Effects of envelopes on cardiac implantable electronic device pocket healing: A head-to-head preclinical evaluation

Renu Virmani; Francois Philippon; Suneet Mittal; Aloke Finn; D'Anne Kudlik; Nicole Kirchhof; Daniel Lexcen; John Kassotis

doi:10.1016/j.hrthm.2024.02.054

Effects of envelopes on cardiac implantable electronic device pocket healing: A head-to-head preclinical evaluation

Heart Rhythm. 2024 Mar 19:S1547-5271(24)00226-1. doi: 10.1016/j.hrthm.2024.02.054. Online ahead of print.

Authors

Renu Virmani¹, Francois Philippon², Suneet Mittal³, Aloke Finn⁴, D'Anne Kudlik⁵, Nicole Kirchhof⁵, Daniel Lexcen⁵, John Kassotis⁶

Affiliations

¹ CV Path Institute, Gaithersburg, Maryland. Electronic address: RVirmani@cvpath.org.
² Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Québec, Canada.
³ Valley Health System, Ridgewood, New Jersey.
⁴ CV Path Institute, Gaithersburg, Maryland.
⁵ Medtronic Inc., Mounds View, Minnesota.
⁶ Peconic Bay Medical Center-Northwell Health, Riverhead, New York.

PMID: 38555971
DOI: 10.1016/j.hrthm.2024.02.054

Abstract

Background: The healing response to cardiac implantable electronic device (CIED) implantation results in inflammation that can lead to fibrous pocket formation, which may disrupt pocket healing or complicate future interventions.

Objective: The purpose of this study was to assess CIED pocket healing with use of the second-generation TYRX absorbable antibacterial envelope (T2), the next-generation (NG) TYRX absorbable antibacterial envelope under development, and the CanGaroo® extracellular matrix envelope (ECM) compared to no envelope.

Methods: A total of 110 CIEDs were implanted in an ovine model, either with (T2, NG, or ECM) or without envelopes. Histopathologic and morphometric analyses were completed at several timepoints after implant (3 days, 7 days, 4 weeks, 12 weeks, 24 weeks). An independent pathologist completed a blinded histopathology assessment of the pockets.

Results: TYRX (T2/NG) pockets showed similar inflammatory and healing profiles to controls with more rapid provisional matrix formation compared to controls and ECM. ECM pockets exhibited increased acute (3 and 7 days) and chronic (24 weeks) inflammation. T2/NG had almost complete (T2) or complete (NG) absorption by week 12. ECM remained present at week 24 and was associated with significantly thicker capsules (ECM 0.80 ± 0.14 mm; NG 0.37 ± 0.10 mm; control 0.56 ± 0.17 mm).

Conclusion: Compared to ECM, pockets with TYRX showed less inflammation, more rapid provisional matrix formation, faster absorption, and thinner capsules. TYRX pockets had low inflammation comparable to controls with accelerated provisional matrix deposition and tissue adhesion. The healing response to CIEDs used with TYRX fosters the formation of a well-healed pocket, which may bring patient benefit beyond its proven infection reduction.

Keywords: Cardiac implantable electronic device; Cardiac implantable electronic device envelope; Cardiac implantable electronic device pocket; Histopathology; Morphometry; Pocket healing.