. All 18 LPs (100%) were successfully retrieved. The time from retrieval catheter insertion to retrieval was 2:35 ± 01:11 and 3:04 ± 01:13 minutes in the mid-term and long-term study groups, respectively.

Results: There were no significant differences in retrieval times using either snare. Intracardiac echocardiography was used pre- and post-retrieval to confirm the absence of pericardial effusion in all 8 sheep. On necropsy, there was no evidence of pericardial bleeding or perforation. Only minor tissue disruption and hemorrhage was noted at the implant site after retrieval. Histology demonstrated fibrous connective tissue at the contact sites of endocardium and LP can and at the helix. There was no evidence of pulmonary thromboembolism.

Conclusions: We demonstrate the feasibility and safety of percutaneous, catheter-based retrieval in chronic LP implants of a maximum duration of approximately 2.5 years.

Keywords: animal model; leadless; pacemaker; retrieval; ventricle.